Version abc90315

4 files changed, 756 insertions, 5 deletions

diff --git a/src/aig/cec/cecCore.c b/src/aig/cec/cecCore.c
index 8e66179f..9274dcb8 100644
--- a/src/aig/cec/cecCore.c
+++ b/src/aig/cec/cecCore.c
@@ -282,6 +282,9 @@ p->timeSim += clock() - clk;
 //            Gia_ManEquivTransform( p->pAig, 1 );
         }
         pSrm = Cec_ManFraSpecReduction( p ); 
+
+//        Gia_WriteAiger( pSrm, "gia_srm.aig", 0, 0 );
+
         if ( pPars->fVeryVerbose )
             Gia_ManPrintStats( pSrm );
         if ( Gia_ManCoNum(pSrm) == 0 )
diff --git a/src/aig/gia/gia.h b/src/aig/gia/gia.h
index 1c3529ba..e3b3f014 100644
--- a/src/aig/gia/gia.h
+++ b/src/aig/gia/gia.h
@@ -435,14 +435,15 @@ static inline int *      Gia_ObjGateFanins( Gia_Man_t * p, int Id )         { re
 ///                    FUNCTION DECLARATIONS                         ///
 ////////////////////////////////////////////////////////////////////////
 
-/*=== giaAig.c ============================================================*/
+/*=== giaAig.c =============================================================*/
 extern Gia_Man_t *         Gia_ManFromAig( Aig_Man_t * p );
 extern Gia_Man_t *         Gia_ManFromAigSwitch( Aig_Man_t * p );
 extern Aig_Man_t *         Gia_ManToAig( Gia_Man_t * p );
-/*=== giaAiger.c ==========================================================*/
+/*=== giaAiger.c ===========================================================*/
 extern Gia_Man_t *         Gia_ReadAiger( char * pFileName, int fCheck );
 extern void                Gia_WriteAiger( Gia_Man_t * p, char * pFileName, int fWriteSymbols, int fCompact );
-/*=== giaCof.c ============================================================*/
+/*=== giaCsat.c ============================================================*/
+/*=== giaCof.c =============================================================*/
 extern void                Gia_ManPrintFanio( Gia_Man_t * pGia, int nNodes );
 extern Gia_Man_t *         Gia_ManDupCof( Gia_Man_t * p, int iVar );
 extern Gia_Man_t *         Gia_ManDupCofAllInt( Gia_Man_t * p, Vec_Int_t * vSigs, int fVerbose );
diff --git a/src/aig/gia/giaCSat0.c b/src/aig/gia/giaCSat0.c
index 599ad43c..a0d567a2 100644
--- a/src/aig/gia/giaCSat0.c
+++ b/src/aig/gia/giaCSat0.c
@@ -122,8 +122,10 @@ void Gia_SatVerifyPattern( Gia_Man_t * p, Gia_Obj_t * pRoot, Vec_Int_t * vCex, V
     }
     Value = Gia_XsimNotCond( Value, Gia_ObjFaninC0(pRoot) );
     if ( Value != GIA_ONE )
-        printf( "Gia_SatVerifyPattern(): Verification failed.\n" );
-    assert( Value == GIA_ONE );
+        printf( "Gia_SatVerifyPattern(): Verification FAILED.\n" );
+//    else
+//        printf( "Gia_SatVerifyPattern(): Verification succeeded.\n" );
+//    assert( Value == GIA_ONE );
     // clean the nodes
     Gia_ManForEachObjVec( vVisit, p, pObj, i )
         Sat_ObjSetXValue( pObj, 0 );
diff --git a/src/aig/gia/giaCSat2.c b/src/aig/gia/giaCSat2.c
new file mode 100644
index 00000000..1e7cc949
--- /dev/null
+++ b/src/aig/gia/giaCSat2.c
@@ -0,0 +1,745 @@
+/**CFile****************************************************************
+
+  FileName    [giaCSat2.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Scalable AIG package.]
