initial commit of public abc

1 files changed, 1788 insertions, 0 deletions

diff --git a/src/aig/gia/giaCTas.c b/src/aig/gia/giaCTas.c
new file mode 100644
index 00000000..c6aa3fec
--- /dev/null
+++ b/src/aig/gia/giaCTas.c
@@ -0,0 +1,1788 @@
+/**CFile****************************************************************
+
+  FileName    [giaCSat.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: giaCSat.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "gia.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+//#define gia_assert(exp)     ((void)0)
+//#define gia_assert(exp)     (assert(exp))
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+typedef struct Tas_Par_t_ Tas_Par_t;
+struct Tas_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           nBTThisNc;    // number of conflicts
+    int           nJustThis;    // max size of the frontier
+    int           nBTTotal;     // total number of conflicts
+    int           nJustTotal;   // total size of the frontier
+    // activity
+    float         VarDecay;     // variable activity decay
+    int           VarInc;       // variable increment
+    // decision heuristics
+    int           fUseActive;   // use most active
+    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 Tas_Cls_t_ Tas_Cls_t;
+struct Tas_Cls_t_
+{
+    int           iNext[2];     // beginning of the queue
+    int           nLits;        // the number of literals
+    int           pLits[0];     // clause literals
+};
+
+typedef struct Tas_Sto_t_ Tas_Sto_t;
+struct Tas_Sto_t_
+{
+    int           iCur;         // current position
+    int           nSize;        // allocated size
+    int *         pData;        // clause information
+};
+
+typedef struct Tas_Que_t_ Tas_Que_t;
+struct Tas_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
+};
+ 
+struct Tas_Man_t_
+{
+    Tas_Par_t     Pars;         // parameters
+    Gia_Man_t *   pAig;         // AIG manager
+    Tas_Que_t     pProp;        // propagation queue
+    Tas_Que_t     pJust;        // justification queue
+    Tas_Que_t     pClauses;     // clause queue
+    Gia_Obj_t **  pIter;        // iterator through clause vars
+    Vec_Int_t *   vLevReas;     // levels and decisions
+    Vec_Int_t *   vModel;       // satisfying assignment
+    Vec_Ptr_t *   vTemp;        // temporary storage
+    // watched clauses
+    Tas_Sto_t     pStore;       // storage for watched clauses
+    int *         pWatches;     // watched lists for each literal
+    Vec_Int_t *   vWatchLits;   // lits whose watched are assigned
+    int           nClauses;     // the counter of clauses
+    // activity
+    float *       pActivity;    // variable activity
+    Vec_Int_t *   vActiveVars;  // variables with activity
+    // SAT calls statistics
+    int           nSatUnsat;    // the number of proofs
+    int           nSatSat;      // the number of failure
+    int           nSatUndec;    // the number of timeouts
+    int           nSatTotal;    // the number of calls
+    // conflicts
+    int           nConfUnsat;   // conflicts in unsat problems
+    int           nConfSat;     // conflicts in sat problems
+    int           nConfUndec;   // conflicts in undec problems
+    // runtime stats
+    int           timeSatUnsat; // unsat
+    int           timeSatSat;   // sat
+    int           timeSatUndec; // undecided
+    int           timeTotal;    // total runtime
+};
+
+static inline int   Tas_VarIsAssigned( Gia_Obj_t * pVar )      { return pVar->fMark0;                        }
+static inline void  Tas_VarAssign( Gia_Obj_t * pVar )          { assert(!pVar->fMark0); pVar->fMark0 = 1;    }
+static inline void  Tas_VarUnassign( Gia_Obj_t * pVar )        { assert(pVar->fMark0);  pVar->fMark0 = 0; pVar->fMark1 = 0; pVar->Value = ~0; }
+static inline int   Tas_VarValue( Gia_Obj_t * pVar )           { assert(pVar->fMark0);  return pVar->fMark1; }
+static inline void  Tas_VarSetValue( Gia_Obj_t * pVar, int v ) { assert(pVar->fMark0);  pVar->fMark1 = v;    }
