Version abc81013

45 files changed, 1044 insertions, 6748 deletions

diff --git a/src/aig/aig/aig.h b/src/aig/aig/aig.h
index 7480df78..18bcb1b4 100644
--- a/src/aig/aig/aig.h
+++ b/src/aig/aig/aig.h
@@ -654,6 +654,8 @@ extern void            Aig_ManCleanPioNumbers( Aig_Man_t * p );
 extern int             Aig_ManCountChoices( Aig_Man_t * p );
 extern char *          Aig_FileNameGenericAppend( char * pBase, char * pSuffix );
 extern unsigned        Aig_ManRandom( int fReset );
+extern void            Aig_NodeUnionLists( Vec_Ptr_t * vArr1, Vec_Ptr_t * vArr2, Vec_Ptr_t * vArr );
+extern void            Aig_NodeIntersectLists( Vec_Ptr_t * vArr1, Vec_Ptr_t * vArr2, Vec_Ptr_t * vArr );
 
 /*=== aigWin.c =========================================================*/
 extern void            Aig_ManFindCut( Aig_Obj_t * pRoot, Vec_Ptr_t * vFront, Vec_Ptr_t * vVisited, int nSizeLimit, int nFanoutLimit );
diff --git a/src/aig/aig/aigUtil.c b/src/aig/aig/aigUtil.c
index fd5fedcc..00685ef8 100644
--- a/src/aig/aig/aigUtil.c
+++ b/src/aig/aig/aigUtil.c
@@ -1122,6 +1122,86 @@ unsigned Aig_ManRandom( int fReset )
 }
 
 
+/**Function*************************************************************
+
+  Synopsis    [Returns the result of merging the two vectors.]
+
+  Description [Assumes that the vectors are sorted in the increasing order.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Aig_NodeUnionLists( Vec_Ptr_t * vArr1, Vec_Ptr_t * vArr2, Vec_Ptr_t * vArr )
+{
+    Aig_Obj_t ** pBeg  = (Aig_Obj_t **)vArr->pArray;
+    Aig_Obj_t ** pBeg1 = (Aig_Obj_t **)vArr1->pArray;
+    Aig_Obj_t ** pBeg2 = (Aig_Obj_t **)vArr2->pArray;
+    Aig_Obj_t ** pEnd1 = (Aig_Obj_t **)vArr1->pArray + vArr1->nSize;
+    Aig_Obj_t ** pEnd2 = (Aig_Obj_t **)vArr2->pArray + vArr2->nSize;
+    Vec_PtrGrow( vArr, Vec_PtrSize(vArr1) + Vec_PtrSize(vArr2) );
+    pBeg  = (Aig_Obj_t **)vArr->pArray;
+    while ( pBeg1 < pEnd1 && pBeg2 < pEnd2 )
+    {
+        if ( (*pBeg1)->Id == (*pBeg2)->Id )
+            *pBeg++ = *pBeg1++, pBeg2++;
+        else if ( (*pBeg1)->Id < (*pBeg2)->Id )
+            *pBeg++ = *pBeg1++;
+        else 
+            *pBeg++ = *pBeg2++;
+    }
+    while ( pBeg1 < pEnd1 )
+        *pBeg++ = *pBeg1++;
+    while ( pBeg2 < pEnd2 )
+        *pBeg++ = *pBeg2++;
+    vArr->nSize = pBeg - (Aig_Obj_t **)vArr->pArray;
+    assert( vArr->nSize <= vArr->nCap );
+    assert( vArr->nSize >= vArr1->nSize );
+    assert( vArr->nSize >= vArr2->nSize );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Returns the result of intersecting the two vectors.]
+
+  Description [Assumes that the vectors are sorted in the increasing order.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Aig_NodeIntersectLists( Vec_Ptr_t * vArr1, Vec_Ptr_t * vArr2, Vec_Ptr_t * vArr )
+{
+    Aig_Obj_t ** pBeg  = (Aig_Obj_t **)vArr->pArray;
+    Aig_Obj_t ** pBeg1 = (Aig_Obj_t **)vArr1->pArray;
+    Aig_Obj_t ** pBeg2 = (Aig_Obj_t **)vArr2->pArray;
+    Aig_Obj_t ** pEnd1 = (Aig_Obj_t **)vArr1->pArray + vArr1->nSize;
+    Aig_Obj_t ** pEnd2 = (Aig_Obj_t **)vArr2->pArray + vArr2->nSize;
+    Vec_PtrGrow( vArr, AIG_MAX( Vec_PtrSize(vArr1), Vec_PtrSize(vArr2) ) );
+    pBeg  = (Aig_Obj_t **)vArr->pArray;
+    while ( pBeg1 < pEnd1 && pBeg2 < pEnd2 )
+    {
+        if ( (*pBeg1)->Id == (*pBeg2)->Id )
+            *pBeg++ = *pBeg1++, pBeg2++;
+        else if ( (*pBeg1)->Id < (*pBeg2)->Id )
+//            *pBeg++ = *pBeg1++;
+            pBeg1++;
+        else 
+//            *pBeg++ = *pBeg2++;
+            pBeg2++;
+    }
+//    while ( pBeg1 < pEnd1 )
+//        *pBeg++ = *pBeg1++;
+//    while ( pBeg2 < pEnd2 )
+//        *pBeg++ = *pBeg2++;
+    vArr->nSize = pBeg - (Aig_Obj_t **)vArr->pArray;
+    assert( vArr->nSize <= vArr->nCap );
+    assert( vArr->nSize <= vArr1->nSize );
+    assert( vArr->nSize <= vArr2->nSize );
+}
+
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
 ////////////////////////////////////////////////////////////////////////
diff --git a/src/aig/saig/module.make b/src/aig/saig/module.make
index c3c0a1b6..48d91438 100644
--- a/src/aig/saig/module.make
+++ b/src/aig/saig/module.make
@@ -3,6 +3,7 @@ SRC +=    src/aig/saig/saigAbs.c \
     src/aig/saig/saigCone.c \
     src/aig/saig/saigDup.c \
     src/aig/saig/saigHaig.c \
+    src/aig/saig/saigInd.c \
     src/aig/saig/saigIoa.c \
     src/aig/saig/saigLoc.c \
     src/aig/saig/saigMiter.c \
diff --git a/src/aig/saig/saig.h b/src/aig/saig/saig.h
index ddae07e0..f0c8fb54 100644
--- a/src/aig/saig/saig.h
+++ b/src/aig/saig/saig.h
@@ -87,6 +87,8 @@ extern Aig_Man_t *       Said_ManDupOrpos( Aig_Man_t * p );
 extern Aig_Man_t *       Saig_ManAbstraction( Aig_Man_t * pAig, Vec_Int_t * vFlops );
 /*=== saigHaig.c ==========================================================*/
 extern Aig_Man_t *       Saig_ManHaigRecord( Aig_Man_t * p, int nIters, int nSteps, int fRetimingOnly, int fAddBugs, int fUseCnf, int fVerbose );
+/*=== saigInd.c ==========================================================*/
+extern int               Saig_ManInduction( Aig_Man_t * p, int nFramesMax, int nConfMax, int fVerbose );
 /*=== saigIoa.c ==========================================================*/
 extern void              Saig_ManDumpBlif( Aig_Man_t * p, char * pFileName );
 extern Aig_Man_t *       Saig_ManReadBlif( char * pFileName );
diff --git a/src/aig/saig/saigAbs.c b/src/aig/saig/saigAbs.c
index 48a26a3c..b1e36fcc 100644
--- a/src/aig/saig/saigAbs.c
+++ b/src/aig/saig/saigAbs.c
@@ -51,7 +51,7 @@ Aig_Man_t * Saig_ManFramesBmcLast( Aig_Man_t * pAig, int nFrames, Aig_Obj_t ***
 {
     Aig_Man_t * pFrames;
     Aig_Obj_t ** ppMap;
-    Aig_Obj_t * pObj, * pObjLi, * pObjLo;
+    Aig_Obj_t * pObj, * pObjLi, * pObjLo, * pResult;
     int i, f;
     assert( Saig_ManRegNum(pAig) > 0 );
     // start the mapping
@@ -61,10 +61,12 @@ Aig_Man_t * Saig_ManFramesBmcLast( Aig_Man_t * pAig, int nFrames, Aig_Obj_t ***
     // create variables for register outputs
     Saig_ManForEachLo( pAig, pObj, i )
     {
-        pObj->pData = Aig_ManConst0( pFrames );
+//        pObj->pData = Aig_ManConst0( pFrames );
+        pObj->pData = Aig_ObjCreatePi( pFrames );
         Saig_ObjSetFrame( ppMap, nFrames, pObj, 0, pObj->pData );
     }
     // add timeframes
+    pResult = Aig_ManConst0(pFrames);
     for ( f = 0; f < nFrames; f++ )
     {
         // map the constant node
@@ -82,14 +84,17 @@ Aig_Man_t * Saig_ManFramesBmcLast( Aig_Man_t * pAig, int nFrames, Aig_Obj_t ***
             pObj->pData = Aig_And( pFrames, Aig_ObjChild0Copy(pObj), Aig_ObjChild1Copy(pObj) );
             Saig_ObjSetFrame( ppMap, nFrames, pObj, f, pObj->pData );
         }
+        // OR the POs
+        Saig_ManForEachPo( pAig, pObj, i )
+            pResult = Aig_Or( pFrames, pResult, Aig_ObjChild0Copy(pObj) );
         // create POs for this frame
         if ( f == nFrames - 1 )
         {
-            Saig_ManForEachPo( pAig, pObj, i )
-            {
-                pObj->pData = Aig_ObjCreatePo( pFrames, Aig_ObjChild0Copy(pObj) );
-                Saig_ObjSetFrame( ppMap, nFrames, pObj, f, pObj->pData );
-            }
+//            Saig_ManForEachPo( pAig, pObj, i )
+//            {
+//               pObj->pData = Aig_ObjCreatePo( pFrames, Aig_ObjChild0Copy(pObj) );
+//               Saig_ObjSetFrame( ppMap, nFrames, pObj, f, pObj->pData );
+//            }
             break;
         }
         // save register inputs
@@ -105,6 +110,7 @@ Aig_Man_t * Saig_ManFramesBmcLast( Aig_Man_t * pAig, int nFrames, Aig_Obj_t ***
             Saig_ObjSetFrame( ppMap, nFrames, pObjLo, f, pObjLo->pData );
         }
     }
+    Aig_ObjCreatePo( pFrames, pResult );
     Aig_ManCleanup( pFrames );
     // remove mapping for the nodes that are no longer there
     for ( i = 0; i < Aig_ManObjNumMax(pAig) * nFrames; i++ )
@@ -124,14 +130,15 @@ Aig_Man_t * Saig_ManFramesBmcLast( Aig_Man_t * pAig, int nFrames, Aig_Obj_t ***
   SeeAlso     []
 
 ***********************************************************************/
-int * Saig_ManFindUnsatVariables( Cnf_Dat_t * pCnf, int nConfMax, int fVerbose )
+int * Saig_ManFindUnsatVariables( Cnf_Dat_t * pCnf, int nRegs, int nConfMax, int fVerbose )
 {
     void * pSatCnf; 
     Intp_Man_t * pManProof;
+    Aig_Obj_t * pObj;
     sat_solver * pSat;
     Vec_Int_t * vCore;
     int * pClause1, * pClause2, * pLit, * pVars, iClause, nVars;
-    int i, RetValue;
+    int i, Lit, RetValue;
     // create the SAT solver
     pSat = sat_solver_new();
     sat_solver_store_alloc( pSat ); 
@@ -145,6 +152,15 @@ int * Saig_ManFindUnsatVariables( Cnf_Dat_t * pCnf, int nConfMax, int fVerbose )
             return NULL;
         }
     }
+    Aig_ManForEachPi( pCnf->pMan, pObj, i )
+    {
+        if ( i == nRegs )
+            break;
+        assert( pCnf->pVarNums[pObj->Id] >= 0 );
+        Lit = toLitCond( pCnf->pVarNums[pObj->Id], 1 );
+        if ( !sat_solver_addclause( pSat, &Lit, &Lit+1 ) )
+            assert( 0 );
+    }
     sat_solver_store_mark_roots( pSat ); 
     // solve the problem
     RetValue = sat_solver_solve( pSat, NULL, NULL, (sint64)nConfMax, (sint64)0, (sint64)0, (sint64)0 );
@@ -240,11 +256,12 @@ Aig_Man_t * Saig_ManProofAbstraction( Aig_Man_t * p, int nFrames, int nConfMax,
         printf( "Performing proof-based abstraction with %d frames and %d max conflicts.\n", nFrames, nConfMax );
     // create the timeframes
     pFrames = Saig_ManFramesBmcLast( p, nFrames, &ppAigToFrames );
+    printf( "AIG nodes = %d. Frames = %d.\n", Aig_ManNodeNum(p), Aig_ManNodeNum(pFrames) );
     // convert them into CNF
 //    pCnf = Cnf_Derive( pFrames, 0 );
     pCnf = Cnf_DeriveSimple( pFrames, 0 );
     // collect CNF variables involved in UNSAT core
-    pUnsatCoreVars = Saig_ManFindUnsatVariables( pCnf, nConfMax, 0 );
+    pUnsatCoreVars = Saig_ManFindUnsatVariables( pCnf, Saig_ManRegNum(p), nConfMax, 0 );
     if ( pUnsatCoreVars == NULL )
     {
         Aig_ManStop( pFrames );
diff --git a/src/aig/saig/saigBmc.c b/src/aig/saig/saigBmc.c
index baf00241..5776cd4a 100644
--- a/src/aig/saig/saigBmc.c
+++ b/src/aig/saig/saigBmc.c
@@ -249,8 +249,10 @@ int Saig_ManBmcSimple( Aig_Man_t * pAig, int nFrames, int nSizeMax, int nConfLim
         {
             Lit = toLitCond( pCnf->pVarNums[pObj->Id], 0 );
             if ( fVerbose )
+            {
                 printf( "Solving output %2d of frame %3d ... \r", 
                     i % Saig_ManPoNum(pAig), i / Saig_ManPoNum(pAig) );
+            }
             clk = clock();
             status = sat_solver_solve( pSat, &Lit, &Lit + 1, (sint64)nConfLimit, (sint64)0, (sint64)0, (sint64)0 );
             if ( fVerbose && (i % Saig_ManPoNum(pAig) == Saig_ManPoNum(pAig) - 1) )
@@ -258,12 +260,22 @@ int Saig_ManBmcSimple( Aig_Man_t * pAig, int nFrames, int nSizeMax, int nConfLim
                 printf( "Solved %2d outputs of frame %3d.  ", 
                     Saig_ManPoNum(pAig), i / Saig_ManPoNum(pAig) );
                 printf( "Conf =%8.0f. Imp =%11.0f. ", (double)pSat->stats.conflicts, (double)pSat->stats.propagations );
-                PRT( "Time", clock() - clkPart );
+                PRT( "T", clock() - clkPart );
                 clkPart = clock();
                 fflush( stdout );
             }
             if ( status == l_False )
             {
+/*
+                Lit = lit_neg( Lit );
+                RetValue = sat_solver_addclause( pSat, &Lit, &Lit + 1 );
+                assert( RetValue );
+                if ( pSat->qtail != pSat->qhead )
+                {
+                    RetValue = sat_solver_simplify(pSat);
+                    assert( RetValue );
+                }
+*/
             }
             else if ( status == l_True )
             {
diff --git a/src/aig/saig/saigInd.c b/src/aig/saig/saigInd.c
new file mode 100644
index 00000000..69c250f6
--- /dev/null
+++ b/src/aig/saig/saigInd.c
@@ -0,0 +1,174 @@
+/**CFile****************************************************************
+
+  FileName    [saigLoc.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Sequential AIG package.]
+
+  Synopsis    [K-step induction for one property only.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: saigLoc.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "saig.h"
+#include "cnf.h"
+#include "satSolver.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Performs localization by unrolling timeframes backward.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Saig_ManInduction( Aig_Man_t * p, int nFramesMax, int nConfMax, int fVerbose )
+{
+    sat_solver * pSat;
+    Aig_Man_t * pAigPart;
+    Cnf_Dat_t * pCnfPart;
+    Vec_Int_t * vTopVarNums;
+    Vec_Ptr_t * vTop, * vBot;
+    Aig_Obj_t * pObjPi, * pObjPiCopy, * pObjPo;
+    int i, f, clk, Lits[2], status, RetValue, nSatVarNum, nConfPrev;
+    assert( Saig_ManPoNum(p) == 1 );
+    Aig_ManSetPioNumbers( p );
+
+    // start the top by including the PO
+    vBot = Vec_PtrAlloc( 100 );
+    vTop = Vec_PtrAlloc( 100 );
+    Vec_PtrPush( vTop, Aig_ManPo(p, 0) );
+    // start the array of CNF variables
+    vTopVarNums = Vec_IntAlloc( 100 );
+    // start the solver
+    pSat = sat_solver_new();
+    sat_solver_setnvars( pSat, 1000 );
+
+    // iterate backward unrolling
+    RetValue = -1;
+    nSatVarNum = 0;
+    if ( fVerbose )
+        printf( "Localization parameters: FramesMax = %5d. ConflictMax = %6d.\n", nFramesMax, nConfMax );
+    for ( f = 0; ; f++ )
+    { 
+        if ( f > 0 )
+        {
+            Aig_ManStop( pAigPart );
+            Cnf_DataFree( pCnfPart );
+        }
+        clk = clock();
+        // get the bottom
+        Aig_SupportNodes( p, (Aig_Obj_t **)Vec_PtrArray(vTop), Vec_PtrSize(vTop), vBot );
+        // derive AIG for the part between top and bottom
+        pAigPart = Aig_ManDupSimpleDfsPart( p, vBot, vTop );
+        // convert it into CNF
+        pCnfPart = Cnf_Derive( pAigPart, Aig_ManPoNum(pAigPart) );
+        Cnf_DataLift( pCnfPart, nSatVarNum );
+        nSatVarNum += pCnfPart->nVars;
+
+        // stitch variables of top and bot
+        assert( Aig_ManPoNum(pAigPart)-1 == Vec_IntSize(vTopVarNums) );
+        Aig_ManForEachPo( pAigPart, pObjPo, i )
+        {
+            if ( i == 0 )
+            {
+                // do not perform inductive strengthening
+//                if ( f > 0 )
+//                    continue;
+                // add topmost literal
+                Lits[0] = toLitCond( pCnfPart->pVarNums[pObjPo->Id], f>0 );
+                if ( !sat_solver_addclause( pSat, Lits, Lits+1 ) )
+                    assert( 0 );
+                continue;
+            }
+            Lits[0] = toLitCond( Vec_IntEntry(vTopVarNums, i-1), 0 );
+            Lits[1] = toLitCond( pCnfPart->pVarNums[pObjPo->Id], 1 );
+            if ( !sat_solver_addclause( pSat, Lits, Lits+2 ) )
+                assert( 0 );
+            Lits[0] = toLitCond( Vec_IntEntry(vTopVarNums, i-1), 1 );
+            Lits[1] = toLitCond( pCnfPart->pVarNums[pObjPo->Id], 0 );
+            if ( !sat_solver_addclause( pSat, Lits, Lits+2 ) )
+                assert( 0 );
+        }
+        // add CNF to the SAT solver
+        for ( i = 0; i < pCnfPart->nClauses; i++ )
+            if ( !sat_solver_addclause( pSat, pCnfPart->pClauses[i], pCnfPart->pClauses[i+1] ) )
+                break;
+        if ( i < pCnfPart->nClauses )
+        {
+//            printf( "SAT solver became UNSAT after adding clauses.\n" );
+            RetValue = 1;
+            break;
+        }
+        // run the SAT solver
+        nConfPrev = pSat->stats.conflicts;
+        status = sat_solver_solve( pSat, NULL, NULL, (sint64)nConfMax, 0, 0, 0 );
+        if ( fVerbose )
+        {
+            printf( "%3d : PI = %5d. PO = %5d. AIG = %5d. Var = %6d. Conf = %6d. ",
+                f+1, Aig_ManPiNum(pAigPart), Aig_ManPoNum(pAigPart), Aig_ManNodeNum(pAigPart), 
+                nSatVarNum, pSat->stats.conflicts-nConfPrev );
+            PRT( "Time", clock() - clk );
+        }
+        if ( status == l_Undef )
+            break;
+        if ( status == l_False )
+        {
+            RetValue = 1;
+            break;
+        }
+        assert( status == l_True );
+        if ( f == nFramesMax - 1 )
+            break;
+        // the problem is SAT - add more clauses
+        // create new set of POs to derive new top
+        Vec_PtrClear( vTop );
+        Vec_PtrPush( vTop, Aig_ManPo(p, 0) );
+        Vec_IntClear( vTopVarNums );
+        Vec_PtrForEachEntry( vBot, pObjPi, i )
+        {
+            assert( Aig_ObjIsPi(pObjPi) );
+            if ( Saig_ObjIsLo(p, pObjPi) )
+            {
+                pObjPiCopy = pObjPi->pData;
+                assert( pObjPiCopy != NULL );
+                Vec_PtrPush( vTop, Saig_ObjLoToLi(p, pObjPi) );
+                Vec_IntPush( vTopVarNums, pCnfPart->pVarNums[pObjPiCopy->Id] );
+            }
+        }
+    }
+//    printf( "Completed %d interations.\n", f+1 );
+    // cleanup
+    sat_solver_delete( pSat );
+    Aig_ManStop( pAigPart );
+    Cnf_DataFree( pCnfPart );
+    Vec_IntFree( vTopVarNums );
+    Vec_PtrFree( vTop );
+    Vec_PtrFree( vBot );
+    return RetValue;
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
diff --git a/src/aig/saig/saigLoc.c b/src/aig/saig/saigLoc.c
index 60c547dd..edbf231c 100644
--- a/src/aig/saig/saigLoc.c
+++ b/src/aig/saig/saigLoc.c
@@ -6,7 +6,7 @@
 
   PackageName [Sequential AIG package.]
 
-  Synopsis    [Localization package.]
+  Synopsis    [Localization.]
 
   Author      [Alan Mishchenko]
   
@@ -19,8 +19,6 @@
 ***********************************************************************/
 
 #include "saig.h"
-#include "cnf.h"
-#include "satSolver.h"
 
 ////////////////////////////////////////////////////////////////////////
 ///                        DECLARATIONS                              ///
@@ -32,7 +30,7 @@
 
 /**Function*************************************************************
 
-  Synopsis    [Performs localization by unrolling timeframes backward.]
+  Synopsis    []
 
   Description []
                
@@ -41,126 +39,7 @@
   SeeAlso     []
 
 ***********************************************************************/
-int Saig_ManLocalization( Aig_Man_t * p, int nFramesMax, int nConfMax, int fVerbose )
-{
-    sat_solver * pSat;
-    Vec_Int_t * vTopVarNums;
-    Vec_Ptr_t * vTop, * vBot;
-    Cnf_Dat_t * pCnfTop, * pCnfBot;
-    Aig_Man_t * pPartTop, * pPartBot;
-    Aig_Obj_t * pObj, * pObjBot;
-    int i, f, clk, Lits[2], status, RetValue, nSatVarNum, nConfPrev;
-    assert( Saig_ManPoNum(p) == 1 );
-    Aig_ManSetPioNumbers( p );
-
-    // start the top by including the PO
-    vBot = Vec_PtrAlloc( 100 );
-    vTop = Vec_PtrAlloc( 100 );
-    Vec_PtrPush( vTop, Aig_ManPo(p, 0) );
-    // create the manager composed of one PI/PO pair
-    pPartTop = Aig_ManStart( 10 );
-    Aig_ObjCreatePo( pPartTop, Aig_ObjCreatePi(pPartTop) );
-    pCnfTop = Cnf_Derive( pPartTop, 0 );
-    // start the array of CNF variables
-    vTopVarNums = Vec_IntAlloc( 100 );
-    Vec_IntPush( vTopVarNums, pCnfTop->pVarNums[Aig_ManPi(pPartTop,0)->Id] );
-    // start the solver
-    pSat = Cnf_DataWriteIntoSolver( pCnfTop, 1, 0 );
-
-    // iterate backward unrolling
-    RetValue = -1;
-    nSatVarNum = pCnfTop->nVars;
-    if ( fVerbose )
-        printf( "Localization parameters: FramesMax = %5d. ConflictMax = %6d.\n", nFramesMax, nConfMax );
-    for ( f = 0; ; f++ )
-    { 
-        clk = clock();
-        // get the bottom
-        Aig_SupportNodes( p, (Aig_Obj_t **)Vec_PtrArray(vTop), Vec_PtrSize(vTop), vBot );
-        // derive AIG for the part between top and bottom
-        pPartBot = Aig_ManDupSimpleDfsPart( p, vBot, vTop );
-        // convert it into CNF
-        pCnfBot = Cnf_Derive( pPartBot, Aig_ManPoNum(pPartBot) );
-        Cnf_DataLift( pCnfBot, nSatVarNum );
-        nSatVarNum += pCnfBot->nVars;
-        // stitch variables of top and bot
-        assert( Aig_ManPoNum(pPartBot) == Vec_IntSize(vTopVarNums) );
-        Aig_ManForEachPo( pPartBot, pObjBot, i )
-        {
-            Lits[0] = toLitCond( Vec_IntEntry(vTopVarNums, i),   0 );
-            Lits[1] = toLitCond( pCnfBot->pVarNums[pObjBot->Id], 1 );
-            if ( !sat_solver_addclause( pSat, Lits, Lits+2 ) )
-                assert( 0 );
-            Lits[0] = toLitCond( Vec_IntEntry(vTopVarNums, i),   1 );
-            Lits[1] = toLitCond( pCnfBot->pVarNums[pObjBot->Id], 0 );
-            if ( !sat_solver_addclause( pSat, Lits, Lits+2 ) )
-                assert( 0 );
-        }
-        // add CNF to the SAT solver
-        for ( i = 0; i < pCnfBot->nClauses; i++ )
-            if ( !sat_solver_addclause( pSat, pCnfBot->pClauses[i], pCnfBot->pClauses[i+1] ) )
-                break;
-        if ( i < pCnfBot->nClauses )
-        {
-//            printf( "SAT solver became UNSAT after adding clauses.\n" );
-            RetValue = 1;
-            break;
-        }
-        // run the SAT solver
-        nConfPrev = pSat->stats.conflicts;
-        status = sat_solver_solve( pSat, NULL, NULL, (sint64)nConfMax, 0, 0, 0 );
-        if ( fVerbose )
-        {
-            printf( "%3d : PI = %5d. PO = %5d. AIG = %5d. Var = %6d. Conf = %6d. ",
-                f+1, Aig_ManPiNum(pPartBot), Aig_ManPoNum(pPartBot), Aig_ManNodeNum(pPartBot), 
-                nSatVarNum, pSat->stats.conflicts-nConfPrev );
-            PRT( "Time", clock() - clk );
-        }
-        if ( status == l_Undef )
-            break;
-        if ( status == l_False )
-        {
-            RetValue = 1;
-            break;
-        }
-        assert( status == l_True );
-        if ( f == nFramesMax - 1 )
-            break;
-        // the problem is SAT - add more clauses
-        // create new set of POs to derive new top
-        Vec_PtrClear( vTop );
-        Vec_IntClear( vTopVarNums );
-        Vec_PtrForEachEntry( vBot, pObj, i )
-        {
-            assert( Aig_ObjIsPi(pObj) );
-            if ( Saig_ObjIsLo(p, pObj) )
-            {
-                pObjBot = pObj->pData;
-                assert( pObjBot != NULL );
-                Vec_PtrPush( vTop, Saig_ObjLoToLi(p, pObj) );
-                Vec_IntPush( vTopVarNums, pCnfBot->pVarNums[pObjBot->Id] );
-            }
-        }
-        // remove old top and replace it by bottom
-        Aig_ManStop( pPartTop );
-        pPartTop = pPartBot;
-        pPartBot = NULL;
-        Cnf_DataFree( pCnfTop );
-        pCnfTop = pCnfBot;
-        pCnfBot = NULL;
-    }
-//    printf( "Completed %d interations.\n", f+1 );
-    // cleanup
-    sat_solver_delete( pSat );
-    Aig_ManStop( pPartTop );
-    Cnf_DataFree( pCnfTop );
-    Aig_ManStop( pPartBot );
-    Cnf_DataFree( pCnfBot );
-    Vec_IntFree( vTopVarNums );
-    Vec_PtrFree( vTop );
-    Vec_PtrFree( vBot );
-    return RetValue;
-}
+
 
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
diff --git a/src/aig/ssw/module.make b/src/aig/ssw/module.make
index 625d72d1..915f7dd0 100644
--- a/src/aig/ssw/module.make
+++ b/src/aig/ssw/module.make
@@ -8,6 +8,7 @@ SRC +=    src/aig/ssw/sswAig.c \
     src/aig/ssw/sswPart.c \
     src/aig/ssw/sswPairs.c \
     src/aig/ssw/sswSat.c \
+    src/aig/ssw/sswSemi.c \
     src/aig/ssw/sswSim.c \
     src/aig/ssw/sswSimSat.c \
     src/aig/ssw/sswSweep.c \
diff --git a/src/aig/ssw/ssw.h b/src/aig/ssw/ssw.h
index 2785bca6..2d067a17 100644
--- a/src/aig/ssw/ssw.h
+++ b/src/aig/ssw/ssw.h
@@ -50,8 +50,8 @@ struct Ssw_Pars_t_
     int              nBTLimit;      // conflict limit at a node
     int              nBTLimitGlobal;// conflict limit for multiple runs
     int              nMinDomSize;   // min clock domain considered for optimization
+    int              nItersStop;    // stop after the given number of iterations
     int              fPolarFlip;    // uses polarity adjustment
-    int              fSkipCheck;    // do not run equivalence check for unaffected cones
     int              fLatchCorr;    // perform register correspondence
     int              fSemiFormal;   // enable semiformal filtering
     int              fUniqueness;   // enable uniqueness constraints
@@ -88,13 +88,13 @@ struct Ssw_Cex_t_
 
 /*=== sswAbs.c ==========================================================*/
 extern Aig_Man_t *   Saig_ManProofAbstraction( Aig_Man_t * p, int nFrames, int nConfMax, int fVerbose );
+/*=== sswBmc.c ==========================================================*/
+extern int           Ssw_BmcDynamic( Aig_Man_t * pAig, int nFramesMax, int nConfLimit, int fVerbose, int * piFrame );
 /*=== sswCore.c ==========================================================*/
 extern void          Ssw_ManSetDefaultParams( Ssw_Pars_t * p );
 extern void          Ssw_ManSetDefaultParamsLcorr( Ssw_Pars_t * p );
 extern Aig_Man_t *   Ssw_SignalCorrespondence( Aig_Man_t * pAig, Ssw_Pars_t * pPars );
 extern Aig_Man_t *   Ssw_LatchCorrespondence( Aig_Man_t * pAig, Ssw_Pars_t * pPars );
-/*=== sswLoc.c ==========================================================*/
-extern int           Saig_ManLocalization( Aig_Man_t * p, int nFramesMax, int nConfMax, int fVerbose );
 /*=== sswMiter.c ===================================================*/
 extern int           Ssw_SecSpecialMiter( Aig_Man_t * pMiter, int fVerbose );
 /*=== sswPart.c ==========================================================*/
diff --git a/src/aig/ssw/sswAig.c b/src/aig/ssw/sswAig.c
index 0d0fdbee..fda05941 100644
--- a/src/aig/ssw/sswAig.c
+++ b/src/aig/ssw/sswAig.c
@@ -30,6 +30,50 @@
 
 /**Function*************************************************************
 
+  Synopsis    [Starts the SAT manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Ssw_Frm_t * Ssw_FrmStart( Aig_Man_t * pAig )
+{
+    Ssw_Frm_t * p;
+    p = ALLOC( Ssw_Frm_t, 1 ); 
+    memset( p, 0, sizeof(Ssw_Frm_t) );
+    p->pAig          = pAig;
+    p->nObjs         = Aig_ManObjNumMax( pAig );
+    p->nFrames       = 0;
+    p->pFrames       = NULL;
+    p->vAig2Frm      = Vec_PtrAlloc( 0 );
+    Vec_PtrFill( p->vAig2Frm, 2 * p->nObjs, NULL );
+    return p;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Starts the SAT manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Ssw_FrmStop( Ssw_Frm_t * p )
+{
+    if ( p->pFrames )
+        Aig_ManStop( p->pFrames );
+    Vec_PtrFree( p->vAig2Frm );
+    free( p );
+}
+
+/**Function*************************************************************
+
   Synopsis    [Performs speculative reduction for one node.]
 
   Description []
@@ -164,7 +208,7 @@ Aig_Man_t * Ssw_SpeculativeReduction( Ssw_Man_t * p )
     assert( Aig_ManRegNum(p->pAig) > 0 );
     assert( Aig_ManRegNum(p->pAig) < Aig_ManPiNum(p->pAig) );
     p->nConstrTotal = p->nConstrReduced = 0;
-
+ 
     // start the fraig package
     pFrames = Aig_ManStart( Aig_ManObjNumMax(p->pAig) * p->nFrames );
     // map constants and PIs
@@ -190,8 +234,8 @@ Aig_Man_t * Ssw_SpeculativeReduction( Ssw_Man_t * p )
     // remove dangling nodes
     Aig_ManCleanup( pFrames );
     Aig_ManSetRegNum( pFrames, Aig_ManRegNum(p->pAig) );
-    printf( "SpecRed: Total constraints = %d. Reduced constraints = %d.\n", 
-        p->nConstrTotal, p->nConstrReduced );
+//    printf( "SpecRed: Total constraints = %d. Reduced constraints = %d.\n", 
+//        p->nConstrTotal, p->nConstrReduced );
     return pFrames;
 }
 
diff --git a/src/aig/ssw/sswBmc.c b/src/aig/ssw/sswBmc.c
index e2d47440..93859c01 100644
--- a/src/aig/ssw/sswBmc.c
+++ b/src/aig/ssw/sswBmc.c
@@ -6,7 +6,7 @@
 
   PackageName [Inductive prover with constraints.]
 
-  Synopsis    [Bounded model checker for equivalence clases.]
+  Synopsis    [Bounded model checker using dynamic unrolling.]
 
   Author      [Alan Mishchenko]
   
@@ -24,32 +24,13 @@
 ///                        DECLARATIONS                              ///
 ////////////////////////////////////////////////////////////////////////
 
-typedef struct Ssw_Bmc_t_ Ssw_Bmc_t; // BMC manager
-
-struct Ssw_Bmc_t_
-{
-    // parameters
-    int              nConfMaxStart;  // the starting conflict limit
-    int              nConfMax;       // the intermediate conflict limit
-    int              nFramesSweep;   // the number of frames to sweep
-    int              fVerbose;       // prints output statistics
-    // equivalences considered
-    Ssw_Man_t *      pMan;           // SAT sweeping manager
-    Vec_Ptr_t *      vTargets;       // the nodes that are watched
-    // storage for patterns
-    int              nPatternsAlloc; // the max number of interesting states
-    int              nPatterns;      // the number of patterns
-    Vec_Ptr_t *      vPatterns;      // storage for the interesting states
-    Vec_Int_t *      vHistory;       // what state and how many steps
-};
-
 ////////////////////////////////////////////////////////////////////////
 ///                     FUNCTION DEFINITIONS                         ///
 ////////////////////////////////////////////////////////////////////////
 
 /**Function*************************************************************
 
-  Synopsis    []
+  Synopsis    [Incrementally unroll the timeframes.]
 
   Description []
                
@@ -58,60 +39,43 @@ struct Ssw_Bmc_t_
   SeeAlso     []
 
 ***********************************************************************/
-Ssw_Bmc_t * Ssw_BmcManStart( Ssw_Man_t * pMan, int nConfMax, int fVerbose )
+Aig_Obj_t * Ssw_BmcUnroll_rec( Ssw_Frm_t * pFrm, Aig_Obj_t * pObj, int f )
 {
-    Ssw_Bmc_t * p;
-    Aig_Obj_t * pObj;
-    int i;
-    // create interpolation manager
-    p = ALLOC( Ssw_Bmc_t, 1 ); 
-    memset( p, 0, sizeof(Ssw_Bmc_t) );
-    p->nConfMaxStart  = nConfMax;
-    p->nConfMax       = nConfMax;
-    p->nFramesSweep   = AIG_MAX( (1<<21)/Aig_ManNodeNum(pMan->pAig), pMan->nFrames );
-    p->fVerbose       = fVerbose;
-    // equivalences considered
-    p->pMan           = pMan;
-    p->vTargets       = Vec_PtrAlloc( Saig_ManPoNum(p->pMan->pAig) );
-    Saig_ManForEachPo( p->pMan->pAig, pObj, i )
-        Vec_PtrPush( p->vTargets, Aig_ObjFanin0(pObj) );
-    // storage for patterns
-    p->nPatternsAlloc = 512;
-    p->nPatterns      = 1;
-    p->vPatterns      = Vec_PtrAllocSimInfo( Aig_ManRegNum(p->pMan->pAig), Aig_BitWordNum(p->nPatternsAlloc) );
-    Vec_PtrCleanSimInfo( p->vPatterns, 0, Aig_BitWordNum(p->nPatternsAlloc) );
-    p->vHistory       = Vec_IntAlloc( 100 );
-    Vec_IntPush( p->vHistory, 0 );
-    // update arrays of the manager
-    free( p->pMan->pNodeToFrames );
-    Vec_IntFree( p->pMan->vSatVars );
-    p->pMan->pNodeToFrames = CALLOC( Aig_Obj_t *, Aig_ManObjNumMax(p->pMan->pAig) * p->nFramesSweep );
-    p->pMan->vSatVars      = Vec_IntStart( Aig_ManObjNumMax(p->pMan->pAig) * (p->nFramesSweep+1) );
-    return p;
-}
-
-/**Function*************************************************************
-
-  Synopsis    []
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_BmcManStop( Ssw_Bmc_t * p )
-{
-    Vec_PtrFree( p->vTargets );
-    Vec_PtrFree( p->vPatterns );
-    Vec_IntFree( p->vHistory );
-    free( p );
+    Aig_Obj_t * pRes, * pRes0, * pRes1;
+    if ( (pRes = Ssw_ObjFrame_(pFrm, pObj, f)) )
+        return pRes;
+    if ( Aig_ObjIsConst1(pObj) )
+        pRes = Aig_ManConst1( pFrm->pFrames );
+    else if ( Saig_ObjIsPi(pFrm->pAig, pObj) )
+        pRes = Aig_ObjCreatePi( pFrm->pFrames );
+    else if ( Aig_ObjIsPo(pObj) )
+    {
+        Ssw_BmcUnroll_rec( pFrm, Aig_ObjFanin0(pObj), f );
+        pRes = Ssw_ObjChild0Fra_( pFrm, pObj, f );
+    }
+    else if ( Saig_ObjIsLo(pFrm->pAig, pObj) )
+    {
+        if ( f == 0 )
+            pRes = Aig_ManConst0( pFrm->pFrames );
+        else 
+            pRes = Ssw_BmcUnroll_rec( pFrm, Saig_ObjLoToLi(pFrm->pAig, pObj), f-1 );
+    }
+    else 
+    {
+        assert( Aig_ObjIsNode(pObj) );
+        Ssw_BmcUnroll_rec( pFrm, Aig_ObjFanin0(pObj), f );
+        Ssw_BmcUnroll_rec( pFrm, Aig_ObjFanin1(pObj), f );
+        pRes0 = Ssw_ObjChild0Fra_( pFrm, pObj, f );
+        pRes1 = Ssw_ObjChild1Fra_( pFrm, pObj, f );
+        pRes = Aig_And( pFrm->pFrames, pRes0, pRes1 );
+    }
+    Ssw_ObjSetFrame_( pFrm, pObj, f, pRes );
+    return pRes;
 }
 
 /**Function*************************************************************
 
-  Synopsis    []
+  Synopsis    [Derives counter-example.]
 
   Description []
                
@@ -120,46 +84,34 @@ void Ssw_BmcManStop( Ssw_Bmc_t * p )
   SeeAlso     []
 
 ***********************************************************************/
-int Ssw_BmcCheckTargets( Ssw_Bmc_t * p )
+Ssw_Cex_t * Ssw_BmcGetCounterExample( Ssw_Frm_t * pFrm, Ssw_Sat_t * pSat, int iPo, int iFrame )
 {
-    Aig_Obj_t * pObj;
-    int i;
-    Vec_PtrForEachEntry( p->vTargets, pObj, i )
-        if ( !Ssw_ObjIsConst1Cand(p->pMan->pAig, pObj) )
-            return 1;
-    return 0;
+    Ssw_Cex_t * pCex;
+    Aig_Obj_t * pObj, * pObjFrames;
+    int f, i, nShift;
+    assert( Saig_ManRegNum(pFrm->pAig) > 0 );
+    // allocate the counter example
+    pCex = Ssw_SmlAllocCounterExample( Saig_ManRegNum(pFrm->pAig), Saig_ManPiNum(pFrm->pAig), iFrame + 1 );
+    pCex->iPo    = iPo;
+    pCex->iFrame = iFrame;
+    // create data-bits
+    nShift = Saig_ManRegNum(pFrm->pAig);
+    for ( f = 0; f <= iFrame; f++, nShift += Saig_ManPiNum(pFrm->pAig) )
+        Saig_ManForEachPi( pFrm->pAig, pObj, i )
+        {
+            pObjFrames = Ssw_ObjFrame_(pFrm, pObj, f);
+            if ( pObjFrames == NULL )
+                continue;
+            if ( Ssw_CnfGetNodeValue( pSat, pObjFrames ) )
+                Aig_InfoSetBit( pCex->pData, nShift + i );
+        }
+    return pCex;
 }
 
-/**Function*************************************************************
-
-  Synopsis    []
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManFilterBmcSavePattern( Ssw_Bmc_t * p )
-{
-    unsigned * pInfo;
-    Aig_Obj_t * pObj;
-    int i;
-    if ( p->nPatterns >= p->nPatternsAlloc )
-        return;
-    Saig_ManForEachLo( p->pMan->pAig, pObj, i )
-    {
-        pInfo = Vec_PtrEntry( p->vPatterns, i );
-        if ( Aig_InfoHasBit( p->pMan->pPatWords, Saig_ManPiNum(p->pMan->pAig) + i ) )
-            Aig_InfoSetBit( pInfo, p->nPatterns );
-    }
-    p->nPatterns++;
-}
 
 /**Function*************************************************************
 
-  Synopsis    [Performs fraiging for the internal nodes.]
+  Synopsis    [Performs BMC for the given AIG.]
 