+
+  Synopsis    [A simple circuit-based solver.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: giaCSat2.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "gia.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+typedef struct Cbs_Par_t_ Cbs_Par_t;
+struct Cbs_Par_t_
+{
+    // conflict limits
+    int           nBTLimit;     // limit on the number of conflicts
+    int           nJustLimit;   // limit on the size of justification queue
+    // current parameters
+    int           nBTThis;      // number of conflicts
+    int           nJustThis;    // max size of the frontier
+    int           nBTTotal;     // total number of conflicts
+    int           nJustTotal;   // total size of the frontier
+    // decision heuristics
+    int           fUseHighest;  // use node with the highest ID
+    int           fUseLowest;   // use node with the highest ID
+    int           fUseMaxFF;    // use node with the largest fanin fanout
+    // other
+    int           fVerbose;
+};
+
+typedef struct Cbs_Que_t_ Cbs_Que_t;
+struct Cbs_Que_t_
+{
+    int           iHead;        // beginning of the queue
+    int           iTail;        // end of the queue
+    int           nSize;        // allocated size
+    Gia_Obj_t **  pData;        // nodes stored in the queue
+};
+
+typedef struct Cbs_Man_t_ Cbs_Man_t;
+struct Cbs_Man_t_
+{
+    Cbs_Par_t     Pars;         // parameters
+    Gia_Man_t *   pAig;         // AIG manager
+    Cbs_Que_t     pProp;        // propagation queue
+    Cbs_Que_t     pJust;        // justification queue
+    Vec_Int_t *   vModel;       // satisfying assignment
+};
+
+static inline int   Cbs_VarIsAssigned( Gia_Obj_t * pVar )      { return pVar->fMark0;                        }
+static inline void  Cbs_VarAssign( Gia_Obj_t * pVar )          { assert(!pVar->fMark0); pVar->fMark0 = 1;    }
+static inline void  Cbs_VarUnassign( Gia_Obj_t * pVar )        { assert(pVar->fMark0);  pVar->fMark0 = 0; pVar->fMark1 = 0;         }
+static inline int   Cbs_VarValue( Gia_Obj_t * pVar )           { assert(pVar->fMark0);  return pVar->fMark1; }
+static inline void  Cbs_VarSetValue( Gia_Obj_t * pVar, int v ) { assert(pVar->fMark0);  pVar->fMark1 = v;    }
+static inline int   Cbs_VarIsJust( Gia_Obj_t * pVar )          { return Gia_ObjIsAnd(pVar) && !Cbs_VarIsAssigned(Gia_ObjFanin0(pVar)) && !Cbs_VarIsAssigned(Gia_ObjFanin1(pVar)); } 
+static inline int   Cbs_VarFanin0Value( Gia_Obj_t * pVar )     { return !Cbs_VarIsAssigned(Gia_ObjFanin0(pVar)) ? 2 : (Cbs_VarValue(Gia_ObjFanin0(pVar)) ^ Gia_ObjFaninC0(pVar)); }
+static inline int   Cbs_VarFanin1Value( Gia_Obj_t * pVar )     { return !Cbs_VarIsAssigned(Gia_ObjFanin1(pVar)) ? 2 : (Cbs_VarValue(Gia_ObjFanin1(pVar)) ^ Gia_ObjFaninC1(pVar)); }
+
+#define Cbs_QueForEachEntry( Que, pObj, i )                    \
+    for ( i = (Que).iHead; (i < (Que).iTail) && ((pObj) = (Que).pData[i]); i++ )
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Sets default values of the parameters.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Cbs_SetDefaultParams( Cbs_Par_t * pPars )
+{
+    memset( pPars, 0, sizeof(Cbs_Par_t) );
+    pPars->nBTLimit    =  1000;   // limit on the number of conflicts
+    pPars->nJustLimit  =   100;   // limit on the size of justification queue
+    pPars->fUseHighest =     1;   // use node with the highest ID
+    pPars->fUseLowest  =     0;   // use node with the highest ID
+    pPars->fUseMaxFF   =     0;   // use node with the largest fanin fanout
+    pPars->fVerbose    =     1;   // print detailed statistics
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Cbs_Man_t * Cbs_ManAlloc()
+{
+    Cbs_Man_t * p;
+    p = ABC_CALLOC( Cbs_Man_t, 1 );
+    p->pProp.nSize = p->pJust.nSize = 10000;
+    p->pProp.pData = ABC_ALLOC( Gia_Obj_t *, p->pProp.nSize );
+    p->pJust.pData = ABC_ALLOC( Gia_Obj_t *, p->pJust.nSize );
+    p->vModel = Vec_IntAlloc( 1000 );
+    Cbs_SetDefaultParams( &p->Pars );
+    return p;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Cbs_ManStop( Cbs_Man_t * p )
+{
+    Vec_IntFree( p->vModel );
+    ABC_FREE( p->pProp.pData );
+    ABC_FREE( p->pJust.pData );
+    ABC_FREE( p );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Returns satisfying assignment.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Int_t * Cbs_ReadModel( Cbs_Man_t * p )