+static inline int   Tas_VarIsJust( Gia_Obj_t * pVar )          { return Gia_ObjIsAnd(pVar) && !Tas_VarIsAssigned(Gia_ObjFanin0(pVar)) && !Tas_VarIsAssigned(Gia_ObjFanin1(pVar)); } 
+static inline int   Tas_VarFanin0Value( Gia_Obj_t * pVar )     { return !Tas_VarIsAssigned(Gia_ObjFanin0(pVar)) ? 2 : (Tas_VarValue(Gia_ObjFanin0(pVar)) ^ Gia_ObjFaninC0(pVar)); }
+static inline int   Tas_VarFanin1Value( Gia_Obj_t * pVar )     { return !Tas_VarIsAssigned(Gia_ObjFanin1(pVar)) ? 2 : (Tas_VarValue(Gia_ObjFanin1(pVar)) ^ Gia_ObjFaninC1(pVar)); }
+static inline int   Tas_VarToLit( Tas_Man_t * p, Gia_Obj_t * pObj ) { assert( Tas_VarIsAssigned(pObj) ); return Gia_Var2Lit( Gia_ObjId(p->pAig, pObj), !Tas_VarValue(pObj) );     }
+static inline int   Tas_LitIsTrue( Gia_Obj_t * pObj, int Lit ) { assert( Tas_VarIsAssigned(pObj) ); return Tas_VarValue(pObj) != Gia_LitIsCompl(Lit);                             }
+
+static inline int         Tas_ClsHandle( Tas_Man_t * p, Tas_Cls_t * pClause ) { return ((int *)pClause) - p->pStore.pData;   }
+static inline Tas_Cls_t * Tas_ClsFromHandle( Tas_Man_t * p, int h )           { return (Tas_Cls_t *)(p->pStore.pData + h);   }
+
+static inline int         Tas_VarDecLevel( Tas_Man_t * p, Gia_Obj_t * pVar )  { assert( pVar->Value != ~0 ); return Vec_IntEntry(p->vLevReas, 3*pVar->Value);          }
+static inline Gia_Obj_t * Tas_VarReason0( Tas_Man_t * p, Gia_Obj_t * pVar )   { assert( pVar->Value != ~0 ); return pVar + Vec_IntEntry(p->vLevReas, 3*pVar->Value+1); }
+static inline Gia_Obj_t * Tas_VarReason1( Tas_Man_t * p, Gia_Obj_t * pVar )   { assert( pVar->Value != ~0 ); return pVar + Vec_IntEntry(p->vLevReas, 3*pVar->Value+2); }
+static inline int         Tas_ClauseDecLevel( Tas_Man_t * p, int hClause )    { return Tas_VarDecLevel( p, p->pClauses.pData[hClause] );                               }
+
+static inline int         Tas_VarHasReasonCls( Tas_Man_t * p, Gia_Obj_t * pVar ) { assert( pVar->Value != ~0 ); return Vec_IntEntry(p->vLevReas, 3*pVar->Value+1) == 0 && Vec_IntEntry(p->vLevReas, 3*pVar->Value+2) != 0; }
+static inline Tas_Cls_t * Tas_VarReasonCls( Tas_Man_t * p, Gia_Obj_t * pVar )    { assert( pVar->Value != ~0 ); return Tas_ClsFromHandle( p, Vec_IntEntry(p->vLevReas, 3*pVar->Value+2) );                                 }
+
+#define Tas_QueForEachEntry( Que, pObj, i )                         \
+    for ( i = (Que).iHead; (i < (Que).iTail) && ((pObj) = (Que).pData[i]); i++ )
+
+#define Tas_ClauseForEachVar( p, hClause, pObj )                    \
+    for ( (p)->pIter = (p)->pClauses.pData + hClause; (pObj = *pIter); (p)->pIter++ )
+#define Tas_ClauseForEachVar1( p, hClause, pObj )                   \
+    for ( (p)->pIter = (p)->pClauses.pData+hClause+1; (pObj = *pIter); (p)->pIter++ )
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Sets default values of the parameters.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Tas_SetDefaultParams( Tas_Par_t * pPars )
+{
+    memset( pPars, 0, sizeof(Tas_Par_t) );
+    pPars->nBTLimit    =        2000;   // limit on the number of conflicts
+    pPars->nJustLimit  =        2000;   // limit on the size of justification queue
+    pPars->fUseActive  =           0;   // use node with the highest activity
+    pPars->fUseHighest =           1;   // use node with the highest ID
+    pPars->fUseLowest  =           0;   // use node with the lowest ID
+    pPars->fUseMaxFF   =           0;   // use node with the largest fanin fanout
+    pPars->fVerbose    =           1;   // print detailed statistics
+    pPars->VarDecay    = (float)0.95;   // variable decay
+    pPars->VarInc      =         1.0;   // variable increment
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Tas_Man_t * Tas_ManAlloc( Gia_Man_t * pAig, int nBTLimit )
+{
+    Tas_Man_t * p;
+    p = ABC_CALLOC( Tas_Man_t, 1 );
+    Tas_SetDefaultParams( &p->Pars );
+    p->pAig           = pAig;
+    p->Pars.nBTLimit  = nBTLimit;