   Description []
                
@@ -168,143 +120,95 @@ void Ssw_ManFilterBmcSavePattern( Ssw_Bmc_t * p )
   SeeAlso     []
 
 ***********************************************************************/
-int Ssw_ManFilterBmc( Ssw_Bmc_t * pBmc, int iPat, int fCheckTargets )
+int Ssw_BmcDynamic( Aig_Man_t * pAig, int nFramesMax, int nConfLimit, int fVerbose, int * piFrame )
 {
-    Ssw_Man_t * p = pBmc->pMan;
-    Aig_Obj_t * pObj, * pObjNew, * pObjLi, * pObjLo;
-    unsigned * pInfo;
-    int i, f, clk, RetValue, fFirst = 0;
-clk = clock();
-
-    // start initialized timeframes
-    p->pFrames = Aig_ManStart( Aig_ManObjNumMax(p->pAig) * 3 );
-    Saig_ManForEachLo( p->pAig, pObj, i )
+    Ssw_Frm_t * pFrm;
+    Ssw_Sat_t * pSat;
+    Aig_Obj_t * pObj, * pObjFrame;
+    int status, clkPart, Lit, i, f, RetValue;
+
+    // start managers
+    assert( Saig_ManRegNum(pAig) > 0 );
+    Aig_ManSetPioNumbers( pAig );
+    pSat = Ssw_SatStart( 0 );
+    pFrm = Ssw_FrmStart( pAig );
+    pFrm->pFrames = Aig_ManStart( Aig_ManObjNumMax(pAig) * 3 );
+    // report statistics
+    if ( fVerbose )
     {
-        pInfo = Vec_PtrEntry( pBmc->vPatterns, i );
-        pObjNew = Aig_NotCond( Aig_ManConst1(p->pFrames), !Aig_InfoHasBit(pInfo, iPat) );
-        Ssw_ObjSetFrame( p, pObj, 0, pObjNew );
+        printf( "AIG:  PI/PO/Reg = %d/%d/%d.  Node = %6d. Lev = %5d.\n", 
+            Saig_ManPiNum(pAig), Saig_ManPoNum(pAig), Saig_ManRegNum(pAig),
+            Aig_ManNodeNum(pAig), Aig_ManLevelNum(pAig) );
+        fflush( stdout );
     }
-
-    // sweep internal nodes
-    Ssw_ManStartSolver( p );
-    RetValue = pBmc->nFramesSweep;
-    for ( f = 0; f < pBmc->nFramesSweep; f++ )
+    // perform dynamic unrolling
+    RetValue = -1;
+    for ( f = 0; f < nFramesMax; f++ )
     {
-        // map constants and PIs
-        Ssw_ObjSetFrame( p, Aig_ManConst1(p->pAig), f, Aig_ManConst1(p->pFrames) );
-        Saig_ManForEachPi( p->pAig, pObj, i )
-            Ssw_ObjSetFrame( p, pObj, f, Aig_ObjCreatePi(p->pFrames) );
-        // sweep internal nodes
-        Aig_ManForEachNode( p->pAig, pObj, i )
+        clkPart = clock();
+        Saig_ManForEachPo( pAig, pObj, i )
         {
-            pObjNew = Aig_And( p->pFrames, Ssw_ObjChild0Fra(p, pObj, f), Ssw_ObjChild1Fra(p, pObj, f) );
-            Ssw_ObjSetFrame( p, pObj, f, pObjNew );
-            if ( Ssw_ManSweepNode( p, pObj, f, 1 ) )
+            // unroll the circuit for this output
+            Ssw_BmcUnroll_rec( pFrm, pObj, f );
+            pObjFrame = Ssw_ObjFrame_( pFrm, pObj, f );
+            Ssw_CnfNodeAddToSolver( pSat, Aig_Regular(pObjFrame) );
+            status = sat_solver_simplify(pSat->pSat);
+            assert( status );
+            // solve
+            Lit = toLitCond( Ssw_ObjSatNum(pSat,pObjFrame), Aig_IsComplement(pObjFrame) );
+            if ( fVerbose )
+            {
+                printf( "Solving output %2d of frame %3d ... \r", 
+                    i % Saig_ManPoNum(pAig), i / Saig_ManPoNum(pAig) );
+            }
+            status = sat_solver_solve( pSat->pSat, &Lit, &Lit + 1, (sint64)nConfLimit, (sint64)0, (sint64)0, (sint64)0 );
+            if ( status == l_False )
             {
-                Ssw_ManFilterBmcSavePattern( pBmc );
-                if ( fFirst == 0 )
+/*
+                Lit = lit_neg( Lit );
+                RetValue = sat_solver_addclause( pSat->pSat, &Lit, &Lit + 1 );
+                assert( RetValue );
+                if ( pSat->pSat->qtail != pSat->pSat->qhead )
                 {
-                    fFirst = 1;
-                    pBmc->nConfMax *= 10;
-                } 
+                    RetValue = sat_solver_simplify(pSat->pSat);
+                    assert( RetValue );
+                }
+*/
+                RetValue = 1;
+                continue;
             }
-            if ( f > 0 && p->pSat->stats.conflicts >= pBmc->nConfMax )
+            else if ( status == l_True )
             {
+                pAig->pSeqModel = Ssw_BmcGetCounterExample( pFrm, pSat, i, f );
+                if ( piFrame )
+                    *piFrame = f;
+                RetValue = 0;
+                break;
+            }
+            else
+            {
+                if ( piFrame )
+                    *piFrame = f;
                 RetValue = -1;
                 break;
             }
         }
-        // quit if this is the last timeframe
-        if ( p->pSat->stats.conflicts >= pBmc->nConfMax )
-        {
-            RetValue += f + 1;
-            break;
-        }
-        if ( fCheckTargets && Ssw_BmcCheckTargets( pBmc ) )
-            break;
-        // transfer latch input to the latch outputs 
-        // build logic cones for register outputs
-        Saig_ManForEachLiLo( p->pAig, pObjLi, pObjLo, i )
-        {
-            pObjNew = Ssw_ObjChild0Fra(p, pObjLi,f);
-            Ssw_ObjSetFrame( p, pObjLo, f+1, pObjNew );
-            Ssw_CnfNodeAddToSolver( p, Aig_Regular(pObjNew) );
-        }
-//printf( "Frame %2d : Conflicts = %6d. \n", f, p->pSat->stats.conflicts );
-    }
-    if ( fFirst )
-        pBmc->nConfMax /= 10;
-
-    // cleanup
-    Ssw_ClassesCheck( p->ppClasses );
-p->timeBmc += clock() - clk;
-    return RetValue;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Returns 1 if one of the targets has failed.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_FilterUsingBmc( Ssw_Man_t * pMan, int fCheckTargets, int nConfMax, int fVerbose )
-{
-    Ssw_Bmc_t * p;
-    int RetValue, Frames, Iter, clk = clock();
-    p = Ssw_BmcManStart( pMan, nConfMax, fVerbose );
-    if ( fCheckTargets && Ssw_BmcCheckTargets( p ) )
-    {
-        assert( 0 );
-        Ssw_BmcManStop( p );
-        return 1;
-    }
-    if ( fVerbose )
-    {
-        printf( "AIG : Const = %6d. Cl = %6d. Nodes = %6d.  ConfMax = %6d. FramesMax = %6d.\n", 
-            Ssw_ClassesCand1Num(p->pMan->ppClasses), Ssw_ClassesClassNum(p->pMan->ppClasses), 
-            Aig_ManNodeNum(p->pMan->pAig), p->nConfMax, p->nFramesSweep );
-    } 
-    RetValue = 0;
-    for ( Iter = 0; Iter < p->nPatterns; Iter++ )
-    {
-clk = clock();
-        Frames = Ssw_ManFilterBmc( p, Iter, fCheckTargets );
         if ( fVerbose )
         {
-            printf( "%3d : Const = %6d. Cl = %6d. NR = %6d. F = %3d. C = %5d. P = %3d. %s ", 
-                Iter, Ssw_ClassesCand1Num(p->pMan->ppClasses), Ssw_ClassesClassNum(p->pMan->ppClasses), 
-                Aig_ManNodeNum(p->pMan->pFrames), Frames, (int)p->pMan->pSat->stats.conflicts, p->nPatterns, 
-                p->pMan->nSatFailsReal? "f" : " " );
-            PRT( "T", clock() - clk );
-        } 
-        Ssw_ManCleanup( p->pMan );
-        if ( fCheckTargets && Ssw_BmcCheckTargets( p ) )
-        {
-            printf( "Target is hit!!!\n" );
-            RetValue = 1;
+            printf( "Solved %2d outputs of frame %3d.  ", Saig_ManPoNum(pAig), f );
+            printf( "Conf =%8.0f. Var =%8d. AIG=%9d. ", 
+                (double)pSat->pSat->stats.conflicts, 
+                pSat->nSatVars, Aig_ManNodeNum(pFrm->pFrames) );
+            PRT( "T", clock() - clkPart );
+            clkPart = clock();
+            fflush( stdout );
         }
-        if ( p->nPatterns >= p->nPatternsAlloc )
+        if ( RetValue != 1 )
             break;
     }
-    Ssw_BmcManStop( p );
-
-    pMan->nStrangers = 0;
-    pMan->nSatCalls = 0;
-    pMan->nSatProof = 0;
-    pMan->nSatFailsReal = 0; 
-    pMan->nSatFailsTotal = 0;
-    pMan->nSatCallsUnsat = 0;
-    pMan->nSatCallsSat = 0;  
-    pMan->timeSimSat = 0;    
-    pMan->timeSat = 0;       
-    pMan->timeSatSat = 0;    
-    pMan->timeSatUnsat = 0;  
-    pMan->timeSatUndec = 0;  
+
+    Ssw_SatStop( pSat );
+    Ssw_FrmStop( pFrm );
     return RetValue;
 }
 
diff --git a/src/aig/ssw/sswCnf.c b/src/aig/ssw/sswCnf.c
index e4b8f9f6..d068bb78 100644
--- a/src/aig/ssw/sswCnf.c
+++ b/src/aig/ssw/sswCnf.c
@@ -30,6 +30,63 @@
 
 /**Function*************************************************************
 
+  Synopsis    [Starts the SAT manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Ssw_Sat_t * Ssw_SatStart( int fPolarFlip )
+{
+    Ssw_Sat_t * p;
+    int Lit;
+    p = ALLOC( Ssw_Sat_t, 1 ); 
+    memset( p, 0, sizeof(Ssw_Sat_t) );
+    p->pAig          = NULL;
+    p->fPolarFlip    = fPolarFlip;
+    p->vSatVars      = Vec_IntStart( 10000 );
+    p->vFanins       = Vec_PtrAlloc( 100 );
+    p->vUsedPis      = Vec_PtrAlloc( 100 );
+    p->pSat          = sat_solver_new();
+    sat_solver_setnvars( p->pSat, 1000 );
+    // var 0 is not used
+    // var 1 is reserved for const1 node - add the clause
+    p->nSatVars = 1;
+    Lit = toLit( p->nSatVars );
+    if ( fPolarFlip )
+        Lit = lit_neg( Lit );
+    sat_solver_addclause( p->pSat, &Lit, &Lit + 1 );
+//    Ssw_ObjSetSatNum( p, Aig_ManConst1(p->pAig), p->nSatVars++ );
+    Vec_IntWriteEntry( p->vSatVars, 0, p->nSatVars++ );
+    return p;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Stop the SAT manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Ssw_SatStop( Ssw_Sat_t * p )
+{
+    if ( p->pSat )
+        sat_solver_delete( p->pSat );
+    Vec_IntFree( p->vSatVars );
+    Vec_PtrFree( p->vFanins );
+    Vec_PtrFree( p->vUsedPis );
+    free( p );
+}
+
+/**Function*************************************************************
+
   Synopsis    [Addes clauses to the solver.]
 
   Description []
@@ -39,7 +96,7 @@
   SeeAlso     []
 
 ***********************************************************************/
-void Ssw_AddClausesMux( Ssw_Man_t * p, Aig_Obj_t * pNode )
+void Ssw_AddClausesMux( Ssw_Sat_t * p, Aig_Obj_t * pNode )
 {
     Aig_Obj_t * pNodeI, * pNodeT, * pNodeE;
     int pLits[4], RetValue, VarF, VarI, VarT, VarE, fCompT, fCompE;
@@ -68,7 +125,7 @@ void Ssw_AddClausesMux( Ssw_Man_t * p, Aig_Obj_t * pNode )
     pLits[0] = toLitCond(VarI, 1);
     pLits[1] = toLitCond(VarT, 1^fCompT);
     pLits[2] = toLitCond(VarF, 0);
-    if ( p->pPars->fPolarFlip )
+    if ( p->fPolarFlip )
     {
         if ( pNodeI->fPhase )               pLits[0] = lit_neg( pLits[0] );
         if ( Aig_Regular(pNodeT)->fPhase )  pLits[1] = lit_neg( pLits[1] );
@@ -79,7 +136,7 @@ void Ssw_AddClausesMux( Ssw_Man_t * p, Aig_Obj_t * pNode )
     pLits[0] = toLitCond(VarI, 1);
     pLits[1] = toLitCond(VarT, 0^fCompT);
     pLits[2] = toLitCond(VarF, 1);
-    if ( p->pPars->fPolarFlip )
+    if ( p->fPolarFlip )
     {
         if ( pNodeI->fPhase )               pLits[0] = lit_neg( pLits[0] );
         if ( Aig_Regular(pNodeT)->fPhase )  pLits[1] = lit_neg( pLits[1] );
@@ -90,7 +147,7 @@ void Ssw_AddClausesMux( Ssw_Man_t * p, Aig_Obj_t * pNode )
     pLits[0] = toLitCond(VarI, 0);
     pLits[1] = toLitCond(VarE, 1^fCompE);
     pLits[2] = toLitCond(VarF, 0);
-    if ( p->pPars->fPolarFlip )
+    if ( p->fPolarFlip )
     {
         if ( pNodeI->fPhase )               pLits[0] = lit_neg( pLits[0] );
         if ( Aig_Regular(pNodeE)->fPhase )  pLits[1] = lit_neg( pLits[1] );
@@ -101,7 +158,7 @@ void Ssw_AddClausesMux( Ssw_Man_t * p, Aig_Obj_t * pNode )
     pLits[0] = toLitCond(VarI, 0);
     pLits[1] = toLitCond(VarE, 0^fCompE);
     pLits[2] = toLitCond(VarF, 1);
-    if ( p->pPars->fPolarFlip )
+    if ( p->fPolarFlip )
     {
         if ( pNodeI->fPhase )               pLits[0] = lit_neg( pLits[0] );
         if ( Aig_Regular(pNodeE)->fPhase )  pLits[1] = lit_neg( pLits[1] );
@@ -126,7 +183,7 @@ void Ssw_AddClausesMux( Ssw_Man_t * p, Aig_Obj_t * pNode )
     pLits[0] = toLitCond(VarT, 0^fCompT);
     pLits[1] = toLitCond(VarE, 0^fCompE);
     pLits[2] = toLitCond(VarF, 1);
-    if ( p->pPars->fPolarFlip )
+    if ( p->fPolarFlip )
     {
         if ( Aig_Regular(pNodeT)->fPhase )  pLits[0] = lit_neg( pLits[0] );
         if ( Aig_Regular(pNodeE)->fPhase )  pLits[1] = lit_neg( pLits[1] );
@@ -137,7 +194,7 @@ void Ssw_AddClausesMux( Ssw_Man_t * p, Aig_Obj_t * pNode )
     pLits[0] = toLitCond(VarT, 1^fCompT);
     pLits[1] = toLitCond(VarE, 1^fCompE);
     pLits[2] = toLitCond(VarF, 0);
-    if ( p->pPars->fPolarFlip )
+    if ( p->fPolarFlip )
     {
         if ( Aig_Regular(pNodeT)->fPhase )  pLits[0] = lit_neg( pLits[0] );
         if ( Aig_Regular(pNodeE)->fPhase )  pLits[1] = lit_neg( pLits[1] );
@@ -158,7 +215,7 @@ void Ssw_AddClausesMux( Ssw_Man_t * p, Aig_Obj_t * pNode )
   SeeAlso     []
 
 ***********************************************************************/
-void Ssw_AddClausesSuper( Ssw_Man_t * p, Aig_Obj_t * pNode, Vec_Ptr_t * vSuper )
+void Ssw_AddClausesSuper( Ssw_Sat_t * p, Aig_Obj_t * pNode, Vec_Ptr_t * vSuper )
 {
     Aig_Obj_t * pFanin;
     int * pLits, nLits, RetValue, i;
@@ -173,7 +230,7 @@ void Ssw_AddClausesSuper( Ssw_Man_t * p, Aig_Obj_t * pNode, Vec_Ptr_t * vSuper )
     {
         pLits[0] = toLitCond(Ssw_ObjSatNum(p,Aig_Regular(pFanin)), Aig_IsComplement(pFanin));
         pLits[1] = toLitCond(Ssw_ObjSatNum(p,pNode), 1);
-        if ( p->pPars->fPolarFlip )
+        if ( p->fPolarFlip )
         {
             if ( Aig_Regular(pFanin)->fPhase )  pLits[0] = lit_neg( pLits[0] );
             if ( pNode->fPhase )                pLits[1] = lit_neg( pLits[1] );
@@ -185,13 +242,13 @@ void Ssw_AddClausesSuper( Ssw_Man_t * p, Aig_Obj_t * pNode, Vec_Ptr_t * vSuper )
     Vec_PtrForEachEntry( vSuper, pFanin, i )
     {
         pLits[i] = toLitCond(Ssw_ObjSatNum(p,Aig_Regular(pFanin)), !Aig_IsComplement(pFanin));
-        if ( p->pPars->fPolarFlip )
+        if ( p->fPolarFlip )
         {
             if ( Aig_Regular(pFanin)->fPhase )  pLits[i] = lit_neg( pLits[i] );
         }
     }
     pLits[nLits-1] = toLitCond(Ssw_ObjSatNum(p,pNode), 0);
-    if ( p->pPars->fPolarFlip )
+    if ( p->fPolarFlip )
     {
         if ( pNode->fPhase )  pLits[nLits-1] = lit_neg( pLits[nLits-1] );
     }
@@ -221,6 +278,7 @@ void Ssw_CollectSuper_rec( Aig_Obj_t * pObj, Vec_Ptr_t * vSuper, int fFirst, int
         Vec_PtrPushUnique( vSuper, pObj );
         return;
     }
+//    pObj->fMarkA = 1;
     // go through the branches
     Ssw_CollectSuper_rec( Aig_ObjChild0(pObj), vSuper, 0, fUseMuxes );
     Ssw_CollectSuper_rec( Aig_ObjChild1(pObj), vSuper, 0, fUseMuxes );
@@ -256,7 +314,7 @@ void Ssw_CollectSuper( Aig_Obj_t * pObj, int fUseMuxes, Vec_Ptr_t * vSuper )
   SeeAlso     []
 
 ***********************************************************************/
-void Ssw_ObjAddToFrontier( Ssw_Man_t * p, Aig_Obj_t * pObj, Vec_Ptr_t * vFrontier )
+void Ssw_ObjAddToFrontier( Ssw_Sat_t * p, Aig_Obj_t * pObj, Vec_Ptr_t * vFrontier )
 {
     assert( !Aig_IsComplement(pObj) );
     if ( Ssw_ObjSatNum(p,pObj) )
@@ -264,12 +322,10 @@ void Ssw_ObjAddToFrontier( Ssw_Man_t * p, Aig_Obj_t * pObj, Vec_Ptr_t * vFrontie
     assert( Ssw_ObjSatNum(p,pObj) == 0 );
     if ( Aig_ObjIsConst1(pObj) )
         return;
-    if ( p->pPars->fLatchCorrOpt )
-    {
-        Vec_PtrPush( p->vUsedNodes, pObj );
-        if ( Aig_ObjIsPi(pObj) )
-            Vec_PtrPush( p->vUsedPis, pObj );
-    }
+//    pObj->fMarkA = 1;
+    // save PIs (used by register correspondence)
+    if ( Aig_ObjIsPi(pObj) )
+        Vec_PtrPush( p->vUsedPis, pObj );
     Ssw_ObjSetSatNum( p, pObj, p->nSatVars++ );
     sat_solver_setnvars( p->pSat, 100 * (1 + p->nSatVars / 100) );
     if ( Aig_ObjIsNode(pObj) )
@@ -287,7 +343,7 @@ void Ssw_ObjAddToFrontier( Ssw_Man_t * p, Aig_Obj_t * pObj, Vec_Ptr_t * vFrontie
   SeeAlso     []
 
 ***********************************************************************/
-void Ssw_CnfNodeAddToSolver( Ssw_Man_t * p, Aig_Obj_t * pObj )
+void Ssw_CnfNodeAddToSolver( Ssw_Sat_t * p, Aig_Obj_t * pObj )
 { 
     Vec_Ptr_t * vFrontier;
     Aig_Obj_t * pNode, * pFanin;
@@ -327,6 +383,36 @@ void Ssw_CnfNodeAddToSolver( Ssw_Man_t * p, Aig_Obj_t * pObj )
 }
 
 
+/**Function*************************************************************
+
+  Synopsis    [Copy pattern from the solver into the internal storage.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Ssw_CnfGetNodeValue( Ssw_Sat_t * p, Aig_Obj_t * pObj )
+{
+    int Value0, Value1, nVarNum;
+    assert( !Aig_IsComplement(pObj) );
+    nVarNum = Ssw_ObjSatNum( p, pObj );
+    if ( nVarNum > 0 )
+        return sat_solver_var_value( p->pSat, nVarNum );
+//    if ( pObj->fMarkA == 1 )
+//        return 0;
+    if ( Aig_ObjIsPi(pObj) )
+        return 0;
+    assert( Aig_ObjIsNode(pObj) );
+    Value0 = Ssw_CnfGetNodeValue( p, Aig_ObjFanin0(pObj) );
+    Value0 ^= Aig_ObjFaninC0(pObj);
+    Value1 = Ssw_CnfGetNodeValue( p, Aig_ObjFanin1(pObj) );
+    Value1 ^= Aig_ObjFaninC1(pObj);
+    return Value0 & Value1;
+}
+
 
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
diff --git a/src/aig/ssw/sswCore.c b/src/aig/ssw/sswCore.c
index 2af9e900..39f4c736 100644
--- a/src/aig/ssw/sswCore.c
+++ b/src/aig/ssw/sswCore.c
@@ -45,13 +45,13 @@ void Ssw_ManSetDefaultParams( Ssw_Pars_t * p )
     p->nPartSize      =       0;  // size of the partition
     p->nOverSize      =       0;  // size of the overlap between partitions
     p->nFramesK       =       1;  // the induction depth
-    p->nFramesAddSim  =       0;  // additional frames to simulate
+    p->nFramesAddSim  =       2;  // additional frames to simulate
     p->nConstrs       =       0;  // treat the last nConstrs POs as seq constraints
     p->nBTLimit       =    1000;  // conflict limit at a node
     p->nBTLimitGlobal = 5000000;  // conflict limit for all runs
     p->nMinDomSize    =     100;  // min clock domain considered for optimization
+    p->nItersStop     =       0;  // stop after the given number of iterations
     p->fPolarFlip     =       0;  // uses polarity adjustment
-    p->fSkipCheck     =       0;  // do not run equivalence check for unaffected cones
     p->fLatchCorr     =       0;  // performs register correspondence
     p->fSemiFormal    =       0;  // enable semiformal filtering
     p->fUniqueness    =       0;  // enable uniqueness constraints
@@ -111,7 +111,12 @@ Aig_Man_t * Ssw_SignalCorrespondenceRefine( Ssw_Man_t * p )
     }
     if ( !p->pPars->fLatchCorr )
     { 
+        p->pMSat = Ssw_SatStart( 0 );
         Ssw_ManSweepBmc( p );
+        if ( p->pPars->nFramesK > 1 && p->pPars->fUniqueness )
+            Ssw_UniqueRegisterPairInfo( p );
+        Ssw_SatStop( p->pMSat );
+        p->pMSat = NULL;
         Ssw_ManCleanup( p );
     }
     if ( p->pPars->fVerbose )
@@ -120,20 +125,23 @@ Aig_Man_t * Ssw_SignalCorrespondenceRefine( Ssw_Man_t * p )
         Ssw_ClassesPrint( p->ppClasses, 0 );
     }
     // apply semi-formal filtering
+/*
     if ( p->pPars->fSemiFormal )
     {
         Aig_Man_t * pSRed;
-        Ssw_FilterUsingBmc( p, 0, 2000, p->pPars->fVerbose );
-//        Ssw_FilterUsingBmc( p, 1, 100000, p->pPars->fVerbose );
+        Ssw_FilterUsingSemi( p, 0, 2000, p->pPars->fVerbose );
+//        Ssw_FilterUsingSemi( p, 1, 100000, p->pPars->fVerbose );
         pSRed = Ssw_SpeculativeReduction( p );
         Aig_ManDumpBlif( pSRed, "srm.blif", NULL, NULL );
         Aig_ManStop( pSRed );
     }
+*/
     // refine classes using induction
     nSatProof = nSatCallsSat = nRecycles = nSatFailsReal = 0;
     for ( nIter = 0; ; nIter++ )
     {
 clk = clock();
+        p->pMSat = Ssw_SatStart( 0 );
         if ( p->pPars->fLatchCorrOpt )
         {
             RetValue = Ssw_ManSweepLatch( p );
@@ -153,34 +161,32 @@ clk = clock();
         else
         {
             RetValue = Ssw_ManSweep( p );
-            p->pPars->nConflicts += p->pSat->stats.conflicts;
+            p->pPars->nConflicts += p->pMSat->pSat->stats.conflicts;
             if ( p->pPars->fVerbose )
             {
                 printf( "%3d : Const = %6d. Cl = %6d. LR = %6d. NR = %6d. U = %3d. F = %2d. ", 
                     nIter, Ssw_ClassesCand1Num(p->ppClasses), Ssw_ClassesClassNum(p->ppClasses), 
                     p->nConstrReduced, Aig_ManNodeNum(p->pFrames), p->nUniques, p->nSatFailsReal );
-                if ( p->pPars->fSkipCheck )
-                    printf( "Use = %5d. Skip = %5d. ", 
-                        p->nRefUse, p->nRefSkip );
                 PRT( "T", clock() - clk );
             } 
         }
+        Ssw_SatStop( p->pMSat );
+        p->pMSat = NULL;
         Ssw_ManCleanup( p );
-        if ( !RetValue )
+        if ( !RetValue ) 
             break;
-/*
+
+        if ( p->pPars->nItersStop && p->pPars->nItersStop == nIter )
         {
-            static int Flag = 0;
-            if ( Flag++ == 4 && nIter == 4 )
-            {
-                Aig_Man_t * pSRed;
-                pSRed = Ssw_SpeculativeReduction( p );
-                Aig_ManDumpBlif( pSRed, "srm.blif", NULL, NULL );
-                Aig_ManStop( pSRed );
-            }
+            Aig_Man_t * pSRed = Ssw_SpeculativeReduction( p );
+            Aig_ManDumpBlif( pSRed, "srm.blif", NULL, NULL );
+            Aig_ManStop( pSRed );
+            printf( "Iterative refinement is stopped after iteration %d.\n", nIter );
+            printf( "The network is reduced using candidate equivalences.\n" );
+            printf( "Speculatively reduced miter is saved in file \"%s\".\n", "srm.blif" );
+            printf( "If the miter is SAT, the reduced result is incorrect.\n" );
+            break;
         }
-*/
-
     } 
     p->pPars->nIters = nIter + 1;
 p->timeTotal = clock() - clkTotal;
@@ -224,6 +230,13 @@ Aig_Man_t * Ssw_SignalCorrespondence( Aig_Man_t * pAig, Ssw_Pars_t * pPars )
         return Aig_ManDupOrdered(pAig);
     }
     // check and update parameters
+    if ( pPars->fUniqueness )
+    {
+        pPars->nFramesAddSim = 0;
+        if ( pPars->nFramesK != 2 )
+            printf( "Setting K = 2 for uniqueness constaints to work.\n" );
+        pPars->nFramesK = 2;
+    }
     if ( pPars->fLatchCorrOpt )
     {
         pPars->fLatchCorr = 1;
@@ -232,8 +245,6 @@ Aig_Man_t * Ssw_SignalCorrespondence( Aig_Man_t * pAig, Ssw_Pars_t * pPars )
     else
     {
         assert( pPars->nFramesK > 0 );
-        if ( pPars->nFramesK > 1 )
-            pPars->fSkipCheck = 0;
         // perform partitioning
         if ( (pPars->nPartSize > 0 && pPars->nPartSize < Aig_ManRegNum(pAig))
              || (pAig->vClockDoms && Vec_VecSize(pAig->vClockDoms) > 0)  )
@@ -259,6 +270,9 @@ Aig_Man_t * Ssw_SignalCorrespondence( Aig_Man_t * pAig, Ssw_Pars_t * pPars )
     }
     // perform refinement of classes
     pAigNew = Ssw_SignalCorrespondenceRefine( p );    
+    if ( pPars->fUniqueness )
+        printf( "Uniqueness constaint = %3d. Prevented counter-examples = %3d.\n", 
+            p->nUniquesAdded, p->nUniquesUseful );
     // cleanup
     Ssw_ManStop( p );
     return pAigNew;
diff --git a/src/aig/ssw/sswInt.h b/src/aig/ssw/sswInt.h
index 636bd139..0a3f7e21 100644
--- a/src/aig/ssw/sswInt.h
+++ b/src/aig/ssw/sswInt.h
@@ -42,6 +42,8 @@ extern "C" {
 ////////////////////////////////////////////////////////////////////////
 
 typedef struct Ssw_Man_t_ Ssw_Man_t; // signal correspondence manager
+typedef struct Ssw_Frm_t_ Ssw_Frm_t; // unrolled frames manager
+typedef struct Ssw_Sat_t_ Ssw_Sat_t; // SAT solver manager
 typedef struct Ssw_Cla_t_ Ssw_Cla_t; // equivalence classe manager
 typedef struct Ssw_Sml_t_ Ssw_Sml_t; // sequential simulation manager
 
@@ -57,17 +59,10 @@ struct Ssw_Man_t_
     // equivalence classes
     Ssw_Cla_t *      ppClasses;      // equivalence classes of nodes
     int              fRefined;       // is set to 1 when refinement happens
-    int              nRefUse;        // the number of equivalences used
-    int              nRefSkip;       // the number of equivalences skipped  
-    // SAT solving
-    sat_solver *     pSat;           // recyclable SAT solver
-    int              nSatVars;       // the counter of SAT variables
-    Vec_Int_t *      vSatVars;       // mapping of each node into its SAT var
-    int              nSatVarsTotal;  // the total number of SAT vars created
-    Vec_Ptr_t *      vFanins;        // fanins of the CNF node
+    // SAT solving 
+    Ssw_Sat_t *      pMSatBmc;       // SAT manager for base case
+    Ssw_Sat_t *      pMSat;          // SAT manager for inductive case
     // SAT solving (latch corr only)
-    Vec_Ptr_t *      vUsedNodes;     // the nodes with SAT variables
-    Vec_Ptr_t *      vUsedPis;       // the PIs with SAT variables
     Vec_Ptr_t *      vSimInfo;       // simulation information for the framed PIs
     int              nPatterns;      // the number of patterns saved
     int              nSimRounds;     // the number of simulation rounds performed
@@ -81,7 +76,10 @@ struct Ssw_Man_t_
     // uniqueness
     Vec_Ptr_t *      vCommon;        // the set of common variables in the logic cones
     int              iOutputLit;     // the output literal of the uniqueness constaint
+    Vec_Int_t *      vDiffPairs;     // is set to 1 if reg pair can be diff
     int              nUniques;       // the number of uniqueness constaints used 
+    int              nUniquesAdded;  // useful uniqueness constraints
+    int              nUniquesUseful; // useful uniqueness constraints
     // sequential simulator
     Ssw_Sml_t *      pSml;
     // counter example storage
@@ -118,12 +116,35 @@ struct Ssw_Man_t_
     int              timeTotal;      // total runtime
 };
 
+// internal SAT manager
+struct Ssw_Sat_t_
+{
+    Aig_Man_t *      pAig;           // the AIG manager
+    int              fPolarFlip;     // flips polarity 
+    sat_solver *     pSat;           // recyclable SAT solver
+    int              nSatVars;       // the counter of SAT variables
+    Vec_Int_t *      vSatVars;       // mapping of each node into its SAT var
+    int              nSatVarsTotal;  // the total number of SAT vars created
+    Vec_Ptr_t *      vFanins;        // fanins of the CNF node
+    Vec_Ptr_t *      vUsedPis;       // the PIs with SAT variables 
+};
+
+// internal frames manager
+struct Ssw_Frm_t_
+{
+    Aig_Man_t *      pAig;           // user-given AIG
+    int              nObjs;          // offset in terms of AIG nodes
+    int              nFrames;        // the number of frames in current unrolling
+    Aig_Man_t *      pFrames;        // unrolled AIG
+    Vec_Ptr_t *      vAig2Frm;       // mapping of AIG nodes into frame nodes
+};
+
 ////////////////////////////////////////////////////////////////////////
 ///                      MACRO DEFINITIONS                           ///
 ////////////////////////////////////////////////////////////////////////
 
-static inline int  Ssw_ObjSatNum( Ssw_Man_t * p, Aig_Obj_t * pObj )             { return Vec_IntEntry( p->vSatVars, pObj->Id );         }
-static inline void Ssw_ObjSetSatNum( Ssw_Man_t * p, Aig_Obj_t * pObj, int Num ) { Vec_IntWriteEntryFill( p->vSatVars, pObj->Id, Num );  }
+static inline int  Ssw_ObjSatNum( Ssw_Sat_t * p, Aig_Obj_t * pObj )             { return Vec_IntGetEntry( p->vSatVars, pObj->Id );  }
+static inline void Ssw_ObjSetSatNum( Ssw_Sat_t * p, Aig_Obj_t * pObj, int Num ) { Vec_IntSetEntry(p->vSatVars, pObj->Id, Num);      }
 
 static inline int  Ssw_ObjIsConst1Cand( Aig_Man_t * pAig, Aig_Obj_t * pObj ) 
 {
@@ -141,15 +162,22 @@ static inline void        Ssw_ObjSetFrame( Ssw_Man_t * p, Aig_Obj_t * pObj, int
 static inline Aig_Obj_t * Ssw_ObjChild0Fra( Ssw_Man_t * p, Aig_Obj_t * pObj, int i ) { assert( !Aig_IsComplement(pObj) ); return Aig_ObjFanin0(pObj)? Aig_NotCond(Ssw_ObjFrame(p, Aig_ObjFanin0(pObj), i), Aig_ObjFaninC0(pObj)) : NULL;  }
 static inline Aig_Obj_t * Ssw_ObjChild1Fra( Ssw_Man_t * p, Aig_Obj_t * pObj, int i ) { assert( !Aig_IsComplement(pObj) ); return Aig_ObjFanin1(pObj)? Aig_NotCond(Ssw_ObjFrame(p, Aig_ObjFanin1(pObj), i), Aig_ObjFaninC1(pObj)) : NULL;  }
 
+static inline Aig_Obj_t * Ssw_ObjFrame_( Ssw_Frm_t * p, Aig_Obj_t * pObj, int i )                       { return Vec_PtrGetEntry( p->vAig2Frm, p->nObjs*i+pObj->Id );     }
+static inline void        Ssw_ObjSetFrame_( Ssw_Frm_t * p, Aig_Obj_t * pObj, int i, Aig_Obj_t * pNode ) { Vec_PtrSetEntry( p->vAig2Frm, p->nObjs*i+pObj->Id, pNode );     }
+
+static inline Aig_Obj_t * Ssw_ObjChild0Fra_( Ssw_Frm_t * p, Aig_Obj_t * pObj, int i ) { assert( !Aig_IsComplement(pObj) ); return Aig_ObjFanin0(pObj)? Aig_NotCond(Ssw_ObjFrame_(p, Aig_ObjFanin0(pObj), i), Aig_ObjFaninC0(pObj)) : NULL;  }
+static inline Aig_Obj_t * Ssw_ObjChild1Fra_( Ssw_Frm_t * p, Aig_Obj_t * pObj, int i ) { assert( !Aig_IsComplement(pObj) ); return Aig_ObjFanin1(pObj)? Aig_NotCond(Ssw_ObjFrame_(p, Aig_ObjFanin1(pObj), i), Aig_ObjFaninC1(pObj)) : NULL;  }
+
 ////////////////////////////////////////////////////////////////////////
 ///                    FUNCTION DECLARATIONS                         ///
 ////////////////////////////////////////////////////////////////////////
 
 /*=== sswAig.c ===================================================*/
+extern Ssw_Frm_t *   Ssw_FrmStart( Aig_Man_t * pAig );
+extern void          Ssw_FrmStop( Ssw_Frm_t * p );
 extern Aig_Man_t *   Ssw_FramesWithClasses( Ssw_Man_t * p );
 extern Aig_Man_t *   Ssw_SpeculativeReduction( Ssw_Man_t * p );
 /*=== sswBmc.c ===================================================*/
-extern int           Ssw_FilterUsingBmc( Ssw_Man_t * pMan, int fCheckTargets, int nConfMax, int fVerbose );
 /*=== sswClass.c =================================================*/
 extern Ssw_Cla_t *   Ssw_ClassesStart( Aig_Man_t * pAig );
 extern void          Ssw_ClassesSetData( Ssw_Cla_t * p, void * pManData,
@@ -177,7 +205,10 @@ extern int           Ssw_ClassesRefineOneClass( Ssw_Cla_t * p, Aig_Obj_t * pRepr
 extern int           Ssw_ClassesRefineConst1Group( Ssw_Cla_t * p, Vec_Ptr_t * vRoots, int fRecursive );
 extern int           Ssw_ClassesRefineConst1( Ssw_Cla_t * p, int fRecursive );
 /*=== sswCnf.c ===================================================*/
-extern void          Ssw_CnfNodeAddToSolver( Ssw_Man_t * p, Aig_Obj_t * pObj );
+extern Ssw_Sat_t *   Ssw_SatStart( int fPolarFlip );
+extern void          Ssw_SatStop( Ssw_Sat_t * p );
+extern void          Ssw_CnfNodeAddToSolver( Ssw_Sat_t * p, Aig_Obj_t * pObj );
+extern int           Ssw_CnfGetNodeValue( Ssw_Sat_t * p, Aig_Obj_t * pObjFraig );
 /*=== sswCore.c ===================================================*/
 extern Aig_Man_t *   Ssw_SignalCorrespondenceRefine( Ssw_Man_t * p );
 /*=== sswLcorr.c ==========================================================*/
@@ -190,6 +221,8 @@ extern void          Ssw_ManStartSolver( Ssw_Man_t * p );
 /*=== sswSat.c ===================================================*/
 extern int           Ssw_NodesAreEquiv( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew );
 extern int           Ssw_NodesAreConstrained( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew );
+/*=== sswSemi.c ===================================================*/
+extern int           Ssw_FilterUsingSemi( Ssw_Man_t * pMan, int fCheckTargets, int nConfMax, int fVerbose );
 /*=== sswSim.c ===================================================*/
 extern unsigned      Ssw_SmlObjHashWord( Ssw_Sml_t * p, Aig_Obj_t * pObj );
 extern int           Ssw_SmlObjIsConstWord( Ssw_Sml_t * p, Aig_Obj_t * pObj );
@@ -214,6 +247,7 @@ extern int           Ssw_ManSweepNode( Ssw_Man_t * p, Aig_Obj_t * pObj, int f, i
 extern int           Ssw_ManSweepBmc( Ssw_Man_t * p );
 extern int           Ssw_ManSweep( Ssw_Man_t * p );
 /*=== sswUnique.c ===================================================*/
+extern void          Ssw_UniqueRegisterPairInfo( Ssw_Man_t * p );
 extern int           Ssw_ManUniqueOne( Ssw_Man_t * p, Aig_Obj_t * pRepr, Aig_Obj_t * pObj );
 extern int           Ssw_ManUniqueAddConstraint( Ssw_Man_t * p, Vec_Ptr_t * vCommon, int f1, int f2 );
 
diff --git a/src/aig/ssw/sswLcorr.c b/src/aig/ssw/sswLcorr.c
index cde9b0c9..d374c5f6 100644
--- a/src/aig/ssw/sswLcorr.c
+++ b/src/aig/ssw/sswLcorr.c
@@ -31,48 +31,6 @@
 
 /**Function*************************************************************
 
-  Synopsis    [Recycles the SAT solver.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManSatSolverRecycle( Ssw_Man_t * p )
-{
-    int Lit;
-    if ( p->pSat )
-    {
-        Aig_Obj_t * pObj;
-        int i;
-        Vec_PtrForEachEntry( p->vUsedNodes, pObj, i )
-            Ssw_ObjSetSatNum( p, pObj, 0 );
-        Vec_PtrClear( p->vUsedNodes );
-        Vec_PtrClear( p->vUsedPis );
-//        memset( p->pSatVars, 0, sizeof(int) * Aig_ManObjNumMax(p->pAigTotal) );
-        sat_solver_delete( p->pSat );
-    }
-    p->pSat = sat_solver_new();
-    sat_solver_setnvars( p->pSat, 1000 );
-    // var 0 is not used
-    // var 1 is reserved for const1 node - add the clause
-    p->nSatVars = 1;
-//    p->nSatVars = 0;
-    Lit = toLit( p->nSatVars );
-    if ( p->pPars->fPolarFlip )
-        Lit = lit_neg( Lit );
-    sat_solver_addclause( p->pSat, &Lit, &Lit + 1 );
-    Ssw_ObjSetSatNum( p, Aig_ManConst1(p->pFrames), p->nSatVars++ );
-
-    p->nRecycles++;
-    p->nRecycleCalls = 0;
-}
-
-
-/**Function*************************************************************
-
   Synopsis    [Tranfers simulation information from FRAIG to AIG.]
 