+{
+    return p->vModel;
+}
+
+
+
+
+/**Function*************************************************************
+
+  Synopsis    [Returns 1 if the solver is out of limits.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Cbs_ManCheckLimits( Cbs_Man_t * p )
+{
+    return p->Pars.nJustThis > p->Pars.nJustLimit || p->Pars.nBTThis > p->Pars.nBTLimit;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Saves the satisfying assignment as an array of literals.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Cbs_ManSaveModel( Cbs_Man_t * p, Vec_Int_t * vCex )
+{
+    Gia_Obj_t * pVar;
+    int i;
+    Vec_IntClear( vCex );
+    p->pProp.iHead = 0;
+    Cbs_QueForEachEntry( p->pProp, pVar, i )
+        if ( Gia_ObjIsCi(pVar) )
+            Vec_IntPush( vCex, Gia_Var2Lit(Gia_ObjId(p->pAig,pVar), !Cbs_VarValue(pVar)) );
+} 
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Cbs_QueIsEmpty( Cbs_Que_t * p )
+{
+    return p->iHead == p->iTail;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Cbs_QuePush( Cbs_Que_t * p, Gia_Obj_t * pObj )
+{
+    if ( p->iTail == p->nSize )
+    {
+        p->nSize *= 2;
+        p->pData = ABC_REALLOC( Gia_Obj_t *, p->pData, p->nSize ); 
+    }
+    p->pData[p->iTail++] = pObj;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Returns 1 if the object in the queue.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Cbs_QueHasNode( Cbs_Que_t * p, Gia_Obj_t * pObj )
+{
+    Gia_Obj_t * pTemp;
+    int i;
+    Cbs_QueForEachEntry( *p, pTemp, i )
+        if ( pTemp == pObj )
+            return 1;
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Cbs_QueStore( Cbs_Que_t * p, int * piHeadOld, int * piTailOld )
+{
+    int i;
+    *piHeadOld = p->iHead;
+    *piTailOld = p->iTail;
+    for ( i = *piHeadOld; i < *piTailOld; i++ )
+        Cbs_QuePush( p, p->pData[i] );
+    p->iHead = *piTailOld;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Cbs_QueRestore( Cbs_Que_t * p, int iHeadOld, int iTailOld )
+{
+    p->iHead = iHeadOld;
+    p->iTail = iTailOld;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Max number of fanins fanouts.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Cbs_VarFaninFanoutMax( Cbs_Man_t * p, Gia_Obj_t * pObj )
+{
+    int Count0, Count1;
+    assert( !Gia_IsComplement(pObj) );
+    assert( Gia_ObjIsAnd(pObj) );
+    Count0 = Gia_ObjRefs( p->pAig, Gia_ObjFanin0(pObj) );
+    Count1 = Gia_ObjRefs( p->pAig, Gia_ObjFanin1(pObj) );
+    return ABC_MAX( Count0, Count1 );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Find variable with the highest ID.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline Gia_Obj_t * Cbs_ManDecideHighest( Cbs_Man_t * p )
+{
+    Gia_Obj_t * pObj, * pObjMax = NULL;
+    int i;
+    Cbs_QueForEachEntry( p->pJust, pObj, i )
+        if ( pObjMax == NULL || pObjMax < pObj )
+            pObjMax = pObj;
+    return pObjMax;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Find variable with the lowest ID.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline Gia_Obj_t * Cbs_ManDecideLowest( Cbs_Man_t * p )
+{
+    Gia_Obj_t * pObj, * pObjMin = NULL;
+    int i;
+    Cbs_QueForEachEntry( p->pJust, pObj, i )
+        if ( pObjMin == NULL || pObjMin > pObj )
+            pObjMin = pObj;
+    return pObjMin;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Find variable with the maximum number of fanin fanouts.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline Gia_Obj_t * Cbs_ManDecideMaxFF( Cbs_Man_t * p )
+{
+    Gia_Obj_t * pObj, * pObjMax = NULL;
+    int i, iMaxFF = 0, iCurFF;
+    assert( p->pAig->pRefs != NULL );
+    Cbs_QueForEachEntry( p->pJust, pObj, i )
+    {
+        iCurFF = Cbs_VarFaninFanoutMax( p, pObj );
+        assert( iCurFF > 0 );
+        if ( iMaxFF < iCurFF )
+        {
+            iMaxFF = iCurFF;
+            pObjMax = pObj;
+        }
+    }
+    return pObjMax;
+}
+
+
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Cbs_ManCancelUntil( Cbs_Man_t * p, int iBound )
+{
+    Gia_Obj_t * pVar;
+    int i;
+    assert( iBound <= p->pProp.iTail );
+    p->pProp.iHead = iBound;
+    Cbs_QueForEachEntry( p->pProp, pVar, i )
+        Cbs_VarUnassign( pVar );
+    p->pProp.iTail = iBound;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Assigns the variables a value.]