+    p->pProp.nSize    = p->pJust.nSize = p->pClauses.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->pClauses.pData = ABC_ALLOC( Gia_Obj_t *, p->pClauses.nSize );
+    p->pClauses.iHead = p->pClauses.iTail = 1;
+    p->vModel         = Vec_IntAlloc( 1000 );
+    p->vLevReas       = Vec_IntAlloc( 1000 );
+    p->vTemp          = Vec_PtrAlloc( 1000 );
+    p->pStore.iCur    = 16;
+    p->pStore.nSize   = 10000;
+    p->pStore.pData   = ABC_ALLOC( int, p->pStore.nSize );
+    p->pWatches       = ABC_CALLOC( int, 2 * Gia_ManObjNum(pAig) );
+    p->vWatchLits     = Vec_IntAlloc( 100 );
+    p->pActivity      = ABC_CALLOC( float, Gia_ManObjNum(pAig) );
+    p->vActiveVars    = Vec_IntAlloc( 100 );
+    return p;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Tas_ManStop( Tas_Man_t * p )
+{
+    Vec_IntFree( p->vActiveVars );
+    Vec_IntFree( p->vWatchLits );
+    Vec_IntFree( p->vLevReas );
+    Vec_IntFree( p->vModel );
+    Vec_PtrFree( p->vTemp );
+    ABC_FREE( p->pActivity );
+    ABC_FREE( p->pWatches );
+    ABC_FREE( p->pStore.pData );
+    ABC_FREE( p->pClauses.pData );
+    ABC_FREE( p->pProp.pData );
+    ABC_FREE( p->pJust.pData );
+    ABC_FREE( p );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Returns satisfying assignment.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Int_t * Tas_ReadModel( Tas_Man_t * p )
+{
+    return p->vModel;
+}
+
+
+
+
+/**Function*************************************************************
+
+  Synopsis    [Returns 1 if the solver is out of limits.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Tas_ManCheckLimits( Tas_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 Tas_ManSaveModel( Tas_Man_t * p, Vec_Int_t * vCex )
+{
+    Gia_Obj_t * pVar;
+    int i;
+    Vec_IntClear( vCex );
+    p->pProp.iHead = 0;
+//    printf( "\n" );
+    Tas_QueForEachEntry( p->pProp, pVar, i )
+    {
+        if ( Gia_ObjIsCi(pVar) )
+//            Vec_IntPush( vCex, Gia_Var2Lit(Gia_ObjId(p->pAig,pVar), !Tas_VarValue(pVar)) );
+            Vec_IntPush( vCex, Gia_Var2Lit(Gia_ObjCioId(pVar), !Tas_VarValue(pVar)) );
+/*
+        printf( "%5d(%d) = ", Gia_ObjId(p->pAig, pVar), Tas_VarValue(pVar) );
+        if ( Gia_ObjIsCi(pVar) )
+            printf( "pi %d\n", Gia_ObjCioId(pVar) );
+        else
+        {
+            printf( "%5d %d  &  ", Gia_ObjFaninId0p(p->pAig, pVar), Gia_ObjFaninC0(pVar) );
+            printf( "%5d %d     ", Gia_ObjFaninId1p(p->pAig, pVar), Gia_ObjFaninC1(pVar) );
+            printf( "\n" );
+        }
+*/
+    }
+} 
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Tas_QueIsEmpty( Tas_Que_t * p )
+{
+    return p->iHead == p->iTail;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Tas_QuePush( Tas_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 Tas_QueHasNode( Tas_Que_t * p, Gia_Obj_t * pObj )
+{
+    Gia_Obj_t * pTemp;
+    int i;
+    Tas_QueForEachEntry( *p, pTemp, i )
+        if ( pTemp == pObj )
+            return 1;
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Tas_QueStore( Tas_Que_t * p, int * piHeadOld, int * piTailOld )
+{
+    int i;
+    *piHeadOld = p->iHead;
+    *piTailOld = p->iTail;
+    for ( i = *piHeadOld; i < *piTailOld; i++ )
+        Tas_QuePush( p, p->pData[i] );
+    p->iHead = *piTailOld;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Tas_QueRestore( Tas_Que_t * p, int iHeadOld, int iTailOld )
+{
+    p->iHead = iHeadOld;
+    p->iTail = iTailOld;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Finalized the clause.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Tas_QueFinish( Tas_Que_t * p )
+{
+    int iHeadOld = p->iHead;
+    assert( p->iHead < p->iTail );
+    Tas_QuePush( p, NULL );
+    p->iHead = p->iTail;
+    return iHeadOld;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Max number of fanins fanouts.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Tas_VarFaninFanoutMax( Tas_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 activity.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline Gia_Obj_t * Tas_ManFindActive( Tas_Man_t * p )