   Description []
@@ -148,11 +106,11 @@ void Ssw_SmlAddPattern( Ssw_Man_t * p, Aig_Obj_t * pRepr, Aig_Obj_t * pCand )
     Aig_Obj_t * pObj;
     unsigned * pInfo;
     int i, nVarNum, Value;
-    Vec_PtrForEachEntry( p->vUsedPis, pObj, i )
+    Vec_PtrForEachEntry( p->pMSat->vUsedPis, pObj, i )
     {
-        nVarNum = Ssw_ObjSatNum( p, pObj );
+        nVarNum = Ssw_ObjSatNum( p->pMSat, pObj );
         assert( nVarNum > 0 );
-        Value = sat_solver_var_value( p->pSat, nVarNum );
+        Value = sat_solver_var_value( p->pMSat->pSat, nVarNum );
         if ( Value == 0 )
             continue;
         pInfo = Vec_PtrEntry( p->vSimInfo, Aig_ObjPioNum(pObj) );
@@ -339,9 +297,14 @@ int Ssw_ManSweepLatch( Ssw_Man_t * p )
             Ssw_ManSweepResimulate( p );
         // attempt recycling the SAT solver
         if ( p->pPars->nSatVarMax && 
-             p->nSatVars > p->pPars->nSatVarMax &&
+             p->pMSat->nSatVars > p->pPars->nSatVarMax &&
              p->nRecycleCalls > p->pPars->nRecycleCalls )
-             Ssw_ManSatSolverRecycle( p );
+        {
+            Ssw_SatStop( p->pMSat );
+            p->pMSat = Ssw_SatStart( 0 );
+            p->nRecycles++;
+            p->nRecycleCalls = 0;
+        }
     }
     // resimulate
     if ( p->nPatterns > 0 )
diff --git a/src/aig/ssw/sswMan.c b/src/aig/ssw/sswMan.c
index d4a26f64..1b29037c 100644
--- a/src/aig/ssw/sswMan.c
+++ b/src/aig/ssw/sswMan.c
@@ -53,12 +53,6 @@ Ssw_Man_t * Ssw_ManCreate( Aig_Man_t * pAig, Ssw_Pars_t * pPars )
     p->pAig          = pAig;
     p->nFrames       = pPars->nFramesK + 1;
     p->pNodeToFrames = CALLOC( Aig_Obj_t *, Aig_ManObjNumMax(p->pAig) * p->nFrames );
-    // SAT solving
-    p->vSatVars      = Vec_IntStart( Aig_ManObjNumMax(p->pAig) * (p->nFrames+1) );
-    p->vFanins       = Vec_PtrAlloc( 100 );
-    // SAT solving (latch corr only)
-    p->vUsedNodes    = Vec_PtrAlloc( 1000 );
-    p->vUsedPis      = Vec_PtrAlloc( 1000 );
     p->vCommon       = Vec_PtrAlloc( 100 );
     p->iOutputLit    = -1;
     // allocate storage for sim pattern
@@ -106,11 +100,11 @@ void Ssw_ManPrintStats( Ssw_Man_t * p )
         p->pPars->nFramesK, p->pPars->nFramesAddSim, p->pPars->nBTLimit, p->pPars->nConstrs, p->pPars->nMaxLevs, nMemory );
     printf( "AIG       : PI = %d. PO = %d. Latch = %d. Node = %d.  Ave SAT vars = %d.\n", 
         Saig_ManPiNum(p->pAig), Saig_ManPoNum(p->pAig), Saig_ManRegNum(p->pAig), Aig_ManNodeNum(p->pAig), 
-        p->nSatVarsTotal/p->pPars->nIters );
+        0/p->pPars->nIters );
     printf( "SAT calls : Proof = %d. Cex = %d. Fail = %d. Equivs = %d. Str = %d.\n", 
         p->nSatProof, p->nSatCallsSat, p->nSatFailsTotal, Ssw_ManCountEquivs(p), p->nStrangers );
     printf( "SAT solver: Vars = %d. Max cone = %d. Recycles = %d. Rounds = %d.\n", 
-        p->nSatVars, p->nConeMax, p->nRecycles, p->nSimRounds );
+        0, p->nConeMax, p->nRecycles, p->nSimRounds );
     printf( "NBeg = %d. NEnd = %d. (Gain = %6.2f %%).  RBeg = %d. REnd = %d. (Gain = %6.2f %%).\n", 
         p->nNodesBeg, p->nNodesEnd, 100.0*(p->nNodesBeg-p->nNodesEnd)/(p->nNodesBeg?p->nNodesBeg:1), 
         p->nRegsBeg, p->nRegsEnd, 100.0*(p->nRegsBeg-p->nRegsEnd)/(p->nRegsBeg?p->nRegsBeg:1) );
@@ -141,23 +135,14 @@ void Ssw_ManPrintStats( Ssw_Man_t * p )
 ***********************************************************************/
 void Ssw_ManCleanup( Ssw_Man_t * p )
 {
+    assert( p->pMSat == NULL );
     if ( p->pFrames )
     {
+        Aig_ManCleanMarkA( p->pFrames );
         Aig_ManStop( p->pFrames );
         p->pFrames = NULL;
         memset( p->pNodeToFrames, 0, sizeof(Aig_Obj_t *) * Aig_ManObjNumMax(p->pAig) * p->nFrames );
     }
-    if ( p->pSat )
-    {
-        int i;
-//        printf( "Vars = %d. Clauses = %d. Learnts = %d.\n", p->pSat->size, p->pSat->clauses.size, p->pSat->learnts.size );
-        p->nSatVarsTotal += p->pSat->size;
-        sat_solver_delete( p->pSat );
-        p->pSat = NULL;
-//        memset( p->pSatVars, 0, sizeof(int) * Aig_ManObjNumMax(p->pAig) * (p->nFrames+1) );
-        for ( i = 0; i < Vec_IntSize(p->vSatVars); i++ )
-            p->vSatVars->pArray[i] = 0;
-    }
     if ( p->vSimInfo )  
     {
         Vec_PtrFree( p->vSimInfo );
@@ -188,46 +173,14 @@ void Ssw_ManStop( Ssw_Man_t * p )
         Ssw_ClassesStop( p->ppClasses );
     if ( p->pSml )      
         Ssw_SmlStop( p->pSml );
-    Vec_PtrFree( p->vFanins );
-    Vec_PtrFree( p->vUsedNodes );
-    Vec_PtrFree( p->vUsedPis );
-    Vec_IntFree( p->vSatVars );
+    if ( p->vDiffPairs )
+        Vec_IntFree( p->vDiffPairs );
     Vec_PtrFree( p->vCommon );
     FREE( p->pNodeToFrames );
     FREE( p->pPatWords );
     free( p );
 }
 
-/**Function*************************************************************
-
-  Synopsis    [Starts the SAT solver.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManStartSolver( Ssw_Man_t * p )
-{
-    int Lit;
-    assert( p->pSat == NULL );
-    p->pSat = sat_solver_new();
-    sat_solver_setnvars( p->pSat, 1000 );
-    // var 0 is not used
-    // var 1 is reserved for const1 node - add the clause
-    p->nSatVars = 1;
-    Lit = toLit( p->nSatVars );
-    if ( p->pPars->fPolarFlip )
-        Lit = lit_neg( Lit );
-    sat_solver_addclause( p->pSat, &Lit, &Lit + 1 );
-    Ssw_ObjSetSatNum( p, Aig_ManConst1(p->pAig), p->nSatVars++ );
-
-    Vec_PtrClear( p->vUsedNodes );
-    Vec_PtrClear( p->vUsedPis );
-}
-
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
 ////////////////////////////////////////////////////////////////////////
diff --git a/src/aig/ssw/sswSat.c b/src/aig/ssw/sswSat.c
index af3bf80e..fc902560 100644
--- a/src/aig/ssw/sswSat.c
+++ b/src/aig/ssw/sswSat.c
@@ -50,18 +50,19 @@ int Ssw_NodesAreEquiv( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew )
     assert( !Aig_IsComplement(pNew) );
     assert( pOld != pNew );
 
-    if ( p->pSat == NULL )
-        Ssw_ManStartSolver( p );
+//    if ( p->pSat == NULL )
+//        Ssw_ManStartSolver( p );
+    assert( p->pMSat != NULL );
 
     // if the nodes do not have SAT variables, allocate them
-    Ssw_CnfNodeAddToSolver( p, pOld );
-    Ssw_CnfNodeAddToSolver( p, pNew );
+    Ssw_CnfNodeAddToSolver( p->pMSat, pOld );
+    Ssw_CnfNodeAddToSolver( p->pMSat, pNew );
 
     // solve under assumptions
     // A = 1; B = 0     OR     A = 1; B = 1 
     nLits = 2;
-    pLits[0] = toLitCond( Ssw_ObjSatNum(p,pOld), 0 );
-    pLits[1] = toLitCond( Ssw_ObjSatNum(p,pNew), pOld->fPhase == pNew->fPhase );
+    pLits[0] = toLitCond( Ssw_ObjSatNum(p->pMSat,pOld), 0 );
+    pLits[1] = toLitCond( Ssw_ObjSatNum(p->pMSat,pNew), pOld->fPhase == pNew->fPhase );
     if ( p->iOutputLit > -1 )
         pLits[nLits++] = p->iOutputLit;
     if ( p->pPars->fPolarFlip )
@@ -71,14 +72,14 @@ int Ssw_NodesAreEquiv( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew )
     }
 //Sat_SolverWriteDimacs( p->pSat, "temp.cnf", pLits, pLits + 2, 1 );
 
-    if ( p->pSat->qtail != p->pSat->qhead )
+    if ( p->pMSat->pSat->qtail != p->pMSat->pSat->qhead )
     {
-        RetValue = sat_solver_simplify(p->pSat);
+        RetValue = sat_solver_simplify(p->pMSat->pSat);
         assert( RetValue != 0 );
     }
 
 clk = clock();
-    RetValue1 = sat_solver_solve( p->pSat, pLits, pLits + nLits, 
+    RetValue1 = sat_solver_solve( p->pMSat->pSat, pLits, pLits + nLits, 
         (sint64)nBTLimit, (sint64)0, (sint64)0, (sint64)0 );
 p->timeSat += clock() - clk;
     if ( RetValue1 == l_False )
@@ -88,8 +89,15 @@ p->timeSatUnsat += clock() - clk;
         {
             pLits[0] = lit_neg( pLits[0] );
             pLits[1] = lit_neg( pLits[1] );
-            RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 2 );
+            RetValue = sat_solver_addclause( p->pMSat->pSat, pLits, pLits + 2 );
             assert( RetValue );
+/*
+            if ( p->pMSat->pSat->qtail != p->pMSat->pSat->qhead )
+            {
+                RetValue = sat_solver_simplify(p->pMSat->pSat);
+                assert( RetValue != 0 );
+            }
+*/
         }
         p->nSatCallsUnsat++;
     }
@@ -116,8 +124,8 @@ p->timeSatUndec += clock() - clk;
     // solve under assumptions
     // A = 0; B = 1     OR     A = 0; B = 0 
     nLits = 2;
-    pLits[0] = toLitCond( Ssw_ObjSatNum(p,pOld), 1 );
-    pLits[1] = toLitCond( Ssw_ObjSatNum(p,pNew), pOld->fPhase ^ pNew->fPhase );
+    pLits[0] = toLitCond( Ssw_ObjSatNum(p->pMSat,pOld), 1 );
+    pLits[1] = toLitCond( Ssw_ObjSatNum(p->pMSat,pNew), pOld->fPhase ^ pNew->fPhase );
     if ( p->iOutputLit > -1 )
         pLits[nLits++] = p->iOutputLit;
     if ( p->pPars->fPolarFlip )
@@ -126,14 +134,14 @@ p->timeSatUndec += clock() - clk;
         if ( pNew->fPhase )  pLits[1] = lit_neg( pLits[1] );
     }
 
-    if ( p->pSat->qtail != p->pSat->qhead )
+    if ( p->pMSat->pSat->qtail != p->pMSat->pSat->qhead )
     {
-        RetValue = sat_solver_simplify(p->pSat);
+        RetValue = sat_solver_simplify(p->pMSat->pSat);
         assert( RetValue != 0 );
     }
 
 clk = clock();
-    RetValue1 = sat_solver_solve( p->pSat, pLits, pLits + nLits, 
+    RetValue1 = sat_solver_solve( p->pMSat->pSat, pLits, pLits + nLits, 
         (sint64)nBTLimit, (sint64)0, (sint64)0, (sint64)0 );
 p->timeSat += clock() - clk;
     if ( RetValue1 == l_False )
@@ -143,8 +151,15 @@ p->timeSatUnsat += clock() - clk;
         {
             pLits[0] = lit_neg( pLits[0] );
             pLits[1] = lit_neg( pLits[1] );
-            RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 2 );
+            RetValue = sat_solver_addclause( p->pMSat->pSat, pLits, pLits + 2 );
             assert( RetValue );
+/*
+            if ( p->pMSat->pSat->qtail != p->pMSat->pSat->qhead )
+            {
+                RetValue = sat_solver_simplify(p->pMSat->pSat);
+                assert( RetValue != 0 );
+            }
+*/
         }
         p->nSatCallsUnsat++;
     }
@@ -183,6 +198,7 @@ int Ssw_NodesAreConstrained( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew )
 
     // sanity checks
     assert( Aig_Regular(pOld) != Aig_Regular(pNew) );
+    assert( Aig_ObjPhaseReal(pOld) == Aig_ObjPhaseReal(pNew) );
 
     // move constant to the old node
     if ( Aig_Regular(pNew) == Aig_ManConst1(p->pFrames) )
@@ -200,13 +216,13 @@ int Ssw_NodesAreConstrained( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew )
         pNew = Aig_Not(pNew);
     }
 
-    // start the solver
-    if ( p->pSat == NULL )
-        Ssw_ManStartSolver( p );
+//    if ( p->pSat == NULL )
+//        Ssw_ManStartSolver( p );
+    assert( p->pMSat != NULL );
 
     // if the nodes do not have SAT variables, allocate them
-    Ssw_CnfNodeAddToSolver( p, pOld );
-    Ssw_CnfNodeAddToSolver( p, Aig_Regular(pNew) );
+    Ssw_CnfNodeAddToSolver( p->pMSat, pOld );
+    Ssw_CnfNodeAddToSolver( p->pMSat, Aig_Regular(pNew) );
 
     // transform the new node
     fComplNew = Aig_IsComplement( pNew );
@@ -216,12 +232,12 @@ int Ssw_NodesAreConstrained( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew )
     if ( pOld == Aig_ManConst1(p->pFrames) )
     {
         // add constaint A = 1  ---->  A
-        pLits[0] = toLitCond( Ssw_ObjSatNum(p,pNew), fComplNew );
+        pLits[0] = toLitCond( Ssw_ObjSatNum(p->pMSat,pNew), fComplNew );
         if ( p->pPars->fPolarFlip )
         {
             if ( pNew->fPhase )  pLits[0] = lit_neg( pLits[0] );
         }
-        RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 1 );
+        RetValue = sat_solver_addclause( p->pMSat->pSat, pLits, pLits + 1 );
         assert( RetValue );
     }
     else
@@ -229,8 +245,8 @@ int Ssw_NodesAreConstrained( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew )
         // add constaint A = B  ---->  (A v !B)(!A v B)
 
         // (A v !B)
-        pLits[0] = toLitCond( Ssw_ObjSatNum(p,pOld), 0 );
-        pLits[1] = toLitCond( Ssw_ObjSatNum(p,pNew), !fComplNew );
+        pLits[0] = toLitCond( Ssw_ObjSatNum(p->pMSat,pOld), 0 );
+        pLits[1] = toLitCond( Ssw_ObjSatNum(p->pMSat,pNew), !fComplNew );
         if ( p->pPars->fPolarFlip )
         {
             if ( pOld->fPhase )  pLits[0] = lit_neg( pLits[0] );
@@ -238,12 +254,12 @@ int Ssw_NodesAreConstrained( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew )
         }
         pLits[0] = lit_neg( pLits[0] );
         pLits[1] = lit_neg( pLits[1] );
-        RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 2 );
+        RetValue = sat_solver_addclause( p->pMSat->pSat, pLits, pLits + 2 );
         assert( RetValue );
 
         // (!A v B)
-        pLits[0] = toLitCond( Ssw_ObjSatNum(p,pOld), 1 );
-        pLits[1] = toLitCond( Ssw_ObjSatNum(p,pNew), fComplNew);
+        pLits[0] = toLitCond( Ssw_ObjSatNum(p->pMSat,pOld), 1 );
+        pLits[1] = toLitCond( Ssw_ObjSatNum(p->pMSat,pNew), fComplNew);
         if ( p->pPars->fPolarFlip )
         {
             if ( pOld->fPhase )  pLits[0] = lit_neg( pLits[0] );
@@ -251,7 +267,7 @@ int Ssw_NodesAreConstrained( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew )
         }
         pLits[0] = lit_neg( pLits[0] );
         pLits[1] = lit_neg( pLits[1] );
-        RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 2 );
+        RetValue = sat_solver_addclause( p->pMSat->pSat, pLits, pLits + 2 );
         assert( RetValue );
     }
     return 1;
diff --git a/src/aig/ssw_old/sswBmc.c b/src/aig/ssw/sswSemi.c
index e2d47440..b445c2c4 100644
--- a/src/aig/ssw_old/sswBmc.c
+++ b/src/aig/ssw/sswSemi.c
@@ -1,12 +1,12 @@
 /**CFile****************************************************************
 
-  FileName    [sswBmc.c]
+  FileName    [sswSemi.c]
 
   SystemName  [ABC: Logic synthesis and verification system.]
 
   PackageName [Inductive prover with constraints.]
 
-  Synopsis    [Bounded model checker for equivalence clases.]
+  Synopsis    [Semiformal for equivalence clases.]
 
   Author      [Alan Mishchenko]
   
@@ -14,7 +14,7 @@
 
   Date        [Ver. 1.0. Started - September 1, 2008.]
 
-  Revision    [$Id: sswBmc.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
+  Revision    [$Id: sswSemi.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
 
 ***********************************************************************/
 
@@ -24,9 +24,9 @@
 ///                        DECLARATIONS                              ///
 ////////////////////////////////////////////////////////////////////////
 
-typedef struct Ssw_Bmc_t_ Ssw_Bmc_t; // BMC manager
+typedef struct Ssw_Sem_t_ Ssw_Sem_t; // BMC manager
 
-struct Ssw_Bmc_t_
+struct Ssw_Sem_t_
 {
     // parameters
     int              nConfMaxStart;  // the starting conflict limit
@@ -58,14 +58,14 @@ struct Ssw_Bmc_t_
   SeeAlso     []
 
 ***********************************************************************/
-Ssw_Bmc_t * Ssw_BmcManStart( Ssw_Man_t * pMan, int nConfMax, int fVerbose )
+Ssw_Sem_t * Ssw_SemManStart( Ssw_Man_t * pMan, int nConfMax, int fVerbose )
 {
-    Ssw_Bmc_t * p;
+    Ssw_Sem_t * p;
     Aig_Obj_t * pObj;
     int i;
     // create interpolation manager
-    p = ALLOC( Ssw_Bmc_t, 1 ); 
-    memset( p, 0, sizeof(Ssw_Bmc_t) );
+    p = ALLOC( Ssw_Sem_t, 1 ); 
+    memset( p, 0, sizeof(Ssw_Sem_t) );
     p->nConfMaxStart  = nConfMax;
     p->nConfMax       = nConfMax;
     p->nFramesSweep   = AIG_MAX( (1<<21)/Aig_ManNodeNum(pMan->pAig), pMan->nFrames );
@@ -83,10 +83,13 @@ Ssw_Bmc_t * Ssw_BmcManStart( Ssw_Man_t * pMan, int nConfMax, int fVerbose )
     p->vHistory       = Vec_IntAlloc( 100 );
     Vec_IntPush( p->vHistory, 0 );
     // update arrays of the manager
+    assert( 0 );
+/*
     free( p->pMan->pNodeToFrames );
     Vec_IntFree( p->pMan->vSatVars );
     p->pMan->pNodeToFrames = CALLOC( Aig_Obj_t *, Aig_ManObjNumMax(p->pMan->pAig) * p->nFramesSweep );
     p->pMan->vSatVars      = Vec_IntStart( Aig_ManObjNumMax(p->pMan->pAig) * (p->nFramesSweep+1) );
+*/
     return p;
 }
 
@@ -101,7 +104,7 @@ Ssw_Bmc_t * Ssw_BmcManStart( Ssw_Man_t * pMan, int nConfMax, int fVerbose )
   SeeAlso     []
 
 ***********************************************************************/
-void Ssw_BmcManStop( Ssw_Bmc_t * p )
+void Ssw_SemManStop( Ssw_Sem_t * p )
 {
     Vec_PtrFree( p->vTargets );
     Vec_PtrFree( p->vPatterns );
@@ -120,7 +123,7 @@ void Ssw_BmcManStop( Ssw_Bmc_t * p )
   SeeAlso     []
 
 ***********************************************************************/
-int Ssw_BmcCheckTargets( Ssw_Bmc_t * p )
+int Ssw_SemCheckTargets( Ssw_Sem_t * p )
 {
     Aig_Obj_t * pObj;
     int i;
@@ -141,7 +144,7 @@ int Ssw_BmcCheckTargets( Ssw_Bmc_t * p )
   SeeAlso     []
 
 ***********************************************************************/
-void Ssw_ManFilterBmcSavePattern( Ssw_Bmc_t * p )
+void Ssw_ManFilterBmcSavePattern( Ssw_Sem_t * p )
 {
     unsigned * pInfo;
     Aig_Obj_t * pObj;
@@ -168,7 +171,7 @@ void Ssw_ManFilterBmcSavePattern( Ssw_Bmc_t * p )
   SeeAlso     []
 
 ***********************************************************************/
-int Ssw_ManFilterBmc( Ssw_Bmc_t * pBmc, int iPat, int fCheckTargets )
+int Ssw_ManFilterBmc( Ssw_Sem_t * pBmc, int iPat, int fCheckTargets )
 {
     Ssw_Man_t * p = pBmc->pMan;
     Aig_Obj_t * pObj, * pObjNew, * pObjLi, * pObjLo;
@@ -186,7 +189,6 @@ clk = clock();
     }
 
     // sweep internal nodes
-    Ssw_ManStartSolver( p );
     RetValue = pBmc->nFramesSweep;
     for ( f = 0; f < pBmc->nFramesSweep; f++ )
     {
@@ -208,19 +210,19 @@ clk = clock();
                     pBmc->nConfMax *= 10;
                 } 
             }
-            if ( f > 0 && p->pSat->stats.conflicts >= pBmc->nConfMax )
+            if ( f > 0 && p->pMSat->pSat->stats.conflicts >= pBmc->nConfMax )
             {
                 RetValue = -1;
                 break;
             }
         }
         // quit if this is the last timeframe
-        if ( p->pSat->stats.conflicts >= pBmc->nConfMax )
+        if ( p->pMSat->pSat->stats.conflicts >= pBmc->nConfMax )
         {
             RetValue += f + 1;
             break;
         }
-        if ( fCheckTargets && Ssw_BmcCheckTargets( pBmc ) )
+        if ( fCheckTargets && Ssw_SemCheckTargets( pBmc ) )
             break;
         // transfer latch input to the latch outputs 
         // build logic cones for register outputs
@@ -228,7 +230,7 @@ clk = clock();
         {
             pObjNew = Ssw_ObjChild0Fra(p, pObjLi,f);
             Ssw_ObjSetFrame( p, pObjLo, f+1, pObjNew );
-            Ssw_CnfNodeAddToSolver( p, Aig_Regular(pObjNew) );
+            Ssw_CnfNodeAddToSolver( p->pMSat, Aig_Regular(pObjNew) );
         }
 //printf( "Frame %2d : Conflicts = %6d. \n", f, p->pSat->stats.conflicts );
     }
@@ -252,15 +254,15 @@ p->timeBmc += clock() - clk;
   SeeAlso     []
 
 ***********************************************************************/
-int Ssw_FilterUsingBmc( Ssw_Man_t * pMan, int fCheckTargets, int nConfMax, int fVerbose )
+int Ssw_FilterUsingSemi( Ssw_Man_t * pMan, int fCheckTargets, int nConfMax, int fVerbose )
 {
-    Ssw_Bmc_t * p;
+    Ssw_Sem_t * p;
     int RetValue, Frames, Iter, clk = clock();
-    p = Ssw_BmcManStart( pMan, nConfMax, fVerbose );
-    if ( fCheckTargets && Ssw_BmcCheckTargets( p ) )
+    p = Ssw_SemManStart( pMan, nConfMax, fVerbose );
+    if ( fCheckTargets && Ssw_SemCheckTargets( p ) )
     {
         assert( 0 );
-        Ssw_BmcManStop( p );
+        Ssw_SemManStop( p );
         return 1;
     }
     if ( fVerbose )
@@ -273,17 +275,18 @@ int Ssw_FilterUsingBmc( Ssw_Man_t * pMan, int fCheckTargets, int nConfMax, int f
     for ( Iter = 0; Iter < p->nPatterns; Iter++ )
     {
 clk = clock();
+        pMan->pMSat = Ssw_SatStart( 0 );
         Frames = Ssw_ManFilterBmc( p, Iter, fCheckTargets );
         if ( fVerbose )
         {
             printf( "%3d : Const = %6d. Cl = %6d. NR = %6d. F = %3d. C = %5d. P = %3d. %s ", 
                 Iter, Ssw_ClassesCand1Num(p->pMan->ppClasses), Ssw_ClassesClassNum(p->pMan->ppClasses), 
-                Aig_ManNodeNum(p->pMan->pFrames), Frames, (int)p->pMan->pSat->stats.conflicts, p->nPatterns, 
+                Aig_ManNodeNum(p->pMan->pFrames), Frames, (int)p->pMan->pMSat->pSat->stats.conflicts, p->nPatterns, 
                 p->pMan->nSatFailsReal? "f" : " " );
             PRT( "T", clock() - clk );
         } 
         Ssw_ManCleanup( p->pMan );
-        if ( fCheckTargets && Ssw_BmcCheckTargets( p ) )
+        if ( fCheckTargets && Ssw_SemCheckTargets( p ) )
         {
             printf( "Target is hit!!!\n" );
             RetValue = 1;
@@ -291,7 +294,7 @@ clk = clock();
         if ( p->nPatterns >= p->nPatternsAlloc )
             break;
     }
-    Ssw_BmcManStop( p );
+    Ssw_SemManStop( p );
 
     pMan->nStrangers = 0;
     pMan->nSatCalls = 0;
diff --git a/src/aig/ssw/sswSim.c b/src/aig/ssw/sswSim.c
index ba8ad247..b80c3710 100644
--- a/src/aig/ssw/sswSim.c
+++ b/src/aig/ssw/sswSim.c
@@ -271,45 +271,6 @@ void Ssw_SmlSavePattern1( Ssw_Man_t * p, int fInit )
         Aig_InfoXorBit( p->pPatWords, nTruePis * p->nFrames + k++ );
 }
 
-/**Function*************************************************************
-
-  Synopsis    [Copy pattern from the solver into the internal storage.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlSavePattern( Ssw_Man_t * p )
-{
-    Aig_Obj_t * pObj;
-    int i;
-    memset( p->pPatWords, 0, sizeof(unsigned) * p->nPatWords );
-    Aig_ManForEachPi( p->pFrames, pObj, i )
-        if ( p->pSat->model.ptr[Ssw_ObjSatNum(p, pObj)] == l_True )
-            Aig_InfoSetBit( p->pPatWords, i );
-/*
-    if ( p->vCex )
-    {
-        Vec_IntClear( p->vCex );
-        for ( i = 0; i < Saig_ManPiNum(p->pAig); i++ )
-            Vec_IntPush( p->vCex, Aig_InfoHasBit( p->pPatWords, i ) );
-        for ( i = Saig_ManPiNum(p->pFrames); i < Aig_ManPiNum(p->pFrames); i++ )
-            Vec_IntPush( p->vCex, Aig_InfoHasBit( p->pPatWords, i ) );
-    }
-*/
-
-/*
-    printf( "Pattern: " );
-    Aig_ManForEachPi( p->pFrames, pObj, i )
-        printf( "%d", Aig_InfoHasBit( p->pPatWords, i ) );
-    printf( "\n" );
-*/
-}
-
-
 
 /**Function*************************************************************
 
diff --git a/src/aig/ssw/sswSweep.c b/src/aig/ssw/sswSweep.c
index b971a13a..36e8bab3 100644
--- a/src/aig/ssw/sswSweep.c
+++ b/src/aig/ssw/sswSweep.c
@@ -31,53 +31,6 @@
 
 /**Function*************************************************************
 
-  Synopsis    [Mark nodes affected by sweep in the previous iteration.]
-
-  Description [Assumes that affected nodes are in p->ppClasses->vRefined.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManSweepMarkRefinement( Ssw_Man_t * p )
-{
-    Vec_Ptr_t * vRefined, * vSupp;
-    Aig_Obj_t * pObj, * pObjLo, * pObjLi;
-    int i, k;
-    vRefined = Ssw_ClassesGetRefined( p->ppClasses );
-    if ( Vec_PtrSize(vRefined) == 0 )
-    {
-        Aig_ManForEachObj( p->pAig, pObj, i )
-            pObj->fMarkA = 1;
-        return;
-    }
-    // mark the nodes to be refined
-    Aig_ManCleanMarkA( p->pAig );
-    Vec_PtrForEachEntry( vRefined, pObj, i )
-    {
-        if ( Aig_ObjIsPi(pObj) )
-        {
-            pObj->fMarkA = 1;
-            continue;
-        }
-        assert( Aig_ObjIsNode(pObj) );
-        vSupp = Aig_Support( p->pAig, pObj );
-        Vec_PtrForEachEntry( vSupp, pObjLo, k )
-            pObjLo->fMarkA = 1;
-        Vec_PtrFree( vSupp );
-    }
-    // mark refinement
-    Aig_ManForEachNode( p->pAig, pObj, i )
-        pObj->fMarkA = Aig_ObjFanin0(pObj)->fMarkA | Aig_ObjFanin1(pObj)->fMarkA;
-    Saig_ManForEachLi( p->pAig, pObj, i )
-        pObj->fMarkA |= Aig_ObjFanin0(pObj)->fMarkA;
-    Saig_ManForEachLiLo( p->pAig, pObjLi, pObjLo, i )
-        pObjLo->fMarkA |= pObjLi->fMarkA;
-}
-
-/**Function*************************************************************
-
   Synopsis    [Retrives value of the PI in the original AIG.]
 
   Description []
@@ -89,12 +42,22 @@ void Ssw_ManSweepMarkRefinement( Ssw_Man_t * p )
 ***********************************************************************/
 int Ssw_ManGetSatVarValue( Ssw_Man_t * p, Aig_Obj_t * pObj, int f )
 {
+    int fUseNoBoundary = 0;
     Aig_Obj_t * pObjFraig;
-    int nVarNum, Value;
+    int Value;
 //    assert( Aig_ObjIsPi(pObj) );
     pObjFraig = Ssw_ObjFrame( p, pObj, f );
-    nVarNum = Ssw_ObjSatNum( p, Aig_Regular(pObjFraig) );
-    Value = (!nVarNum)? 0 : (Aig_IsComplement(pObjFraig) ^ sat_solver_var_value( p->pSat, nVarNum ));
+    if ( fUseNoBoundary )
+    {
+        Value = Ssw_CnfGetNodeValue( p->pMSat, Aig_Regular(pObjFraig) );
+        Value ^= Aig_IsComplement(pObjFraig);
+    }
+    else
+    {
+        int nVarNum = Ssw_ObjSatNum( p->pMSat, Aig_Regular(pObjFraig) );
+        Value = (!nVarNum)? 0 : (Aig_IsComplement(pObjFraig) ^ sat_solver_var_value( p->pMSat->pSat, nVarNum ));
+    }
+
 //    Value = (Aig_IsComplement(pObjFraig) ^ ((!nVarNum)? 0 : sat_solver_var_value( p->pSat, nVarNum )));
 //    Value = (!nVarNum)? Aig_ManRandom(0) & 1 : (Aig_IsComplement(pObjFraig) ^ sat_solver_var_value( p->pSat, nVarNum ));
     if ( p->pPars->fPolarFlip )
@@ -181,15 +144,8 @@ int Ssw_ManSweepNode( Ssw_Man_t * p, Aig_Obj_t * pObj, int f, int fBmc )
         // if the fraiged nodes are the same, return
         if ( Aig_Regular(pObjFraig) == Aig_Regular(pObjReprFraig) )
             return 0; 
-        // count the number of skipped calls
-        if ( !pObj->fMarkA && !pObjRepr->fMarkA )
-            p->nRefSkip++;
-        else
-            p->nRefUse++;
         // call equivalence checking
-        if ( p->pPars->fSkipCheck && !fBmc && !pObj->fMarkA && !pObjRepr->fMarkA )
-            RetValue = 1;
-        else if ( Aig_Regular(pObjFraig) != Aig_ManConst1(p->pFrames) )
+        if ( Aig_Regular(pObjFraig) != Aig_ManConst1(p->pFrames) )
             RetValue = Ssw_NodesAreEquiv( p, Aig_Regular(pObjReprFraig), Aig_Regular(pObjFraig) );
         else
             RetValue = Ssw_NodesAreEquiv( p, Aig_Regular(pObjFraig), Aig_Regular(pObjReprFraig) );
@@ -204,18 +160,13 @@ int Ssw_ManSweepNode( Ssw_Man_t * p, Aig_Obj_t * pObj, int f, int fBmc )
             Ssw_ClassesRemoveNode( p->ppClasses, pObj );
             return 1;
         }
-        // check if skipping calls works correctly
-        if ( p->pPars->fSkipCheck && !fBmc && !pObj->fMarkA && !pObjRepr->fMarkA )
-        {
-            assert( 0 );
-            printf( "\nSsw_ManSweepNode(): Error!\n" );
-        }
         // disproved the equivalence
         Ssw_SmlSavePatternAig( p, f );
     }
     if ( !fBmc && p->pPars->fUniqueness && p->pPars->nFramesK > 1 && 
         Ssw_ManUniqueOne( p, pObjRepr, pObj ) && p->iOutputLit == -1 )
     {
+/*
         if ( Ssw_ManUniqueAddConstraint( p, p->vCommon, 0, 1 ) )
         {
             int RetValue;
@@ -224,12 +175,39 @@ int Ssw_ManSweepNode( Ssw_Man_t * p, Aig_Obj_t * pObj, int f, int fBmc )
             p->iOutputLit = -1;
             return RetValue;
         }
+*/
+        if ( Ssw_ManUniqueAddConstraint( p, p->vCommon, 0, 1 ) )
+        {
+            int RetValue2 = Ssw_NodesAreEquiv( p, Aig_Regular(pObjReprFraig), Aig_Regular(pObjFraig) );
+            p->iOutputLit = -1;
+            p->nUniques++;
+            p->nUniquesAdded++;
+            if ( RetValue2 == 0 )
+            {
+                int x;
+//                printf( "Second time:\n" );
+                x = Ssw_ManUniqueOne( p, pObjRepr, pObj );
+                Ssw_SmlSavePatternAig( p, f );
+                Ssw_ManResimulateWord( p, pObj, pObjRepr, f );
+                if ( Aig_ObjRepr( p->pAig, pObj ) == pObjRepr )
+                    printf( "Ssw_ManSweepNode(): Refinement did not happen!!!.\n" );
+                return 1;
+            }
+            else
+                p->nUniquesUseful++;
+//                printf( "Counter-example prevented!!!\n" );
+            return 0;
+        }
     }
     if ( p->pPars->nConstrs == 0 )
         Ssw_ManResimulateWord( p, pObj, pObjRepr, f );
     else
         Ssw_ManResimulateBit( p, pObj, pObjRepr );
     assert( Aig_ObjRepr( p->pAig, pObj ) != pObjRepr );
+    if ( Aig_ObjRepr( p->pAig, pObj ) == pObjRepr )
+    {
+        printf( "Ssw_ManSweepNode(): Failed to refine representative.\n" );
+    }
     return 1;
 }
 
@@ -260,7 +238,7 @@ clk = clock();
     p->fRefined = 0;
     if ( p->pPars->fVerbose )
         pProgress = Bar_ProgressStart( stdout, Aig_ManObjNumMax(p->pAig) * p->pPars->nFramesK );
-    Ssw_ManStartSolver( p );
+//    Ssw_ManStartSolver( p );
     for ( f = 0; f < p->pPars->nFramesK; f++ )
     {
         // map constants and PIs
@@ -285,7 +263,7 @@ clk = clock();
         {
             pObjNew = Ssw_ObjChild0Fra(p, pObjLi,f);
             Ssw_ObjSetFrame( p, pObjLo, f+1, pObjNew );
-            Ssw_CnfNodeAddToSolver( p, Aig_Regular(pObjNew) );
+            Ssw_CnfNodeAddToSolver( p->pMSat, Aig_Regular(pObjNew) );//
         }
     }
     if ( p->pPars->fVerbose )
@@ -308,19 +286,63 @@ p->timeBmc += clock() - clk;
   SeeAlso     []
 
 ***********************************************************************/
-int Ssw_ManSweep( Ssw_Man_t * p )
+void Ssw_CheckConstaints( Ssw_Man_t * p )
 {
+    Aig_Obj_t * pObj, * pObj2;
+    int nConstrPairs, i;
+    int Counter = 0;
+    nConstrPairs = Aig_ManPoNum(p->pFrames)-Aig_ManRegNum(p->pAig);
+    assert( (nConstrPairs & 1) == 0 );
+    for ( i = 0; i < nConstrPairs; i += 2 )
+    {
+        pObj  = Aig_ManPo( p->pFrames, i   );
+        pObj2 = Aig_ManPo( p->pFrames, i+1 );
+        if ( Ssw_NodesAreEquiv( p, Aig_ObjFanin0(pObj), Aig_ObjFanin0(pObj2) ) != 1 )
+        {
+            Ssw_NodesAreConstrained( p, Aig_ObjChild0(pObj), Aig_ObjChild0(pObj2) );
+            Counter++;
+        }
+    }
+    printf( "Total constraints = %d. Added constraints = %d.\n", nConstrPairs/2, Counter );
+ }
+
+/**Function*************************************************************
+
+  Synopsis    [Performs fraiging for the internal nodes.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Ssw_ManSweep( Ssw_Man_t * p )
+{ 
     Bar_Progress_t * pProgress = NULL;
     Aig_Obj_t * pObj, * pObj2, * pObjNew;
     int nConstrPairs, clk, i, f;
-    int v;
+//    int v; 
 
     // perform speculative reduction
 clk = clock();
     // create timeframes
     p->pFrames = Ssw_FramesWithClasses( p );
     // add constraints
-    Ssw_ManStartSolver( p );
+//    p->pMSat = Ssw_SatStart( 0 );
+//    Ssw_ManStartSolver( p );
+/*
+    {
+        int clk2 = clock();
+        Ssw_CheckConstaints( p );
+        PRT( "Time", clock() - clk2 );
+    }
+
+    Ssw_ManCleanup( p );
+    p->pFrames = Ssw_FramesWithClasses( p );
+    p->pMSat = Ssw_SatStart( 0 );
+//    Ssw_ManStartSolver( p );
+*/
     nConstrPairs = Aig_ManPoNum(p->pFrames)-Aig_ManRegNum(p->pAig);
     assert( (nConstrPairs & 1) == 0 );
     for ( i = 0; i < nConstrPairs; i += 2 )
@@ -333,17 +355,11 @@ clk = clock();
     for ( i = 0; i < Aig_ManRegNum(p->pAig); i++ )
     {
         pObj  = Aig_ManPo( p->pFrames, nConstrPairs + i );
-        Ssw_CnfNodeAddToSolver( p, Aig_ObjFanin0(pObj) );
+        Ssw_CnfNodeAddToSolver( p->pMSat, Aig_ObjFanin0(pObj) );//
     }
-    sat_solver_simplify( p->pSat );
+    sat_solver_simplify( p->pMSat->pSat );
 p->timeReduce += clock() - clk;
 
-    // mark nodes that do not have to be refined
-clk = clock();
-    if ( p->pPars->fSkipCheck )
-        Ssw_ManSweepMarkRefinement( p );
-p->timeMarkCones += clock() - clk;
-
 //Ssw_ManUnique( p );
 
     // map constants and PIs of the last frame
@@ -354,17 +370,26 @@ p->timeMarkCones += clock() - clk;
     // make sure LOs are assigned
     Saig_ManForEachLo( p->pAig, pObj, i )
         assert( Ssw_ObjFrame( p, pObj, f ) != NULL );
+/*
+    // mark the PI/LO of the last frame
+    Aig_ManForEachPi( p->pAig, pObj, i )
+    {
+        pObjNew = Ssw_ObjFrame( p, pObj, f );
+        Aig_Regular(pObjNew)->fMarkA = 1;
+    }
+*/
 ////    
+/*
     // bring up the previous frames
     if ( p->pPars->fUniqueness )
         for ( v = 0; v < f; v++ )
             Saig_ManForEachLo( p->pAig, pObj, i )
-                Ssw_CnfNodeAddToSolver( p, Aig_Regular(Ssw_ObjFrame(p, pObj, v)) );
+                Ssw_CnfNodeAddToSolver( p->pMSat, Aig_Regular(Ssw_ObjFrame(p, pObj, v)) );
+*/
 ////
     // sweep internal nodes
     p->fRefined = 0;
     p->nSatFailsReal = 0;
-    p->nRefUse = p->nRefSkip = 0;
     p->nUniques = 0;
     Ssw_ClassesClearRefined( p->ppClasses );
     if ( p->pPars->fVerbose )
diff --git a/src/aig/ssw/sswUnique.c b/src/aig/ssw/sswUnique.c
index 888ed3da..0d9b016f 100644
--- a/src/aig/ssw/sswUnique.c
+++ b/src/aig/ssw/sswUnique.c
@@ -30,83 +30,39 @@
 
 /**Function*************************************************************
 
-  Synopsis    [Returns the result of merging the two vectors.]
+  Synopsis    [Performs computation of signal correspondence with constraints.]
 
-  Description [Assumes that the vectors are sorted in the increasing order.]
+  Description []
                
   SideEffects []
 
   SeeAlso     []
 
 ***********************************************************************/
-static inline void Vec_PtrTwoMerge( Vec_Ptr_t * vArr1, Vec_Ptr_t * vArr2, Vec_Ptr_t * vArr )
+void Ssw_UniqueRegisterPairInfo( Ssw_Man_t * p )
 {
-    Aig_Obj_t ** pBeg  = (Aig_Obj_t **)vArr->pArray;
-    Aig_Obj_t ** pBeg1 = (Aig_Obj_t **)vArr1->pArray;
-    Aig_Obj_t ** pBeg2 = (Aig_Obj_t **)vArr2->pArray;
-    Aig_Obj_t ** pEnd1 = (Aig_Obj_t **)vArr1->pArray + vArr1->nSize;
-    Aig_Obj_t ** pEnd2 = (Aig_Obj_t **)vArr2->pArray + vArr2->nSize;
-    Vec_PtrGrow( vArr, Vec_PtrSize(vArr1) + Vec_PtrSize(vArr2) );
-    pBeg  = (Aig_Obj_t **)vArr->pArray;
-    while ( pBeg1 < pEnd1 && pBeg2 < pEnd2 )
+    Aig_Obj_t * pObjLo, * pObj0, * pObj1;
+    int i;
+    if ( p->vDiffPairs == NULL )
+        p->vDiffPairs = Vec_IntAlloc( Saig_ManRegNum(p->pAig) );
+    Vec_IntClear( p->vDiffPairs );
+    Saig_ManForEachLo( p->pAig, pObjLo, i )
     {
-        if ( (*pBeg1)->Id == (*pBeg2)->Id )
-            *pBeg++ = *pBeg1++, pBeg2++;
-        else if ( (*pBeg1)->Id < (*pBeg2)->Id )
-            *pBeg++ = *pBeg1++;
+        pObj0 = Ssw_ObjFrame( p, pObjLo, 0 );
+        pObj1 = Ssw_ObjFrame( p, pObjLo, 1 );
+        if ( pObj0 == pObj1 )
+            Vec_IntPush( p->vDiffPairs, 0 );
+        else if ( pObj0 == Aig_Not(pObj1) )
+            Vec_IntPush( p->vDiffPairs, 1 );
         else 
-            *pBeg++ = *pBeg2++;
+        {
+            // assume that if the nodes are structurally different
+            // they can also be functionally different
+            Vec_IntPush( p->vDiffPairs, 1 );
+        }
     }
-    while ( pBeg1 < pEnd1 )
-        *pBeg++ = *pBeg1++;
-    while ( pBeg2 < pEnd2 )
-        *pBeg++ = *pBeg2++;
-    vArr->nSize = pBeg - (Aig_Obj_t **)vArr->pArray;
-    assert( vArr->nSize <= vArr->nCap );
-    assert( vArr->nSize >= vArr1->nSize );
-    assert( vArr->nSize >= vArr2->nSize );
 }
 
-/**Function*************************************************************
-
-  Synopsis    [Returns the result of merging the two vectors.]
-
-  Description [Assumes that the vectors are sorted in the increasing order.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-static inline void Vec_PtrTwoCommon( Vec_Ptr_t * vArr1, Vec_Ptr_t * vArr2, Vec_Ptr_t * vArr )
-{
-    Aig_Obj_t ** pBeg  = (Aig_Obj_t **)vArr->pArray;
-    Aig_Obj_t ** pBeg1 = (Aig_Obj_t **)vArr1->pArray;
-    Aig_Obj_t ** pBeg2 = (Aig_Obj_t **)vArr2->pArray;
-    Aig_Obj_t ** pEnd1 = (Aig_Obj_t **)vArr1->pArray + vArr1->nSize;
-    Aig_Obj_t ** pEnd2 = (Aig_Obj_t **)vArr2->pArray + vArr2->nSize;
-    Vec_PtrGrow( vArr, AIG_MAX( Vec_PtrSize(vArr1), Vec_PtrSize(vArr2) ) );
-    pBeg  = (Aig_Obj_t **)vArr->pArray;
-    while ( pBeg1 < pEnd1 && pBeg2 < pEnd2 )
-    {
-        if ( (*pBeg1)->Id == (*pBeg2)->Id )
-            *pBeg++ = *pBeg1++, pBeg2++;
-        else if ( (*pBeg1)->Id < (*pBeg2)->Id )
-//            *pBeg++ = *pBeg1++;
-            pBeg1++;
-        else 
-//            *pBeg++ = *pBeg2++;
-            pBeg2++;
-    }
-//    while ( pBeg1 < pEnd1 )
-//        *pBeg++ = *pBeg1++;
-//    while ( pBeg2 < pEnd2 )
-//        *pBeg++ = *pBeg2++;
-    vArr->nSize = pBeg - (Aig_Obj_t **)vArr->pArray;
-    assert( vArr->nSize <= vArr->nCap );
-    assert( vArr->nSize <= vArr1->nSize );
-    assert( vArr->nSize <= vArr2->nSize );
-}
 
 /**Function*************************************************************
 
@@ -123,56 +79,32 @@ int Ssw_ManUniqueOne( Ssw_Man_t * p, Aig_Obj_t * pRepr, Aig_Obj_t * pObj )
 {
     int fVerbose = 0;
     Aig_Obj_t * ppObjs[2], * pTemp;
-    Vec_Ptr_t * vSupp, * vSupp2;
-    int i, k, Value0, Value1, RetValue;
-    assert( p->pPars->nFramesK > 1 );
+    int i, k, Value0, Value1, RetValue, fFeasible;
 
-    vSupp  = Vec_PtrAlloc( 100 );
-    vSupp2 = Vec_PtrAlloc( 100 );
-    Vec_PtrClear( p->vCommon );
+    assert( p->pPars->nFramesK > 1 );
+    assert( p->vDiffPairs && Vec_IntSize(p->vDiffPairs) == Saig_ManRegNum(p->pAig) );
 
     // compute the first support in terms of LOs
     ppObjs[0] = pRepr; 
     ppObjs[1] = pObj;
-    Aig_SupportNodes( p->pAig, ppObjs, 2, vSupp );
-    // modify support to be in terms of LIs
+    Aig_SupportNodes( p->pAig, ppObjs, 2, p->vCommon );
+    // keep only LOs
+    RetValue = Vec_PtrSize( p->vCommon );
+    fFeasible = 0;
     k = 0;
-    Vec_PtrForEachEntry( vSupp, pTemp, i )
+    Vec_PtrForEachEntry( p->vCommon, pTemp, i )
         if ( Saig_ObjIsLo(p->pAig, pTemp) )
-            Vec_PtrWriteEntry( vSupp, k++, Saig_ObjLoToLi(p->pAig, pTemp) );
-    Vec_PtrShrink( vSupp, k );
-    // compute the support of support
-    Aig_SupportNodes( p->pAig, (Aig_Obj_t **)Vec_PtrArray(vSupp), Vec_PtrSize(vSupp), vSupp2 );
-    // return support to LO
-    Vec_PtrForEachEntry( vSupp, pTemp, i )
-        Vec_PtrWriteEntry( vSupp, i, Saig_ObjLiToLo(p->pAig, pTemp) );
-    // find the number of common vars
-    Vec_PtrSort( vSupp, Aig_ObjCompareIdIncrease );
-    Vec_PtrSort( vSupp2, Aig_ObjCompareIdIncrease );
-    Vec_PtrTwoCommon( vSupp, vSupp2, p->vCommon );
-/*
-    {
-        Vec_Ptr_t * vNew = Vec_PtrDup(vSupp);
-        Vec_PtrUniqify( vNew, Aig_ObjCompareIdIncrease );
-        if ( Vec_PtrSize(vNew) != Vec_PtrSize(vSupp) )
-            printf( "Not unique!\n" );
-    }
-    {
-        Vec_Ptr_t * vNew = Vec_PtrDup(vSupp2);
-        Vec_PtrUniqify( vNew, Aig_ObjCompareIdIncrease );
-        if ( Vec_PtrSize(vNew) != Vec_PtrSize(vSupp2) )
-            printf( "Not unique!\n" );
-    }
-    {
-        Vec_Ptr_t * vNew = Vec_PtrDup(p->vCommon);
-        Vec_PtrUniqify( vNew, Aig_ObjCompareIdIncrease );
-        if ( Vec_PtrSize(vNew) != Vec_PtrSize(p->vCommon) )
-            printf( "Not unique!\n" );
-    }
-*/
+        {
+            Vec_PtrWriteEntry( p->vCommon, k++, pTemp );
+            if ( Vec_IntEntry(p->vDiffPairs, Aig_ObjPioNum(pTemp) - Saig_ManPiNum(p->pAig)) )
+                fFeasible = 1;
+        }
+    Vec_PtrShrink( p->vCommon, k );
+
     if ( fVerbose )
-        printf( "Node = %5d : One = %3d. Two = %3d. Common = %3d.  ",
-            Aig_ObjId(pObj), Vec_PtrSize(vSupp), Vec_PtrSize(vSupp2), Vec_PtrSize(p->vCommon) );
+        printf( "Node = %5d : Supp = %3d. Regs = %3d. Feasible = %s. ",
+            Aig_ObjId(pObj), RetValue, Vec_PtrSize(p->vCommon),
+            fFeasible? "yes": "no " );
 
     // check the current values
     RetValue = 1;
@@ -185,14 +117,10 @@ int Ssw_ManUniqueOne( Ssw_Man_t * p, Aig_Obj_t * pRepr, Aig_Obj_t * pObj )
         if ( fVerbose )
             printf( "%d", Value0 ^ Value1 );
     }
-    if ( Vec_PtrSize(p->vCommon) == 0 )
-        RetValue = 0;
     if ( fVerbose )
         printf( "\n" );
 
-    Vec_PtrFree( vSupp );
-    Vec_PtrFree( vSupp2 );
-    return RetValue;
+    return RetValue && fFeasible;
 }
 