+
+  Description [Returns 1 if conflict; 0 if no conflict.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Cbs_ManAssign( Cbs_Man_t * p, Gia_Obj_t * pObj )
+{
+    Gia_Obj_t * pObjR = Gia_Regular(pObj);
+    assert( Gia_ObjIsCand(pObjR) );
+    assert( !Cbs_VarIsAssigned(pObjR) );
+    Cbs_VarAssign( pObjR );
+    Cbs_VarSetValue( pObjR, !Gia_IsComplement(pObj) );
+    Cbs_QuePush( &p->pProp, pObjR );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Propagates a variable.]
+
+  Description [Returns 1 if conflict; 0 if no conflict.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Cbs_ManPropagateOne( Cbs_Man_t * p, Gia_Obj_t * pVar )
+{
+    int Value0, Value1;
+    assert( !Gia_IsComplement(pVar) );
+    assert( Cbs_VarIsAssigned(pVar) );
+    if ( Gia_ObjIsCi(pVar) )
+        return 0;
+    assert( Gia_ObjIsAnd(pVar) );
+    Value0 = Cbs_VarFanin0Value(pVar);
+    Value1 = Cbs_VarFanin1Value(pVar);
+    if ( Cbs_VarValue(pVar) )
+    { // value is 1
+        if ( Value0 == 0 || Value1 == 0 ) // one is 0
+            return 1;
+        if ( Value0 == 2 ) // first is unassigned
+            Cbs_ManAssign( p, Gia_ObjChild0(pVar) );
+        if ( Value1 == 2 ) // first is unassigned
+            Cbs_ManAssign( p, Gia_ObjChild1(pVar) );
+        return 0;
+    }
+    // value is 0
+    if ( Value0 == 0 || Value1 == 0 ) // one is 0
+        return 0;
+    if ( Value0 == 1 && Value1 == 1 ) // both are 1
+        return 1;
+    if ( Value0 == 1 || Value1 == 1 ) // one is 1 
+    {
+        if ( Value0 == 2 ) // first is unassigned
+            Cbs_ManAssign( p, Gia_Not(Gia_ObjChild0(pVar)) );
+        if ( Value1 == 2 ) // first is unassigned
+            Cbs_ManAssign( p, Gia_Not(Gia_ObjChild1(pVar)) );
+        return 0;
+    }
+    assert( Cbs_VarIsJust(pVar) );
+    assert( !Cbs_QueHasNode( &p->pJust, pVar ) );
+    Cbs_QuePush( &p->pJust, pVar );
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Propagates a variable.]
+
+  Description [Returns 1 if conflict; 0 if no conflict.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Cbs_ManPropagateTwo( Cbs_Man_t * p, Gia_Obj_t * pVar )
+{
+    int Value0, Value1;
+    assert( !Gia_IsComplement(pVar) );
+    assert( Gia_ObjIsAnd(pVar) );
+    assert( Cbs_VarIsAssigned(pVar) );
+    assert( !Cbs_VarValue(pVar) );
+    Value0 = Cbs_VarFanin0Value(pVar);
+    Value1 = Cbs_VarFanin1Value(pVar);
+    // value is 0
+    if ( Value0 == 0 || Value1 == 0 ) // one is 0
+        return 0;
+    if ( Value0 == 1 && Value1 == 1 ) // both are 1
+        return 1;
+    assert( Value0 == 1 || Value1 == 1 );
+    if ( Value0 == 2 ) // first is unassigned
+        Cbs_ManAssign( p, Gia_Not(Gia_ObjChild0(pVar)) );
+    if ( Value1 == 2 ) // first is unassigned
+        Cbs_ManAssign( p, Gia_Not(Gia_ObjChild1(pVar)) );
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Propagates all variables.]