+{
+    Gia_Obj_t * pObj, * pObjMax = NULL;
+    float BestCost = 0.0;
+    int i, ObjId;
+    Tas_QueForEachEntry( p->pJust, pObj, i )
+    {
+        assert( Gia_ObjIsAnd(pObj) );
+        ObjId = Gia_ObjId( p->pAig, pObj );
+        if ( pObjMax == NULL || 
+             p->pActivity[Gia_ObjFaninId0(pObj,ObjId)] > BestCost || 
+            (p->pActivity[Gia_ObjFaninId0(pObj,ObjId)] == BestCost && pObjMax < Gia_ObjFanin0(pObj)) )
+        {
+            pObjMax  = Gia_ObjFanin0(pObj);
+            BestCost = p->pActivity[Gia_ObjFaninId0(pObj,ObjId)];
+        }
+        if ( p->pActivity[Gia_ObjFaninId1(pObj,ObjId)] > BestCost || 
+            (p->pActivity[Gia_ObjFaninId1(pObj,ObjId)] == BestCost && pObjMax < Gia_ObjFanin1(pObj)) )
+        {
+            pObjMax  = Gia_ObjFanin1(pObj);
+            BestCost = p->pActivity[Gia_ObjFaninId1(pObj,ObjId)];
+        }
+    }
+    return pObjMax;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Find variable with the highest activity.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline Gia_Obj_t * Tas_ManDecideHighestFanin( Tas_Man_t * p )
+{
+    Gia_Obj_t * pObj, * pObjMax = NULL;
+    int i, ObjId;
+    Tas_QueForEachEntry( p->pJust, pObj, i )
+    {
+        assert( Gia_ObjIsAnd(pObj) );
+        ObjId = Gia_ObjId( p->pAig, pObj );
+        if ( pObjMax == NULL || pObjMax < Gia_ObjFanin0(pObj) )
+            pObjMax  = Gia_ObjFanin0(pObj);
+        if ( pObjMax < Gia_ObjFanin1(pObj) )
+            pObjMax  = Gia_ObjFanin1(pObj);
+    }
+    return pObjMax;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Find variable with the highest ID.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline Gia_Obj_t * Tas_ManDecideHighest( Tas_Man_t * p )
+{
+    Gia_Obj_t * pObj, * pObjMax = NULL;
+    int i;
+    Tas_QueForEachEntry( p->pJust, pObj, i )
+    {
+//printf( "%d %6.2f   ", Gia_ObjId(p->pAig, pObj), p->pActivity[Gia_ObjId(p->pAig, pObj)] );
+        if ( pObjMax == NULL || pObjMax < pObj )
+            pObjMax = pObj;
+    }
+//printf( "\n" );
+    return pObjMax;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Find variable with the highest ID.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline Gia_Obj_t * Tas_ManDecideHighestA( Tas_Man_t * p )
+{
+    Gia_Obj_t * pObj, * pObjMax = NULL;
+    int i;
+    Tas_QueForEachEntry( p->pJust, pObj, i )
+    {
+        if ( pObjMax == NULL || 
+             p->pActivity[Gia_ObjId(p->pAig, pObjMax)] < p->pActivity[Gia_ObjId(p->pAig, pObj)] )
+            pObjMax = pObj;
+    }
+    return pObjMax;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Find variable with the lowest ID.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline Gia_Obj_t * Tas_ManDecideLowest( Tas_Man_t * p )
+{
+    Gia_Obj_t * pObj, * pObjMin = NULL;
+    int i;
+    Tas_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 * Tas_ManDecideMaxFF( Tas_Man_t * p )
+{
+    Gia_Obj_t * pObj, * pObjMax = NULL;
+    int i, iMaxFF = 0, iCurFF;
+    assert( p->pAig->pRefs != NULL );
+    Tas_QueForEachEntry( p->pJust, pObj, i )
+    {
+        iCurFF = Tas_VarFaninFanoutMax( p, pObj );
+        assert( iCurFF > 0 );
+        if ( iMaxFF < iCurFF )
+        {
+            iMaxFF = iCurFF;
+            pObjMax = pObj;
+        }
+    }
+    return pObjMax; 
+}
+
+
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Tas_ManCancelUntil( Tas_Man_t * p, int iBound )
+{
+    Gia_Obj_t * pVar;
+    int i;
+    assert( iBound <= p->pProp.iTail );
+    p->pProp.iHead = iBound;
+    Tas_QueForEachEntry( p->pProp, pVar, i )
+        Tas_VarUnassign( pVar );
+    p->pProp.iTail = iBound;
+    Vec_IntShrink( p->vLevReas, 3*iBound );
+}
+
+int s_Counter2 = 0;
+int s_Counter3 = 0;
+int s_Counter4 = 0;
+
+/**Function*************************************************************
+
+  Synopsis    [Assigns the variables a value.]