 /**Function*************************************************************
@@ -227,11 +155,10 @@ int Ssw_ManUniqueAddConstraint( Ssw_Man_t * p, Vec_Ptr_t * vCommon, int f1, int
 //        printf( "Skipped\n" );
         return 0;
     }
-    p->nUniques++;
     // create CNF
-    Ssw_CnfNodeAddToSolver( p, Aig_Regular(pTotal) );
+    Ssw_CnfNodeAddToSolver( p->pMSat, Aig_Regular(pTotal) );
     // add output constraint
-    pLits[0] = toLitCond( Ssw_ObjSatNum(p,Aig_Regular(pTotal)), Aig_IsComplement(pTotal) );
+    pLits[0] = toLitCond( Ssw_ObjSatNum(p->pMSat,Aig_Regular(pTotal)), Aig_IsComplement(pTotal) );
 /*
     RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 1 );
     assert( RetValue );
diff --git a/src/aig/ssw_old/module.make b/src/aig/ssw_old/module.make
deleted file mode 100644
index 625d72d1..00000000
--- a/src/aig/ssw_old/module.make
+++ /dev/null
@@ -1,14 +0,0 @@
-SRC +=    src/aig/ssw/sswAig.c \
-    src/aig/ssw/sswBmc.c \
-    src/aig/ssw/sswClass.c \
-    src/aig/ssw/sswCnf.c \
-    src/aig/ssw/sswCore.c \
-    src/aig/ssw/sswLcorr.c \
-    src/aig/ssw/sswMan.c \
-    src/aig/ssw/sswPart.c \
-    src/aig/ssw/sswPairs.c \
-    src/aig/ssw/sswSat.c \
-    src/aig/ssw/sswSim.c \
-    src/aig/ssw/sswSimSat.c \
-    src/aig/ssw/sswSweep.c \
-    src/aig/ssw/sswUnique.c
diff --git a/src/aig/ssw_old/ssw.h b/src/aig/ssw_old/ssw.h
deleted file mode 100644
index 766407d4..00000000
--- a/src/aig/ssw_old/ssw.h
+++ /dev/null
@@ -1,117 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [ssw.h] 
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [External declarations.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: ssw.h,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
- 
-#ifndef __SSW_H__
-#define __SSW_H__
-
-#ifdef __cplusplus
-extern "C" { 
-#endif
-
-////////////////////////////////////////////////////////////////////////
-///                          INCLUDES                                ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                         PARAMETERS                               ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                         BASIC TYPES                              ///
-////////////////////////////////////////////////////////////////////////
-
-// choicing parameters
-typedef struct Ssw_Pars_t_ Ssw_Pars_t;
-struct Ssw_Pars_t_
-{
-    int              nPartSize;     // size of the partition
-    int              nOverSize;     // size of the overlap between partitions
-    int              nFramesK;      // the induction depth
-    int              nFramesAddSim; // the number of additional frames to simulate
-    int              nConstrs;      // treat the last nConstrs POs as seq constraints
-    int              nMaxLevs;      // the max number of levels of nodes to consider
-    int              nBTLimit;      // conflict limit at a node
-    int              nMinDomSize;   // min clock domain considered for optimization
-    int              fPolarFlip;    // uses polarity adjustment
-    int              fSkipCheck;    // do not run equivalence check for unaffected cones
-    int              fLatchCorr;    // perform register correspondence
-    int              fSemiFormal;   // enable semiformal filtering
-    int              fUniqueness;   // enable uniqueness constraints
-    int              fVerbose;      // verbose stats
-    // optimized latch correspondence
-    int              fLatchCorrOpt; // perform register correspondence (optimized)
-    int              nSatVarMax;    // max number of SAT vars before recycling SAT solver (optimized latch corr only)
-    int              nRecycleCalls; // calls to perform before recycling SAT solver (optimized latch corr only)
-    // internal parameters
-    int              nIters;        // the number of iterations performed
-};
-
-// sequential counter-example
-typedef struct Ssw_Cex_t_   Ssw_Cex_t;
-struct Ssw_Cex_t_
-{
-    int              iPo;               // the zero-based number of PO, for which verification failed
-    int              iFrame;            // the zero-based number of the time-frame, for which verificaiton failed
-    int              nRegs;             // the number of registers in the miter 
-    int              nPis;              // the number of primary inputs in the miter
-    int              nBits;             // the number of words of bit data used
-    unsigned         pData[0];          // the cex bit data (the number of bits: nRegs + (iFrame+1) * nPis)
-};
-
-////////////////////////////////////////////////////////////////////////
-///                      MACRO DEFINITIONS                           ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                    FUNCTION DECLARATIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/*=== sswAbs.c ==========================================================*/
-extern Aig_Man_t *   Saig_ManProofAbstraction( Aig_Man_t * p, int nFrames, int nConfMax, int fVerbose );
-/*=== sswCore.c ==========================================================*/
-extern void          Ssw_ManSetDefaultParams( Ssw_Pars_t * p );
-extern void          Ssw_ManSetDefaultParamsLcorr( Ssw_Pars_t * p );
-extern Aig_Man_t *   Ssw_SignalCorrespondence( Aig_Man_t * pAig, Ssw_Pars_t * pPars );
-extern Aig_Man_t *   Ssw_LatchCorrespondence( Aig_Man_t * pAig, Ssw_Pars_t * pPars );
-/*=== sswLoc.c ==========================================================*/
-extern int           Saig_ManLocalization( Aig_Man_t * p, int nFramesMax, int nConfMax, int fVerbose );
-/*=== sswPart.c ==========================================================*/
-extern Aig_Man_t *   Ssw_SignalCorrespondencePart( Aig_Man_t * pAig, Ssw_Pars_t * pPars );
-/*=== sswPairs.c ===================================================*/
-extern int           Ssw_SecWithPairs( Aig_Man_t * pAig1, Aig_Man_t * pAig2, Vec_Int_t * vIds1, Vec_Int_t * vIds2, Ssw_Pars_t * pPars );
-extern int           Ssw_SecGeneral( Aig_Man_t * pAig1, Aig_Man_t * pAig2, Ssw_Pars_t * pPars );
-extern int           Ssw_SecGeneralMiter( Aig_Man_t * pMiter, Ssw_Pars_t * pPars );
-/*=== sswSim.c ===================================================*/
-extern Ssw_Cex_t *   Ssw_SmlAllocCounterExample( int nRegs, int nRealPis, int nFrames );
-extern void          Ssw_SmlFreeCounterExample( Ssw_Cex_t * pCex );
-extern int           Ssw_SmlRunCounterExample( Aig_Man_t * pAig, Ssw_Cex_t * p );
-extern int           Ssw_SmlFindOutputCounterExample( Aig_Man_t * pAig, Ssw_Cex_t * p );
-extern Ssw_Cex_t *   Ssw_SmlDupCounterExample( Ssw_Cex_t * p, int nRegsNew );
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
diff --git a/src/aig/ssw_old/sswAig.c b/src/aig/ssw_old/sswAig.c
deleted file mode 100644
index 7b6d1bb0..00000000
--- a/src/aig/ssw_old/sswAig.c
+++ /dev/null
@@ -1,205 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswAig.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [AIG manipulation.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswAig.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Performs speculative reduction for one node.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-static inline void Ssw_FramesConstrainNode( Ssw_Man_t * p, Aig_Man_t * pFrames, Aig_Man_t * pAig, Aig_Obj_t * pObj, int iFrame, int fTwoPos )
-{
-    Aig_Obj_t * pObjNew, * pObjNew2, * pObjRepr, * pObjReprNew, * pMiter;
-    // skip nodes without representative
-    pObjRepr = Aig_ObjRepr(pAig, pObj);
-    if ( pObjRepr == NULL )
-        return;
-    p->nConstrTotal++;
-    assert( pObjRepr->Id < pObj->Id );
-    // get the new node 
-    pObjNew = Ssw_ObjFrame( p, pObj, iFrame );
-    // get the new node of the representative
-    pObjReprNew = Ssw_ObjFrame( p, pObjRepr, iFrame );
-    // if this is the same node, no need to add constraints
-    if ( pObj->fPhase == pObjRepr->fPhase )
-    {
-        assert( pObjNew != Aig_Not(pObjReprNew) );
-        if ( pObjNew == pObjReprNew )
-            return;
-    }
-    else
-    {
-        assert( pObjNew != pObjReprNew );
-        if ( pObjNew == Aig_Not(pObjReprNew) )
-            return;
-    }
-    p->nConstrReduced++;
-    // these are different nodes - perform speculative reduction
-    pObjNew2 = Aig_NotCond( pObjReprNew, pObj->fPhase ^ pObjRepr->fPhase );
-    // set the new node
-    Ssw_ObjSetFrame( p, pObj, iFrame, pObjNew2 );
-    // add the constraint
-    if ( fTwoPos )
-    {
-        Aig_ObjCreatePo( pFrames, pObjNew2 );
-        Aig_ObjCreatePo( pFrames, pObjNew );
-    }
-    else
-    {
-        pMiter = Aig_Exor( pFrames, pObjNew, pObjNew2 );
-        Aig_ObjCreatePo( pFrames, Aig_NotCond(pMiter, Aig_ObjPhaseReal(pMiter)) );
-    }
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Prepares the inductive case with speculative reduction.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Aig_Man_t * Ssw_FramesWithClasses( Ssw_Man_t * p )
-{
-    Aig_Man_t * pFrames;
-    Aig_Obj_t * pObj, * pObjLi, * pObjLo, * pObjNew;
-    int i, f;
-    assert( p->pFrames == NULL );
-    assert( Aig_ManRegNum(p->pAig) > 0 );
-    assert( Aig_ManRegNum(p->pAig) < Aig_ManPiNum(p->pAig) );
-    p->nConstrTotal = p->nConstrReduced = 0;
-
-    // start the fraig package
-    pFrames = Aig_ManStart( Aig_ManObjNumMax(p->pAig) * p->nFrames );
-    // create latches for the first frame
-    Saig_ManForEachLo( p->pAig, pObj, i )
-        Ssw_ObjSetFrame( p, pObj, 0, Aig_ObjCreatePi(pFrames) );
-    // add timeframes
-    for ( f = 0; f < p->pPars->nFramesK; f++ )
-    {
-        // map constants and PIs
-        Ssw_ObjSetFrame( p, Aig_ManConst1(p->pAig), f, Aig_ManConst1(pFrames) );
-        Saig_ManForEachPi( p->pAig, pObj, i )
-            Ssw_ObjSetFrame( p, pObj, f, Aig_ObjCreatePi(pFrames) );
-        // set the constraints on the latch outputs
-        Saig_ManForEachLo( p->pAig, pObj, i )
-            Ssw_FramesConstrainNode( p, pFrames, p->pAig, pObj, f, 1 );
-        // add internal nodes of this frame
-        Aig_ManForEachNode( p->pAig, pObj, i )
-        {
-            pObjNew = Aig_And( pFrames, Ssw_ObjChild0Fra(p, pObj, f), Ssw_ObjChild1Fra(p, pObj, f) );
-            Ssw_ObjSetFrame( p, pObj, f, pObjNew );
-            Ssw_FramesConstrainNode( p, pFrames, p->pAig, pObj, f, 1 );
-        }
-        // transfer latch input to the latch outputs 
-        Saig_ManForEachLiLo( p->pAig, pObjLi, pObjLo, i )
-            Ssw_ObjSetFrame( p, pObjLo, f+1, Ssw_ObjChild0Fra(p, pObjLi,f) );
-    }
-    // add the POs for the latch outputs of the last frame
-//    Saig_ManForEachLo( p->pAig, pObj, i )
-//        Aig_ObjCreatePo( pFrames, Ssw_ObjFrame( p, pObj, p->pPars->nFramesK ) );
-    for ( f = 0; f <= p->pPars->nFramesK; f++ )
-        Saig_ManForEachLo( p->pAig, pObj, i )
-            Aig_ObjCreatePo( pFrames, Ssw_ObjFrame( p, pObj, f ) );
-
-    // remove dangling nodes
-    Aig_ManCleanup( pFrames );
-    // make sure the satisfying assignment is node assigned
-    assert( pFrames->pData == NULL );
-//Aig_ManShow( pFrames, 0, NULL );
-    return pFrames;
-}
-
-
-
-/**Function*************************************************************
-
-  Synopsis    [Prepares the inductive case with speculative reduction.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Aig_Man_t * Ssw_SpeculativeReduction( Ssw_Man_t * p )
-{
-    Aig_Man_t * pFrames;
-    Aig_Obj_t * pObj, * pObjNew;
-    int i;
-    assert( p->pFrames == NULL );
-    assert( Aig_ManRegNum(p->pAig) > 0 );
-    assert( Aig_ManRegNum(p->pAig) < Aig_ManPiNum(p->pAig) );
-    p->nConstrTotal = p->nConstrReduced = 0;
-
-    // start the fraig package
-    pFrames = Aig_ManStart( Aig_ManObjNumMax(p->pAig) * p->nFrames );
-    // map constants and PIs
-    Ssw_ObjSetFrame( p, Aig_ManConst1(p->pAig), 0, Aig_ManConst1(pFrames) );
-    Saig_ManForEachPi( p->pAig, pObj, i )
-        Ssw_ObjSetFrame( p, pObj, 0, Aig_ObjCreatePi(pFrames) );
-    // create latches for the first frame
-    Saig_ManForEachLo( p->pAig, pObj, i )
-        Ssw_ObjSetFrame( p, pObj, 0, Aig_ObjCreatePi(pFrames) );
-    // set the constraints on the latch outputs
-    Saig_ManForEachLo( p->pAig, pObj, i )
-        Ssw_FramesConstrainNode( p, pFrames, p->pAig, pObj, 0, 0 );
-    // add internal nodes of this frame
-    Aig_ManForEachNode( p->pAig, pObj, i )
-    {
-        pObjNew = Aig_And( pFrames, Ssw_ObjChild0Fra(p, pObj, 0), Ssw_ObjChild1Fra(p, pObj, 0) );
-        Ssw_ObjSetFrame( p, pObj, 0, pObjNew );
-        Ssw_FramesConstrainNode( p, pFrames, p->pAig, pObj, 0, 0 );
-    }
-    // add the POs for the latch outputs of the last frame
-    Saig_ManForEachLi( p->pAig, pObj, i )
-        Aig_ObjCreatePo( pFrames, Ssw_ObjChild0Fra(p, pObj,0) );
-    // remove dangling nodes
-    Aig_ManCleanup( pFrames );
-    Aig_ManSetRegNum( pFrames, Aig_ManRegNum(p->pAig) );
-    printf( "SpecRed: Total constraints = %d. Reduced constraints = %d.\n", 
-        p->nConstrTotal, p->nConstrReduced );
-    return pFrames;
-}
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswClass.c b/src/aig/ssw_old/sswClass.c
deleted file mode 100644
index cfbb138c..00000000
--- a/src/aig/ssw_old/sswClass.c
+++ /dev/null
@@ -1,941 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswClass.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [Representation of candidate equivalence classes.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswClass.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-
-/*
-    The candidate equivalence classes are stored as a vector of pointers 
-    to the array of pointers to the nodes in each class.
-    The first node of the class is its representative node.
-    The representative has the smallest topological order among the class nodes.
-    The nodes inside each class are ordered according to their topological order.
-    The classes are ordered according to the topo order of their representatives.
-*/
-
-// internal representation of candidate equivalence classes
-struct Ssw_Cla_t_
-{
-    // class information
-    Aig_Man_t *      pAig;             // original AIG manager
-    Aig_Obj_t ***    pId2Class;        // non-const classes by ID of repr node
-    int *            pClassSizes;      // sizes of each equivalence class
-    // statistics
-    int              nClasses;         // the total number of non-const classes
-    int              nCands1;          // the total number of const candidates
-    int              nLits;            // the number of literals in all classes
-    // memory
-    Aig_Obj_t **     pMemClasses;      // memory allocated for equivalence classes
-    Aig_Obj_t **     pMemClassesFree;  // memory allocated for equivalence classes to be used
-    // temporary data
-    Vec_Ptr_t *      vClassOld;        // old equivalence class after splitting
-    Vec_Ptr_t *      vClassNew;        // new equivalence class(es) after splitting
-    Vec_Ptr_t *      vRefined;         // the nodes refined since the last iteration
-    // procedures used for class refinement
-    void *           pManData;
-    unsigned (*pFuncNodeHash) (void *,Aig_Obj_t *);              // returns hash key of the node
-    int (*pFuncNodeIsConst)   (void *,Aig_Obj_t *);              // returns 1 if the node is a constant
-    int (*pFuncNodesAreEqual) (void *,Aig_Obj_t *, Aig_Obj_t *); // returns 1 if nodes are equal up to a complement
-};
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-static inline Aig_Obj_t *  Ssw_ObjNext( Aig_Obj_t ** ppNexts, Aig_Obj_t * pObj )                       { return ppNexts[pObj->Id];  }
-static inline void         Ssw_ObjSetNext( Aig_Obj_t ** ppNexts, Aig_Obj_t * pObj, Aig_Obj_t * pNext ) { ppNexts[pObj->Id] = pNext; }
-
-// iterator through the equivalence classes
-#define Ssw_ManForEachClass( p, ppClass, i )                 \
-    for ( i = 0; i < Aig_ManObjNumMax(p->pAig); i++ )        \
-        if ( ((ppClass) = p->pId2Class[i]) == NULL ) {} else
-// iterator through the nodes in one class
-#define Ssw_ClassForEachNode( p, pRepr, pNode, i )           \
-    for ( i = 0; i < p->pClassSizes[pRepr->Id]; i++ )        \
-        if ( ((pNode) = p->pId2Class[pRepr->Id][i]) == NULL ) {} else
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Creates one equivalence class.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-static inline void Ssw_ObjAddClass( Ssw_Cla_t * p, Aig_Obj_t * pRepr, Aig_Obj_t ** pClass, int nSize ) 
-{
-    assert( p->pId2Class[pRepr->Id] == NULL );
-    assert( pClass[0] == pRepr );
-    p->pId2Class[pRepr->Id] = pClass; 
-    assert( p->pClassSizes[pRepr->Id] == 0 );
-    assert( nSize > 1 );
-    p->pClassSizes[pRepr->Id] = nSize;
-    p->nClasses++;
-    p->nLits += nSize - 1;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Removes one equivalence class.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-static inline Aig_Obj_t ** Ssw_ObjRemoveClass( Ssw_Cla_t * p, Aig_Obj_t * pRepr ) 
-{
-    Aig_Obj_t ** pClass = p->pId2Class[pRepr->Id];
-    int nSize;
-    assert( pClass != NULL );
-    p->pId2Class[pRepr->Id] = NULL; 
-    nSize = p->pClassSizes[pRepr->Id];
-    assert( nSize > 1 );
-    p->nClasses--;
-    p->nLits -= nSize - 1;
-    p->pClassSizes[pRepr->Id] = 0;
-    return pClass;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Starts representation of equivalence classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Cla_t * Ssw_ClassesStart( Aig_Man_t * pAig )
-{
-    Ssw_Cla_t * p;
-    p = ALLOC( Ssw_Cla_t, 1 );
-    memset( p, 0, sizeof(Ssw_Cla_t) );
-    p->pAig         = pAig;
-    p->pId2Class    = CALLOC( Aig_Obj_t **, Aig_ManObjNumMax(pAig) );
-    p->pClassSizes  = CALLOC( int, Aig_ManObjNumMax(pAig) );
-    p->vClassOld    = Vec_PtrAlloc( 100 );
-    p->vClassNew    = Vec_PtrAlloc( 100 );
-    p->vRefined     = Vec_PtrAlloc( 1000 );
-    assert( pAig->pReprs == NULL );
-    Aig_ManReprStart( pAig, Aig_ManObjNumMax(pAig) );
-    return p;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Starts representation of equivalence classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ClassesSetData( Ssw_Cla_t * p, void * pManData, 
-    unsigned (*pFuncNodeHash)(void *,Aig_Obj_t *),               // returns hash key of the node
-    int (*pFuncNodeIsConst)(void *,Aig_Obj_t *),                 // returns 1 if the node is a constant
-    int (*pFuncNodesAreEqual)(void *,Aig_Obj_t *, Aig_Obj_t *) ) // returns 1 if nodes are equal up to a complement
-{
-    p->pManData           = pManData;
-    p->pFuncNodeHash      = pFuncNodeHash;
-    p->pFuncNodeIsConst   = pFuncNodeIsConst;
-    p->pFuncNodesAreEqual = pFuncNodesAreEqual;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Stop representation of equivalence classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ClassesStop( Ssw_Cla_t * p )
-{
-    if ( p->vClassNew )    Vec_PtrFree( p->vClassNew );
-    if ( p->vClassOld )    Vec_PtrFree( p->vClassOld );
-    Vec_PtrFree( p->vRefined );
-    FREE( p->pId2Class );
-    FREE( p->pClassSizes );
-    FREE( p->pMemClasses );
-    free( p );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Stop representation of equivalence classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Aig_Man_t * Ssw_ClassesReadAig( Ssw_Cla_t * p )
-{
-    return p->pAig;
-}
-
-/**Function*************************************************************
-
-  Synopsis    []
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Vec_Ptr_t * Ssw_ClassesGetRefined( Ssw_Cla_t * p )
-{
-    return p->vRefined;
-}
-
-/**Function*************************************************************
-
-  Synopsis    []
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ClassesClearRefined( Ssw_Cla_t * p )
-{
-    Vec_PtrClear( p->vRefined );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Stop representation of equivalence classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ClassesCand1Num( Ssw_Cla_t * p )
-{
-    return p->nCands1;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Stop representation of equivalence classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ClassesClassNum( Ssw_Cla_t * p )
-{
-    return p->nClasses;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Stop representation of equivalence classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ClassesLitNum( Ssw_Cla_t * p )
-{
-    return p->nLits;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Stop representation of equivalence classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Aig_Obj_t ** Ssw_ClassesReadClass( Ssw_Cla_t * p, Aig_Obj_t * pRepr, int * pnSize )
-{
-    if ( p->pId2Class[pRepr->Id] == NULL )
-        return NULL;
-    assert( p->pId2Class[pRepr->Id] != NULL );
-    assert( p->pClassSizes[pRepr->Id] > 1 );
-    *pnSize = p->pClassSizes[pRepr->Id];
-    return p->pId2Class[pRepr->Id];
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Stop representation of equivalence classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ClassesCollectClass( Ssw_Cla_t * p, Aig_Obj_t * pRepr, Vec_Ptr_t * vClass )
-{
-    int i;
-    Vec_PtrClear( vClass );
-    if ( p->pId2Class[pRepr->Id] == NULL )
-        return;
-    assert( p->pClassSizes[pRepr->Id] > 1 );
-    for ( i = 1; i < p->pClassSizes[pRepr->Id]; i++ )
-        Vec_PtrPush( vClass, p->pId2Class[pRepr->Id][i] );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Checks candidate equivalence classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ClassesCheck( Ssw_Cla_t * p )
-{
-    Aig_Obj_t * pObj, * pPrev, ** ppClass;
-    int i, k, nLits, nClasses, nCands1;
-    nClasses = nLits = 0;
-    Ssw_ManForEachClass( p, ppClass, k )
-    {
-        pPrev = NULL;
-        assert( p->pClassSizes[ppClass[0]->Id] >= 2 );
-        Ssw_ClassForEachNode( p, ppClass[0], pObj, i )
-        {
-            if ( i == 0 )
-                assert( Aig_ObjRepr(p->pAig, pObj) == NULL );
-            else
-            {
-                assert( Aig_ObjRepr(p->pAig, pObj) == ppClass[0] );
-                assert( pPrev->Id < pObj->Id );
-                nLits++;
-            }
-            pPrev = pObj;
-        }
-        nClasses++;
-    }
-    nCands1 = 0;
-    Aig_ManForEachObj( p->pAig, pObj, i )
-        nCands1 += Ssw_ObjIsConst1Cand( p->pAig, pObj );
-    assert( p->nLits == nLits );
-    assert( p->nCands1 == nCands1 );
-    assert( p->nClasses == nClasses );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Prints simulation classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ClassesPrintOne( Ssw_Cla_t * p, Aig_Obj_t * pRepr )
-{
-    Aig_Obj_t * pObj;
-    int i;
-    printf( "{ " );
-    Ssw_ClassForEachNode( p, pRepr, pObj, i )
-        printf( "%d(%d,%d) ", pObj->Id, pObj->Level, Aig_SupportSize(p->pAig,pObj) );
-    printf( "}\n" );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Prints simulation classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ClassesPrint( Ssw_Cla_t * p, int fVeryVerbose )
-{
-    Aig_Obj_t ** ppClass;
-    Aig_Obj_t * pObj;
-    int i;
-    printf( "Equivalence classes: Const1 = %5d. Class = %5d. Lit = %5d.\n", 
-        p->nCands1, p->nClasses, p->nCands1+p->nLits );
-    if ( !fVeryVerbose )
-        return;
-    printf( "Constants { " );
-    Aig_ManForEachObj( p->pAig, pObj, i )
-        if ( Ssw_ObjIsConst1Cand( p->pAig, pObj ) )
-            printf( "%d(%d,%d) ", pObj->Id, pObj->Level, Aig_SupportSize(p->pAig,pObj) );
-    printf( "}\n" );
-    Ssw_ManForEachClass( p, ppClass, i )
-    {
-        printf( "%3d (%3d) : ", i, p->pClassSizes[i] );
-        Ssw_ClassesPrintOne( p, ppClass[0] );
-    }
-    printf( "\n" );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Prints simulation classes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ClassesRemoveNode( Ssw_Cla_t * p, Aig_Obj_t * pObj )
-{
-    Aig_Obj_t * pRepr, * pTemp;
-    assert( p->pClassSizes[pObj->Id] == 0 );
-    assert( p->pId2Class[pObj->Id] == NULL );
-    pRepr = Aig_ObjRepr( p->pAig, pObj );
-    assert( pRepr != NULL );
-    Vec_PtrPush( p->vRefined, pObj );
-    if ( Ssw_ObjIsConst1Cand( p->pAig, pObj ) )
-    {
-        assert( p->pClassSizes[pRepr->Id] == 0 );
-        assert( p->pId2Class[pRepr->Id] == NULL );
-        Aig_ObjSetRepr( p->pAig, pObj, NULL );
-        p->nCands1--;
-        return;
-    }
-    Vec_PtrPush( p->vRefined, pRepr );
-    Aig_ObjSetRepr( p->pAig, pObj, NULL );
-    assert( p->pId2Class[pRepr->Id][0] == pRepr );
-    assert( p->pClassSizes[pRepr->Id] >= 2 );
-    if ( p->pClassSizes[pRepr->Id] == 2 )
-    {
-        p->pId2Class[pRepr->Id] = NULL;
-        p->nClasses--;
-        p->pClassSizes[pRepr->Id] = 0;
-        p->nLits--;
-    }
-    else
-    {
-        int i, k = 0;
-        // remove the entry from the class
-        Ssw_ClassForEachNode( p, pRepr, pTemp, i )
-            if ( pTemp != pObj )
-                p->pId2Class[pRepr->Id][k++] = pTemp;
-        assert( k + 1 == p->pClassSizes[pRepr->Id] );
-        // reduce the class
-        p->pClassSizes[pRepr->Id]--;
-        p->nLits--;
-    }
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Creates initial simulation classes.]
-
-  Description [Assumes that simulation info is assigned.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Cla_t * Ssw_ClassesPrepare( Aig_Man_t * pAig, int fLatchCorr, int nMaxLevs, int fVerbose )
-{
-    Ssw_Cla_t * p;
-    Ssw_Sml_t * pSml;
-    Aig_Obj_t ** ppTable, ** ppNexts, ** ppClassNew;
-    Aig_Obj_t * pObj, * pTemp, * pRepr;
-    int i, k, nTableSize, nNodes, iEntry, nEntries, nEntries2;
-    int clk;
-
-    // start the classes
-    p = Ssw_ClassesStart( pAig );
-
-    // perform sequential simulation
-clk = clock();
-    pSml = Ssw_SmlSimulateSeq( pAig, 0, 32, 4 );
-if ( fVerbose )
-{
-PRT( "Simulation of 32 frames with 4 words", clock() - clk );
-}
-
-    // set comparison procedures
-clk = clock();
-    Ssw_ClassesSetData( p, pSml, Ssw_SmlObjHashWord, Ssw_SmlObjIsConstWord, Ssw_SmlObjsAreEqualWord );
-
-    // allocate the hash table hashing simulation info into nodes
-    nTableSize = Aig_PrimeCudd( Aig_ManObjNumMax(p->pAig)/4 );
-    ppTable = CALLOC( Aig_Obj_t *, nTableSize ); 
-    ppNexts = CALLOC( Aig_Obj_t *, Aig_ManObjNumMax(p->pAig) ); 
-
-    // add all the nodes to the hash table
-    nEntries = 0;
-    Aig_ManForEachObj( p->pAig, pObj, i )
-    {
-        if ( fLatchCorr )
-        {
-            if ( !Saig_ObjIsLo(p->pAig, pObj) )
-                continue;
-        }
-        else
-        {
-            if ( !Aig_ObjIsNode(pObj) && !Aig_ObjIsPi(pObj) )
-                continue;
-            // skip the node with more that the given number of levels
-            if ( nMaxLevs && (int)pObj->Level > nMaxLevs )
-                continue;
-        }
-        // check if the node belongs to the class of constant 1
-        if ( p->pFuncNodeIsConst( p->pManData, pObj ) )
-        {
-            Ssw_ObjSetConst1Cand( p->pAig, pObj );
-            p->nCands1++;
-            continue;
-        }
-        // hash the node by its simulation info
-        iEntry = p->pFuncNodeHash( p->pManData, pObj ) % nTableSize;
-        // add the node to the class
-        if ( ppTable[iEntry] == NULL )
-            ppTable[iEntry] = pObj;
-        else
-        {
-            // set the representative of this node
-            pRepr = ppTable[iEntry];
-            Aig_ObjSetRepr( p->pAig, pObj, pRepr );
-            // add node to the table
-            if ( Ssw_ObjNext( ppNexts, pRepr ) == NULL )
-            { // this will be the second entry
-                p->pClassSizes[pRepr->Id]++;
-                nEntries++;
-            }
-            // add the entry to the list
-            Ssw_ObjSetNext( ppNexts, pObj, Ssw_ObjNext( ppNexts, pRepr ) );
-            Ssw_ObjSetNext( ppNexts, pRepr, pObj );
-            p->pClassSizes[pRepr->Id]++;
-            nEntries++;
-        }
-    }
-
-    // allocate room for classes
-    p->pMemClasses = ALLOC( Aig_Obj_t *, nEntries + p->nCands1 );
-    p->pMemClassesFree = p->pMemClasses + nEntries;
- 
-    // copy the entries into storage in the topological order
-    nEntries2 = 0;
-    Aig_ManForEachObj( p->pAig, pObj, i )
-    {
-        if ( !Aig_ObjIsNode(pObj) && !Aig_ObjIsPi(pObj) )
-            continue;
-        nNodes = p->pClassSizes[pObj->Id];
-        // skip the nodes that are not representatives of non-trivial classes
-        if ( nNodes == 0 )
-            continue;
-        assert( nNodes > 1 );
-        // add the nodes to the class in the topological order
-        ppClassNew = p->pMemClasses + nEntries2;
-        ppClassNew[0] = pObj;
-        for ( pTemp = Ssw_ObjNext(ppNexts, pObj), k = 1; pTemp; 
-              pTemp = Ssw_ObjNext(ppNexts, pTemp), k++ )
-        {
-            ppClassNew[nNodes-k] = pTemp;
-        }
-        // add the class of nodes
-        p->pClassSizes[pObj->Id] = 0;
-        Ssw_ObjAddClass( p, pObj, ppClassNew, nNodes );
-        // increment the number of entries
-        nEntries2 += nNodes;
-    }
-    assert( nEntries == nEntries2 );
-    free( ppTable );
-    free( ppNexts );
-
-    // now it is time to refine the classes
-    Ssw_ClassesRefine( p, 1 );
-    Ssw_ClassesCheck( p );
-    Ssw_SmlStop( pSml );
-//    Ssw_ClassesPrint( p, 0 );
-if ( fVerbose )
-{
-PRT( "Collecting candidate equival classes", clock() - clk );
-}
-    return p;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Creates initial simulation classes.]
-
-  Description [Assumes that simulation info is assigned.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Cla_t * Ssw_ClassesPrepareSimple( Aig_Man_t * pAig, int fLatchCorr, int nMaxLevs )
-{
-    Ssw_Cla_t * p;
-    Aig_Obj_t * pObj;
-    int i;
-    // start the classes
-    p = Ssw_ClassesStart( pAig );
-    // go through the nodes
-    p->nCands1 = 0;
-    Aig_ManForEachObj( pAig, pObj, i )
-    {
-        if ( fLatchCorr )
-        {
-            if ( !Saig_ObjIsLo(pAig, pObj) )
-                continue;
-        }
-        else
-        {
-            if ( !Aig_ObjIsNode(pObj) && !Saig_ObjIsLo(pAig, pObj) )
-                continue;
-            // skip the node with more that the given number of levels
-            if ( nMaxLevs && (int)pObj->Level > nMaxLevs )
-                continue;
-        }
-        Ssw_ObjSetConst1Cand( pAig, pObj );
-        p->nCands1++;
-    }
-    // allocate room for classes
-    p->pMemClassesFree = p->pMemClasses = ALLOC( Aig_Obj_t *, p->nCands1 );
-//    Ssw_ClassesPrint( p, 0 );
-    return p;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Creates initial simulation classes.]
-
-  Description [Assumes that simulation info is assigned.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Cla_t * Ssw_ClassesPrepareTargets( Aig_Man_t * pAig )
-{
-    Ssw_Cla_t * p;
-    Aig_Obj_t * pObj;
-    int i;
-    // start the classes
-    p = Ssw_ClassesStart( pAig );
-    // go through the nodes
-    p->nCands1 = 0;
-    Saig_ManForEachPo( pAig, pObj, i )
-    {
-        Ssw_ObjSetConst1Cand( pAig, Aig_ObjFanin0(pObj) );
-        p->nCands1++;
-    }
-    // allocate room for classes
-    p->pMemClassesFree = p->pMemClasses = ALLOC( Aig_Obj_t *, p->nCands1 );
-//    Ssw_ClassesPrint( p, 0 );
-    return p;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Creates classes from the temporary representation.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Cla_t * Ssw_ClassesPreparePairs( Aig_Man_t * pAig, Vec_Int_t ** pvClasses )
-{
-    Ssw_Cla_t * p;
-    Aig_Obj_t ** ppClassNew;
-    Aig_Obj_t * pObj, * pRepr, * pPrev;
-    int i, k, nTotalObjs, nEntries, Entry;
-    // start the classes
-    p = Ssw_ClassesStart( pAig );
-    // count the number of entries in the classes
-    nTotalObjs = 0;
-    for ( i = 0; i < Aig_ManObjNumMax(pAig); i++ )
-        nTotalObjs += pvClasses[i] ? Vec_IntSize(pvClasses[i]) : 0; 
-    // allocate memory for classes
-    p->pMemClasses = ALLOC( Aig_Obj_t *, nTotalObjs );
-    // create constant-1 class
-    if ( pvClasses[0] )
-    Vec_IntForEachEntry( pvClasses[0], Entry, i )
-    {
-        assert( (i == 0) == (Entry == 0) );
-        if ( i == 0 )
-            continue;
-        pObj = Aig_ManObj( pAig, Entry );
-        Ssw_ObjSetConst1Cand( pAig, pObj );
-        p->nCands1++;
-    }
-    // create classes
-    nEntries = 0;
-    for ( i = 1; i < Aig_ManObjNumMax(pAig); i++ )
-    {
-        if ( pvClasses[i] == NULL )
-            continue;
-        // get room for storing the class
-        ppClassNew = p->pMemClasses + nEntries;
-        nEntries  += Vec_IntSize( pvClasses[i] );
-        // store the nodes of the class
-        pPrev = pRepr = Aig_ManObj( pAig, Vec_IntEntry(pvClasses[i],0) );
-        ppClassNew[0] = pRepr;
-        Vec_IntForEachEntryStart( pvClasses[i], Entry, k, 1 )
-        {
-            pObj = Aig_ManObj( pAig, Entry );
-            assert( pPrev->Id < pObj->Id );
-            pPrev = pObj;
-            ppClassNew[k] = pObj;
-            Aig_ObjSetRepr( pAig, pObj, pRepr );
-        }
-        // create new class
-        Ssw_ObjAddClass( p, pRepr, ppClassNew, Vec_IntSize(pvClasses[i]) );
-    }
-    // prepare room for new classes
-    p->pMemClassesFree = p->pMemClasses + nEntries;
-    Ssw_ClassesCheck( p );
-//    Ssw_ClassesPrint( p, 0 );
-    return p;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Iteratively refines the classes after simulation.]
-
-  Description [Returns the number of refinements performed.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ClassesRefineOneClass( Ssw_Cla_t * p, Aig_Obj_t * pReprOld, int fRecursive )
-{
-    Aig_Obj_t ** pClassOld, ** pClassNew;
-    Aig_Obj_t * pObj, * pReprNew;
-    int i;
-
-    // split the class
-    Vec_PtrClear( p->vClassOld );
-    Vec_PtrClear( p->vClassNew );
-    Ssw_ClassForEachNode( p, pReprOld, pObj, i )
-        if ( p->pFuncNodesAreEqual(p->pManData, pReprOld, pObj) )
-            Vec_PtrPush( p->vClassOld, pObj );
-        else
-            Vec_PtrPush( p->vClassNew, pObj );
-    // check if splitting happened
-    if ( Vec_PtrSize(p->vClassNew) == 0 )
-        return 0;
-    // remember that this class is refined
-    Ssw_ClassForEachNode( p, pReprOld, pObj, i )
-        Vec_PtrPush( p->vRefined, pObj );
-
-    // get the new representative
-    pReprNew = Vec_PtrEntry( p->vClassNew, 0 );
-    assert( Vec_PtrSize(p->vClassOld) > 0 );
-    assert( Vec_PtrSize(p->vClassNew) > 0 );
-
-    // create old class
-    pClassOld = Ssw_ObjRemoveClass( p, pReprOld );
-    Vec_PtrForEachEntry( p->vClassOld, pObj, i )
-    {
-        pClassOld[i] = pObj;
-        Aig_ObjSetRepr( p->pAig, pObj, i? pReprOld : NULL );
-    }
-    // create new class
-    pClassNew = pClassOld + i;
-    Vec_PtrForEachEntry( p->vClassNew, pObj, i )
-    {
-        pClassNew[i] = pObj;
-        Aig_ObjSetRepr( p->pAig, pObj, i? pReprNew : NULL );
-    }
-
-    // put classes back
-    if ( Vec_PtrSize(p->vClassOld) > 1 )
-        Ssw_ObjAddClass( p, pReprOld, pClassOld, Vec_PtrSize(p->vClassOld) );
-    if ( Vec_PtrSize(p->vClassNew) > 1 )
-        Ssw_ObjAddClass( p, pReprNew, pClassNew, Vec_PtrSize(p->vClassNew) );
-
-    // check if the class should be recursively refined
-    if ( fRecursive && Vec_PtrSize(p->vClassNew) > 1 )
-        return 1 + Ssw_ClassesRefineOneClass( p, pReprNew, 1 );
-    return 1;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Refines the classes after simulation.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ClassesRefine( Ssw_Cla_t * p, int fRecursive )
-{
-    Aig_Obj_t ** ppClass;
-    int i, nRefis = 0;
-    Ssw_ManForEachClass( p, ppClass, i )
-        nRefis += Ssw_ClassesRefineOneClass( p, ppClass[0], fRecursive );
-    return nRefis;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Refine the group of constant 1 nodes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ClassesRefineConst1Group( Ssw_Cla_t * p, Vec_Ptr_t * vRoots, int fRecursive )
-{
-    Aig_Obj_t * pObj, * pReprNew, ** ppClassNew;
-    int i;
-    if ( Vec_PtrSize(vRoots) == 0 )
-        return 0;
-    // collect the nodes to be refined
-    Vec_PtrClear( p->vClassNew );
-    Vec_PtrForEachEntry( vRoots, pObj, i )
-        if ( !p->pFuncNodeIsConst( p->pManData, pObj ) )
-            Vec_PtrPush( p->vClassNew, pObj );
-    // check if there is a new class
-    if ( Vec_PtrSize(p->vClassNew) == 0 )
-        return 0;
-    p->nCands1 -= Vec_PtrSize(p->vClassNew);
-    pReprNew = Vec_PtrEntry( p->vClassNew, 0 );
-    Aig_ObjSetRepr( p->pAig, pReprNew, NULL );
-    if ( Vec_PtrSize(p->vClassNew) == 1 )
-        return 1;
-    // create a new class composed of these nodes
-    ppClassNew = p->pMemClassesFree;
-    p->pMemClassesFree += Vec_PtrSize(p->vClassNew);
-    Vec_PtrForEachEntry( p->vClassNew, pObj, i )
-    {
-        ppClassNew[i] = pObj;
-        Aig_ObjSetRepr( p->pAig, pObj, i? pReprNew : NULL );
-    }
-    Ssw_ObjAddClass( p, pReprNew, ppClassNew, Vec_PtrSize(p->vClassNew) );
-    // refine them recursively
-    if ( fRecursive )
-        return 1 + Ssw_ClassesRefineOneClass( p, pReprNew, 1 );
-    return 1;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Refine the group of constant 1 nodes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ClassesRefineConst1( Ssw_Cla_t * p, int fRecursive )
-{
-    Aig_Obj_t * pObj, * pReprNew, ** ppClassNew;
-    int i;
-    // collect the nodes to be refined
-    Vec_PtrClear( p->vClassNew );
-    for ( i = 0; i < Vec_PtrSize(p->pAig->vObjs); i++ )
-        if ( p->pAig->pReprs[i] == Aig_ManConst1(p->pAig) )
-        {
-            pObj = Aig_ManObj( p->pAig, i );
-            if ( !p->pFuncNodeIsConst( p->pManData, pObj ) )
-            {
-                Vec_PtrPush( p->vClassNew, pObj );
-                Vec_PtrPush( p->vRefined, pObj );
-            }
-        }
-    // check if there is a new class
-    if ( Vec_PtrSize(p->vClassNew) == 0 )
-        return 0;
-    p->nCands1 -= Vec_PtrSize(p->vClassNew);
-    pReprNew = Vec_PtrEntry( p->vClassNew, 0 );
-    Aig_ObjSetRepr( p->pAig, pReprNew, NULL );
-    if ( Vec_PtrSize(p->vClassNew) == 1 )
-        return 1;
-    // create a new class composed of these nodes
-    ppClassNew = p->pMemClassesFree;
-    p->pMemClassesFree += Vec_PtrSize(p->vClassNew);
-    Vec_PtrForEachEntry( p->vClassNew, pObj, i )
-    {
-        ppClassNew[i] = pObj;
-        Aig_ObjSetRepr( p->pAig, pObj, i? pReprNew : NULL );
-    }
-    Ssw_ObjAddClass( p, pReprNew, ppClassNew, Vec_PtrSize(p->vClassNew) );
-    // refine them recursively
-    if ( fRecursive )
-        return 1 + Ssw_ClassesRefineOneClass( p, pReprNew, 1 );
-    return 1;
-}
-
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswCnf.c b/src/aig/ssw_old/sswCnf.c
deleted file mode 100644
index e4b8f9f6..00000000
--- a/src/aig/ssw_old/sswCnf.c
+++ /dev/null
@@ -1,335 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswCnf.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [Computation of CNF.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswCnf.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Addes clauses to the solver.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_AddClausesMux( Ssw_Man_t * p, Aig_Obj_t * pNode )
-{
-    Aig_Obj_t * pNodeI, * pNodeT, * pNodeE;
-    int pLits[4], RetValue, VarF, VarI, VarT, VarE, fCompT, fCompE;
-
-    assert( !Aig_IsComplement( pNode ) );
-    assert( Aig_ObjIsMuxType( pNode ) );
-    // get nodes (I = if, T = then, E = else)
-    pNodeI = Aig_ObjRecognizeMux( pNode, &pNodeT, &pNodeE );
-    // get the variable numbers
-    VarF = Ssw_ObjSatNum(p,pNode);
-    VarI = Ssw_ObjSatNum(p,pNodeI);
-    VarT = Ssw_ObjSatNum(p,Aig_Regular(pNodeT));
-    VarE = Ssw_ObjSatNum(p,Aig_Regular(pNodeE));
-    // get the complementation flags
-    fCompT = Aig_IsComplement(pNodeT);
-    fCompE = Aig_IsComplement(pNodeE);
-
-    // f = ITE(i, t, e)
-
-    // i' + t' + f
-    // i' + t  + f'
-    // i  + e' + f
-    // i  + e  + f'
-
-    // create four clauses
-    pLits[0] = toLitCond(VarI, 1);
-    pLits[1] = toLitCond(VarT, 1^fCompT);
-    pLits[2] = toLitCond(VarF, 0);
-    if ( p->pPars->fPolarFlip )
-    {
-        if ( pNodeI->fPhase )               pLits[0] = lit_neg( pLits[0] );
-        if ( Aig_Regular(pNodeT)->fPhase )  pLits[1] = lit_neg( pLits[1] );
-        if ( pNode->fPhase )                pLits[2] = lit_neg( pLits[2] );
-    }
-    RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 3 );
-    assert( RetValue );
-    pLits[0] = toLitCond(VarI, 1);
-    pLits[1] = toLitCond(VarT, 0^fCompT);
-    pLits[2] = toLitCond(VarF, 1);
-    if ( p->pPars->fPolarFlip )
-    {
-        if ( pNodeI->fPhase )               pLits[0] = lit_neg( pLits[0] );
-        if ( Aig_Regular(pNodeT)->fPhase )  pLits[1] = lit_neg( pLits[1] );
-        if ( pNode->fPhase )                pLits[2] = lit_neg( pLits[2] );
-    }
-    RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 3 );
-    assert( RetValue );
-    pLits[0] = toLitCond(VarI, 0);
-    pLits[1] = toLitCond(VarE, 1^fCompE);
-    pLits[2] = toLitCond(VarF, 0);
-    if ( p->pPars->fPolarFlip )
-    {
-        if ( pNodeI->fPhase )               pLits[0] = lit_neg( pLits[0] );
-        if ( Aig_Regular(pNodeE)->fPhase )  pLits[1] = lit_neg( pLits[1] );
-        if ( pNode->fPhase )                pLits[2] = lit_neg( pLits[2] );
-    }
-    RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 3 );
-    assert( RetValue );
-    pLits[0] = toLitCond(VarI, 0);
-    pLits[1] = toLitCond(VarE, 0^fCompE);
-    pLits[2] = toLitCond(VarF, 1);
-    if ( p->pPars->fPolarFlip )
-    {
-        if ( pNodeI->fPhase )               pLits[0] = lit_neg( pLits[0] );
-        if ( Aig_Regular(pNodeE)->fPhase )  pLits[1] = lit_neg( pLits[1] );
-        if ( pNode->fPhase )                pLits[2] = lit_neg( pLits[2] );
-    }
-    RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 3 );
-    assert( RetValue );
-
-    // two additional clauses
-    // t' & e' -> f'
-    // t  & e  -> f 
-
-    // t  + e   + f'
-    // t' + e'  + f 
-
-    if ( VarT == VarE )
-    {
-//        assert( fCompT == !fCompE );
-        return;
-    }
-
-    pLits[0] = toLitCond(VarT, 0^fCompT);
-    pLits[1] = toLitCond(VarE, 0^fCompE);
-    pLits[2] = toLitCond(VarF, 1);
-    if ( p->pPars->fPolarFlip )
-    {
-        if ( Aig_Regular(pNodeT)->fPhase )  pLits[0] = lit_neg( pLits[0] );
-        if ( Aig_Regular(pNodeE)->fPhase )  pLits[1] = lit_neg( pLits[1] );
-        if ( pNode->fPhase )                pLits[2] = lit_neg( pLits[2] );
-    }
-    RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 3 );
-    assert( RetValue );
-    pLits[0] = toLitCond(VarT, 1^fCompT);
-    pLits[1] = toLitCond(VarE, 1^fCompE);
-    pLits[2] = toLitCond(VarF, 0);
-    if ( p->pPars->fPolarFlip )
-    {
-        if ( Aig_Regular(pNodeT)->fPhase )  pLits[0] = lit_neg( pLits[0] );
-        if ( Aig_Regular(pNodeE)->fPhase )  pLits[1] = lit_neg( pLits[1] );
-        if ( pNode->fPhase )                pLits[2] = lit_neg( pLits[2] );
-    }
-    RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 3 );
-    assert( RetValue );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Addes clauses to the solver.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_AddClausesSuper( Ssw_Man_t * p, Aig_Obj_t * pNode, Vec_Ptr_t * vSuper )
-{
-    Aig_Obj_t * pFanin;
-    int * pLits, nLits, RetValue, i;
-    assert( !Aig_IsComplement(pNode) );
-    assert( Aig_ObjIsNode( pNode ) );
-    // create storage for literals
-    nLits = Vec_PtrSize(vSuper) + 1;
-    pLits = ALLOC( int, nLits );
-    // suppose AND-gate is A & B = C
-    // add !A => !C   or   A + !C
-    Vec_PtrForEachEntry( vSuper, pFanin, i )
-    {
-        pLits[0] = toLitCond(Ssw_ObjSatNum(p,Aig_Regular(pFanin)), Aig_IsComplement(pFanin));
-        pLits[1] = toLitCond(Ssw_ObjSatNum(p,pNode), 1);
-        if ( p->pPars->fPolarFlip )
-        {
-            if ( Aig_Regular(pFanin)->fPhase )  pLits[0] = lit_neg( pLits[0] );
-            if ( pNode->fPhase )                pLits[1] = lit_neg( pLits[1] );
-        }
-        RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 2 );
-        assert( RetValue );
-    }
-    // add A & B => C   or   !A + !B + C
-    Vec_PtrForEachEntry( vSuper, pFanin, i )
-    {
-        pLits[i] = toLitCond(Ssw_ObjSatNum(p,Aig_Regular(pFanin)), !Aig_IsComplement(pFanin));
-        if ( p->pPars->fPolarFlip )
-        {
-            if ( Aig_Regular(pFanin)->fPhase )  pLits[i] = lit_neg( pLits[i] );
-        }
-    }
-    pLits[nLits-1] = toLitCond(Ssw_ObjSatNum(p,pNode), 0);
-    if ( p->pPars->fPolarFlip )
-    {
-        if ( pNode->fPhase )  pLits[nLits-1] = lit_neg( pLits[nLits-1] );
-    }
-    RetValue = sat_solver_addclause( p->pSat, pLits, pLits + nLits );
-    assert( RetValue );
-    free( pLits );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Collects the supergate.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_CollectSuper_rec( Aig_Obj_t * pObj, Vec_Ptr_t * vSuper, int fFirst, int fUseMuxes )
-{
-    // if the new node is complemented or a PI, another gate begins
-    if ( Aig_IsComplement(pObj) || Aig_ObjIsPi(pObj) || 
-         (!fFirst && Aig_ObjRefs(pObj) > 1) || 
-         (fUseMuxes && Aig_ObjIsMuxType(pObj)) )
-    {
-        Vec_PtrPushUnique( vSuper, pObj );
-        return;
-    }
-    // go through the branches
-    Ssw_CollectSuper_rec( Aig_ObjChild0(pObj), vSuper, 0, fUseMuxes );
-    Ssw_CollectSuper_rec( Aig_ObjChild1(pObj), vSuper, 0, fUseMuxes );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Collects the supergate.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_CollectSuper( Aig_Obj_t * pObj, int fUseMuxes, Vec_Ptr_t * vSuper )
-{
-    assert( !Aig_IsComplement(pObj) );
-    assert( !Aig_ObjIsPi(pObj) );
-    Vec_PtrClear( vSuper );
-    Ssw_CollectSuper_rec( pObj, vSuper, 1, fUseMuxes );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Updates the solver clause database.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ObjAddToFrontier( Ssw_Man_t * p, Aig_Obj_t * pObj, Vec_Ptr_t * vFrontier )
-{
-    assert( !Aig_IsComplement(pObj) );
-    if ( Ssw_ObjSatNum(p,pObj) )
-        return;
-    assert( Ssw_ObjSatNum(p,pObj) == 0 );
-    if ( Aig_ObjIsConst1(pObj) )
-        return;
-    if ( p->pPars->fLatchCorrOpt )
-    {
-        Vec_PtrPush( p->vUsedNodes, pObj );
-        if ( Aig_ObjIsPi(pObj) )
-            Vec_PtrPush( p->vUsedPis, pObj );
-    }
-    Ssw_ObjSetSatNum( p, pObj, p->nSatVars++ );
-    sat_solver_setnvars( p->pSat, 100 * (1 + p->nSatVars / 100) );
-    if ( Aig_ObjIsNode(pObj) )
-        Vec_PtrPush( vFrontier, pObj );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Updates the solver clause database.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_CnfNodeAddToSolver( Ssw_Man_t * p, Aig_Obj_t * pObj )
-{ 
-    Vec_Ptr_t * vFrontier;
-    Aig_Obj_t * pNode, * pFanin;
-    int i, k, fUseMuxes = 1;
-    // quit if CNF is ready
-    if ( Ssw_ObjSatNum(p,pObj) )
-        return;
-    // start the frontier
-    vFrontier = Vec_PtrAlloc( 100 );
-    Ssw_ObjAddToFrontier( p, pObj, vFrontier );
-    // explore nodes in the frontier
-    Vec_PtrForEachEntry( vFrontier, pNode, i )
-    {
-        // create the supergate
-        assert( Ssw_ObjSatNum(p,pNode) );
-        if ( fUseMuxes && Aig_ObjIsMuxType(pNode) )
-        {
-            Vec_PtrClear( p->vFanins );
-            Vec_PtrPushUnique( p->vFanins, Aig_ObjFanin0( Aig_ObjFanin0(pNode) ) );
-            Vec_PtrPushUnique( p->vFanins, Aig_ObjFanin0( Aig_ObjFanin1(pNode) ) );
-            Vec_PtrPushUnique( p->vFanins, Aig_ObjFanin1( Aig_ObjFanin0(pNode) ) );
-            Vec_PtrPushUnique( p->vFanins, Aig_ObjFanin1( Aig_ObjFanin1(pNode) ) );
-            Vec_PtrForEachEntry( p->vFanins, pFanin, k )
-                Ssw_ObjAddToFrontier( p, Aig_Regular(pFanin), vFrontier );
-            Ssw_AddClausesMux( p, pNode );
-        }
-        else
-        {
-            Ssw_CollectSuper( pNode, fUseMuxes, p->vFanins );
-            Vec_PtrForEachEntry( p->vFanins, pFanin, k )
-                Ssw_ObjAddToFrontier( p, Aig_Regular(pFanin), vFrontier );
-            Ssw_AddClausesSuper( p, pNode, p->vFanins );
-        }
-        assert( Vec_PtrSize(p->vFanins) > 1 );
-    }
-    Vec_PtrFree( vFrontier );
-}
-
-
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswCore.c b/src/aig/ssw_old/sswCore.c
deleted file mode 100644
index 5b33d96c..00000000
--- a/src/aig/ssw_old/sswCore.c
+++ /dev/null
@@ -1,293 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswCore.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [The core procedures.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswCore.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [This procedure sets default parameters.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManSetDefaultParams( Ssw_Pars_t * p )
-{
-    memset( p, 0, sizeof(Ssw_Pars_t) );
-    p->nPartSize      =     0;  // size of the partition
-    p->nOverSize      =     0;  // size of the overlap between partitions
-    p->nFramesK       =     1;  // the induction depth
-    p->nFramesAddSim  =     0;  // additional frames to simulate
-    p->nConstrs       =     0;  // treat the last nConstrs POs as seq constraints
-    p->nBTLimit       =  1000;  // conflict limit at a node
-    p->nMinDomSize    =   100;  // min clock domain considered for optimization
-    p->fPolarFlip     =     0;  // uses polarity adjustment
-    p->fSkipCheck     =     0;  // do not run equivalence check for unaffected cones
-    p->fLatchCorr     =     0;  // performs register correspondence
-    p->fSemiFormal    =     0;  // enable semiformal filtering
-    p->fUniqueness    =     0;  // enable uniqueness constraints
-    p->fVerbose       =     0;  // verbose stats
-    // latch correspondence
-    p->fLatchCorrOpt  =     0;  // performs optimized register correspondence
-    p->nSatVarMax     =  1000;  // the max number of SAT variables
-    p->nRecycleCalls  =    50;  // calls to perform before recycling SAT solver
-    // return values
-    p->nIters         =     0;  // the number of iterations performed
-}
-
-/**Function*************************************************************
-
-  Synopsis    [This procedure sets default parameters.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManSetDefaultParamsLcorr( Ssw_Pars_t * p )
-{
-    Ssw_ManSetDefaultParams( p );
-    p->fLatchCorrOpt = 1;
-    p->nBTLimit      = 10000;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Performs computation of signal correspondence with constraints.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Aig_Man_t * Ssw_SignalCorrespondenceRefine( Ssw_Man_t * p )
-{
-    int nSatProof, nSatCallsSat, nRecycles, nSatFailsReal;
-    Aig_Man_t * pAigNew;
-    int RetValue, nIter;
-    int clk, clkTotal = clock();
-    // get the starting stats
-    p->nLitsBeg  = Ssw_ClassesLitNum( p->ppClasses );
-    p->nNodesBeg = Aig_ManNodeNum(p->pAig);
-    p->nRegsBeg  = Aig_ManRegNum(p->pAig);
-    // refine classes using BMC
-    if ( p->pPars->fVerbose )
-    {
-        printf( "Before BMC: " );
-        Ssw_ClassesPrint( p->ppClasses, 0 );
-    }
-    if ( !p->pPars->fLatchCorr )
-    { 
-        Ssw_ManSweepBmc( p );
-        Ssw_ManCleanup( p );
-    }
-    if ( p->pPars->fVerbose )
-    {
-        printf( "After  BMC: " );
-        Ssw_ClassesPrint( p->ppClasses, 0 );
-    }
-    // apply semi-formal filtering
-    if ( p->pPars->fSemiFormal )
-    {
-        Aig_Man_t * pSRed;
-        Ssw_FilterUsingBmc( p, 0, 2000, p->pPars->fVerbose );
-//        Ssw_FilterUsingBmc( p, 1, 100000, p->pPars->fVerbose );
-        pSRed = Ssw_SpeculativeReduction( p );
-        Aig_ManDumpBlif( pSRed, "srm.blif", NULL, NULL );
-        Aig_ManStop( pSRed );
-    }
-    // refine classes using induction
-    nSatProof = nSatCallsSat = nRecycles = nSatFailsReal = 0;
-    for ( nIter = 0; ; nIter++ )
-    {
-clk = clock();
-        if ( p->pPars->fLatchCorrOpt )
-        {
-            RetValue = Ssw_ManSweepLatch( p );
-            if ( p->pPars->fVerbose )
-            {
-                printf( "%3d : Const = %6d. Cl = %6d. Pr = %5d. Cex = %5d. Rcl = %3d. F = %3d. ", 
-                    nIter, Ssw_ClassesCand1Num(p->ppClasses), Ssw_ClassesClassNum(p->ppClasses), 
-                    p->nSatProof-nSatProof, p->nSatCallsSat-nSatCallsSat, 
-                    p->nRecycles-nRecycles, p->nSatFailsReal-nSatFailsReal );
-                PRT( "T", clock() - clk );
-                nSatProof     = p->nSatProof;
-                nSatCallsSat  = p->nSatCallsSat;
-                nRecycles     = p->nRecycles;
-                nSatFailsReal = p->nSatFailsReal;
-            } 
-        }
-        else
-        {
-//            if ( nIter == 6 )
-//                p->pPars->fUniqueness = 0;
-
-            RetValue = Ssw_ManSweep( p );
-            if ( p->pPars->fVerbose )
-            {
-                printf( "%3d : Const = %6d. Cl = %6d. LR = %6d. NR = %6d. U = %3d. F = %2d. ", 
-                    nIter, Ssw_ClassesCand1Num(p->ppClasses), Ssw_ClassesClassNum(p->ppClasses), 
-                    p->nConstrReduced, Aig_ManNodeNum(p->pFrames), p->nUniques, p->nSatFailsReal );
-                if ( p->pPars->fSkipCheck )
-                    printf( "Use = %5d. Skip = %5d. ", 
-                        p->nRefUse, p->nRefSkip );
-                PRT( "T", clock() - clk );
-            } 
-        }
-        Ssw_ManCleanup( p );
-        if ( !RetValue )
-            break;
-/*
-        {
-            static int Flag = 0;
-            if ( Flag++ == 4 && nIter == 4 )
-            {
-                Aig_Man_t * pSRed;
-                pSRed = Ssw_SpeculativeReduction( p );
-                Aig_ManDumpBlif( pSRed, "srm.blif", NULL, NULL );
-                Aig_ManStop( pSRed );
-            }
-        }
-*/
-
-    } 
-    p->pPars->nIters = nIter + 1;
-p->timeTotal = clock() - clkTotal;
-    pAigNew = Aig_ManDupRepr( p->pAig, 0 );
-    Aig_ManSeqCleanup( pAigNew );
-    // get the final stats
-    p->nLitsEnd  = Ssw_ClassesLitNum( p->ppClasses );
-    p->nNodesEnd = Aig_ManNodeNum(pAigNew);
-    p->nRegsEnd  = Aig_ManRegNum(pAigNew);
-    return pAigNew;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Performs computation of signal correspondence with constraints.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Aig_Man_t * Ssw_SignalCorrespondence( Aig_Man_t * pAig, Ssw_Pars_t * pPars )
-{
-    Ssw_Pars_t Pars;
-    Aig_Man_t * pAigNew;
-    Ssw_Man_t * p;
-    assert( Aig_ManRegNum(pAig) > 0 );
-    // reset random numbers
-    Aig_ManRandom( 1 );
-    // if parameters are not given, create them
-    if ( pPars == NULL )
-        Ssw_ManSetDefaultParams( pPars = &Pars );
-    // consider the case of empty AIG
-    if ( Aig_ManNodeNum(pAig) == 0 )
-    {
-        pPars->nIters = 0;
-        // Ntl_ManFinalize() needs the following to satisfy an assertion
-        Aig_ManReprStart( pAig,Aig_ManObjNumMax(pAig) );
-        return Aig_ManDupOrdered(pAig);
-    }
-    // check and update parameters
-    if ( pPars->fLatchCorrOpt )
-    {
-        pPars->fLatchCorr = 1;
-        pPars->nFramesAddSim = 0;
-    }
-    else
-    {
-        assert( pPars->nFramesK > 0 );
-        if ( pPars->nFramesK > 1 )
-            pPars->fSkipCheck = 0;
-        // perform partitioning
-        if ( (pPars->nPartSize > 0 && pPars->nPartSize < Aig_ManRegNum(pAig))
-             || (pAig->vClockDoms && Vec_VecSize(pAig->vClockDoms) > 0)  )
-            return Ssw_SignalCorrespondencePart( pAig, pPars );
-    }
-    // start the induction manager
-    p = Ssw_ManCreate( pAig, pPars );
-    // compute candidate equivalence classes
-//    p->pPars->nConstrs = 1;
-    if ( p->pPars->nConstrs == 0 )
-    {
-        // perform one round of seq simulation and generate candidate equivalence classes
-        p->ppClasses = Ssw_ClassesPrepare( pAig, pPars->fLatchCorr, pPars->nMaxLevs, pPars->fVerbose );
-//        p->ppClasses = Ssw_ClassesPrepareTargets( pAig );
-//        p->pSml = Ssw_SmlStart( pAig, 0, p->nFrames + p->pPars->nFramesAddSim, 1 );
-        p->pSml = Ssw_SmlStart( pAig, 0, 1, 1 );
-        Ssw_ClassesSetData( p->ppClasses, p->pSml, Ssw_SmlObjHashWord, Ssw_SmlObjIsConstWord, Ssw_SmlObjsAreEqualWord );
-    }
-    else
-    {
-        // create trivial equivalence classes with all nodes being candidates for constant 1
-        p->ppClasses = Ssw_ClassesPrepareSimple( pAig, pPars->fLatchCorr, pPars->nMaxLevs );
-        Ssw_ClassesSetData( p->ppClasses, NULL, NULL, Ssw_SmlObjIsConstBit, Ssw_SmlObjsAreEqualBit );
-    }
-    // perform refinement of classes
-    pAigNew = Ssw_SignalCorrespondenceRefine( p );    
-    // cleanup
-    Ssw_ManStop( p );
-    return pAigNew;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Performs computation of latch correspondence.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Aig_Man_t * Ssw_LatchCorrespondence( Aig_Man_t * pAig, Ssw_Pars_t * pPars )
-{
-    Ssw_Pars_t Pars;
-    if ( pPars == NULL )
-        Ssw_ManSetDefaultParamsLcorr( pPars = &Pars );
-    return Ssw_SignalCorrespondence( pAig, pPars );
-}
-
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswInt.h b/src/aig/ssw_old/sswInt.h
deleted file mode 100644
index d7bf46a8..00000000
--- a/src/aig/ssw_old/sswInt.h
+++ /dev/null
@@ -1,232 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswInt.h]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [External declarations.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswInt.h,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
- 
-#ifndef __SSW_INT_H__
-#define __SSW_INT_H__
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-////////////////////////////////////////////////////////////////////////
-///                          INCLUDES                                ///
-////////////////////////////////////////////////////////////////////////
-
-#include "saig.h"
-#include "satSolver.h"
-#include "ssw.h"
-
-////////////////////////////////////////////////////////////////////////
-///                         PARAMETERS                               ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                         BASIC TYPES                              ///
-////////////////////////////////////////////////////////////////////////
-
-typedef struct Ssw_Man_t_ Ssw_Man_t; // signal correspondence manager
-typedef struct Ssw_Cla_t_ Ssw_Cla_t; // equivalence classe manager
-typedef struct Ssw_Sml_t_ Ssw_Sml_t; // sequential simulation manager
-
-struct Ssw_Man_t_
-{
-    // parameters
-    Ssw_Pars_t *     pPars;          // parameters