+
+  Description [Returns 1 if conflict; 0 if no conflict.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Cbs_ManPropagate( Cbs_Man_t * p )
+{
+    Gia_Obj_t * pVar;
+    int i, k;
+    while ( 1 )
+    {
+        Cbs_QueForEachEntry( p->pProp, pVar, i )
+        {
+            if ( Cbs_ManPropagateOne( p, pVar ) )
+                return 1;
+        }
+        p->pProp.iHead = p->pProp.iTail;
+        k = p->pJust.iHead;
+        Cbs_QueForEachEntry( p->pJust, pVar, i )
+        {
+            if ( Cbs_VarIsJust( pVar ) )
+                p->pJust.pData[k++] = pVar;
+            else if ( Cbs_ManPropagateTwo( p, pVar ) )
+                return 1;
+        }
+        if ( k == p->pJust.iTail )
+            break;
+        p->pJust.iTail = k;
+    }
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Solve the problem recursively.]
+
+  Description [Returns 1 if unsat or undecided; 0 if satisfiable.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Cbs_ManSolve_rec( Cbs_Man_t * p )
+{
+    Gia_Obj_t * pVar;
+    int iPropHead, iJustHead, iJustTail;
+    // propagate assignments
+    assert( !Cbs_QueIsEmpty(&p->pProp) );
+    if ( Cbs_ManPropagate( p ) )
+        return 1;
+    // check for satisfying assignment
+    assert( Cbs_QueIsEmpty(&p->pProp) );
+    if ( Cbs_QueIsEmpty(&p->pJust) )
+        return 0;
+    // quit using resource limits
+    p->Pars.nBTThis++;
+    p->Pars.nJustThis = ABC_MAX( p->Pars.nJustThis, p->pJust.iTail - p->pJust.iHead );
+    if ( Cbs_ManCheckLimits( p ) )
+        return 1;
+    // remember the state before branching
+    iPropHead = p->pProp.iHead;
+    Cbs_QueStore( &p->pJust, &iJustHead, &iJustTail );
+    // find the decision variable
+    if ( p->Pars.fUseHighest )
+        pVar = Cbs_ManDecideHighest( p );
+    else if ( p->Pars.fUseLowest )
+        pVar = Cbs_ManDecideLowest( p );
+    else if ( p->Pars.fUseMaxFF )
+        pVar = Cbs_ManDecideMaxFF( p );
+    else assert( 0 );
+    assert( Cbs_VarIsJust( pVar ) );
+    // decide using fanout count!
+    if ( Gia_ObjRefs(p->pAig, Gia_ObjFanin0(pVar)) < Gia_ObjRefs(p->pAig, Gia_ObjFanin1(pVar)) )
+    {
+        // decide on first fanin
+        Cbs_ManAssign( p, Gia_Not(Gia_ObjChild0(pVar)) );
+        if ( !Cbs_ManSolve_rec( p ) )
+            return 0;
+        if ( Cbs_ManCheckLimits( p ) )
+            return 1;
+        Cbs_ManCancelUntil( p, iPropHead );
+        Cbs_QueRestore( &p->pJust, iJustHead, iJustTail );
+        // decide on second fanin
+        Cbs_ManAssign( p, Gia_Not(Gia_ObjChild1(pVar)) );
+    }
+    else
+    {
+        // decide on first fanin
+        Cbs_ManAssign( p, Gia_Not(Gia_ObjChild1(pVar)) );
+        if ( !Cbs_ManSolve_rec( p ) )
+            return 0;
+        if ( Cbs_ManCheckLimits( p ) )
+            return 1;
+        Cbs_ManCancelUntil( p, iPropHead );
+        Cbs_QueRestore( &p->pJust, iJustHead, iJustTail );
+        // decide on second fanin
+        Cbs_ManAssign( p, Gia_Not(Gia_ObjChild0(pVar)) );
+    }
+    if ( !Cbs_ManSolve_rec( p ) )
+        return 0;
+    if ( Cbs_ManCheckLimits( p ) )
+        return 1;
+    return 1;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Looking for a satisfying assignment of the node.]
+
+  Description [Assumes that each node has flag pObj->fMark0 set to 0.
+  Returns 1 if unsatisfiable, 0 if satisfiable, and -1 if undecided.