-    int              nFrames;        // for quick lookup
-    // AIGs used in the package
-    Aig_Man_t *      pAig;           // user-given AIG
-    Aig_Man_t *      pFrames;        // final AIG
-    Aig_Obj_t **     pNodeToFrames;  // mapping of AIG nodes into FRAIG nodes
-    // equivalence classes
-    Ssw_Cla_t *      ppClasses;      // equivalence classes of nodes
-    int              fRefined;       // is set to 1 when refinement happens
-    int              nRefUse;        // the number of equivalences used
-    int              nRefSkip;       // the number of equivalences skipped  
-    // SAT solving
-    sat_solver *     pSat;           // recyclable SAT solver
-    int              nSatVars;       // the counter of SAT variables
-    Vec_Int_t *      vSatVars;       // mapping of each node into its SAT var
-    int              nSatVarsTotal;  // the total number of SAT vars created
-    Vec_Ptr_t *      vFanins;        // fanins of the CNF node
-    // SAT solving (latch corr only)
-    Vec_Ptr_t *      vUsedNodes;     // the nodes with SAT variables
-    Vec_Ptr_t *      vUsedPis;       // the PIs with SAT variables
-    Vec_Ptr_t *      vSimInfo;       // simulation information for the framed PIs
-    int              nPatterns;      // the number of patterns saved
-    int              nSimRounds;     // the number of simulation rounds performed
-    int              nCallsCount;    // the number of calls in this round
-    int              nCallsDelta;    // the number of calls to skip
-    int              nCallsSat;      // the number of SAT calls in this round
-    int              nCallsUnsat;    // the number of UNSAT calls in this round
-    int              nRecycleCalls;  // the number of calls since last recycling
-    int              nRecycles;      // the number of time SAT solver was recycled
-    int              nConeMax;       // the maximum cone size
-    // uniqueness
-    Vec_Ptr_t *      vCommon;        // the set of common variables in the logic cones
-    int              iOutputLit;     // the output literal of the uniqueness constaint
-    int              nUniques;       // the number of uniqueness constaints used 
-    // sequential simulator
-    Ssw_Sml_t *      pSml;
-    // counter example storage
-    int              nPatWords;      // the number of words in the counter example
-    unsigned *       pPatWords;      // the counter example
-    unsigned *       pPatWords2;      // the counter example
-    // constraints
-    int              nConstrTotal;   // the number of total constraints
-    int              nConstrReduced; // the number of reduced constraints
-    int              nStrangers;     // the number of strange situations
-    // SAT calls statistics
-    int              nSatCalls;      // the number of SAT calls
-    int              nSatProof;      // the number of proofs
-    int              nSatFailsReal;  // the number of timeouts
-    int              nSatFailsTotal; // the number of timeouts
-    int              nSatCallsUnsat; // the number of unsat SAT calls
-    int              nSatCallsSat;   // the number of sat SAT calls
-    // node/register/lit statistics
-    int              nLitsBeg;
-    int              nLitsEnd;
-    int              nNodesBeg;
-    int              nNodesEnd;
-    int              nRegsBeg;
-    int              nRegsEnd;
-    // runtime stats
-    int              timeBmc;        // bounded model checking
-    int              timeReduce;     // speculative reduction
-    int              timeMarkCones;  // marking the cones not to be refined
-    int              timeSimSat;     // simulation of the counter-examples
-    int              timeSat;        // solving SAT
-    int              timeSatSat;     // sat
-    int              timeSatUnsat;   // unsat
-    int              timeSatUndec;   // undecided
-    int              timeOther;      // other runtime
-    int              timeTotal;      // total runtime
-};
-
-////////////////////////////////////////////////////////////////////////
-///                      MACRO DEFINITIONS                           ///
-////////////////////////////////////////////////////////////////////////
-
-static inline int  Ssw_ObjSatNum( Ssw_Man_t * p, Aig_Obj_t * pObj )             { return Vec_IntEntry( p->vSatVars, pObj->Id );         }
-static inline void Ssw_ObjSetSatNum( Ssw_Man_t * p, Aig_Obj_t * pObj, int Num ) { Vec_IntWriteEntryFill( p->vSatVars, pObj->Id, Num );  }
-
-static inline int  Ssw_ObjIsConst1Cand( Aig_Man_t * pAig, Aig_Obj_t * pObj ) 
-{
-    return Aig_ObjRepr(pAig, pObj) == Aig_ManConst1(pAig);
-}
-static inline void Ssw_ObjSetConst1Cand( Aig_Man_t * pAig, Aig_Obj_t * pObj ) 
-{
-    assert( !Ssw_ObjIsConst1Cand( pAig, pObj ) );
-    Aig_ObjSetRepr( pAig, pObj, Aig_ManConst1(pAig) );
-}
-
-static inline Aig_Obj_t * Ssw_ObjFrame( Ssw_Man_t * p, Aig_Obj_t * pObj, int i )                       { return p->pNodeToFrames[p->nFrames*pObj->Id + i];  }
-static inline void        Ssw_ObjSetFrame( Ssw_Man_t * p, Aig_Obj_t * pObj, int i, Aig_Obj_t * pNode ) { p->pNodeToFrames[p->nFrames*pObj->Id + i] = pNode; }
-
-static inline Aig_Obj_t * Ssw_ObjChild0Fra( Ssw_Man_t * p, Aig_Obj_t * pObj, int i ) { assert( !Aig_IsComplement(pObj) ); return Aig_ObjFanin0(pObj)? Aig_NotCond(Ssw_ObjFrame(p, Aig_ObjFanin0(pObj), i), Aig_ObjFaninC0(pObj)) : NULL;  }
-static inline Aig_Obj_t * Ssw_ObjChild1Fra( Ssw_Man_t * p, Aig_Obj_t * pObj, int i ) { assert( !Aig_IsComplement(pObj) ); return Aig_ObjFanin1(pObj)? Aig_NotCond(Ssw_ObjFrame(p, Aig_ObjFanin1(pObj), i), Aig_ObjFaninC1(pObj)) : NULL;  }
-
-////////////////////////////////////////////////////////////////////////
-///                    FUNCTION DECLARATIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/*=== sswAig.c ===================================================*/
-extern Aig_Man_t *   Ssw_FramesWithClasses( Ssw_Man_t * p );
-extern Aig_Man_t *   Ssw_SpeculativeReduction( Ssw_Man_t * p );
-/*=== sswBmc.c ===================================================*/
-extern int           Ssw_FilterUsingBmc( Ssw_Man_t * pMan, int fCheckTargets, int nConfMax, int fVerbose );
-/*=== sswClass.c =================================================*/
-extern Ssw_Cla_t *   Ssw_ClassesStart( Aig_Man_t * pAig );
-extern void          Ssw_ClassesSetData( Ssw_Cla_t * p, void * pManData,
-                         unsigned (*pFuncNodeHash)(void *,Aig_Obj_t *),
-                         int (*pFuncNodeIsConst)(void *,Aig_Obj_t *),
-                         int (*pFuncNodesAreEqual)(void *,Aig_Obj_t *, Aig_Obj_t *) );
-extern void          Ssw_ClassesStop( Ssw_Cla_t * p );
-extern Aig_Man_t *   Ssw_ClassesReadAig( Ssw_Cla_t * p );
-extern Vec_Ptr_t *   Ssw_ClassesGetRefined( Ssw_Cla_t * p );
-extern void          Ssw_ClassesClearRefined( Ssw_Cla_t * p );
-extern int           Ssw_ClassesCand1Num( Ssw_Cla_t * p );
-extern int           Ssw_ClassesClassNum( Ssw_Cla_t * p );
-extern int           Ssw_ClassesLitNum( Ssw_Cla_t * p );
-extern Aig_Obj_t **  Ssw_ClassesReadClass( Ssw_Cla_t * p, Aig_Obj_t * pRepr, int * pnSize );
-extern void          Ssw_ClassesCollectClass( Ssw_Cla_t * p, Aig_Obj_t * pRepr, Vec_Ptr_t * vClass );
-extern void          Ssw_ClassesCheck( Ssw_Cla_t * p );
-extern void          Ssw_ClassesPrint( Ssw_Cla_t * p, int fVeryVerbose );
-extern void          Ssw_ClassesRemoveNode( Ssw_Cla_t * p, Aig_Obj_t * pObj );
-extern Ssw_Cla_t *   Ssw_ClassesPrepare( Aig_Man_t * pAig, int fLatchCorr, int nMaxLevs, int fVerbose );
-extern Ssw_Cla_t *   Ssw_ClassesPrepareSimple( Aig_Man_t * pAig, int fLatchCorr, int nMaxLevs );
-extern Ssw_Cla_t *   Ssw_ClassesPrepareTargets( Aig_Man_t * pAig );
-extern Ssw_Cla_t *   Ssw_ClassesPreparePairs( Aig_Man_t * pAig, Vec_Int_t ** pvClasses );
-extern int           Ssw_ClassesRefine( Ssw_Cla_t * p, int fRecursive );
-extern int           Ssw_ClassesRefineOneClass( Ssw_Cla_t * p, Aig_Obj_t * pRepr, int fRecursive );
-extern int           Ssw_ClassesRefineConst1Group( Ssw_Cla_t * p, Vec_Ptr_t * vRoots, int fRecursive );
-extern int           Ssw_ClassesRefineConst1( Ssw_Cla_t * p, int fRecursive );
-/*=== sswCnf.c ===================================================*/
-extern void          Ssw_CnfNodeAddToSolver( Ssw_Man_t * p, Aig_Obj_t * pObj );
-/*=== sswCore.c ===================================================*/
-extern Aig_Man_t *   Ssw_SignalCorrespondenceRefine( Ssw_Man_t * p );
-/*=== sswLcorr.c ==========================================================*/
-extern int           Ssw_ManSweepLatch( Ssw_Man_t * p );
-/*=== sswMan.c ===================================================*/
-extern Ssw_Man_t *   Ssw_ManCreate( Aig_Man_t * pAig, Ssw_Pars_t * pPars );
-extern void          Ssw_ManCleanup( Ssw_Man_t * p );
-extern void          Ssw_ManStop( Ssw_Man_t * p );
-extern void          Ssw_ManStartSolver( Ssw_Man_t * p );
-/*=== sswSat.c ===================================================*/
-extern int           Ssw_NodesAreEquiv( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew );
-extern int           Ssw_NodesAreConstrained( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew );
-/*=== sswSim.c ===================================================*/
-extern unsigned      Ssw_SmlObjHashWord( Ssw_Sml_t * p, Aig_Obj_t * pObj );
-extern int           Ssw_SmlObjIsConstWord( Ssw_Sml_t * p, Aig_Obj_t * pObj );
-extern int           Ssw_SmlObjsAreEqualWord( Ssw_Sml_t * p, Aig_Obj_t * pObj0, Aig_Obj_t * pObj1 );
-extern int           Ssw_SmlObjIsConstBit( void * p, Aig_Obj_t * pObj );
-extern int           Ssw_SmlObjsAreEqualBit( void * p, Aig_Obj_t * pObj0, Aig_Obj_t * pObj1 );
-extern Ssw_Sml_t *   Ssw_SmlStart( Aig_Man_t * pAig, int nPref, int nFrames, int nWordsFrame );
-extern void          Ssw_SmlClean( Ssw_Sml_t * p );
-extern void          Ssw_SmlStop( Ssw_Sml_t * p );
-extern void          Ssw_SmlObjAssignConst( Ssw_Sml_t * p, Aig_Obj_t * pObj, int fConst1, int iFrame );
-extern unsigned      Ssw_SmlObjGetWord( Ssw_Sml_t * p, Aig_Obj_t * pObj, int iWord, int iFrame );
-extern void          Ssw_SmlObjSetWord( Ssw_Sml_t * p, Aig_Obj_t * pObj, unsigned Word, int iWord, int iFrame );
-extern void          Ssw_SmlAssignDist1Plus( Ssw_Sml_t * p, unsigned * pPat );
-extern void          Ssw_SmlSimulateOne( Ssw_Sml_t * p );
-extern void          Ssw_SmlSimulateOneFrame( Ssw_Sml_t * p );
-extern Ssw_Sml_t *   Ssw_SmlSimulateSeq( Aig_Man_t * pAig, int nPref, int nFrames, int nWords );
-/*=== sswSimSat.c ===================================================*/
-extern void          Ssw_ManResimulateBit( Ssw_Man_t * p, Aig_Obj_t * pObj, Aig_Obj_t * pRepr );
-extern void          Ssw_ManResimulateWord( Ssw_Man_t * p, Aig_Obj_t * pCand, Aig_Obj_t * pRepr, int f );
-extern void          Ssw_ManResimulateWord2( Ssw_Man_t * p, Aig_Obj_t * pCand, Aig_Obj_t * pRepr, int f );
-/*=== sswSweep.c ===================================================*/
-extern int           Ssw_ManGetSatVarValue( Ssw_Man_t * p, Aig_Obj_t * pObj, int f );
-extern int           Ssw_ManSweepNode( Ssw_Man_t * p, Aig_Obj_t * pObj, int f, int fBmc );
-extern int           Ssw_ManSweepBmc( Ssw_Man_t * p );
-extern int           Ssw_ManSweep( Ssw_Man_t * p );
-/*=== sswUnique.c ===================================================*/
-extern int           Ssw_ManUniqueOne( Ssw_Man_t * p, Aig_Obj_t * pRepr, Aig_Obj_t * pObj );
-extern int           Ssw_ManUniqueAddConstraint( Ssw_Man_t * p, Vec_Ptr_t * vCommon, int f1, int f2 );
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
diff --git a/src/aig/ssw_old/sswLcorr.c b/src/aig/ssw_old/sswLcorr.c
deleted file mode 100644
index cde9b0c9..00000000
--- a/src/aig/ssw_old/sswLcorr.c
+++ /dev/null
@@ -1,364 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswLcorr.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [Latch correspondence.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswLcorr.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-//#include "bar.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Recycles the SAT solver.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManSatSolverRecycle( Ssw_Man_t * p )
-{
-    int Lit;
-    if ( p->pSat )
-    {
-        Aig_Obj_t * pObj;
-        int i;
-        Vec_PtrForEachEntry( p->vUsedNodes, pObj, i )
-            Ssw_ObjSetSatNum( p, pObj, 0 );
-        Vec_PtrClear( p->vUsedNodes );
-        Vec_PtrClear( p->vUsedPis );
-//        memset( p->pSatVars, 0, sizeof(int) * Aig_ManObjNumMax(p->pAigTotal) );
-        sat_solver_delete( p->pSat );
-    }
-    p->pSat = sat_solver_new();
-    sat_solver_setnvars( p->pSat, 1000 );
-    // var 0 is not used
-    // var 1 is reserved for const1 node - add the clause
-    p->nSatVars = 1;
-//    p->nSatVars = 0;
-    Lit = toLit( p->nSatVars );
-    if ( p->pPars->fPolarFlip )
-        Lit = lit_neg( Lit );
-    sat_solver_addclause( p->pSat, &Lit, &Lit + 1 );
-    Ssw_ObjSetSatNum( p, Aig_ManConst1(p->pFrames), p->nSatVars++ );
-
-    p->nRecycles++;
-    p->nRecycleCalls = 0;
-}
-
-
-/**Function*************************************************************
-
-  Synopsis    [Tranfers simulation information from FRAIG to AIG.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManSweepTransfer( Ssw_Man_t * p )
-{
-    Aig_Obj_t * pObj, * pObjFraig;
-    unsigned * pInfo;
-    int i;
-    // transfer simulation information
-    Aig_ManForEachPi( p->pAig, pObj, i )
-    {
-        pObjFraig = Ssw_ObjFrame( p, pObj, 0 );
-        if ( pObjFraig == Aig_ManConst0(p->pFrames) )
-        {
-            Ssw_SmlObjAssignConst( p->pSml, pObj, 0, 0 );
-            continue;
-        }
-        assert( !Aig_IsComplement(pObjFraig) );
-        assert( Aig_ObjIsPi(pObjFraig) );
-        pInfo = Vec_PtrEntry( p->vSimInfo, Aig_ObjPioNum(pObjFraig) );
-        Ssw_SmlObjSetWord( p->pSml, pObj, pInfo[0], 0, 0 );
-    }
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Performs one round of simulation with counter-examples.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ManSweepResimulate( Ssw_Man_t * p )
-{
-    int RetValue1, RetValue2, clk = clock();
-    // transfer PI simulation information from storage
-    Ssw_ManSweepTransfer( p );
-    // simulate internal nodes
-    Ssw_SmlSimulateOneFrame( p->pSml );
-    // check equivalence classes
-    RetValue1 = Ssw_ClassesRefineConst1( p->ppClasses, 1 );
-    RetValue2 = Ssw_ClassesRefine( p->ppClasses, 1 );
-    // prepare simulation info for the next round
-    Vec_PtrCleanSimInfo( p->vSimInfo, 0, 1 );
-    p->nPatterns = 0;
-    p->nSimRounds++;
-p->timeSimSat += clock() - clk;
-    return RetValue1 > 0 || RetValue2 > 0;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Saves one counter-example into internal storage.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlAddPattern( Ssw_Man_t * p, Aig_Obj_t * pRepr, Aig_Obj_t * pCand )
-{
-    Aig_Obj_t * pObj;
-    unsigned * pInfo;
-    int i, nVarNum, Value;
-    Vec_PtrForEachEntry( p->vUsedPis, pObj, i )
-    {
-        nVarNum = Ssw_ObjSatNum( p, pObj );
-        assert( nVarNum > 0 );
-        Value = sat_solver_var_value( p->pSat, nVarNum );
-        if ( Value == 0 )
-            continue;
-        pInfo = Vec_PtrEntry( p->vSimInfo, Aig_ObjPioNum(pObj) );
-        Aig_InfoSetBit( pInfo, p->nPatterns );
-    }
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Builds fraiged logic cone of the node.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManBuildCone_rec( Ssw_Man_t * p, Aig_Obj_t * pObj )
-{
-    Aig_Obj_t * pObjNew;
-    assert( !Aig_IsComplement(pObj) );
-    if ( Ssw_ObjFrame( p, pObj, 0 ) )
-        return;
-    assert( Aig_ObjIsNode(pObj) );
-    Ssw_ManBuildCone_rec( p, Aig_ObjFanin0(pObj) );
-    Ssw_ManBuildCone_rec( p, Aig_ObjFanin1(pObj) );
-    pObjNew = Aig_And( p->pFrames, Ssw_ObjChild0Fra(p, pObj, 0), Ssw_ObjChild1Fra(p, pObj, 0) );
-    Ssw_ObjSetFrame( p, pObj, 0, pObjNew );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Recycles the SAT solver.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManSweepLatchOne( Ssw_Man_t * p, Aig_Obj_t * pObjRepr, Aig_Obj_t * pObj )
-{
-    Aig_Obj_t * pObjFraig, * pObjReprFraig, * pObjLi;
-    int RetValue, clk;
-    assert( Aig_ObjIsPi(pObj) );
-    assert( Aig_ObjIsPi(pObjRepr) || Aig_ObjIsConst1(pObjRepr) );
-    // check if it makes sense to skip some calls
-    if ( p->nCallsCount > 100 && p->nCallsUnsat < p->nCallsSat )
-    {
-        if ( ++p->nCallsDelta < 0 )
-            return;
-    }
-    p->nCallsDelta = 0;
-clk = clock();
-    // get the fraiged node
-    pObjLi = Saig_ObjLoToLi( p->pAig, pObj ); 
-    Ssw_ManBuildCone_rec( p, Aig_ObjFanin0(pObjLi) );
-    pObjFraig = Ssw_ObjChild0Fra( p, pObjLi, 0 );
-    // get the fraiged representative
-    if ( Aig_ObjIsPi(pObjRepr) )
-    {
-        pObjLi = Saig_ObjLoToLi( p->pAig, pObjRepr ); 
-        Ssw_ManBuildCone_rec( p, Aig_ObjFanin0(pObjLi) );
-        pObjReprFraig = Ssw_ObjChild0Fra( p, pObjLi, 0 );
-    }
-    else 
-        pObjReprFraig = Ssw_ObjFrame( p, pObjRepr, 0 );
-p->timeReduce += clock() - clk;
-    // if the fraiged nodes are the same, return
-    if ( Aig_Regular(pObjFraig) == Aig_Regular(pObjReprFraig) )
-        return;
-    p->nRecycleCalls++;
-    p->nCallsCount++;
-
-    // check equivalence of the two nodes
-    if ( (pObj->fPhase == pObjRepr->fPhase) != (Aig_ObjPhaseReal(pObjFraig) == Aig_ObjPhaseReal(pObjReprFraig)) )
-    {
-        p->nPatterns++;
-        p->nStrangers++;
-        p->fRefined = 1;
-    }
-    else
-    { 
-        RetValue = Ssw_NodesAreEquiv( p, Aig_Regular(pObjReprFraig), Aig_Regular(pObjFraig) );
-        if ( RetValue == 1 )  // proved equivalence
-        {
-            p->nCallsUnsat++;
-            return;
-        }
-        if ( RetValue == -1 ) // timed out
-        {
-            Ssw_ClassesRemoveNode( p->ppClasses, pObj );
-            p->nCallsUnsat++;
-            p->fRefined = 1;
-            return;
-        }
-        else // disproved equivalence
-        {       
-            Ssw_SmlAddPattern( p, pObjRepr, pObj );
-            p->nPatterns++;
-            p->nCallsSat++;
-            p->fRefined = 1;
-        }
-    }
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Performs one iteration of sweeping latches.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ManSweepLatch( Ssw_Man_t * p )
-{
-//    Bar_Progress_t * pProgress = NULL;
-    Vec_Ptr_t * vClass;
-    Aig_Obj_t * pObj, * pRepr, * pTemp;
-    int i, k;
-
-    // start the timeframe
-    p->pFrames = Aig_ManStart( Aig_ManObjNumMax(p->pAig) );
-    // map constants and PIs
-    Ssw_ObjSetFrame( p, Aig_ManConst1(p->pAig), 0, Aig_ManConst1(p->pFrames) );
-    Saig_ManForEachPi( p->pAig, pObj, i )
-        Ssw_ObjSetFrame( p, pObj, 0, Aig_ObjCreatePi(p->pFrames) );
-
-    // implement equivalence classes
-    Saig_ManForEachLo( p->pAig, pObj, i )
-    {
-        pRepr = Aig_ObjRepr( p->pAig, pObj );
-        if ( pRepr == NULL )
-        {
-            pTemp = Aig_ObjCreatePi(p->pFrames);
-            pTemp->pData = pObj;
-        }
-        else
-            pTemp = Aig_NotCond( Ssw_ObjFrame(p, pRepr, 0), pRepr->fPhase ^ pObj->fPhase );
-        Ssw_ObjSetFrame( p, pObj, 0, pTemp );
-    }
-    Aig_ManSetPioNumbers( p->pFrames );
-
-    // prepare simulation info
-    assert( p->vSimInfo == NULL );
-    p->vSimInfo = Vec_PtrAllocSimInfo( Aig_ManPiNum(p->pFrames), 1 );
-    Vec_PtrCleanSimInfo( p->vSimInfo, 0, 1 );
-
-    // go through the registers
-//    if ( p->pPars->fVerbose )
-//        pProgress = Bar_ProgressStart( stdout, Aig_ManRegNum(p->pAig) );
-    vClass = Vec_PtrAlloc( 100 );
-    p->fRefined = 0;
-    p->nCallsCount = p->nCallsSat = p->nCallsUnsat = 0;
-    Saig_ManForEachLo( p->pAig, pObj, i )
-    {
-//        if ( p->pPars->fVerbose )
-//            Bar_ProgressUpdate( pProgress, i, NULL );
-        // consider the case of constant candidate
-        if ( Ssw_ObjIsConst1Cand( p->pAig, pObj ) )
-            Ssw_ManSweepLatchOne( p, Aig_ManConst1(p->pAig), pObj );
-        else
-        {
-            // consider the case of equivalence class
-            Ssw_ClassesCollectClass( p->ppClasses, pObj, vClass );
-            if ( Vec_PtrSize(vClass) == 0 )
-                continue;
-            // try to prove equivalences in this class
-            Vec_PtrForEachEntry( vClass, pTemp, k )
-                if ( Aig_ObjRepr(p->pAig, pTemp) == pObj )
-                {
-                    Ssw_ManSweepLatchOne( p, pObj, pTemp );
-                    if ( p->nPatterns == 32 )
-                        break;
-                }
-        }
-        // resimulate
-        if ( p->nPatterns == 32 )
-            Ssw_ManSweepResimulate( p );
-        // attempt recycling the SAT solver
-        if ( p->pPars->nSatVarMax && 
-             p->nSatVars > p->pPars->nSatVarMax &&
-             p->nRecycleCalls > p->pPars->nRecycleCalls )
-             Ssw_ManSatSolverRecycle( p );
-    }
-    // resimulate
-    if ( p->nPatterns > 0 )
-        Ssw_ManSweepResimulate( p );
-    // cleanup
-    Vec_PtrFree( vClass );
-    p->nSatFailsTotal += p->nSatFailsReal;
-//    if ( p->pPars->fVerbose )
-//        Bar_ProgressStop( pProgress );
-
-    // cleanup
-//    Ssw_ClassesCheck( p->ppClasses );
-    return p->fRefined;
-}
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswMan.c b/src/aig/ssw_old/sswMan.c
deleted file mode 100644
index 84b041b4..00000000
--- a/src/aig/ssw_old/sswMan.c
+++ /dev/null
@@ -1,237 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswMan.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [Calls to the SAT solver.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswMan.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Creates the manager.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Man_t * Ssw_ManCreate( Aig_Man_t * pAig, Ssw_Pars_t * pPars )
-{
-    Ssw_Man_t * p;
-    // prepare the sequential AIG
-    assert( Saig_ManRegNum(pAig) > 0 );
-    Aig_ManFanoutStart( pAig );
-    Aig_ManSetPioNumbers( pAig );
-    // create interpolation manager
-    p = ALLOC( Ssw_Man_t, 1 ); 
-    memset( p, 0, sizeof(Ssw_Man_t) );
-    p->pPars         = pPars;
-    p->pAig          = pAig;
-    p->nFrames       = pPars->nFramesK + 1;
-    p->pNodeToFrames = CALLOC( Aig_Obj_t *, Aig_ManObjNumMax(p->pAig) * p->nFrames );
-    // SAT solving
-    p->vSatVars      = Vec_IntStart( Aig_ManObjNumMax(p->pAig) * (p->nFrames+1) );
-    p->vFanins       = Vec_PtrAlloc( 100 );
-    // SAT solving (latch corr only)
-    p->vUsedNodes    = Vec_PtrAlloc( 1000 );
-    p->vUsedPis      = Vec_PtrAlloc( 1000 );
-    p->vCommon       = Vec_PtrAlloc( 100 );
-    p->iOutputLit    = -1;
-    // allocate storage for sim pattern
-    p->nPatWords     = Aig_BitWordNum( Saig_ManPiNum(pAig) * p->nFrames + Saig_ManRegNum(pAig) );
-    p->pPatWords     = ALLOC( unsigned, p->nPatWords ); 
-    p->pPatWords2     = ALLOC( unsigned, p->nPatWords ); 
-    return p;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Prints stats of the manager.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ManCountEquivs( Ssw_Man_t * p )
-{
-    Aig_Obj_t * pObj;
-    int i, nEquivs = 0;
-    Aig_ManForEachObj( p->pAig, pObj, i )
-        nEquivs += ( Aig_ObjRepr(p->pAig, pObj) != NULL );
-    return nEquivs;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Prints stats of the manager.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManPrintStats( Ssw_Man_t * p )
-{
-    double nMemory = 1.0*Aig_ManObjNumMax(p->pAig)*p->nFrames*(2*sizeof(int)+2*sizeof(void*))/(1<<20);
-
-    printf( "Parameters: F = %d. AddF = %d. C-lim = %d. Constr = %d. MaxLev = %d. Mem = %0.2f Mb.\n", 
-        p->pPars->nFramesK, p->pPars->nFramesAddSim, p->pPars->nBTLimit, p->pPars->nConstrs, p->pPars->nMaxLevs, nMemory );
-    printf( "AIG       : PI = %d. PO = %d. Latch = %d. Node = %d.  Ave SAT vars = %d.\n", 
-        Saig_ManPiNum(p->pAig), Saig_ManPoNum(p->pAig), Saig_ManRegNum(p->pAig), Aig_ManNodeNum(p->pAig), 
-        p->nSatVarsTotal/p->pPars->nIters );
-    printf( "SAT calls : Proof = %d. Cex = %d. Fail = %d. Equivs = %d. Str = %d.\n", 
-        p->nSatProof, p->nSatCallsSat, p->nSatFailsTotal, Ssw_ManCountEquivs(p), p->nStrangers );
-    printf( "SAT solver: Vars = %d. Max cone = %d. Recycles = %d. Rounds = %d.\n", 
-        p->nSatVars, p->nConeMax, p->nRecycles, p->nSimRounds );
-    printf( "NBeg = %d. NEnd = %d. (Gain = %6.2f %%).  RBeg = %d. REnd = %d. (Gain = %6.2f %%).\n", 
-        p->nNodesBeg, p->nNodesEnd, 100.0*(p->nNodesBeg-p->nNodesEnd)/(p->nNodesBeg?p->nNodesBeg:1), 
-        p->nRegsBeg, p->nRegsEnd, 100.0*(p->nRegsBeg-p->nRegsEnd)/(p->nRegsBeg?p->nRegsBeg:1) );
-
-    p->timeOther = p->timeTotal-p->timeBmc-p->timeReduce-p->timeMarkCones-p->timeSimSat-p->timeSat;
-    PRTP( "BMC        ", p->timeBmc,       p->timeTotal );
-    PRTP( "Spec reduce", p->timeReduce,    p->timeTotal );
-    PRTP( "Mark cones ", p->timeMarkCones, p->timeTotal );
-    PRTP( "Sim SAT    ", p->timeSimSat,    p->timeTotal );
-    PRTP( "SAT solving", p->timeSat,       p->timeTotal );
-    PRTP( "  unsat    ", p->timeSatUnsat,  p->timeTotal );
-    PRTP( "  sat      ", p->timeSatSat,    p->timeTotal );
-    PRTP( "  undecided", p->timeSatUndec,  p->timeTotal );
-    PRTP( "Other      ", p->timeOther,     p->timeTotal );
-    PRTP( "TOTAL      ", p->timeTotal,     p->timeTotal );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Frees the manager.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManCleanup( Ssw_Man_t * p )
-{
-    if ( p->pFrames )
-    {
-        Aig_ManStop( p->pFrames );
-        p->pFrames = NULL;
-        memset( p->pNodeToFrames, 0, sizeof(Aig_Obj_t *) * Aig_ManObjNumMax(p->pAig) * p->nFrames );
-    }
-    if ( p->pSat )
-    {
-        int i;
-//        printf( "Vars = %d. Clauses = %d. Learnts = %d.\n", p->pSat->size, p->pSat->clauses.size, p->pSat->learnts.size );
-        p->nSatVarsTotal += p->pSat->size;
-        sat_solver_delete( p->pSat );
-        p->pSat = NULL;
-//        memset( p->pSatVars, 0, sizeof(int) * Aig_ManObjNumMax(p->pAig) * (p->nFrames+1) );
-        for ( i = 0; i < Vec_IntSize(p->vSatVars); i++ )
-            p->vSatVars->pArray[i] = 0;
-    }
-    if ( p->vSimInfo )  
-    {
-        Vec_PtrFree( p->vSimInfo );
-        p->vSimInfo = NULL;
-    }
-    p->nConstrTotal = 0;
-    p->nConstrReduced = 0;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Frees the manager.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManStop( Ssw_Man_t * p )
-{
-    Aig_ManCleanMarkA( p->pAig );
-    Aig_ManCleanMarkB( p->pAig );
-    if ( p->pPars->fVerbose )
-        Ssw_ManPrintStats( p );
-    if ( p->ppClasses )
-        Ssw_ClassesStop( p->ppClasses );
-    if ( p->pSml )      
-        Ssw_SmlStop( p->pSml );
-    Vec_PtrFree( p->vFanins );
-    Vec_PtrFree( p->vUsedNodes );
-    Vec_PtrFree( p->vUsedPis );
-    Vec_IntFree( p->vSatVars );
-    Vec_PtrFree( p->vCommon );
-    FREE( p->pNodeToFrames );
-    FREE( p->pPatWords );
-    FREE( p->pPatWords2 );
-    free( p );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Starts the SAT solver.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManStartSolver( Ssw_Man_t * p )
-{
-    int Lit;
-    assert( p->pSat == NULL );
-    p->pSat = sat_solver_new();
-    sat_solver_setnvars( p->pSat, 1000 );
-    // var 0 is not used
-    // var 1 is reserved for const1 node - add the clause
-    p->nSatVars = 1;
-    Lit = toLit( p->nSatVars );
-    if ( p->pPars->fPolarFlip )
-        Lit = lit_neg( Lit );
-    sat_solver_addclause( p->pSat, &Lit, &Lit + 1 );
-    Ssw_ObjSetSatNum( p, Aig_ManConst1(p->pAig), p->nSatVars++ );
-
-    Vec_PtrClear( p->vUsedNodes );
-    Vec_PtrClear( p->vUsedPis );
-}
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswPairs.c b/src/aig/ssw_old/sswPairs.c
deleted file mode 100644
index c77ad30d..00000000
--- a/src/aig/ssw_old/sswPairs.c
+++ /dev/null
@@ -1,470 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswPairs.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [Calls to the SAT solver.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswPairs.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Reports the status of the miter.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_MiterStatus( Aig_Man_t * p, int fVerbose )
-{
-    Aig_Obj_t * pObj, * pChild;
-    int i, CountConst0 = 0, CountNonConst0 = 0, CountUndecided = 0;
-//    if ( p->pData )
-//        return 0;
-    Saig_ManForEachPo( p, pObj, i )
-    {
-        pChild = Aig_ObjChild0(pObj);
-        // check if the output is constant 0
-        if ( pChild == Aig_ManConst0(p) )
-        {
-            CountConst0++;
-            continue;
-        }
-        // check if the output is constant 1
-        if ( pChild == Aig_ManConst1(p) )
-        {
-            CountNonConst0++;
-            continue;
-        }
-        // check if the output is a primary input
-        if ( p->nRegs == 0 && Aig_ObjIsPi(Aig_Regular(pChild)) )
-        {
-            CountNonConst0++;
-            continue;
-        }
-        // check if the output can be not constant 0
-        if ( Aig_Regular(pChild)->fPhase != (unsigned)Aig_IsComplement(pChild) )
-        {
-            CountNonConst0++;
-            continue;
-        }
-        CountUndecided++;
-    }
-
-    if ( fVerbose )
-    {
-        printf( "Miter has %d outputs. ", Saig_ManPoNum(p) );
-        printf( "Const0 = %d.  ", CountConst0 );
-        printf( "NonConst0 = %d.  ", CountNonConst0 );
-        printf( "Undecided = %d.  ", CountUndecided );
-        printf( "\n" );
-    }
-
-    if ( CountNonConst0 )
-        return 0;
-    if ( CountUndecided )
-        return -1;
-    return 1;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Transfer equivalent pairs to the miter.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Vec_Int_t * Ssw_TransferSignalPairs( Aig_Man_t * pMiter, Aig_Man_t * pAig1, Aig_Man_t * pAig2, Vec_Int_t * vIds1, Vec_Int_t * vIds2 )
-{
-    Vec_Int_t * vIds;
-    Aig_Obj_t * pObj1, * pObj2;
-    Aig_Obj_t * pObj1m, * pObj2m;
-    int i;
-    vIds = Vec_IntAlloc( 2 * Vec_IntSize(vIds1) );
-    for ( i = 0; i < Vec_IntSize(vIds1); i++ )
-    {
-        pObj1 = Aig_ManObj( pAig1, Vec_IntEntry(vIds1, i) );
-        pObj2 = Aig_ManObj( pAig2, Vec_IntEntry(vIds2, i) );
-        pObj1m = Aig_Regular(pObj1->pData);
-        pObj2m = Aig_Regular(pObj2->pData);
-        assert( pObj1m && pObj2m );
-        if ( pObj1m == pObj2m )
-            continue;
-        if ( pObj1m->Id < pObj2m->Id )
-        {
-            Vec_IntPush( vIds, pObj1m->Id );
-            Vec_IntPush( vIds, pObj2m->Id );
-        }
-        else
-        {
-            Vec_IntPush( vIds, pObj2m->Id );
-            Vec_IntPush( vIds, pObj1m->Id );
-        }
-    }
-    return vIds;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Transform pairs into class representation.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Vec_Int_t ** Ssw_TransformPairsIntoTempClasses( Vec_Int_t * vPairs, int nObjNumMax )
-{
-    Vec_Int_t ** pvClasses;   // vector of classes
-    int * pReprs;             // mapping nodes into their representatives
-    int Entry, idObj, idRepr, idReprObj, idReprRepr, i;
-    // allocate data-structures
-    pvClasses = CALLOC( Vec_Int_t *, nObjNumMax );
-    pReprs    = ALLOC( int, nObjNumMax );
-    for ( i = 0; i < nObjNumMax; i++ )
-        pReprs[i] = -1;
-    // consider pairs
-    for ( i = 0; i < Vec_IntSize(vPairs); i += 2 )
-    {
-        // get both objects
-        idRepr = Vec_IntEntry( vPairs, i   );
-        idObj  = Vec_IntEntry( vPairs, i+1 );
-        assert( idObj > 0 );
-        assert( (pReprs[idRepr] == -1) || (pvClasses[pReprs[idRepr]] != NULL) );
-        assert( (pReprs[idObj]  == -1) || (pvClasses[pReprs[idObj] ] != NULL) );
-        // get representatives of both objects
-        idReprRepr = pReprs[idRepr];
-        idReprObj  = pReprs[idObj];
-        // check different situations
-        if ( idReprRepr == -1 && idReprObj == -1 )
-        {   // they do not have classes
-            // create a class
-            pvClasses[idRepr] = Vec_IntAlloc( 4 );
-            Vec_IntPush( pvClasses[idRepr], idRepr );
-            Vec_IntPush( pvClasses[idRepr], idObj );
-            pReprs[ idRepr ] = idRepr;
-            pReprs[ idObj  ] = idRepr;
-        }
-        else if ( idReprRepr >= 0 && idReprObj == -1 )
-        {   // representative has a class
-            // add iObj to the same class
-            Vec_IntPushUniqueOrder( pvClasses[idReprRepr], idObj );
-            pReprs[ idObj ] = idReprRepr;
-        }
-        else if ( idReprRepr == -1 && idReprObj >= 0 )
-        {   // object has a class
-            assert( idReprObj != idRepr );
-            if ( idReprObj < idRepr ) 
-            { // add idRepr to the same class
-                Vec_IntPushUniqueOrder( pvClasses[idReprObj], idRepr );
-                pReprs[ idRepr ] = idReprObj;
-            }
-            else // if ( idReprObj > idRepr ) 
-            { // make idRepr new representative
-                Vec_IntPushFirst( pvClasses[idReprObj], idRepr );
-                pvClasses[idRepr] = pvClasses[idReprObj];
-                pvClasses[idReprObj] = NULL;
-                // set correct representatives of each node
-                Vec_IntForEachEntry( pvClasses[idRepr], Entry, i )
-                    pReprs[ Entry ] = idRepr;
-            }
-        }
-        else // if ( idReprRepr >= 0 && idReprObj >= 0 )
-        {   // both have classes
-            if ( idReprRepr == idReprObj )
-            {  // the classes are the same
-                // nothing to do
-            }
-            else
-            {  // the classes are different
-                // find the repr of the new class
-                if ( idReprRepr < idReprObj )
-                {
-                    Vec_IntForEachEntry( pvClasses[idReprObj], Entry, i )
-                    {
-                        Vec_IntPushUniqueOrder( pvClasses[idReprRepr], Entry );
-                        pReprs[ Entry ] = idReprRepr;
-                    }
-                    Vec_IntFree( pvClasses[idReprObj] );
-                    pvClasses[idReprObj] = NULL;
-                }
-                else // if ( idReprRepr > idReprObj )
-                {
-                    Vec_IntForEachEntry( pvClasses[idReprRepr], Entry, i )
-                    {
-                        Vec_IntPushUniqueOrder( pvClasses[idReprObj], Entry );
-                        pReprs[ Entry ] = idReprObj;
-                    }
-                    Vec_IntFree( pvClasses[idReprRepr] );
-                    pvClasses[idReprRepr] = NULL;
-                }
-            }
-        }
-    }
-    free( pReprs );
-    return pvClasses;
-}
-
-/**Function*************************************************************
-
-  Synopsis    []
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_FreeTempClasses( Vec_Int_t ** pvClasses, int nObjNumMax )
-{
-    int i;
-    for ( i = 0; i < nObjNumMax; i++ )
-        if ( pvClasses[i] ) 
-            Vec_IntFree( pvClasses[i] );
-    free( pvClasses );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Performs signal correspondence for the miter of two AIGs with node pairs defined.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Aig_Man_t * Ssw_SignalCorrespondenceWithPairs( Aig_Man_t * pAig1, Aig_Man_t * pAig2, Vec_Int_t * vIds1, Vec_Int_t * vIds2, Ssw_Pars_t * pPars )
-{
-    Ssw_Man_t * p; 
-    Aig_Man_t * pAigNew, * pMiter;
-    Ssw_Pars_t Pars;
-    Vec_Int_t * vPairs;
-    Vec_Int_t ** pvClasses;
-    assert( Vec_IntSize(vIds1) == Vec_IntSize(vIds2) );
-    // create sequential miter
-    pMiter = Saig_ManCreateMiter( pAig1, pAig2, 0 );
-    // transfer information to the miter
-    vPairs = Ssw_TransferSignalPairs( pMiter, pAig1, pAig2, vIds1, vIds2 );
-    // create representation of the classes
-    pvClasses = Ssw_TransformPairsIntoTempClasses( vPairs, Aig_ManObjNumMax(pMiter) );
-    Vec_IntFree( vPairs );
-    // if parameters are not given, create them
-    if ( pPars == NULL )
-        Ssw_ManSetDefaultParams( pPars = &Pars );
-    // start the induction manager
-    p = Ssw_ManCreate( pMiter, pPars );
-    // create equivalence classes using these IDs
-    p->ppClasses = Ssw_ClassesPreparePairs( pMiter, pvClasses );
-    p->pSml = Ssw_SmlStart( pMiter, 0, p->nFrames + p->pPars->nFramesAddSim, 1 );
-    Ssw_ClassesSetData( p->ppClasses, p->pSml, Ssw_SmlObjHashWord, Ssw_SmlObjIsConstWord, Ssw_SmlObjsAreEqualWord );
-    // perform refinement of classes
-    pAigNew = Ssw_SignalCorrespondenceRefine( p );
-    // cleanup
-    Ssw_FreeTempClasses( pvClasses, Aig_ManObjNumMax(pMiter) );
-    Ssw_ManStop( p );
-    Aig_ManStop( pMiter );
-    return pAigNew;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Runs inductive SEC for the miter of two AIGs with node pairs defined.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Aig_Man_t * Ssw_SignalCorrespondeceTestPairs( Aig_Man_t * pAig )
-{
-    Aig_Man_t * pAigNew, * pAigRes;
-    Ssw_Pars_t Pars, * pPars = &Pars;
-    Vec_Int_t * vIds1, * vIds2;
-    Aig_Obj_t * pObj, * pRepr;
-    int RetValue, i, clk = clock();
-    Ssw_ManSetDefaultParams( pPars );
-    pPars->fVerbose = 1;
-    pAigNew = Ssw_SignalCorrespondence( pAig, pPars );
-    // record pairs of equivalent nodes
-    vIds1 = Vec_IntAlloc( Aig_ManObjNumMax(pAig) );
-    vIds2 = Vec_IntAlloc( Aig_ManObjNumMax(pAig) );
-    Aig_ManForEachObj( pAig, pObj, i )
-    {
-        pRepr = Aig_Regular(pObj->pData);
-        if ( pRepr == NULL )
-            continue;
-        if ( Aig_ManObj(pAigNew, pRepr->Id) == NULL )
-            continue;
-/*
-        if ( Aig_ObjIsNode(pObj) )
-            printf( "n " );
-        else if ( Saig_ObjIsPi(pAig, pObj) )
-            printf( "pi " );
-        else if ( Saig_ObjIsLo(pAig, pObj) )
-            printf( "lo " );
-*/
-        Vec_IntPush( vIds1, Aig_ObjId(pObj) );
-        Vec_IntPush( vIds2, Aig_ObjId(pRepr) );
-    }
-    printf( "Recorded %d pairs (before: %d  after: %d).\n", Vec_IntSize(vIds1), Aig_ManObjNumMax(pAig), Aig_ManObjNumMax(pAigNew) );
-    // try the new AIGs
-    pAigRes = Ssw_SignalCorrespondenceWithPairs( pAig, pAigNew, vIds1, vIds2, pPars );
-    Vec_IntFree( vIds1 );
-    Vec_IntFree( vIds2 );
-    // report the results
-    RetValue = Ssw_MiterStatus( pAigRes, 1 );
-    if ( RetValue == 1 )
-        printf( "Verification successful.  " );
-    else if ( RetValue == 0 )
-        printf( "Verification failed with the counter-example.  " );
-    else
-        printf( "Verification UNDECIDED. Remaining registers %d (total %d).  ", 
-            Aig_ManRegNum(pAigRes), Aig_ManRegNum(pAig) + Aig_ManRegNum(pAigNew) );
-    PRT( "Time", clock() - clk );
-    // cleanup
-    Aig_ManStop( pAigNew );
-    return pAigRes;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Runs inductive SEC for the miter of two AIGs with node pairs defined.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SecWithPairs( Aig_Man_t * pAig1, Aig_Man_t * pAig2, Vec_Int_t * vIds1, Vec_Int_t * vIds2, Ssw_Pars_t * pPars )
-{
-    Aig_Man_t * pAigRes;
-    int RetValue, clk = clock();
-    assert( vIds1 != NULL && vIds2 != NULL );
-    // try the new AIGs
-    printf( "Performing specialized verification with node pairs.\n" );
-    pAigRes = Ssw_SignalCorrespondenceWithPairs( pAig1, pAig2, vIds1, vIds2, pPars );
-    // report the results
-    RetValue = Ssw_MiterStatus( pAigRes, 1 );
-    if ( RetValue == 1 )
-        printf( "Verification successful.  " );
-    else if ( RetValue == 0 )
-        printf( "Verification failed with a counter-example.  " );
-    else
-        printf( "Verification UNDECIDED. The number of remaining regs = %d (total = %d).  ", 
-            Aig_ManRegNum(pAigRes), Aig_ManRegNum(pAig1) + Aig_ManRegNum(pAig2) );
-    PRT( "Time", clock() - clk );
-    // cleanup
-    Aig_ManStop( pAigRes );
-    return RetValue;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Runs inductive SEC for the miter of two AIGs.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SecGeneral( Aig_Man_t * pAig1, Aig_Man_t * pAig2, Ssw_Pars_t * pPars )
-{
-    Aig_Man_t * pAigRes, * pMiter;
-    int RetValue, clk = clock();
-    // try the new AIGs
-    printf( "Performing general verification without node pairs.\n" );
-    pMiter = Saig_ManCreateMiter( pAig1, pAig2, 0 );
-    pAigRes = Ssw_SignalCorrespondence( pMiter, pPars );
-    Aig_ManStop( pMiter );
-    // report the results
-    RetValue = Ssw_MiterStatus( pAigRes, 1 );
-    if ( RetValue == 1 )
-        printf( "Verification successful.  " );
-    else if ( RetValue == 0 )
-        printf( "Verification failed with a counter-example.  " );
-    else
-        printf( "Verification UNDECIDED. The number of remaining regs = %d (total = %d).  ", 
-            Aig_ManRegNum(pAigRes), Aig_ManRegNum(pAig1) + Aig_ManRegNum(pAig2) );
-    PRT( "Time", clock() - clk );
-    // cleanup
-    Aig_ManStop( pAigRes );
-    return RetValue;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Runs inductive SEC for the miter of two AIGs.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SecGeneralMiter( Aig_Man_t * pMiter, Ssw_Pars_t * pPars )
-{
-    Aig_Man_t * pAigRes;
-    int RetValue, clk = clock();
-    // try the new AIGs
-//    printf( "Performing general verification without node pairs.\n" );
-    pAigRes = Ssw_SignalCorrespondence( pMiter, pPars );
-    // report the results
-    RetValue = Ssw_MiterStatus( pAigRes, 1 );
-    if ( RetValue == 1 )
-        printf( "Verification successful.  " );
-    else if ( RetValue == 0 )
-        printf( "Verification failed with a counter-example.  " );
-    else
-        printf( "Verification UNDECIDED. The number of remaining regs = %d (total = %d).  ", 
-            Aig_ManRegNum(pAigRes), Aig_ManRegNum(pMiter) );
-    PRT( "Time", clock() - clk );
-    // cleanup
-    Aig_ManStop( pAigRes );
-    return RetValue;
-}
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswPart.c b/src/aig/ssw_old/sswPart.c
deleted file mode 100644
index 7eb6b8fe..00000000
--- a/src/aig/ssw_old/sswPart.c
+++ /dev/null
@@ -1,129 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswPart.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [Partitioned signal correspondence.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswPart.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Performs partitioned sequential SAT sweepingG.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Aig_Man_t * Ssw_SignalCorrespondencePart( Aig_Man_t * pAig, Ssw_Pars_t * pPars )
-{
-    int fPrintParts = 0;
-    char Buffer[100];
-    Aig_Man_t * pTemp, * pNew;
-    Vec_Ptr_t * vResult;
-    Vec_Int_t * vPart;
-    int * pMapBack;
-    int i, nCountPis, nCountRegs;
-    int nClasses, nPartSize, fVerbose;
-    int clk = clock();
-
-    // save parameters
-    nPartSize = pPars->nPartSize; pPars->nPartSize = 0;
-    fVerbose  = pPars->fVerbose;  pPars->fVerbose = 0;
-    // generate partitions
-    if ( pAig->vClockDoms )
-    {
-        // divide large clock domains into separate partitions
-        vResult = Vec_PtrAlloc( 100 );
-        Vec_PtrForEachEntry( (Vec_Ptr_t *)pAig->vClockDoms, vPart, i )
-        {
-            if ( nPartSize && Vec_IntSize(vPart) > nPartSize )
-                Aig_ManPartDivide( vResult, vPart, nPartSize, pPars->nOverSize );
-            else
-                Vec_PtrPush( vResult, Vec_IntDup(vPart) );
-        }
-    }
-    else
-        vResult = Aig_ManRegPartitionSimple( pAig, nPartSize, pPars->nOverSize );
-//    vResult = Aig_ManPartitionSmartRegisters( pAig, nPartSize, 0 ); 
-//    vResult = Aig_ManRegPartitionSmart( pAig, nPartSize );
-    if ( fPrintParts )
-    {
-        // print partitions
-        printf( "Simple partitioning. %d partitions are saved:\n", Vec_PtrSize(vResult) );
-        Vec_PtrForEachEntry( vResult, vPart, i )
-        {
-            extern void Ioa_WriteAiger( Aig_Man_t * pMan, char * pFileName, int fWriteSymbols, int fCompact );
-            sprintf( Buffer, "part%03d.aig", i );
-            pTemp = Aig_ManRegCreatePart( pAig, vPart, &nCountPis, &nCountRegs, NULL );
-            Ioa_WriteAiger( pTemp, Buffer, 0, 0 );
-            printf( "part%03d.aig : Reg = %4d. PI = %4d. (True = %4d. Regs = %4d.) And = %5d.\n", 
-                i, Vec_IntSize(vPart), Aig_ManPiNum(pTemp)-Vec_IntSize(vPart), nCountPis, nCountRegs, Aig_ManNodeNum(pTemp) );
-            Aig_ManStop( pTemp );
-        }
-    }
-
-    // perform SSW with partitions
-    Aig_ManReprStart( pAig, Aig_ManObjNumMax(pAig) );
-    Vec_PtrForEachEntry( vResult, vPart, i )
-    {
-        pTemp = Aig_ManRegCreatePart( pAig, vPart, &nCountPis, &nCountRegs, &pMapBack );
-        Aig_ManSetRegNum( pTemp, pTemp->nRegs );
-        // create the projection of 1-hot registers
-        if ( pAig->vOnehots )
-            pTemp->vOnehots = Aig_ManRegProjectOnehots( pAig, pTemp, pAig->vOnehots, fVerbose );
-        // run SSW
-        pNew = Ssw_SignalCorrespondence( pTemp, pPars );
-        nClasses = Aig_TransferMappedClasses( pAig, pTemp, pMapBack );
-        if ( fVerbose )
-            printf( "%3d : Reg = %4d. PI = %4d. (True = %4d. Regs = %4d.) And = %5d. It = %3d. Cl = %5d.\n", 
-                i, Vec_IntSize(vPart), Aig_ManPiNum(pTemp)-Vec_IntSize(vPart), nCountPis, nCountRegs, Aig_ManNodeNum(pTemp), pPars->nIters, nClasses );
-        Aig_ManStop( pNew );
-        Aig_ManStop( pTemp );
-        free( pMapBack );
-    }
-    // remap the AIG
-    pNew = Aig_ManDupRepr( pAig, 0 );
-    Aig_ManSeqCleanup( pNew );
-//    Aig_ManPrintStats( pAig );
-//    Aig_ManPrintStats( pNew );
-    Vec_VecFree( (Vec_Vec_t *)vResult );
-    pPars->nPartSize = nPartSize;
-    pPars->fVerbose = fVerbose;
-    if ( fVerbose )
-    {
-        PRT( "Total time", clock() - clk );
-    }
-    return pNew;
-}
-
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswSat.c b/src/aig/ssw_old/sswSat.c
deleted file mode 100644
index 85d3b8c1..00000000
--- a/src/aig/ssw_old/sswSat.c
+++ /dev/null
@@ -1,264 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswSat.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [Calls to the SAT solver.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswSat.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Runs equivalence test for the two nodes.]
-
-  Description [Both nodes should be regular and different from each other.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_NodesAreEquiv( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew )
-{
-    int nBTLimit = p->pPars->nBTLimit;
-    int pLits[3], nLits, RetValue, RetValue1, clk;//, status;
-    p->nSatCalls++;
-
-    // sanity checks
-    assert( !Aig_IsComplement(pOld) );
-    assert( !Aig_IsComplement(pNew) );
-    assert( pOld != pNew );
-
-    if ( p->pSat == NULL )
-        Ssw_ManStartSolver( p );
-
-    // if the nodes do not have SAT variables, allocate them
-    Ssw_CnfNodeAddToSolver( p, pOld );
-    Ssw_CnfNodeAddToSolver( p, pNew );
-
-    if ( p->pSat->qtail != p->pSat->qhead )
-    {
-        RetValue = sat_solver_simplify(p->pSat);
-        assert( RetValue != 0 );
-    }
-
-    // solve under assumptions
-    // A = 1; B = 0     OR     A = 1; B = 1 
-    nLits = 2;
-    pLits[0] = toLitCond( Ssw_ObjSatNum(p,pOld), 0 );
-    pLits[1] = toLitCond( Ssw_ObjSatNum(p,pNew), pOld->fPhase == pNew->fPhase );
-    if ( p->iOutputLit > -1 )
-        pLits[nLits++] = p->iOutputLit;
-    if ( p->pPars->fPolarFlip )
-    {
-        if ( pOld->fPhase )  pLits[0] = lit_neg( pLits[0] );
-        if ( pNew->fPhase )  pLits[1] = lit_neg( pLits[1] );
-    }
-//Sat_SolverWriteDimacs( p->pSat, "temp.cnf", pLits, pLits + 2, 1 );
-
-clk = clock();
-    RetValue1 = sat_solver_solve( p->pSat, pLits, pLits + nLits, 
-        (sint64)nBTLimit, (sint64)0, (sint64)0, (sint64)0 );
-p->timeSat += clock() - clk;
-    if ( RetValue1 == l_False )
-    {
-p->timeSatUnsat += clock() - clk;
-        if ( nLits == 2 )
-        {
-            pLits[0] = lit_neg( pLits[0] );
-            pLits[1] = lit_neg( pLits[1] );
-            RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 2 );
-            assert( RetValue );
-        }
-        p->nSatCallsUnsat++;
-    }
-    else if ( RetValue1 == l_True )
-    {
-p->timeSatSat += clock() - clk;
-        p->nSatCallsSat++;
-        return 0;
-    }
-    else // if ( RetValue1 == l_Undef )
-    {
-p->timeSatUndec += clock() - clk;
-        p->nSatFailsReal++;
-        return -1;
-    }
-
-    // if the old node was constant 0, we already know the answer
-    if ( pOld == Aig_ManConst1(p->pFrames) )
-    {
-        p->nSatProof++;
-        return 1;
-    }
-
-    // solve under assumptions
-    // A = 0; B = 1     OR     A = 0; B = 0 
-    nLits = 2;
-    pLits[0] = toLitCond( Ssw_ObjSatNum(p,pOld), 1 );
-    pLits[1] = toLitCond( Ssw_ObjSatNum(p,pNew), pOld->fPhase ^ pNew->fPhase );
-    if ( p->iOutputLit > -1 )
-        pLits[nLits++] = p->iOutputLit;
-    if ( p->pPars->fPolarFlip )
-    {
-        if ( pOld->fPhase )  pLits[0] = lit_neg( pLits[0] );
-        if ( pNew->fPhase )  pLits[1] = lit_neg( pLits[1] );
-    }
-/*
-    if ( p->pSat->qtail != p->pSat->qhead )
-    {
-        RetValue = sat_solver_simplify(p->pSat);
-        assert( RetValue != 0 );
-    }
-*/
-clk = clock();
-    RetValue1 = sat_solver_solve( p->pSat, pLits, pLits + nLits, 
-        (sint64)nBTLimit, (sint64)0, (sint64)0, (sint64)0 );
-p->timeSat += clock() - clk;
-    if ( RetValue1 == l_False )
-    {
-p->timeSatUnsat += clock() - clk;
-        if ( nLits == 2 )
-        {
-            pLits[0] = lit_neg( pLits[0] );
-            pLits[1] = lit_neg( pLits[1] );
-            RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 2 );
-            assert( RetValue );
-        }
-        p->nSatCallsUnsat++;
-    }
-    else if ( RetValue1 == l_True )
-    {
-p->timeSatSat += clock() - clk;
-        p->nSatCallsSat++;
-        return 0;
-    }
-    else // if ( RetValue1 == l_Undef )
-    {
-p->timeSatUndec += clock() - clk;
-        p->nSatFailsReal++;
-        return -1;
-    }
-    // return SAT proof
-    p->nSatProof++;
-    return 1;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Constrains two nodes to be equivalent in the SAT solver.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_NodesAreConstrained( Ssw_Man_t * p, Aig_Obj_t * pOld, Aig_Obj_t * pNew )
-{
-    int pLits[2], RetValue, fComplNew;
-    Aig_Obj_t * pTemp;
-
-    // sanity checks
-    assert( Aig_Regular(pOld) != Aig_Regular(pNew) );
-
-    // move constant to the old node
-    if ( Aig_Regular(pNew) == Aig_ManConst1(p->pFrames) )
-    {
-        assert( Aig_Regular(pOld) != Aig_ManConst1(p->pFrames) );
-        pTemp = pOld;
-        pOld  = pNew;
-        pNew  = pTemp;
-    }
-
-    // move complement to the new node
-    if ( Aig_IsComplement(pOld) )
-    {
-        pOld = Aig_Regular(pOld);
-        pNew = Aig_Not(pNew);
-    }
-
-    // start the solver
-    if ( p->pSat == NULL )
-        Ssw_ManStartSolver( p );
-
-    // if the nodes do not have SAT variables, allocate them
-    Ssw_CnfNodeAddToSolver( p, pOld );
-    Ssw_CnfNodeAddToSolver( p, Aig_Regular(pNew) );
-
-    // transform the new node
-    fComplNew = Aig_IsComplement( pNew );
-    pNew = Aig_Regular( pNew );
-
-    // consider the constant 1 case
-    if ( pOld == Aig_ManConst1(p->pFrames) )
-    {
-        // add constaint A = 1  ---->  A
-        pLits[0] = toLitCond( Ssw_ObjSatNum(p,pNew), fComplNew );
-        if ( p->pPars->fPolarFlip )
-        {
-            if ( pNew->fPhase )  pLits[0] = lit_neg( pLits[0] );
-        }
-        RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 1 );
-        assert( RetValue );
-    }
-    else
-    {
-        // add constaint A = B  ---->  (A v !B)(!A v B)
-
-        // (A v !B)
-        pLits[0] = toLitCond( Ssw_ObjSatNum(p,pOld), 0 );
-        pLits[1] = toLitCond( Ssw_ObjSatNum(p,pNew), !fComplNew );
-        if ( p->pPars->fPolarFlip )
-        {
-            if ( pOld->fPhase )  pLits[0] = lit_neg( pLits[0] );
-            if ( pNew->fPhase )  pLits[1] = lit_neg( pLits[1] );
-        }
-        pLits[0] = lit_neg( pLits[0] );
-        pLits[1] = lit_neg( pLits[1] );
-        RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 2 );
-        assert( RetValue );
-
-        // (!A v B)
-        pLits[0] = toLitCond( Ssw_ObjSatNum(p,pOld), 1 );
-        pLits[1] = toLitCond( Ssw_ObjSatNum(p,pNew), fComplNew);
-        if ( p->pPars->fPolarFlip )
-        {
-            if ( pOld->fPhase )  pLits[0] = lit_neg( pLits[0] );
-            if ( pNew->fPhase )  pLits[1] = lit_neg( pLits[1] );
-        }
-        pLits[0] = lit_neg( pLits[0] );
-        pLits[1] = lit_neg( pLits[1] );
-        RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 2 );
-        assert( RetValue );
-    }
-    return 1;
-}
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswSim.c b/src/aig/ssw_old/sswSim.c
deleted file mode 100644
index 3fdb5cbc..00000000
--- a/src/aig/ssw_old/sswSim.c
+++ /dev/null
@@ -1,1334 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswSim.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [Sequential simulator used by the inductive prover.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswSim.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-// simulation manager
-struct Ssw_Sml_t_
-{
-    Aig_Man_t *      pAig;              // the original AIG manager
-    int              nPref;             // the number of timeframes in the prefix
-    int              nFrames;           // the number of timeframes 
-    int              nWordsFrame;       // the number of words in each timeframe
-    int              nWordsTotal;       // the total number of words at a node
-    int              nWordsPref;        // the number of word in the prefix
-    int              fNonConstOut;      // have seen a non-const-0 output during simulation
-    int              nSimRounds;        // statistics
-    int              timeSim;           // statistics
-    unsigned         pData[0];          // simulation data for the nodes
-};
-
-static inline unsigned * Ssw_ObjSim( Ssw_Sml_t * p, int Id )  { return p->pData + p->nWordsTotal * Id; }
-static inline unsigned   Ssw_ObjRandomSim()                   { return Aig_ManRandom(0);               }
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Computes hash value of the node using its simulation info.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-unsigned Ssw_SmlObjHashWord( Ssw_Sml_t * p, Aig_Obj_t * pObj )
-{
-    static int s_SPrimes[128] = { 
-        1009, 1049, 1093, 1151, 1201, 1249, 1297, 1361, 1427, 1459, 
-        1499, 1559, 1607, 1657, 1709, 1759, 1823, 1877, 1933, 1997, 
-        2039, 2089, 2141, 2213, 2269, 2311, 2371, 2411, 2467, 2543, 
-        2609, 2663, 2699, 2741, 2797, 2851, 2909, 2969, 3037, 3089, 
-        3169, 3221, 3299, 3331, 3389, 3461, 3517, 3557, 3613, 3671, 
-        3719, 3779, 3847, 3907, 3943, 4013, 4073, 4129, 4201, 4243, 
-        4289, 4363, 4441, 4493, 4549, 4621, 4663, 4729, 4793, 4871, 
-        4933, 4973, 5021, 5087, 5153, 5227, 5281, 5351, 5417, 5471, 
-        5519, 5573, 5651, 5693, 5749, 5821, 5861, 5923, 6011, 6073, 
-        6131, 6199, 6257, 6301, 6353, 6397, 6481, 6563, 6619, 6689, 
-        6737, 6803, 6863, 6917, 6977, 7027, 7109, 7187, 7237, 7309, 
-        7393, 7477, 7523, 7561, 7607, 7681, 7727, 7817, 7877, 7933, 
-        8011, 8039, 8059, 8081, 8093, 8111, 8123, 8147
-    };
-    unsigned * pSims;
-    unsigned uHash;
-    int i;
-    assert( p->nWordsTotal <= 128 );
-    uHash = 0;
-    pSims = Ssw_ObjSim(p, pObj->Id);
-    for ( i = p->nWordsPref; i < p->nWordsTotal; i++ )
-        uHash ^= pSims[i] * s_SPrimes[i & 0x7F];
-    return uHash;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Returns 1 if simulation info is composed of all zeros.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlObjIsConstWord( Ssw_Sml_t * p, Aig_Obj_t * pObj )
-{
-    unsigned * pSims;
-    int i;
-    pSims = Ssw_ObjSim(p, pObj->Id);
-    for ( i = p->nWordsPref; i < p->nWordsTotal; i++ )
-        if ( pSims[i] )
-            return 0;
-    return 1;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Returns 1 if simulation infos are equal.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlObjsAreEqualWord( Ssw_Sml_t * p, Aig_Obj_t * pObj0, Aig_Obj_t * pObj1 )
-{
-    unsigned * pSims0, * pSims1;
-    int i;
-    pSims0 = Ssw_ObjSim(p, pObj0->Id);
-    pSims1 = Ssw_ObjSim(p, pObj1->Id);
-    for ( i = p->nWordsPref; i < p->nWordsTotal; i++ )
-        if ( pSims0[i] != pSims1[i] )
-            return 0;
-    return 1;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Returns 1 if the node appears to be constant 1 candidate.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlObjIsConstBit( void * p, Aig_Obj_t * pObj )
-{
-    return pObj->fPhase == pObj->fMarkB;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Returns 1 if the nodes appear equal.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlObjsAreEqualBit( void * p, Aig_Obj_t * pObj0, Aig_Obj_t * pObj1 )
-{
-    return (pObj0->fPhase == pObj1->fPhase) == (pObj0->fMarkB == pObj1->fMarkB);
-}
-
-
-/**Function*************************************************************
-
-  Synopsis    [Counts the number of 1s in the XOR of simulation data.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlNodeNotEquWeight( Ssw_Sml_t * p, int Left, int Right )
-{
-    unsigned * pSimL, * pSimR;
-    int k, Counter = 0;
-    pSimL = Ssw_ObjSim( p, Left );
-    pSimR = Ssw_ObjSim( p, Right );
-    for ( k = p->nWordsPref; k < p->nWordsTotal; k++ )
-        Counter += Aig_WordCountOnes( pSimL[k] ^ pSimR[k] );
-    return Counter;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Returns 1 if simulation info is composed of all zeros.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlNodeIsZero( Ssw_Sml_t * p, Aig_Obj_t * pObj )
-{
-    unsigned * pSims;
-    int i;
-    pSims = Ssw_ObjSim(p, pObj->Id);
-    for ( i = p->nWordsPref; i < p->nWordsTotal; i++ )
-        if ( pSims[i] )
-            return 0;
-    return 1;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Counts the number of one's in the patten of the output.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlNodeCountOnes( Ssw_Sml_t * p, Aig_Obj_t * pObj )
-{
-    unsigned * pSims;
-    int i, Counter = 0;
-    pSims = Ssw_ObjSim(p, pObj->Id);
-    for ( i = 0; i < p->nWordsTotal; i++ )
-        Counter += Aig_WordCountOnes( pSims[i] );
-    return Counter;
-}
-
-
-
-/**Function*************************************************************
-
-  Synopsis    [Generated const 0 pattern.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlSavePattern0( Ssw_Man_t * p, int fInit )
-{
-    memset( p->pPatWords, 0, sizeof(unsigned) * p->nPatWords );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [[Generated const 1 pattern.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlSavePattern1( Ssw_Man_t * p, int fInit )
-{
-    Aig_Obj_t * pObj;
-    int i, k, nTruePis;
-    memset( p->pPatWords, 0xff, sizeof(unsigned) * p->nPatWords );
-    if ( !fInit )
-        return;
-    // clear the state bits to correspond to all-0 initial state
-    nTruePis = Saig_ManPiNum(p->pAig);
-    k = 0;
-    Saig_ManForEachLo( p->pAig, pObj, i )
-        Aig_InfoXorBit( p->pPatWords, nTruePis * p->nFrames + k++ );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Copy pattern from the solver into the internal storage.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlSavePattern( Ssw_Man_t * p )
-{
-    Aig_Obj_t * pObj;
-    int i;
-    memset( p->pPatWords, 0, sizeof(unsigned) * p->nPatWords );
-    Aig_ManForEachPi( p->pFrames, pObj, i )
-        if ( p->pSat->model.ptr[Ssw_ObjSatNum(p, pObj)] == l_True )
-            Aig_InfoSetBit( p->pPatWords, i );
-/*
-    if ( p->vCex )
-    {
-        Vec_IntClear( p->vCex );
-        for ( i = 0; i < Saig_ManPiNum(p->pAig); i++ )
-            Vec_IntPush( p->vCex, Aig_InfoHasBit( p->pPatWords, i ) );
-        for ( i = Saig_ManPiNum(p->pFrames); i < Aig_ManPiNum(p->pFrames); i++ )
-            Vec_IntPush( p->vCex, Aig_InfoHasBit( p->pPatWords, i ) );
-    }
-*/
-
-/*
-    printf( "Pattern: " );
-    Aig_ManForEachPi( p->pFrames, pObj, i )
-        printf( "%d", Aig_InfoHasBit( p->pPatWords, i ) );
-    printf( "\n" );
-*/
-}
-
-
-
-/**Function*************************************************************
-
-  Synopsis    [Creates the counter-example from the successful pattern.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int * Ssw_SmlCheckOutputSavePattern( Ssw_Sml_t * p, Aig_Obj_t * pObjPo )
-{ 
-    Aig_Obj_t * pFanin, * pObjPi;
-    unsigned * pSims;
-    int i, k, BestPat, * pModel;
-    // find the word of the pattern
-    pFanin = Aig_ObjFanin0(pObjPo);
-    pSims = Ssw_ObjSim(p, pFanin->Id);
-    for ( i = 0; i < p->nWordsTotal; i++ )
-        if ( pSims[i] )
-            break;
-    assert( i < p->nWordsTotal );
-    // find the bit of the pattern
-    for ( k = 0; k < 32; k++ )
-        if ( pSims[i] & (1 << k) )
-            break;
-    assert( k < 32 );
-    // determine the best pattern
-    BestPat = i * 32 + k;
-    // fill in the counter-example data
-    pModel = ALLOC( int, Aig_ManPiNum(p->pAig)+1 );
-    Aig_ManForEachPi( p->pAig, pObjPi, i )
-    {
-        pModel[i] = Aig_InfoHasBit(Ssw_ObjSim(p, pObjPi->Id), BestPat);
-//        printf( "%d", pModel[i] );
-    }
-    pModel[Aig_ManPiNum(p->pAig)] = pObjPo->Id;
-//    printf( "\n" );
-    return pModel;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Returns 1 if the one of the output is already non-constant 0.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int * Ssw_SmlCheckOutput( Ssw_Sml_t * p )
-{
-    Aig_Obj_t * pObj;
-    int i;
-    // make sure the reference simulation pattern does not detect the bug
-    pObj = Aig_ManPo( p->pAig, 0 );
-    assert( Aig_ObjFanin0(pObj)->fPhase == (unsigned)Aig_ObjFaninC0(pObj) ); 
-    Aig_ManForEachPo( p->pAig, pObj, i )
-    {
-        if ( !Ssw_SmlObjIsConstWord( p, Aig_ObjFanin0(pObj) ) )
-        {
-            // create the counter-example from this pattern
-            return Ssw_SmlCheckOutputSavePattern( p, pObj );
-        }
-    }
-    return NULL;
-}
-
-
-
-/**Function*************************************************************
-
-  Synopsis    [Assigns random patterns to the PI node.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlAssignRandom( Ssw_Sml_t * p, Aig_Obj_t * pObj )
-{
-    unsigned * pSims;
-    int i;
-    assert( Aig_ObjIsPi(pObj) );
-    pSims = Ssw_ObjSim( p, pObj->Id );
-    for ( i = 0; i < p->nWordsTotal; i++ )
-        pSims[i] = Ssw_ObjRandomSim();
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Assigns random patterns to the PI node.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlAssignRandomFrame( Ssw_Sml_t * p, Aig_Obj_t * pObj, int iFrame )
-{
-    unsigned * pSims;
-    int i;
-    assert( Aig_ObjIsPi(pObj) );
-    pSims = Ssw_ObjSim( p, pObj->Id ) + p->nWordsFrame * iFrame;
-    for ( i = 0; i < p->nWordsFrame; i++ )
-        pSims[i] = Ssw_ObjRandomSim();
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Assigns constant patterns to the PI node.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlObjAssignConst( Ssw_Sml_t * p, Aig_Obj_t * pObj, int fConst1, int iFrame )
-{
-    unsigned * pSims;
-    int i;
-    assert( Aig_ObjIsPi(pObj) );
-    pSims = Ssw_ObjSim( p, pObj->Id ) + p->nWordsFrame * iFrame;
-    for ( i = 0; i < p->nWordsFrame; i++ )
-        pSims[i] = fConst1? ~(unsigned)0 : 0;
-} 
-
-/**Function*************************************************************
-
-  Synopsis    [Assigns constant patterns to the PI node.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-unsigned Ssw_SmlObjGetWord( Ssw_Sml_t * p, Aig_Obj_t * pObj, int iWord, int iFrame )
-{
-    unsigned * pSims;
-//    assert( Aig_ObjIsPi(pObj) );
-    pSims = Ssw_ObjSim( p, pObj->Id ) + p->nWordsFrame * iFrame;
-    return pSims[iWord];
-} 
-
-/**Function*************************************************************
-
-  Synopsis    [Assigns constant patterns to the PI node.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlObjSetWord( Ssw_Sml_t * p, Aig_Obj_t * pObj, unsigned Word, int iWord, int iFrame )
-{
-    unsigned * pSims;
-    assert( Aig_ObjIsPi(pObj) );
-    pSims = Ssw_ObjSim( p, pObj->Id ) + p->nWordsFrame * iFrame;
-    pSims[iWord] = Word;
-} 
-
-/**Function*************************************************************
-
-  Synopsis    [Assings random simulation info for the PIs.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlInitialize( Ssw_Sml_t * p, int fInit )
-{
-    Aig_Obj_t * pObj;
-    int i;
-    if ( fInit )
-    {
-        assert( Aig_ManRegNum(p->pAig) > 0 );
-        assert( Aig_ManRegNum(p->pAig) < Aig_ManPiNum(p->pAig) );
-        // assign random info for primary inputs
-        Saig_ManForEachPi( p->pAig, pObj, i )
-            Ssw_SmlAssignRandom( p, pObj );
-        // assign the initial state for the latches
-        Saig_ManForEachLo( p->pAig, pObj, i )
-            Ssw_SmlObjAssignConst( p, pObj, 0, 0 );
-    }
-    else
-    {
-        Aig_ManForEachPi( p->pAig, pObj, i )
-            Ssw_SmlAssignRandom( p, pObj );
-    }
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Assings distance-1 simulation info for the PIs.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlAssignDist1( Ssw_Sml_t * p, unsigned * pPat )
-{
-    Aig_Obj_t * pObj;
-    int f, i, k, Limit, nTruePis;
-    assert( p->nFrames > 0 );
-    if ( p->nFrames == 1 )
-    {
-        // copy the PI info 
-        Aig_ManForEachPi( p->pAig, pObj, i )
-            Ssw_SmlObjAssignConst( p, pObj, Aig_InfoHasBit(pPat, i), 0 );
-        // flip one bit
-        Limit = AIG_MIN( Aig_ManPiNum(p->pAig), p->nWordsTotal * 32 - 1 );
-        for ( i = 0; i < Limit; i++ )
-            Aig_InfoXorBit( Ssw_ObjSim( p, Aig_ManPi(p->pAig,i)->Id ), i+1 );
-    }
-    else
-    {
-        int fUseDist1 = 0;
-
-        // copy the PI info for each frame
-        nTruePis = Aig_ManPiNum(p->pAig) - Aig_ManRegNum(p->pAig);
-        for ( f = 0; f < p->nFrames; f++ )
-            Saig_ManForEachPi( p->pAig, pObj, i )
-                Ssw_SmlObjAssignConst( p, pObj, Aig_InfoHasBit(pPat, nTruePis * f + i), f );
-        // copy the latch info 
-        k = 0;
-        Saig_ManForEachLo( p->pAig, pObj, i )
-            Ssw_SmlObjAssignConst( p, pObj, Aig_InfoHasBit(pPat, nTruePis * p->nFrames + k++), 0 );
-//        assert( p->pFrames == NULL || nTruePis * p->nFrames + k == Aig_ManPiNum(p->pFrames) );
-
-        // flip one bit of the last frame
-        if ( fUseDist1 ) //&& p->nFrames == 2 )
-        {
-            Limit = AIG_MIN( nTruePis, p->nWordsFrame * 32 - 1 );
-            for ( i = 0; i < Limit; i++ )
-                Aig_InfoXorBit( Ssw_ObjSim( p, Aig_ManPi(p->pAig, i)->Id ) + p->nWordsFrame*(p->nFrames-1), i+1 );
-        }
-    }
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Assings distance-1 simulation info for the PIs.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlAssignDist1Plus( Ssw_Sml_t * p, unsigned * pPat )
-{
-    Aig_Obj_t * pObj;
-    int f, i, Limit;
-    assert( p->nFrames > 0 );
-
-    // copy the pattern into the primary inputs
-    Aig_ManForEachPi( p->pAig, pObj, i )
-        Ssw_SmlObjAssignConst( p, pObj, Aig_InfoHasBit(pPat, i), 0 );
-/*
-    // set distance one PIs for the first frame
-    Limit = AIG_MIN( Saig_ManPiNum(p->pAig), p->nWordsFrame * 32 - 1 );
-    for ( i = 0; i < Limit; i++ )
-        Aig_InfoXorBit( Ssw_ObjSim( p, Aig_ManPi(p->pAig, i)->Id ), i+1 );
-*/
-    // create random info for the remaining timeframes
-    for ( f = 1; f < p->nFrames; f++ )
-        Saig_ManForEachPi( p->pAig, pObj, i )
-            Ssw_SmlAssignRandomFrame( p, pObj, f );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Simulates one node.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlNodeSimulate( Ssw_Sml_t * p, Aig_Obj_t * pObj, int iFrame )
-{
-    unsigned * pSims, * pSims0, * pSims1;
-    int fCompl, fCompl0, fCompl1, i;
-    assert( !Aig_IsComplement(pObj) );
-    assert( Aig_ObjIsNode(pObj) );
-    assert( iFrame == 0 || p->nWordsFrame < p->nWordsTotal );
-    // get hold of the simulation information
-    pSims  = Ssw_ObjSim(p, pObj->Id) + p->nWordsFrame * iFrame;
-    pSims0 = Ssw_ObjSim(p, Aig_ObjFanin0(pObj)->Id) + p->nWordsFrame * iFrame;
-    pSims1 = Ssw_ObjSim(p, Aig_ObjFanin1(pObj)->Id) + p->nWordsFrame * iFrame;
-    // get complemented attributes of the children using their random info
-    fCompl  = pObj->fPhase;
-    fCompl0 = Aig_ObjPhaseReal(Aig_ObjChild0(pObj));
-    fCompl1 = Aig_ObjPhaseReal(Aig_ObjChild1(pObj));
-    // simulate
-    if ( fCompl0 && fCompl1 )
-    {
-        if ( fCompl )
-            for ( i = 0; i < p->nWordsFrame; i++ )
-                pSims[i] = (pSims0[i] | pSims1[i]);
-        else
-            for ( i = 0; i < p->nWordsFrame; i++ )
-                pSims[i] = ~(pSims0[i] | pSims1[i]);
-    }
-    else if ( fCompl0 && !fCompl1 )
-    {
-        if ( fCompl )
-            for ( i = 0; i < p->nWordsFrame; i++ )
-                pSims[i] = (pSims0[i] | ~pSims1[i]);
-        else
-            for ( i = 0; i < p->nWordsFrame; i++ )
-                pSims[i] = (~pSims0[i] & pSims1[i]);
-    }
-    else if ( !fCompl0 && fCompl1 )
-    {
-        if ( fCompl )
-            for ( i = 0; i < p->nWordsFrame; i++ )
-                pSims[i] = (~pSims0[i] | pSims1[i]);
-        else
-            for ( i = 0; i < p->nWordsFrame; i++ )
-                pSims[i] = (pSims0[i] & ~pSims1[i]);
-    }
-    else // if ( !fCompl0 && !fCompl1 )
-    {
-        if ( fCompl )
-            for ( i = 0; i < p->nWordsFrame; i++ )
-                pSims[i] = ~(pSims0[i] & pSims1[i]);
-        else
-            for ( i = 0; i < p->nWordsFrame; i++ )
-                pSims[i] = (pSims0[i] & pSims1[i]);
-    }
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Simulates one node.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlNodesCompareInFrame( Ssw_Sml_t * p, Aig_Obj_t * pObj0, Aig_Obj_t * pObj1, int iFrame0, int iFrame1 )
-{
-    unsigned * pSims0, * pSims1;
-    int i;
-    assert( !Aig_IsComplement(pObj0) );
-    assert( !Aig_IsComplement(pObj1) );
-    assert( iFrame0 == 0 || p->nWordsFrame < p->nWordsTotal );
-    assert( iFrame1 == 0 || p->nWordsFrame < p->nWordsTotal );
-    // get hold of the simulation information
-    pSims0  = Ssw_ObjSim(p, pObj0->Id) + p->nWordsFrame * iFrame0;
-    pSims1  = Ssw_ObjSim(p, pObj1->Id) + p->nWordsFrame * iFrame1;
-    // compare
-    for ( i = 0; i < p->nWordsFrame; i++ )
-        if ( pSims0[i] != pSims1[i] )
-            return 0;
-    return 1;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Simulates one node.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlNodeCopyFanin( Ssw_Sml_t * p, Aig_Obj_t * pObj, int iFrame )
-{
-    unsigned * pSims, * pSims0;
-    int fCompl, fCompl0, i;
-    assert( !Aig_IsComplement(pObj) );
-    assert( Aig_ObjIsPo(pObj) );
-    assert( iFrame == 0 || p->nWordsFrame < p->nWordsTotal );
-    // get hold of the simulation information
-    pSims  = Ssw_ObjSim(p, pObj->Id) + p->nWordsFrame * iFrame;
-    pSims0 = Ssw_ObjSim(p, Aig_ObjFanin0(pObj)->Id) + p->nWordsFrame * iFrame;
-    // get complemented attributes of the children using their random info
-    fCompl  = pObj->fPhase;
-    fCompl0 = Aig_ObjPhaseReal(Aig_ObjChild0(pObj));
-    // copy information as it is
-    if ( fCompl0 )
-        for ( i = 0; i < p->nWordsFrame; i++ )
-            pSims[i] = ~pSims0[i];
-    else
-        for ( i = 0; i < p->nWordsFrame; i++ )
-            pSims[i] = pSims0[i];
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Simulates one node.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlNodeTransferNext( Ssw_Sml_t * p, Aig_Obj_t * pOut, Aig_Obj_t * pIn, int iFrame )
-{
-    unsigned * pSims0, * pSims1;
-    int i;
-    assert( !Aig_IsComplement(pOut) );
-    assert( !Aig_IsComplement(pIn) );
-    assert( Aig_ObjIsPo(pOut) );
-    assert( Aig_ObjIsPi(pIn) );
-    assert( iFrame == 0 || p->nWordsFrame < p->nWordsTotal );
-    // get hold of the simulation information
-    pSims0 = Ssw_ObjSim(p, pOut->Id) + p->nWordsFrame * iFrame;
-    pSims1 = Ssw_ObjSim(p, pIn->Id) + p->nWordsFrame * (iFrame+1);
-    // copy information as it is
-    for ( i = 0; i < p->nWordsFrame; i++ )
-        pSims1[i] = pSims0[i];
-}
-
-
-/**Function*************************************************************
-
-  Synopsis    [Check if any of the POs becomes non-constant.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlCheckNonConstOutputs( Ssw_Sml_t * p )
-{
-    Aig_Obj_t * pObj;
-    int i;
-    Saig_ManForEachPo( p->pAig, pObj, i )
-        if ( !Ssw_SmlNodeIsZero(p, pObj) )
-            return 1;
-    return 0;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Simulates AIG manager.]
-
-  Description [Assumes that the PI simulation info is attached.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlSimulateOne( Ssw_Sml_t * p )
-{
-    Aig_Obj_t * pObj, * pObjLi, * pObjLo;
-    int f, i, clk;
-clk = clock();
-    for ( f = 0; f < p->nFrames; f++ )
-    {
-        // simulate the nodes
-        Aig_ManForEachNode( p->pAig, pObj, i )
-            Ssw_SmlNodeSimulate( p, pObj, f );
-        // copy simulation info into outputs
-        Saig_ManForEachPo( p->pAig, pObj, i )
-            Ssw_SmlNodeCopyFanin( p, pObj, f );
-        // quit if this is the last timeframe
-        if ( f == p->nFrames - 1 )
-            break;
-        // copy simulation info into outputs
-        Saig_ManForEachLi( p->pAig, pObj, i )
-            Ssw_SmlNodeCopyFanin( p, pObj, f );
-        // copy simulation info into the inputs
-        Saig_ManForEachLiLo( p->pAig, pObjLi, pObjLo, i )
-            Ssw_SmlNodeTransferNext( p, pObjLi, pObjLo, f );
-    }
-p->timeSim += clock() - clk;
-p->nSimRounds++;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Simulates AIG manager.]
-
-  Description [Assumes that the PI simulation info is attached.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlSimulateOneFrame( Ssw_Sml_t * p )
-{
-    Aig_Obj_t * pObj, * pObjLi, * pObjLo;
-    int i, clk;
-clk = clock();
-    // simulate the nodes
-    Aig_ManForEachNode( p->pAig, pObj, i )
-        Ssw_SmlNodeSimulate( p, pObj, 0 );
-    // copy simulation info into outputs
-    Saig_ManForEachLi( p->pAig, pObj, i )
-        Ssw_SmlNodeCopyFanin( p, pObj, 0 );
-    // copy simulation info into the inputs
-    Saig_ManForEachLiLo( p->pAig, pObjLi, pObjLo, i )
-        Ssw_SmlNodeTransferNext( p, pObjLi, pObjLo, 0 );
-p->timeSim += clock() - clk;
-p->nSimRounds++;
-}
-
-
-/**Function*************************************************************
-
-  Synopsis    [Allocates simulation manager.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Sml_t * Ssw_SmlStart( Aig_Man_t * pAig, int nPref, int nFrames, int nWordsFrame )
-{
-    Ssw_Sml_t * p;
-    p = (Ssw_Sml_t *)malloc( sizeof(Ssw_Sml_t) + sizeof(unsigned) * Aig_ManObjNumMax(pAig) * (nPref + nFrames) * nWordsFrame );
-    memset( p, 0, sizeof(Ssw_Sml_t) + sizeof(unsigned) * (nPref + nFrames) * nWordsFrame );
-    p->pAig        = pAig;
-    p->nPref       = nPref;
-    p->nFrames     = nPref + nFrames;
-    p->nWordsFrame = nWordsFrame;
-    p->nWordsTotal = (nPref + nFrames) * nWordsFrame;
-    p->nWordsPref  = nPref * nWordsFrame;
-    return p;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Allocates simulation manager.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlClean( Ssw_Sml_t * p )
-{
-    memset( p->pData, 0, sizeof(unsigned) * Aig_ManObjNumMax(p->pAig) * p->nWordsTotal );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Deallocates simulation manager.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlStop( Ssw_Sml_t * p )
-{
-    free( p );
-}
-
-
-/**Function*************************************************************
-
-  Synopsis    [Performs simulation of the uninitialized circuit.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Sml_t * Ssw_SmlSimulateComb( Aig_Man_t * pAig, int nWords )
-{
-    Ssw_Sml_t * p;
-    p = Ssw_SmlStart( pAig, 0, 1, nWords );
-    Ssw_SmlInitialize( p, 0 );
-    Ssw_SmlSimulateOne( p );
-    return p;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Performs simulation of the initialized circuit.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Sml_t * Ssw_SmlSimulateSeq( Aig_Man_t * pAig, int nPref, int nFrames, int nWords )
-{
-    Ssw_Sml_t * p;
-    p = Ssw_SmlStart( pAig, nPref, nFrames, nWords );
-    Ssw_SmlInitialize( p, 1 );
-    Ssw_SmlSimulateOne( p );
-    p->fNonConstOut = Ssw_SmlCheckNonConstOutputs( p );
-    return p;
-}
-
-
-
-/**Function*************************************************************
-
-  Synopsis    [Allocates a counter-example.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Cex_t * Ssw_SmlAllocCounterExample( int nRegs, int nRealPis, int nFrames )
-{
-    Ssw_Cex_t * pCex;
-    int nWords = Aig_BitWordNum( nRegs + nRealPis * nFrames );
-    pCex = (Ssw_Cex_t *)malloc( sizeof(Ssw_Cex_t) + sizeof(unsigned) * nWords );
-    memset( pCex, 0, sizeof(Ssw_Cex_t) + sizeof(unsigned) * nWords );
-    pCex->nRegs  = nRegs;
-    pCex->nPis   = nRealPis;
-    pCex->nBits  = nRegs + nRealPis * nFrames;
-    return pCex;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Frees the counter-example.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlFreeCounterExample( Ssw_Cex_t * pCex )
-{
-    free( pCex );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Resimulates the counter-example.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlRunCounterExample( Aig_Man_t * pAig, Ssw_Cex_t * p )
-{
-    Ssw_Sml_t * pSml;
-    Aig_Obj_t * pObj;
-    int RetValue, i, k, iBit;
-    assert( Aig_ManRegNum(pAig) > 0 );
-    assert( Aig_ManRegNum(pAig) < Aig_ManPiNum(pAig) );
-    // start a new sequential simulator
-    pSml = Ssw_SmlStart( pAig, 0, p->iFrame+1, 1 );
-    // assign simulation info for the registers
-    iBit = 0;
-    Saig_ManForEachLo( pAig, pObj, i )
-        Ssw_SmlObjAssignConst( pSml, pObj, Aig_InfoHasBit(p->pData, iBit++), 0 );
-    // assign simulation info for the primary inputs
-    for ( i = 0; i <= p->iFrame; i++ )
-        Saig_ManForEachPi( pAig, pObj, k )
-            Ssw_SmlObjAssignConst( pSml, pObj, Aig_InfoHasBit(p->pData, iBit++), i );
-    assert( iBit == p->nBits );
-    // run random simulation
-    Ssw_SmlSimulateOne( pSml );
-    // check if the given output has failed
-    RetValue = !Ssw_SmlNodeIsZero( pSml, Aig_ManPo(pAig, p->iPo) );
-    Ssw_SmlStop( pSml );
-    return RetValue;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Resimulates the counter-example.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlFindOutputCounterExample( Aig_Man_t * pAig, Ssw_Cex_t * p )
-{
-    Ssw_Sml_t * pSml;
-    Aig_Obj_t * pObj;
-    int i, k, iBit, iOut;
-    assert( Aig_ManRegNum(pAig) > 0 );
-    assert( Aig_ManRegNum(pAig) < Aig_ManPiNum(pAig) );
-    // start a new sequential simulator
-    pSml = Ssw_SmlStart( pAig, 0, p->iFrame+1, 1 );
-    // assign simulation info for the registers
-    iBit = 0;
-    Saig_ManForEachLo( pAig, pObj, i )
-        Ssw_SmlObjAssignConst( pSml, pObj, Aig_InfoHasBit(p->pData, iBit++), 0 );
-    // assign simulation info for the primary inputs
-    for ( i = 0; i <= p->iFrame; i++ )
-        Saig_ManForEachPi( pAig, pObj, k )
-            Ssw_SmlObjAssignConst( pSml, pObj, Aig_InfoHasBit(p->pData, iBit++), i );
-    assert( iBit == p->nBits );
-    // run random simulation
-    Ssw_SmlSimulateOne( pSml );
-    // check if the given output has failed
-    iOut = -1;
-    Saig_ManForEachPo( pAig, pObj, k )
-        if ( !Ssw_SmlNodeIsZero( pSml, Aig_ManPo(pAig, k) ) )
-        {
-            iOut = k;
-            break;
-        }
-    Ssw_SmlStop( pSml );
-    return iOut;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Creates sequential counter-example from the simulation info.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Cex_t * Ssw_SmlGetCounterExample( Ssw_Sml_t * p )
-{
-    Ssw_Cex_t * pCex;
-    Aig_Obj_t * pObj;
-    unsigned * pSims;
-    int iPo, iFrame, iBit, i, k;
-
-    // make sure the simulation manager has it
-    assert( p->fNonConstOut );
-
-    // find the first output that failed
-    iPo = -1;
-    iBit = -1;
-    iFrame = -1;
-    Saig_ManForEachPo( p->pAig, pObj, iPo )
-    {
-        if ( Ssw_SmlNodeIsZero(p, pObj) )
-            continue;
-        pSims = Ssw_ObjSim( p, pObj->Id );
-        for ( i = p->nWordsPref; i < p->nWordsTotal; i++ )
-            if ( pSims[i] )
-            {
-                iFrame = i / p->nWordsFrame;
-                iBit = 32 * (i % p->nWordsFrame) + Aig_WordFindFirstBit( pSims[i] );
-                break;
-            }
-        break;
-    }
-    assert( iPo < Aig_ManPoNum(p->pAig)-Aig_ManRegNum(p->pAig) );
-    assert( iFrame < p->nFrames );
-    assert( iBit < 32 * p->nWordsFrame );
-
-    // allocate the counter example
-    pCex = Ssw_SmlAllocCounterExample( Aig_ManRegNum(p->pAig), Aig_ManPiNum(p->pAig) - Aig_ManRegNum(p->pAig), iFrame + 1 );
-    pCex->iPo    = iPo;
-    pCex->iFrame = iFrame;
-
-    // copy the bit data
-    Saig_ManForEachLo( p->pAig, pObj, k )
-    {
-        pSims = Ssw_ObjSim( p, pObj->Id );
-        if ( Aig_InfoHasBit( pSims, iBit ) )
-            Aig_InfoSetBit( pCex->pData, k );
-    }
-    for ( i = 0; i <= iFrame; i++ )
-    {
-        Saig_ManForEachPi( p->pAig, pObj, k )
-        {
-            pSims = Ssw_ObjSim( p, pObj->Id );
-            if ( Aig_InfoHasBit( pSims, 32 * p->nWordsFrame * i + iBit ) )
-                Aig_InfoSetBit( pCex->pData, pCex->nRegs + pCex->nPis * i + k );
-        }
-    }
-    // verify the counter example
-    if ( !Ssw_SmlRunCounterExample( p->pAig, pCex ) )
-    {
-        printf( "Ssw_SmlGetCounterExample(): Counter-example is invalid.\n" );
-        Ssw_SmlFreeCounterExample( pCex );
-        pCex = NULL;
-    }
-    return pCex;
-}
- 
-/**Function*************************************************************
-
-  Synopsis    [Generates seq counter-example from the combinational one.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Cex_t * Ssw_SmlCopyCounterExample( Aig_Man_t * pAig, Aig_Man_t * pFrames, int * pModel )
-{
-    Ssw_Cex_t * pCex;
-    Aig_Obj_t * pObj;
-    int i, nFrames, nTruePis, nTruePos, iPo, iFrame;
-    // get the number of frames
-    assert( Aig_ManRegNum(pAig) > 0 );
-    assert( Aig_ManRegNum(pFrames) == 0 );
-    nTruePis = Aig_ManPiNum(pAig)-Aig_ManRegNum(pAig);
-    nTruePos = Aig_ManPoNum(pAig)-Aig_ManRegNum(pAig);
-    nFrames = Aig_ManPiNum(pFrames) / nTruePis;
-    assert( nTruePis * nFrames == Aig_ManPiNum(pFrames) );
-    assert( nTruePos * nFrames == Aig_ManPoNum(pFrames) );
-    // find the PO that failed
-    iPo = -1;
-    iFrame = -1;
-    Aig_ManForEachPo( pFrames, pObj, i )
-        if ( pObj->Id == pModel[Aig_ManPiNum(pFrames)] )
-        {
-            iPo = i % nTruePos;
-            iFrame = i / nTruePos;
-            break;
-        }
-    assert( iPo >= 0 );
-    // allocate the counter example
-    pCex = Ssw_SmlAllocCounterExample( Aig_ManRegNum(pAig), nTruePis, iFrame + 1 );
-    pCex->iPo    = iPo;
-    pCex->iFrame = iFrame;
-
-    // copy the bit data
-    for ( i = 0; i < Aig_ManPiNum(pFrames); i++ )
-    {
-        if ( pModel[i] )
-            Aig_InfoSetBit( pCex->pData, pCex->nRegs + i );
-        if ( pCex->nRegs + i == pCex->nBits - 1 )
-            break;
-    }
-
-    // verify the counter example
-    if ( !Ssw_SmlRunCounterExample( pAig, pCex ) )
-    {
-        printf( "Ssw_SmlGetCounterExample(): Counter-example is invalid.\n" );
-        Ssw_SmlFreeCounterExample( pCex );
-        pCex = NULL;
-    }
-    return pCex;
-
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Make the trivial counter-example for the trivially asserted output.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Cex_t * Ssw_SmlTrivCounterExample( Aig_Man_t * pAig, int iFrameOut )
-{
-    Ssw_Cex_t * pCex;
-    int nTruePis, nTruePos, iPo, iFrame;
-    assert( Aig_ManRegNum(pAig) > 0 );
-    nTruePis = Aig_ManPiNum(pAig)-Aig_ManRegNum(pAig);
-    nTruePos = Aig_ManPoNum(pAig)-Aig_ManRegNum(pAig);
-    iPo = iFrameOut % nTruePos;
-    iFrame = iFrameOut / nTruePos;
-    // allocate the counter example
-    pCex = Ssw_SmlAllocCounterExample( Aig_ManRegNum(pAig), nTruePis, iFrame + 1 );
-    pCex->iPo    = iPo;
-    pCex->iFrame = iFrame;
-    return pCex;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Make the trivial counter-example for the trivially asserted output.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-Ssw_Cex_t * Ssw_SmlDupCounterExample( Ssw_Cex_t * p, int nRegsNew )
-{
-    Ssw_Cex_t * pCex;
-    int i;
-    pCex = Ssw_SmlAllocCounterExample( nRegsNew, p->nPis, p->iFrame+1 );
-    pCex->iPo    = p->iPo;
-    pCex->iFrame = p->iFrame;
-    for ( i = p->nRegs; i < p->nBits; i++ )
-        if ( Aig_InfoHasBit(p->pData, i) )
-            Aig_InfoSetBit( pCex->pData, pCex->nRegs + i - p->nRegs );
-    return pCex;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Resimulates the counter-example.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_SmlWriteCounterExample( FILE * pFile, Aig_Man_t * pAig, Ssw_Cex_t * p )
-{
-    Ssw_Sml_t * pSml;
-    Aig_Obj_t * pObj;
-    int RetValue, i, k, iBit;
-    unsigned * pSims;
-    assert( Aig_ManRegNum(pAig) > 0 );
-    assert( Aig_ManRegNum(pAig) < Aig_ManPiNum(pAig) );
-    // start a new sequential simulator
-    pSml = Ssw_SmlStart( pAig, 0, p->iFrame+1, 1 );
-    // assign simulation info for the registers
-    iBit = 0;
-    Saig_ManForEachLo( pAig, pObj, i )
-//        Ssw_SmlObjAssignConst( pSml, pObj, Aig_InfoHasBit(p->pData, iBit++), 0 );
-        Ssw_SmlObjAssignConst( pSml, pObj, 0, 0 );
-    // assign simulation info for the primary inputs
-    iBit = p->nRegs;
-    for ( i = 0; i <= p->iFrame; i++ )
-        Saig_ManForEachPi( pAig, pObj, k )
-            Ssw_SmlObjAssignConst( pSml, pObj, Aig_InfoHasBit(p->pData, iBit++), i );
-    assert( iBit == p->nBits );
-    // run random simulation
-    Ssw_SmlSimulateOne( pSml );
-    // check if the given output has failed
-    RetValue = !Ssw_SmlNodeIsZero( pSml, Aig_ManPo(pAig, p->iPo) );
-
-    // write the output file
-    for ( i = 0; i <= p->iFrame; i++ )
-    {
-/*
-        Saig_ManForEachLo( pAig, pObj, k )
-        {
-            pSims = Ssw_ObjSim(pSml, pObj->Id);
-            fprintf( pFile, "%d", (int)(pSims[i] != 0) );
-        }
-        fprintf( pFile, " " );
-*/
-        Saig_ManForEachPi( pAig, pObj, k )
-        {
-            pSims = Ssw_ObjSim(pSml, pObj->Id);
-            fprintf( pFile, "%d", (int)(pSims[i] != 0) );
-        }
-/*
-        fprintf( pFile, " " );
-        Saig_ManForEachPo( pAig, pObj, k )
-        {
-            pSims = Ssw_ObjSim(pSml, pObj->Id);
-            fprintf( pFile, "%d", (int)(pSims[i] != 0) );
-        }
-        fprintf( pFile, " " );
-        Saig_ManForEachLi( pAig, pObj, k )
-        {
-            pSims = Ssw_ObjSim(pSml, pObj->Id);
-            fprintf( pFile, "%d", (int)(pSims[i] != 0) );
-        }
-*/
-        fprintf( pFile, "\n" );
-    }
-
-    Ssw_SmlStop( pSml );
-    return RetValue;
-}
-
-
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswSimSat.c b/src/aig/ssw_old/sswSimSat.c
deleted file mode 100644
index cbb6d0c1..00000000
--- a/src/aig/ssw_old/sswSimSat.c
+++ /dev/null
@@ -1,199 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswSimSat.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [Performs resimulation using counter-examples.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswSimSat.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Handle the counter-example.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManResimulateBit( Ssw_Man_t * p, Aig_Obj_t * pCand, Aig_Obj_t * pRepr )
-{
-    Aig_Obj_t * pObj;
-    int i, RetValue1, RetValue2, clk = clock();
-    // set the PI simulation information
-    Aig_ManConst1(p->pAig)->fMarkB = 1;
-    Aig_ManForEachPi( p->pAig, pObj, i )
-        pObj->fMarkB = Aig_InfoHasBit( p->pPatWords, i );
-    // simulate internal nodes
-    Aig_ManForEachNode( p->pAig, pObj, i )
-        pObj->fMarkB = ( Aig_ObjFanin0(pObj)->fMarkB ^ Aig_ObjFaninC0(pObj) )
-                     & ( Aig_ObjFanin1(pObj)->fMarkB ^ Aig_ObjFaninC1(pObj) );
-    // check equivalence classes
-    RetValue1 = Ssw_ClassesRefineConst1( p->ppClasses, 0 );
-    RetValue2 = Ssw_ClassesRefine( p->ppClasses, 0 );
-    // make sure refinement happened
-    if ( Aig_ObjIsConst1(pRepr) ) 
-    {
-        assert( RetValue1 );
-        if ( RetValue1 == 0 )
-            printf( "\nSsw_ManResimulateBit() Error: RetValue1 does not hold.\n" );
-    }
-    else
-    {
-        assert( RetValue2 );
-        if ( RetValue2 == 0 )
-            printf( "\nSsw_ManResimulateBit() Error: RetValue2 does not hold.\n" );
-    }
-p->timeSimSat += clock() - clk;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Verifies the result of simulation.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManResimulateWordVerify( Ssw_Man_t * p, int f )
-{
-    Aig_Obj_t * pObj, * pObjFraig;
-    unsigned uWord;
-    int Value1, Value2;
-    int i, nVarNum, Counter = 0;
-    Aig_ManForEachObj( p->pAig, pObj, i )
-    {
-        pObjFraig = Ssw_ObjFrame( p, pObj, f );
-        if ( pObjFraig == NULL )
-            continue;
-        nVarNum = Ssw_ObjSatNum( p, Aig_Regular(pObjFraig) );
-        if ( nVarNum == 0 )
-            continue;
-        Value1 = Ssw_ManGetSatVarValue( p, pObj, f );
-        uWord  = Ssw_SmlObjGetWord( p->pSml, pObj, 0, 0 );
-        Value2 = ((uWord != 0) ^ pObj->fPhase);
-        Counter += (Value1 != Value2);
-        if ( Value1 != Value2 )
-        {
-/*
-            int Value1f = Ssw_ManGetSatVarValue( p, Aig_ObjFanin0(pObj), f );
-            int Value2f = Ssw_ManGetSatVarValue( p, Aig_ObjFanin1(pObj), f );
-*/
-            int x = 0;
-            int Value3 = Ssw_ManGetSatVarValue( p, pObj, f );
-        }
-    }
-    if ( Counter )
-        printf( "Counter = %d.\n", Counter );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Handle the counter-example.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManResimulateWord( Ssw_Man_t * p, Aig_Obj_t * pCand, Aig_Obj_t * pRepr, int f )
-{
-    int RetValue1, RetValue2, clk = clock();
-    // set the PI simulation information
-    Ssw_SmlAssignDist1Plus( p->pSml, p->pPatWords );
-    // simulate internal nodes
-    Ssw_SmlSimulateOne( p->pSml );
-    Ssw_ManResimulateWordVerify( p, f );
-
-    // check equivalence classes
-    RetValue1 = Ssw_ClassesRefineConst1( p->ppClasses, 1 );
-    RetValue2 = Ssw_ClassesRefine( p->ppClasses, 1 );
-    // make sure refinement happened
-    if ( Aig_ObjIsConst1(pRepr) )
-    {
-        assert( RetValue1 );
-        if ( RetValue1 == 0 )
-            printf( "\nSsw_ManResimulateWord() Error: RetValue1 does not hold.\n" );
-    }
-    else
-    {
-        assert( RetValue2 );
-        if ( RetValue2 == 0 )
-            printf( "\nSsw_ManResimulateWord() Error: RetValue2 does not hold.\n" );
-    }
-p->timeSimSat += clock() - clk;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Handle the counter-example.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManResimulateWord2( Ssw_Man_t * p, Aig_Obj_t * pCand, Aig_Obj_t * pRepr, int f )
-{
-    int RetValue1, RetValue2, clk = clock();
-    // set the PI simulation information
-    Ssw_SmlAssignDist1Plus( p->pSml, p->pPatWords2 );
-    // simulate internal nodes
-    Ssw_SmlSimulateOne( p->pSml );
-    Ssw_ManResimulateWordVerify( p, f );
-
-    // check equivalence classes
-    RetValue1 = Ssw_ClassesRefineConst1( p->ppClasses, 1 );
-    RetValue2 = Ssw_ClassesRefine( p->ppClasses, 1 );
-    // make sure refinement happened
-    if ( Aig_ObjIsConst1(pRepr) )
-    {
-        assert( RetValue1 );
-        if ( RetValue1 == 0 )
-            printf( "\nSsw_ManResimulateWord() Error: RetValue1 does not hold.\n" );
-    }
-    else
-    {
-        assert( RetValue2 );
-        if ( RetValue2 == 0 )
-            printf( "\nSsw_ManResimulateWord() Error: RetValue2 does not hold.\n" );
-    }
-p->timeSimSat += clock() - clk;
-
-}
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswSweep.c b/src/aig/ssw_old/sswSweep.c
deleted file mode 100644
index b9d4ad63..00000000
--- a/src/aig/ssw_old/sswSweep.c
+++ /dev/null
@@ -1,473 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswSweep.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [One round of SAT sweeping.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswSweep.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-#include "bar.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Mark nodes affected by sweep in the previous iteration.]
-
-  Description [Assumes that affected nodes are in p->ppClasses->vRefined.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_ManSweepMarkRefinement( Ssw_Man_t * p )
-{
-    Vec_Ptr_t * vRefined, * vSupp;
-    Aig_Obj_t * pObj, * pObjLo, * pObjLi;
-    int i, k;
-    vRefined = Ssw_ClassesGetRefined( p->ppClasses );
-    if ( Vec_PtrSize(vRefined) == 0 )
-    {
-        Aig_ManForEachObj( p->pAig, pObj, i )
-            pObj->fMarkA = 1;
-        return;
-    }
-    // mark the nodes to be refined
-    Aig_ManCleanMarkA( p->pAig );
-    Vec_PtrForEachEntry( vRefined, pObj, i )
-    {
-        if ( Aig_ObjIsPi(pObj) )
-        {
-            pObj->fMarkA = 1;
-            continue;
-        }
-        assert( Aig_ObjIsNode(pObj) );
-        vSupp = Aig_Support( p->pAig, pObj );
-        Vec_PtrForEachEntry( vSupp, pObjLo, k )
-            pObjLo->fMarkA = 1;
-        Vec_PtrFree( vSupp );
-    }
-    // mark refinement
-    Aig_ManForEachNode( p->pAig, pObj, i )
-        pObj->fMarkA = Aig_ObjFanin0(pObj)->fMarkA | Aig_ObjFanin1(pObj)->fMarkA;
-    Saig_ManForEachLi( p->pAig, pObj, i )
-        pObj->fMarkA |= Aig_ObjFanin0(pObj)->fMarkA;
-    Saig_ManForEachLiLo( p->pAig, pObjLi, pObjLo, i )
-        pObjLo->fMarkA |= pObjLi->fMarkA;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Retrives value of the PI in the original AIG.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ManGetSatVarValue( Ssw_Man_t * p, Aig_Obj_t * pObj, int f )
-{
-    Aig_Obj_t * pObjFraig;
-    int nVarNum, Value;
-//    assert( Aig_ObjIsPi(pObj) );
-    pObjFraig = Ssw_ObjFrame( p, pObj, f );
-    nVarNum = Ssw_ObjSatNum( p, Aig_Regular(pObjFraig) );
-    assert( nVarNum > 0 );
-    if ( nVarNum == 0 )
-        printf( "Variable is not assigned.\n" );
-    Value = (!nVarNum)? 0 : (Aig_IsComplement(pObjFraig) ^ sat_solver_var_value( p->pSat, nVarNum ));
-//    Value = (Aig_IsComplement(pObjFraig) ^ ((!nVarNum)? 0 : sat_solver_var_value( p->pSat, nVarNum )));
-//    Value = (!nVarNum)? Aig_ManRandom(0) & 1 : (Aig_IsComplement(pObjFraig) ^ sat_solver_var_value( p->pSat, nVarNum ));
-    if ( p->pPars->fPolarFlip )
-    {
-        if ( Aig_Regular(pObjFraig)->fPhase )  Value ^= 1;
-    }
-    return Value;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Copy pattern from the solver into the internal storage.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlSavePatternAig( Ssw_Man_t * p, int f )
-{
-    Aig_Obj_t * pObj;
-    int i;
-    memset( p->pPatWords, 0, sizeof(unsigned) * p->nPatWords );
-    Aig_ManForEachPi( p->pAig, pObj, i )
-        if ( Ssw_ManGetSatVarValue( p, pObj, f ) )
-            Aig_InfoSetBit( p->pPatWords, i );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Copy pattern from the solver into the internal storage.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlSavePatternAig2( Ssw_Man_t * p, int f )
-{
-    Aig_Obj_t * pObj;
-    int i;
-    memset( p->pPatWords2, 0, sizeof(unsigned) * p->nPatWords );
-    Aig_ManForEachPi( p->pAig, pObj, i )
-        if ( Ssw_ManGetSatVarValue( p, pObj, f ) )
-            Aig_InfoSetBit( p->pPatWords2, i );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Copy pattern from the solver into the internal storage.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-void Ssw_SmlSavePatternAigPhase( Ssw_Man_t * p, int f )
-{
-    Aig_Obj_t * pObj;
-    int i;
-    memset( p->pPatWords, 0, sizeof(unsigned) * p->nPatWords );
-    Aig_ManForEachPi( p->pAig, pObj, i )
-        if ( Aig_ObjPhaseReal( Ssw_ObjFrame(p, pObj, f) ) )
-            Aig_InfoSetBit( p->pPatWords, i );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Performs fraiging for one node.]
-
-  Description [Returns the fraiged node.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ManSweepNode( Ssw_Man_t * p, Aig_Obj_t * pObj, int f, int fBmc )
-{ 
-    Aig_Obj_t * pObjRepr, * pObjFraig, * pObjFraig2, * pObjReprFraig;
-    int RetValue;
-    // get representative of this class
-    pObjRepr = Aig_ObjRepr( p->pAig, pObj );
-    if ( pObjRepr == NULL )
-        return 0;
-    // get the fraiged node
-    pObjFraig = Ssw_ObjFrame( p, pObj, f );
-    // get the fraiged representative
-    pObjReprFraig = Ssw_ObjFrame( p, pObjRepr, f );
-    // check if constant 0 pattern distinquishes these nodes
-    assert( pObjFraig != NULL && pObjReprFraig != NULL );
-    if ( (pObj->fPhase == pObjRepr->fPhase) != (Aig_ObjPhaseReal(pObjFraig) == Aig_ObjPhaseReal(pObjReprFraig)) )
-    {
-        p->nStrangers++;
-        Ssw_SmlSavePatternAigPhase( p, f );
-    }
-    else
-    { 
-        // if the fraiged nodes are the same, return
-        if ( Aig_Regular(pObjFraig) == Aig_Regular(pObjReprFraig) )
-            return 0; 
-        // count the number of skipped calls
-        if ( !pObj->fMarkA && !pObjRepr->fMarkA )
-            p->nRefSkip++;
-        else
-            p->nRefUse++;
-        // call equivalence checking
-        if ( p->pPars->fSkipCheck && !fBmc && !pObj->fMarkA && !pObjRepr->fMarkA )
-            RetValue = 1;
-        else if ( Aig_Regular(pObjFraig) != Aig_ManConst1(p->pFrames) )
-            RetValue = Ssw_NodesAreEquiv( p, Aig_Regular(pObjReprFraig), Aig_Regular(pObjFraig) );
-        else
-            RetValue = Ssw_NodesAreEquiv( p, Aig_Regular(pObjFraig), Aig_Regular(pObjReprFraig) );
-        if ( RetValue == 1 )  // proved equivalent
-        {
-            pObjFraig2 = Aig_NotCond( pObjReprFraig, pObj->fPhase ^ pObjRepr->fPhase );
-            Ssw_ObjSetFrame( p, pObj, f, pObjFraig2 );
-            return 0;
-        } 
-        if ( RetValue == -1 ) // timed out
-        {
-            Ssw_ClassesRemoveNode( p->ppClasses, pObj );
-            return 1;
-        }
-        // check if skipping calls works correctly
-        if ( p->pPars->fSkipCheck && !fBmc && !pObj->fMarkA && !pObjRepr->fMarkA )
-        {
-            assert( 0 );
-            printf( "\nSsw_ManSweepNode(): Error!\n" );
-        }
-        // disproved the equivalence
-        Ssw_SmlSavePatternAig( p, f );
-    } 
-    if ( !fBmc && p->pPars->fUniqueness && p->pPars->nFramesK > 1 && 
-        Ssw_ManUniqueOne( p, pObjRepr, pObj ) && p->iOutputLit == -1 )
-    { 
-        if ( Ssw_ManUniqueAddConstraint( p, p->vCommon, 0, 1 ) )
-        {
-            int RetValue2 = Ssw_NodesAreEquiv( p, Aig_Regular(pObjReprFraig), Aig_Regular(pObjFraig) );
-            p->iOutputLit = -1;
-
-            {
-                int Flag = 0;
-                if ( Flag )
-                {
-                    Aig_Obj_t * pFan0 = Aig_ObjFanin0(pObj);
-                    Aig_Obj_t * pFan1 = Aig_ObjFanin1(pObj);
-                    Aig_Obj_t * pFan00 = Aig_ObjFanin0(pFan0);
-                    Aig_Obj_t * pFan01 = Aig_ObjFanin1(pFan0);
-                    Aig_Obj_t * pFan10 = Aig_ObjFanin0(pFan1);
-                    Aig_Obj_t * pFan11 = Aig_ObjFanin1(pFan1);
-                }
-            }
-
-            if ( RetValue2 == 0 )
-            {
-                int x = Ssw_ManUniqueOne( p, pObjRepr, pObj );
-//                Ssw_SmlSavePatternAig2( p, f );
-//                Ssw_ManResimulateWord2( p, pObj, pObjRepr, f );
-                Ssw_SmlSavePatternAig( p, f );
-                Ssw_ManResimulateWord( p, pObj, pObjRepr, f );
-                if ( Aig_ObjRepr( p->pAig, pObj ) == pObjRepr )
-                    printf( "Ssw_ManSweepNode(): Refinement did not happen!!!!!!!!!!!!!!!!!!!!.\n" );
-                return 1;
-            }
-            return 0;
-
-
-/*
-            int RetValue;
-            assert( p->iOutputLit > -1 );
-            RetValue = Ssw_ManSweepNode( p, pObj, f, 0 );
-            p->iOutputLit = -1;
-            return RetValue;
-*/
-        }
-    }
-    if ( p->pPars->nConstrs == 0 )
-        Ssw_ManResimulateWord( p, pObj, pObjRepr, f );
-    else
-        Ssw_ManResimulateBit( p, pObj, pObjRepr );
-    assert( Aig_ObjRepr( p->pAig, pObj ) != pObjRepr );
-    if ( Aig_ObjRepr( p->pAig, pObj ) == pObjRepr )
-        printf( "Ssw_ManSweepNode(): Refinement did not happen.\n" );
-    return 1;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Performs fraiging for the internal nodes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ManSweepBmc( Ssw_Man_t * p )
-{
-    Bar_Progress_t * pProgress = NULL;
-    Aig_Obj_t * pObj, * pObjNew, * pObjLi, * pObjLo;
-    int i, f, clk;
-clk = clock();
-
-    // start initialized timeframes
-    p->pFrames = Aig_ManStart( Aig_ManObjNumMax(p->pAig) * p->pPars->nFramesK );
-    Saig_ManForEachLo( p->pAig, pObj, i )
-        Ssw_ObjSetFrame( p, pObj, 0, Aig_ManConst0(p->pFrames) );
-
-    // sweep internal nodes
-    p->fRefined = 0;
-    if ( p->pPars->fVerbose )
-        pProgress = Bar_ProgressStart( stdout, Aig_ManObjNumMax(p->pAig) * p->pPars->nFramesK );
-    Ssw_ManStartSolver( p );
-    for ( f = 0; f < p->pPars->nFramesK; f++ )
-    {
-        // map constants and PIs
-        Ssw_ObjSetFrame( p, Aig_ManConst1(p->pAig), f, Aig_ManConst1(p->pFrames) );
-        Saig_ManForEachPi( p->pAig, pObj, i )
-        { 
-            pObjNew = Aig_ObjCreatePi(p->pFrames);
-            Ssw_ObjSetFrame( p, pObj, f, pObjNew );
-            Ssw_CnfNodeAddToSolver( p, Aig_Regular(pObjNew) );
-        }
-        // sweep internal nodes
-        Aig_ManForEachNode( p->pAig, pObj, i )
-        {
-            if ( p->pPars->fVerbose )
-                Bar_ProgressUpdate( pProgress, Aig_ManObjNumMax(p->pAig) * f + i, NULL );
-            pObjNew = Aig_And( p->pFrames, Ssw_ObjChild0Fra(p, pObj, f), Ssw_ObjChild1Fra(p, pObj, f) );
-            Ssw_ObjSetFrame( p, pObj, f, pObjNew );
-            p->fRefined |= Ssw_ManSweepNode( p, pObj, f, 1 );
-        }
-        // quit if this is the last timeframe
-        if ( f == p->pPars->nFramesK - 1 )
-            break;
-        // transfer latch input to the latch outputs 
-        // build logic cones for register outputs
-        Saig_ManForEachLiLo( p->pAig, pObjLi, pObjLo, i )
-        {
-            pObjNew = Ssw_ObjChild0Fra(p, pObjLi,f);
-            Ssw_ObjSetFrame( p, pObjLo, f+1, pObjNew );
-            Ssw_CnfNodeAddToSolver( p, Aig_Regular(pObjNew) );
-        }
-    }
-    if ( p->pPars->fVerbose )
-        Bar_ProgressStop( pProgress );
-
-    // cleanup
-//    Ssw_ClassesCheck( p->ppClasses );
-p->timeBmc += clock() - clk;
-    return p->fRefined;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Performs fraiging for the internal nodes.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ManSweep( Ssw_Man_t * p )
-{
-    Bar_Progress_t * pProgress = NULL;
-    Aig_Obj_t * pObj, * pObj2, * pObjNew;
-    int nConstrPairs, clk, i, f;
-    int v;
-
-    // perform speculative reduction
-clk = clock();
-    // create timeframes
-    p->pFrames = Ssw_FramesWithClasses( p );
-    // add constraints
-    Ssw_ManStartSolver( p );
-//    nConstrPairs = Aig_ManPoNum(p->pFrames)-Aig_ManRegNum(p->pAig);
-    nConstrPairs = Aig_ManPoNum(p->pFrames)-p->nFrames*Aig_ManRegNum(p->pAig);
-    assert( (nConstrPairs & 1) == 0 );
-    for ( i = 0; i < nConstrPairs; i += 2 )
-    {
-        pObj  = Aig_ManPo( p->pFrames, i   );
-        pObj2 = Aig_ManPo( p->pFrames, i+1 );
-        Ssw_NodesAreConstrained( p, Aig_ObjChild0(pObj), Aig_ObjChild0(pObj2) );
-    }
-/*
-    // build logic cones for register inputs
-    for ( i = 0; i < Aig_ManRegNum(p->pAig); i++ )
-    {
-        pObj  = Aig_ManPo( p->pFrames, nConstrPairs + i );
-        Ssw_CnfNodeAddToSolver( p, Aig_ObjFanin0(pObj) );
-    }
-*/
-p->timeReduce += clock() - clk;
-
-    // mark nodes that do not have to be refined
-clk = clock();
-    if ( p->pPars->fSkipCheck )
-        Ssw_ManSweepMarkRefinement( p );
-p->timeMarkCones += clock() - clk;
-
-//Ssw_ManUnique( p );
-
-    // map constants and PIs of the last frame
-    f = p->pPars->nFramesK;
-    Ssw_ObjSetFrame( p, Aig_ManConst1(p->pAig), f, Aig_ManConst1(p->pFrames) );
-    Saig_ManForEachPi( p->pAig, pObj, i )
-        Ssw_ObjSetFrame( p, pObj, f, Aig_ObjCreatePi(p->pFrames) );
-////    
-    // bring up the previous frames
-//    if ( p->pPars->fUniqueness )
-        for ( v = 0; v <= f; v++ )
-//            Saig_ManForEachLo( p->pAig, pObj, i )
-            Aig_ManForEachPi( p->pAig, pObj, i )
-        {
-/*
-            if ( i == 53 && v == 1 )
-            {
-                int x = 0;
-            }
-*/
-                Ssw_CnfNodeAddToSolver( p, Aig_Regular(Ssw_ObjFrame(p, pObj, v)) );
-        }
-////
-    sat_solver_simplify( p->pSat );
-    // make sure LOs are assigned
-    Saig_ManForEachLo( p->pAig, pObj, i )
-        assert( Ssw_ObjFrame( p, pObj, f ) != NULL );
-    // sweep internal nodes
-    p->fRefined = 0;
-    p->nSatFailsReal = 0;
-    p->nRefUse = p->nRefSkip = 0;
-    p->nUniques = 0;
-    Ssw_ClassesClearRefined( p->ppClasses );
-    if ( p->pPars->fVerbose )
-        pProgress = Bar_ProgressStart( stdout, Aig_ManObjNumMax(p->pAig) );
-    Aig_ManForEachObj( p->pAig, pObj, i )
-    {
-        if ( p->pPars->fVerbose )
-            Bar_ProgressUpdate( pProgress, i, NULL );
-        if ( Saig_ObjIsLo(p->pAig, pObj) )
-            p->fRefined |= Ssw_ManSweepNode( p, pObj, f, 0 );
-        else if ( Aig_ObjIsNode(pObj) )
-        { 
-            pObj->fMarkA = Aig_ObjFanin0(pObj)->fMarkA | Aig_ObjFanin1(pObj)->fMarkA;
-            pObjNew = Aig_And( p->pFrames, Ssw_ObjChild0Fra(p, pObj, f), Ssw_ObjChild1Fra(p, pObj, f) );
-            Ssw_ObjSetFrame( p, pObj, f, pObjNew );
-            p->fRefined |= Ssw_ManSweepNode( p, pObj, f, 0 );
-        }
-    }
-    p->nSatFailsTotal += p->nSatFailsReal;
-    if ( p->pPars->fVerbose )
-        Bar_ProgressStop( pProgress );
-
-    // cleanup
-//    Ssw_ClassesCheck( p->ppClasses );
-    return p->fRefined;
-}
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/aig/ssw_old/sswUnique.c b/src/aig/ssw_old/sswUnique.c
deleted file mode 100644
index 2beeed09..00000000
--- a/src/aig/ssw_old/sswUnique.c
+++ /dev/null
@@ -1,290 +0,0 @@
-/**CFile****************************************************************
-
-  FileName    [sswSat.c]
-
-  SystemName  [ABC: Logic synthesis and verification system.]
-
-  PackageName [Inductive prover with constraints.]
-
-  Synopsis    [On-demand uniqueness constraints.]
-
-  Author      [Alan Mishchenko]
-  
-  Affiliation [UC Berkeley]
-
-  Date        [Ver. 1.0. Started - September 1, 2008.]
-
-  Revision    [$Id: sswSat.c,v 1.00 2008/09/01 00:00:00 alanmi Exp $]
-
-***********************************************************************/
-
-#include "sswInt.h"
-
-////////////////////////////////////////////////////////////////////////
-///                        DECLARATIONS                              ///
-////////////////////////////////////////////////////////////////////////
-
-////////////////////////////////////////////////////////////////////////
-///                     FUNCTION DEFINITIONS                         ///
-////////////////////////////////////////////////////////////////////////
-
-/**Function*************************************************************
-
-  Synopsis    [Returns the result of merging the two vectors.]
-
-  Description [Assumes that the vectors are sorted in the increasing order.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-static inline void Vec_PtrTwoMerge( Vec_Ptr_t * vArr1, Vec_Ptr_t * vArr2, Vec_Ptr_t * vArr )
-{
-    Aig_Obj_t ** pBeg  = (Aig_Obj_t **)vArr->pArray;
-    Aig_Obj_t ** pBeg1 = (Aig_Obj_t **)vArr1->pArray;
-    Aig_Obj_t ** pBeg2 = (Aig_Obj_t **)vArr2->pArray;
-    Aig_Obj_t ** pEnd1 = (Aig_Obj_t **)vArr1->pArray + vArr1->nSize;
-    Aig_Obj_t ** pEnd2 = (Aig_Obj_t **)vArr2->pArray + vArr2->nSize;
-    Vec_PtrGrow( vArr, Vec_PtrSize(vArr1) + Vec_PtrSize(vArr2) );
-    pBeg  = (Aig_Obj_t **)vArr->pArray;
-    while ( pBeg1 < pEnd1 && pBeg2 < pEnd2 )
-    {
-        if ( (*pBeg1)->Id == (*pBeg2)->Id )
-            *pBeg++ = *pBeg1++, pBeg2++;
-        else if ( (*pBeg1)->Id < (*pBeg2)->Id )
-            *pBeg++ = *pBeg1++;
-        else 
-            *pBeg++ = *pBeg2++;
-    }
-    while ( pBeg1 < pEnd1 )
-        *pBeg++ = *pBeg1++;
-    while ( pBeg2 < pEnd2 )
-        *pBeg++ = *pBeg2++;
-    vArr->nSize = pBeg - (Aig_Obj_t **)vArr->pArray;
-    assert( vArr->nSize <= vArr->nCap );
-    assert( vArr->nSize >= vArr1->nSize );
-    assert( vArr->nSize >= vArr2->nSize );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Returns the result of merging the two vectors.]
-
-  Description [Assumes that the vectors are sorted in the increasing order.]
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-static inline void Vec_PtrTwoCommon( Vec_Ptr_t * vArr1, Vec_Ptr_t * vArr2, Vec_Ptr_t * vArr )
-{
-    Aig_Obj_t ** pBeg  = (Aig_Obj_t **)vArr->pArray;
-    Aig_Obj_t ** pBeg1 = (Aig_Obj_t **)vArr1->pArray;
-    Aig_Obj_t ** pBeg2 = (Aig_Obj_t **)vArr2->pArray;
-    Aig_Obj_t ** pEnd1 = (Aig_Obj_t **)vArr1->pArray + vArr1->nSize;
-    Aig_Obj_t ** pEnd2 = (Aig_Obj_t **)vArr2->pArray + vArr2->nSize;
-    Vec_PtrGrow( vArr, AIG_MIN( Vec_PtrSize(vArr1), Vec_PtrSize(vArr2) ) );
-    pBeg  = (Aig_Obj_t **)vArr->pArray;
-    while ( pBeg1 < pEnd1 && pBeg2 < pEnd2 )
-    {
-        if ( (*pBeg1)->Id == (*pBeg2)->Id )
-            *pBeg++ = *pBeg1++, pBeg2++;
-        else if ( (*pBeg1)->Id < (*pBeg2)->Id )
-//            *pBeg++ = *pBeg1++;
-            pBeg1++;
-        else 
-//            *pBeg++ = *pBeg2++;
-            pBeg2++;
-    }
-//    while ( pBeg1 < pEnd1 )
-//        *pBeg++ = *pBeg1++;
-//    while ( pBeg2 < pEnd2 )
-//        *pBeg++ = *pBeg2++;
-    vArr->nSize = pBeg - (Aig_Obj_t **)vArr->pArray;
-    assert( vArr->nSize <= vArr->nCap );
-    assert( vArr->nSize <= vArr1->nSize );
-    assert( vArr->nSize <= vArr2->nSize );
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Returns 1 if uniqueness constraints can be added.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ManUniqueOne( Ssw_Man_t * p, Aig_Obj_t * pRepr, Aig_Obj_t * pObj )
-{
-    int fVerbose = 1;
-    Aig_Obj_t * ppObjs[2], * pTemp;
-    Vec_Ptr_t * vSupp, * vSupp2;
-    int i, k, Value0, Value1, RetValue;
-    assert( p->pPars->nFramesK > 1 );
-
-    vSupp  = Vec_PtrAlloc( 100 );
-    vSupp2 = Vec_PtrAlloc( 100 );
-    Vec_PtrClear( p->vCommon );
-
-    // compute the first support in terms of LOs
-    ppObjs[0] = pRepr; 
-    ppObjs[1] = pObj;
-    Aig_SupportNodes( p->pAig, ppObjs, 2, vSupp );
-    // modify support to be in terms of LIs
-    k = 0;
-    Vec_PtrForEachEntry( vSupp, pTemp, i )
-        if ( Saig_ObjIsLo(p->pAig, pTemp) )
-            Vec_PtrWriteEntry( vSupp, k++, Saig_ObjLoToLi(p->pAig, pTemp) );
-    Vec_PtrShrink( vSupp, k );
-    // compute the support of support
-    Aig_SupportNodes( p->pAig, (Aig_Obj_t **)Vec_PtrArray(vSupp), Vec_PtrSize(vSupp), vSupp2 );
-    // return support to LO
-    Vec_PtrForEachEntry( vSupp, pTemp, i )
-        Vec_PtrWriteEntry( vSupp, i, Saig_ObjLiToLo(p->pAig, pTemp) );
-    // find the number of common vars
-    Vec_PtrSort( vSupp, Aig_ObjCompareIdIncrease );
-    Vec_PtrSort( vSupp2, Aig_ObjCompareIdIncrease );
-    Vec_PtrTwoCommon( vSupp, vSupp2, p->vCommon );
-//    Vec_PtrTwoMerge( vSupp, vSupp2, p->vCommon );
-
-/*
-    {
-        Vec_Ptr_t * vNew = Vec_PtrDup(vSupp);
-        Vec_PtrUniqify( vNew, Aig_ObjCompareIdIncrease );
-        if ( Vec_PtrSize(vNew) != Vec_PtrSize(vSupp) )
-            printf( "Not unique!\n" );
-        Vec_PtrFree( vNew );
-        Vec_PtrForEachEntry( vSupp, pTemp, i )
-            printf( "%d ", pTemp->Id );
-        printf( "\n" );
-    }
-    {
-        Vec_Ptr_t * vNew = Vec_PtrDup(vSupp2);
-        Vec_PtrUniqify( vNew, Aig_ObjCompareIdIncrease );
-        if ( Vec_PtrSize(vNew) != Vec_PtrSize(vSupp2) )
-            printf( "Not unique!\n" );
-        Vec_PtrFree( vNew );
-        Vec_PtrForEachEntry( vSupp2, pTemp, i )
-            printf( "%d ", pTemp->Id );
-        printf( "\n" );
-    }
-    {
-        Vec_Ptr_t * vNew = Vec_PtrDup(p->vCommon);
-        Vec_PtrUniqify( vNew, Aig_ObjCompareIdIncrease );
-        if ( Vec_PtrSize(vNew) != Vec_PtrSize(p->vCommon) )
-            printf( "Not unique!\n" );
-        Vec_PtrFree( vNew );
-        Vec_PtrForEachEntry( p->vCommon, pTemp, i )
-            printf( "%d ", pTemp->Id );
-        printf( "\n" );
-    }
-*/
-
-    if ( fVerbose )
-        printf( "Node = %5d : One = %3d. Two = %3d. Common = %3d.  ",
-            Aig_ObjId(pObj), Vec_PtrSize(vSupp), Vec_PtrSize(vSupp2), Vec_PtrSize(p->vCommon) );
-
-//    Vec_PtrClear( vSupp );
-//    Vec_PtrForEachEntry( vSupp2, pTemp, i )
-//        Vec_PtrPush( vSupp, pTemp );
-
-    // check the current values
-    RetValue = 1;
-//    Vec_PtrForEachEntry( p->vCommon, pTemp, i )
-    Vec_PtrForEachEntry( vSupp, pTemp, i )
-    {
-        Value0 = Ssw_ManGetSatVarValue( p, pTemp, 0 );
-        Value1 = Ssw_ManGetSatVarValue( p, pTemp, 1 );
-        if ( Value0 != Value1 )
-            RetValue = 0;
-        if ( fVerbose )
-            printf( "%d", Value0 ^ Value1 );
-    }
-    if ( Vec_PtrSize(p->vCommon) == 0 )
-        RetValue = 0;
-
-    Vec_PtrForEachEntry( vSupp, pTemp, i )
-        printf( " %d", pTemp->Id );
-
-    if ( fVerbose )
-        printf( "\n" );
-
-
-    Vec_PtrClear( p->vCommon );
-    Vec_PtrForEachEntry( vSupp, pTemp, i )
-        Vec_PtrPush( p->vCommon, pTemp );
-
-    Vec_PtrFree( vSupp );
-    Vec_PtrFree( vSupp2 );
-    return RetValue;
-}
-
-/**Function*************************************************************
-
-  Synopsis    [Returns the output of the uniqueness constraint.]
-
-  Description []
-               
-  SideEffects []
-
-  SeeAlso     []
-
-***********************************************************************/
-int Ssw_ManUniqueAddConstraint( Ssw_Man_t * p, Vec_Ptr_t * vCommon, int f1, int f2 )
-{
-    Aig_Obj_t * pObj, * pObj1New, * pObj2New, * pMiter, * pTotal;
-    int i, pLits[2];
-//    int RetValue;
-    assert( Vec_PtrSize(vCommon) > 0 );
-    // generate the constraint
-    pTotal = Aig_ManConst0(p->pFrames);
-    Vec_PtrForEachEntry( vCommon, pObj, i )
-    {
-        assert( Saig_ObjIsLo(p->pAig, pObj) );
-        pObj1New = Ssw_ObjFrame( p, pObj, f1 );
-        pObj2New = Ssw_ObjFrame( p, pObj, f2 );
-        pMiter = Aig_Exor( p->pFrames, pObj1New, pObj2New );
-        pTotal = Aig_Or( p->pFrames, pTotal, pMiter );
-    }
-/*
-    if ( Aig_ObjIsConst1(Aig_Regular(pTotal)) )
-    {
-//        printf( "Skipped\n" );
-        return 0;
-    }
-*/
-    p->nUniques++;
-    // create CNF
-//    {
-//        int Num1 = p->nSatVars;
-    Ssw_CnfNodeAddToSolver( p, Aig_Regular(pTotal) );
-//    printf( "Created variable %d while vars are %d. (diff = %d)\n", 
-//        Ssw_ObjSatNum( p, Aig_Regular(pTotal) ), p->nSatVars, p->nSatVars - Num1 );
-//    }
-    // add output constraint
-    pLits[0] = toLitCond( Ssw_ObjSatNum(p,Aig_Regular(pTotal)), Aig_IsComplement(pTotal) );
-/*
-    RetValue = sat_solver_addclause( p->pSat, pLits, pLits + 1 );
-    assert( RetValue );
-    // simplify the solver
-    if ( p->pSat->qtail != p->pSat->qhead )
-    {
-        RetValue = sat_solver_simplify(p->pSat);
-        assert( RetValue != 0 );
-    }
-*/
-    assert( p->iOutputLit == -1 );
-    p->iOutputLit = pLits[0];
-    return 1;
-}
-
-////////////////////////////////////////////////////////////////////////
-///                       END OF FILE                                ///
-////////////////////////////////////////////////////////////////////////
-
-
diff --git a/src/base/abci/abc.c b/src/base/abci/abc.c
index d6bbd5e6..1dce3257 100644
--- a/src/base/abci/abc.c
+++ b/src/base/abci/abc.c
@@ -215,7 +215,7 @@ static int Abc_CommandBmc            ( Abc_Frame_t * pAbc, int argc, char ** arg
 static int Abc_CommandBmcInter       ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandIndcut         ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandEnlarge        ( Abc_Frame_t * pAbc, int argc, char ** argv );
-static int Abc_CommandLocalize       ( Abc_Frame_t * pAbc, int argc, char ** argv );
+static int Abc_CommandInduction      ( Abc_Frame_t * pAbc, int argc, char ** argv );
 