+  The node may be complemented. ]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Cbs_ManSolve( Cbs_Man_t * p, Gia_Obj_t * pObj )
+{
+//    Gia_Obj_t * pTemp;
+//    int i;
+    int RetValue;
+//    Gia_ManForEachObj( p->pAig, pTemp, i )
+//        assert( pTemp->fMark0 == 0 );
+    assert( !p->pProp.iHead && !p->pProp.iTail );
+    assert( !p->pJust.iHead && !p->pJust.iTail );
+    p->Pars.nBTThis = p->Pars.nJustThis = 0;
+    Cbs_ManAssign( p, pObj );
+    RetValue = Cbs_ManSolve_rec( p );
+    if ( RetValue == 0 )
+        Cbs_ManSaveModel( p, p->vModel );
+    Cbs_ManCancelUntil( p, 0 );
+    p->pJust.iHead = p->pJust.iTail = 0;
+    p->Pars.nBTTotal += p->Pars.nBTThis;
+    p->Pars.nJustTotal = ABC_MAX( p->Pars.nJustTotal, p->Pars.nJustThis );
+    if ( Cbs_ManCheckLimits( p ) )
+        return -1;
+    return RetValue;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Procedure to test the new SAT solver.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Cbs_ManSolveTest( Gia_Man_t * pGia )
+{
+    extern void Gia_SatVerifyPattern( Gia_Man_t * p, Gia_Obj_t * pRoot, Vec_Int_t * vCex, Vec_Int_t * vVisit );
+    int nConfsMax = 1000;
+    int CountUnsat, CountSat, CountUndec;
+    Cbs_Man_t * p; 
+    Vec_Int_t * vCex;
+    Vec_Int_t * vVisit;
+    Gia_Obj_t * pRoot; 
+    int i, RetValue, clk = clock();
+    Gia_ManCreateRefs( pGia );
+    // create logic network
+    p = Cbs_ManAlloc();
+    p->pAig = pGia;
+    // prepare AIG
+    Gia_ManCleanValue( pGia );
+    Gia_ManCleanMark0( pGia );
+    Gia_ManCleanMark1( pGia );
+//    vCex   = Vec_IntAlloc( 100 );
+    vVisit = Vec_IntAlloc( 100 );
+    // solve for each output
+    CountUnsat = CountSat = CountUndec = 0;
+    Gia_ManForEachCo( pGia, pRoot, i )
+    {
+        if ( Gia_ObjIsConst0(Gia_ObjFanin0(pRoot)) )
+            continue;
+
+//        Gia_ManIncrementTravId( pGia );
+
+//printf( "Output %6d : ", i );
+//        iLit = Gia_Var2Lit( Gia_ObjHandle(Gia_ObjFanin0(pRoot)), Gia_ObjFaninC0(pRoot) );
+//        RetValue = Cbs_ManSolve( p, &iLit, 1, nConfsMax, vCex );
+        RetValue = Cbs_ManSolve( p, Gia_ObjChild0(pRoot) );
+        if ( RetValue == 1 )
+            CountUnsat++;
+        else if ( RetValue == -1 )
+            CountUndec++;
+        else 
+        {
+            int iLit, k;
+            vCex = Cbs_ReadModel( p );
+
+//        printf( "complemented = %d.  ", Gia_ObjFaninC0(pRoot) );
+//printf( "conflicts = %6d  max-frontier = %6d \n", p->Pars.nBTThis, p->Pars.nJustThis );
+//            Vec_IntForEachEntry( vCex, iLit, k )
+//                printf( "%s%d ", Gia_LitIsCompl(iLit)? "!": "", Gia_ObjCioId(Gia_ManObj(pGia,Gia_Lit2Var(iLit))) );
+//            printf( "\n" );
+
+            Gia_SatVerifyPattern( pGia, pRoot, vCex, vVisit );
+            assert( RetValue == 0 );
+            CountSat++;
+        }
+//        Gia_ManCheckMark0( p );
+//        Gia_ManCheckMark1( p );
+    }
+    Cbs_ManStop( p );
+//    Vec_IntFree( vCex );
+    Vec_IntFree( vVisit );
+    printf( "Unsat = %d. Sat = %d. Undec = %d.  ", CountUnsat, CountSat, CountUndec );
+    ABC_PRT( "Time", clock() - clk );
+}
+
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+