 static int Abc_CommandTraceStart     ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandTraceCheck     ( Abc_Frame_t * pAbc, int argc, char ** argv );
@@ -483,7 +483,7 @@ void Abc_Init( Abc_Frame_t * pAbc )
     Cmd_CommandAdd( pAbc, "Verification", "int",           Abc_CommandBmcInter,         0 );
     Cmd_CommandAdd( pAbc, "Verification", "indcut",        Abc_CommandIndcut,           0 );
     Cmd_CommandAdd( pAbc, "Verification", "enlarge",       Abc_CommandEnlarge,          1 );
-    Cmd_CommandAdd( pAbc, "Verification", "loc",           Abc_CommandLocalize,         0 );
+    Cmd_CommandAdd( pAbc, "Verification", "ind",           Abc_CommandInduction,        0 );
 
 
     Cmd_CommandAdd( pAbc, "ABC8",         "*r",            Abc_CommandAbc8Read,         0 );
@@ -620,7 +620,7 @@ int Abc_CommandPrintStats( Abc_Frame_t * pAbc, int argc, char ** argv )
     fDumpResult = 0;
     fUseLutLib = 0;
     fPrintTime = 0;
-    fPrintMuxes = 1;
+    fPrintMuxes = 0;
     Extra_UtilGetoptReset();
     while ( ( c = Extra_UtilGetopt( argc, argv, "fbdltmh" ) ) != EOF )
     {
@@ -7936,7 +7936,7 @@ int Abc_CommandTest( Abc_Frame_t * pAbc, int argc, char ** argv )
     Abc_FrameReplaceCurrentNetwork( pAbc, pNtkRes );
 */
 
-/*
+
     pNtkRes = Abc_NtkDarTestNtk( pNtk );
     if ( pNtkRes == NULL )
     {
@@ -7945,9 +7945,9 @@ int Abc_CommandTest( Abc_Frame_t * pAbc, int argc, char ** argv )
     }
     // replace the current network
     Abc_FrameReplaceCurrentNetwork( pAbc, pNtkRes );
-*/
 
-    Abc_NtkDarTest( pNtk );
+
+//    Abc_NtkDarTest( pNtk );
 
     return 0;
 usage:
@@ -13559,7 +13559,7 @@ int Abc_CommandSeqSweep2( Abc_Frame_t * pAbc, int argc, char ** argv )
     // set defaults
     Ssw_ManSetDefaultParams( pPars );
     Extra_UtilGetoptReset();
-    while ( ( c = Extra_UtilGetopt( argc, argv, "PQFCLNSplsfuvwh" ) ) != EOF )
+    while ( ( c = Extra_UtilGetopt( argc, argv, "PQFCLNSIplfuvwh" ) ) != EOF )
     {
         switch ( c )
         {
@@ -13640,15 +13640,23 @@ int Abc_CommandSeqSweep2( Abc_Frame_t * pAbc, int argc, char ** argv )
             if ( pPars->nFramesAddSim < 0 ) 
                 goto usage;
             break;
+        case 'I':
+            if ( globalUtilOptind >= argc )
+            {
+                fprintf( pErr, "Command line switch \"-I\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            pPars->nItersStop = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( pPars->nItersStop < 0 ) 
+                goto usage;
+            break;
         case 'p':
             pPars->fPolarFlip ^= 1;
             break;
         case 'l':
             pPars->fLatchCorr ^= 1;
             break;
-        case 's':
-            pPars->fSkipCheck ^= 1;
-            break;
         case 'f':
             pPars->fSemiFormal ^= 1;
             break;
@@ -13710,7 +13718,7 @@ int Abc_CommandSeqSweep2( Abc_Frame_t * pAbc, int argc, char ** argv )
     return 0;
 
 usage:
-    fprintf( pErr, "usage: scorr [-PQFCLNS <num>] [-plsfuvwh]\n" );
+    fprintf( pErr, "usage: scorr [-PQFCLNSI <num>] [-plfuvwh]\n" );
     fprintf( pErr, "\t         performs sequential sweep using K-step induction\n" );
     fprintf( pErr, "\t-P num : max partition size (0 = no partitioning) [default = %d]\n", pPars->nPartSize );
     fprintf( pErr, "\t-Q num : partition overlap (0 = no overlap) [default = %d]\n", pPars->nOverSize );
@@ -13719,10 +13727,10 @@ usage:
     fprintf( pErr, "\t-L num : max number of levels to consider (0=all) [default = %d]\n", pPars->nMaxLevs );
     fprintf( pErr, "\t-N num : number of last POs treated as constraints (0=none) [default = %d]\n", pPars->nConstrs );
     fprintf( pErr, "\t-S num : additional simulation frames for c-examples (0=none) [default = %d]\n", pPars->nFramesAddSim );
+    fprintf( pErr, "\t-I num : iteration number to stop and output SR-model (0=none) [default = %d]\n", pPars->nItersStop );
     fprintf( pErr, "\t-p     : toggle alighning polarity of SAT variables [default = %s]\n", pPars->fPolarFlip? "yes": "no" );
     fprintf( pErr, "\t-l     : toggle latch correspondence only [default = %s]\n", pPars->fLatchCorr? "yes": "no" );
-    fprintf( pErr, "\t-s     : toggle skipping unaffected cones [default = %s]\n", pPars->fSkipCheck? "yes": "no" );
-    fprintf( pErr, "\t-f     : toggle filtering using interative BMC [default = %s]\n", pPars->fSemiFormal? "yes": "no" );
+//    fprintf( pErr, "\t-f     : toggle filtering using interative BMC [default = %s]\n", pPars->fSemiFormal? "yes": "no" );
     fprintf( pErr, "\t-u     : toggle using uniqueness constraints [default = %s]\n", pPars->fUniqueness? "yes": "no" );
     fprintf( pErr, "\t-v     : toggle verbose output [default = %s]\n", pPars->fVerbose? "yes": "no" );
     fprintf( pErr, "\t-w     : toggle printout of flop equivalences [default = %s]\n", pPars->fFlopVerbose? "yes": "no" );
@@ -16560,7 +16568,7 @@ usage:
   SeeAlso     []
 
 ***********************************************************************/
-int Abc_CommandLocalize( Abc_Frame_t * pAbc, int argc, char ** argv )
+int Abc_CommandInduction( Abc_Frame_t * pAbc, int argc, char ** argv )
 {
     FILE * pOut, * pErr;
     Abc_Ntk_t * pNtk;
@@ -16575,8 +16583,8 @@ int Abc_CommandLocalize( Abc_Frame_t * pAbc, int argc, char ** argv )
     pErr = Abc_FrameReadErr(pAbc);
 
     // set defaults
-    nFramesMax =    50;
-    nConfMax   =   500;
+    nFramesMax =   100;
+    nConfMax   =  1000;
     fVerbose   =     0;
     Extra_UtilGetoptReset();
     while ( ( c = Extra_UtilGetopt( argc, argv, "FCvh" ) ) != EOF )
@@ -16639,8 +16647,8 @@ int Abc_CommandLocalize( Abc_Frame_t * pAbc, int argc, char ** argv )
     Abc_NtkDarLocalize( pNtk, nFramesMax, nConfMax, fVerbose );
     return 0;
 usage:
-    fprintf( pErr, "usage: loc [-FC num] [-vh]\n" );
-    fprintf( pErr, "\t         performs localization for single-output miter\n" );
+    fprintf( pErr, "usage: ind [-FC num] [-vh]\n" );
+    fprintf( pErr, "\t         runs K-step induction for the property output\n" );
     fprintf( pErr, "\t-F num : the max number of timeframes [default = %d]\n", nFramesMax );
     fprintf( pErr, "\t-C num : the max number of conflicts by SAT solver [default = %d]\n", nConfMax );
     fprintf( pErr, "\t-v     : toggle printing verbose information [default = %s]\n", fVerbose? "yes": "no" );
@@ -19121,7 +19129,7 @@ int Abc_CommandAbc8Scorr( Abc_Frame_t * pAbc, int argc, char ** argv )
     // set defaults
     Ssw_ManSetDefaultParams( pPars );
     Extra_UtilGetoptReset();
-    while ( ( c = Extra_UtilGetopt( argc, argv, "PQFCLNSDplsvh" ) ) != EOF )
+    while ( ( c = Extra_UtilGetopt( argc, argv, "PQFCLNSDplvh" ) ) != EOF )
     {
         switch ( c )
         {
@@ -19219,9 +19227,6 @@ int Abc_CommandAbc8Scorr( Abc_Frame_t * pAbc, int argc, char ** argv )
         case 'l':
             pPars->fLatchCorr ^= 1;
             break;
-        case 's':
-            pPars->fSkipCheck ^= 1;
-            break;
         case 'v':
             pPars->fVerbose ^= 1;
             break;
@@ -19268,7 +19273,7 @@ int Abc_CommandAbc8Scorr( Abc_Frame_t * pAbc, int argc, char ** argv )
     return 0;
 
 usage:
-    fprintf( stdout, "usage: *scorr [-PQFCLNSD <num>] [-plsvh]\n" );
+    fprintf( stdout, "usage: *scorr [-PQFCLNSD <num>] [-plvh]\n" );
     fprintf( stdout, "\t         performs sequential sweep using K-step induction\n" );
     fprintf( stdout, "\t-P num : max partition size (0 = no partitioning) [default = %d]\n", pPars->nPartSize );
     fprintf( stdout, "\t-Q num : partition overlap (0 = no overlap) [default = %d]\n", pPars->nOverSize );
@@ -19280,7 +19285,6 @@ usage:
     fprintf( stdout, "\t-D num : min size of a clock domain used for synthesis [default = %d]\n", pPars->nMinDomSize );
     fprintf( stdout, "\t-p     : toggle alighning polarity of SAT variables [default = %s]\n", pPars->fPolarFlip? "yes": "no" );
     fprintf( stdout, "\t-l     : toggle latch correspondence only [default = %s]\n", pPars->fLatchCorr? "yes": "no" );
-    fprintf( stdout, "\t-s     : toggle skipping unaffected cones [default = %s]\n", pPars->fSkipCheck? "yes": "no" );
     fprintf( stdout, "\t-v     : toggle verbose output [default = %s]\n", pPars->fVerbose? "yes": "no" );
     fprintf( stdout, "\t-h     : print the command usage\n");
     return 1;
diff --git a/src/base/abci/abcDar.c b/src/base/abci/abcDar.c
index c64fb0f5..a142de31 100644
--- a/src/base/abci/abcDar.c
+++ b/src/base/abci/abcDar.c
@@ -1465,7 +1465,7 @@ Abc_Ntk_t * Abc_NtkDarLcorrNew( Abc_Ntk_t * pNtk, int nVarsMax, int nConfMax, in
 int Abc_NtkDarBmc( Abc_Ntk_t * pNtk, int nFrames, int nSizeMax, int nBTLimit, int fRewrite, int fNewAlgo, int fVerbose )
 {
     Aig_Man_t * pMan;
-    int RetValue = -1, clk = clock();
+    int status, RetValue = -1, clk = clock();
     // derive the AIG manager
     pMan = Abc_NtkToDar( pNtk, 0, 1 );
     if ( pMan == NULL )
@@ -1494,6 +1494,7 @@ int Abc_NtkDarBmc( Abc_Ntk_t * pNtk, int nFrames, int nSizeMax, int nBTLimit, in
     }
     else
     {
+/*
         Fra_BmcPerformSimple( pMan, nFrames, nBTLimit, fRewrite, fVerbose );
         FREE( pNtk->pModel );
         FREE( pNtk->pSeqModel );
@@ -1509,8 +1510,30 @@ int Abc_NtkDarBmc( Abc_Ntk_t * pNtk, int nFrames, int nSizeMax, int nBTLimit, in
             printf( "No output was asserted in %d frames. ", nFrames );
             RetValue = 1;
         }
+*/
+        int iFrame;
+        RetValue = Ssw_BmcDynamic( pMan, nFrames, nBTLimit, fVerbose, &iFrame );
+        FREE( pNtk->pModel );
+        FREE( pNtk->pSeqModel );
+        pNtk->pSeqModel = pMan->pSeqModel; pMan->pSeqModel = NULL;
+        if ( RetValue == 1 )
+            printf( "No output was asserted in %d frames. ", iFrame );
+        else if ( RetValue == -1 )
+            printf( "No output was asserted in %d frames. Reached conflict limit (%d). ", iFrame, nBTLimit );
+        else // if ( RetValue == 0 )
+        {
+            Fra_Cex_t * pCex = pNtk->pSeqModel;
+            printf( "Output %d was asserted in frame %d (use \"write_counter\" to dump a witness). ", pCex->iPo, pCex->iFrame );
+        }
     }
 PRT( "Time", clock() - clk );
+    // verify counter-example
+    if ( pNtk->pSeqModel ) 
+    {
+        status = Ssw_SmlRunCounterExample( pMan, pNtk->pSeqModel );
+        if ( status == 0 )
+            printf( "Abc_NtkDarBmc(): Counter-example verification has FAILED.\n" );
+    }
     Aig_ManStop( pMan );
     return RetValue;
 }
@@ -2128,7 +2151,7 @@ void Abc_NtkDarLocalize( Abc_Ntk_t * pNtk, int nFramesMax, int nConfMax, int fVe
     pMan = Abc_NtkToDar( pNtk, 0, 1 );
     if ( pMan == NULL )
         return;
-    RetValue = Saig_ManLocalization( pTemp = pMan, nFramesMax, nConfMax, fVerbose );
+    RetValue = Saig_ManInduction( pTemp = pMan, nFramesMax, nConfMax, fVerbose );
     Aig_ManStop( pTemp );
     if ( RetValue == 1 )
     {
diff --git a/src/base/abci/abcPrint.c b/src/base/abci/abcPrint.c
index 2e01a141..23a44eb3 100644
--- a/src/base/abci/abcPrint.c
+++ b/src/base/abci/abcPrint.c
@@ -114,7 +114,6 @@ int Abc_NtkCompareAndSaveBest( Abc_Ntk_t * pNtk )
 void Abc_NtkPrintStats( FILE * pFile, Abc_Ntk_t * pNtk, int fFactored, int fSaveBest, int fDumpResult, int fUseLutLib, int fPrintMuxes )
 {
     int Num;
-
     if ( fSaveBest )
         Abc_NtkCompareAndSaveBest( pNtk );
     if ( fDumpResult )
@@ -147,15 +146,11 @@ void Abc_NtkPrintStats( FILE * pFile, Abc_Ntk_t * pNtk, int fFactored, int fSave
         fprintf( pFile, "  and = %5d", Abc_NtkNodeNum(pNtk) );
         if ( (Num = Abc_NtkGetChoiceNum(pNtk)) )
             fprintf( pFile, " (choice = %d)", Num );
-        if ( (Num = Abc_NtkGetExorNum(pNtk)) )
-            fprintf( pFile, " (exor = %d)", Num );
-//        if ( Num2 = Abc_NtkGetMuxNum(pNtk) )
-//            fprintf( pFile, " (mux = %d)", Num2-Num );
-//        if ( Num2 )
-//            fprintf( pFile, " (other = %d)", Abc_NtkNodeNum(pNtk)-3*Num2 );
         if ( fPrintMuxes )
         {
             extern int Abc_NtkCountMuxes( Abc_Ntk_t * pNtk );
+            Num = Abc_NtkGetExorNum(pNtk);
+            fprintf( pFile, " (exor = %d)", Num );
             fprintf( pFile, " (mux = %d)", Abc_NtkCountMuxes(pNtk)-Num );
             fprintf( pFile, " (pure and = %d)", Abc_NtkNodeNum(pNtk) - (Abc_NtkCountMuxes(pNtk) * 3) );
         }
diff --git a/src/map/pcm/module.make b/src/map/pcm/module.make
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/src/map/pcm/module.make
diff --git a/src/map/ply/module.make b/src/map/ply/module.make
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/src/map/ply/module.make
diff --git a/src/misc/vec/vecInt.h b/src/misc/vec/vecInt.h
index 437b4d8e..c944df3f 100644
--- a/src/misc/vec/vecInt.h
+++ b/src/misc/vec/vecInt.h
@@ -382,12 +382,12 @@ static inline void Vec_IntGrow( Vec_Int_t * p, int nCapMin )
   SeeAlso     []
 
 ***********************************************************************/
-static inline void Vec_IntFill( Vec_Int_t * p, int nSize, int Entry )
+static inline void Vec_IntFill( Vec_Int_t * p, int nSize, int Fill )
 {
     int i;
     Vec_IntGrow( p, nSize );
     for ( i = 0; i < nSize; i++ )
-        p->pArray[i] = Entry;
+        p->pArray[i] = Fill;
     p->nSize = nSize;
 }
 
@@ -402,20 +402,40 @@ static inline void Vec_IntFill( Vec_Int_t * p, int nSize, int Entry )
   SeeAlso     []
 
 ***********************************************************************/
-static inline void Vec_IntFillExtra( Vec_Int_t * p, int nSize, int Entry )
+static inline void Vec_IntFillExtra( Vec_Int_t * p, int nSize, int Fill )
 {
     int i;
     if ( p->nSize >= nSize )
         return;
-    Vec_IntGrow( p, nSize );
+    if ( 2 * p->nSize > nSize )
+        Vec_IntGrow( p, 2 * nSize );
+    else
+        Vec_IntGrow( p, nSize );
     for ( i = p->nSize; i < nSize; i++ )
-        p->pArray[i] = Entry;
+        p->pArray[i] = Fill;
     p->nSize = nSize;
 }
 
 /**Function*************************************************************
 
-  Synopsis    []
+  Synopsis    [Returns the entry even if the place not exist.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Vec_IntGetEntry( Vec_Int_t * p, int i )
+{
+    Vec_IntFillExtra( p, i + 1, 0 );
+    return Vec_IntEntry( p, i );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Inserts the entry even if the place does not exist.]
 
   Description []
                
@@ -424,11 +444,9 @@ static inline void Vec_IntFillExtra( Vec_Int_t * p, int nSize, int Entry )
   SeeAlso     []
 
 ***********************************************************************/
-static inline void Vec_IntWriteEntryFill( Vec_Int_t * p, int i, int Entry )
+static inline void Vec_IntSetEntry( Vec_Int_t * p, int i, int Entry )
 {
-    assert( i >= 0 );
-    if ( i >= p->nSize )
-        Vec_IntFillExtra( p, 2 * i, 0 );
+    Vec_IntFillExtra( p, i + 1, 0 );
     Vec_IntWriteEntry( p, i, Entry );
 }
 
diff --git a/src/sat/bsat/satInter.c b/src/sat/bsat/satInter.c
index 6dc6db0c..fe2ed113 100644
--- a/src/sat/bsat/satInter.c
+++ b/src/sat/bsat/satInter.c
@@ -718,6 +718,27 @@ int Int_ManProofTraceOne( Int_Man_t * p, Sto_Cls_t * pConflict, Sto_Cls_t * pFin
             Int_ManPrintResolvent( p->pResLits, p->nResLits );
             Int_ManPrintClause( p, pFinal );
         }
+
+        // if there are literals in the clause that are not in the resolvent
+        // it means that the derived resolvent is stronger than the clause
+        // we can replace the clause with the resolvent by removing these literals
+        if ( p->nResLits != (int)pFinal->nLits )
+        {
+            for ( v1 = 0; v1 < (int)pFinal->nLits; v1++ )
+            {
+                for ( v2 = 0; v2 < p->nResLits; v2++ )
+                    if ( pFinal->pLits[v1] == p->pResLits[v2] )
+                        break;
+                if ( v2 < p->nResLits )
+                    continue;
+                // remove literal v1 from the final clause
+                pFinal->nLits--;
+                for ( v2 = v1; v2 < (int)pFinal->nLits; v2++ )
+                    pFinal->pLits[v2] = pFinal->pLits[v2+1];
+                v1--;
+            }
+            assert( p->nResLits == (int)pFinal->nLits );
+        }
     }
 p->timeTrace += clock() - clk;
 
@@ -727,6 +748,8 @@ p->timeTrace += clock() - clk;
 //        Int_ManPrintInterOne( p, pFinal );
     }
     Int_ManProofSet( p, pFinal, p->Counter );
+    // make sure the same proof ID is not asssigned to two consecutive clauses
+    assert( p->pProofNums[pFinal->Id-1] != p->Counter );
     return p->Counter;
 }
 
@@ -754,6 +777,13 @@ int Int_ManProofRecordOne( Int_Man_t * p, Sto_Cls_t * pClause )
     // add assumptions to the trail
     assert( !pClause->fRoot );
     assert( p->nTrailSize == p->nRootSize );
+
+    // if any of the clause literals are already assumed
+    // it means that the clause is redundant and can be skipped
+    for ( i = 0; i < (int)pClause->nLits; i++ )
+        if ( p->pAssigns[lit_var(pClause->pLits[i])] == pClause->pLits[i] )
+            return 1;
+
     for ( i = 0; i < (int)pClause->nLits; i++ )
         if ( !Int_ManEnqueue( p, lit_neg(pClause->pLits[i]), NULL ) )
         {
@@ -769,6 +799,27 @@ int Int_ManProofRecordOne( Int_Man_t * p, Sto_Cls_t * pClause )
         return 0;
     }
 
+    // skip the clause if it is weaker or the same as the conflict clause
+    if ( pClause->nLits >= pConflict->nLits )
+    {
+        // check if every literal of conflict clause can be found in the given clause
+        int j;
+        for ( i = 0; i < (int)pConflict->nLits; i++ )
+        {
+            for ( j = 0; j < (int)pClause->nLits; j++ )
+                if ( pConflict->pLits[i] == pClause->pLits[j] )
+                    break;
+            if ( j == (int)pClause->nLits ) // literal pConflict->pLits[i] is not found
+                break;
+        }
+        if ( i == (int)pConflict->nLits ) // all lits are found
+        {
+            // undo to the root level
+            Int_ManCancelUntil( p, p->nRootSize );
+            return 1;
+        }
+    }
+
     // construct the proof
     Int_ManProofTraceOne( p, pConflict, pClause );
 
@@ -854,8 +905,12 @@ int Int_ManProcessRoots( Int_Man_t * p )
         if ( !Int_ManEnqueue( p, pClause->pLits[0], pClause ) )
         {
             // detected root level conflict
-            printf( "Error in Int_ManProcessRoots(): Detected a root-level conflict too early!\n" );
-            assert( 0 );
+//            printf( "Error in Int_ManProcessRoots(): Detected a root-level conflict too early!\n" );
+//            assert( 0 );
+            // detected root level conflict
+            Int_ManProofTraceOne( p, pClause, p->pCnf->pEmpty );
+            if ( p->fVerbose )
+                printf( "Found root level conflict!\n" );
             return 0;
         }
     }