+
+  Description [Returns 1 if conflict; 0 if no conflict.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Tas_ManAssign( Tas_Man_t * p, Gia_Obj_t * pObj, int Level, Gia_Obj_t * pRes0, Gia_Obj_t * pRes1 )
+{
+    Gia_Obj_t * pObjR = Gia_Regular(pObj);
+    assert( Gia_ObjIsCand(pObjR) );
+    assert( !Tas_VarIsAssigned(pObjR) );
+    Tas_VarAssign( pObjR );
+    Tas_VarSetValue( pObjR, !Gia_IsComplement(pObj) );
+    assert( pObjR->Value == ~0 );
+    pObjR->Value = p->pProp.iTail;
+    Tas_QuePush( &p->pProp, pObjR );
+    Vec_IntPush( p->vLevReas, Level );
+    if ( pRes0 == NULL && pRes1 != 0 ) // clause
+    {
+        Vec_IntPush( p->vLevReas, 0 );
+        Vec_IntPush( p->vLevReas, Tas_ClsHandle( p, (Tas_Cls_t *)pRes1 ) );
+    }
+    else
+    {
+        Vec_IntPush( p->vLevReas, pRes0 ? pRes0-pObjR : 0 );
+        Vec_IntPush( p->vLevReas, pRes1 ? pRes1-pObjR : 0 );
+    }
+    assert( Vec_IntSize(p->vLevReas) == 3 * p->pProp.iTail );
+    s_Counter2++;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Returns clause size.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Tas_ManClauseSize( Tas_Man_t * p, int hClause )
+{
+    Tas_Que_t * pQue = &(p->pClauses);
+    Gia_Obj_t ** pIter;
+    for ( pIter = pQue->pData + hClause; *pIter; pIter++ );
+    return pIter - pQue->pData - hClause ;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Prints conflict clause.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Tas_ManPrintClause( Tas_Man_t * p, int Level, int hClause )
+{
+    Tas_Que_t * pQue = &(p->pClauses);
+    Gia_Obj_t * pObj;
+    int i;
+    assert( Tas_QueIsEmpty( pQue ) );
+    printf( "Level %2d : ", Level );
+    for ( i = hClause; (pObj = pQue->pData[i]); i++ )
+        printf( "%d=%d(%d) ", Gia_ObjId(p->pAig, pObj), Tas_VarValue(pObj), Tas_VarDecLevel(p, pObj) );
+    printf( "\n" );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Prints conflict clause.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Tas_ManPrintClauseNew( Tas_Man_t * p, int Level, int hClause )
+{
+    Tas_Que_t * pQue = &(p->pClauses);
+    Gia_Obj_t * pObj;
+    int i;
+    assert( Tas_QueIsEmpty( pQue ) );
+    printf( "Level %2d : ", Level );
+    for ( i = hClause; (pObj = pQue->pData[i]); i++ )
+        printf( "%c%d ", Tas_VarValue(pObj)? '+':'-', Gia_ObjId(p->pAig, pObj) );
+    printf( "\n" );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Returns conflict clause.]
+
+  Description [Performs conflict analysis.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Tas_ManDeriveReason( Tas_Man_t * p, int Level )
+{
+    Tas_Que_t * pQue = &(p->pClauses);
+    Gia_Obj_t * pObj, * pReason;
+    int i, k, j, iLitLevel, iLitLevel2;//, Id;
+    assert( pQue->pData[pQue->iHead] == NULL );
+    assert( pQue->iHead + 1 < pQue->iTail );
+/*
+    for ( i = pQue->iHead + 1; i < pQue->iTail; i++ )
+    {
+        pObj = pQue->pData[i];
+        assert( pObj->fPhase == 0 );
+    }
+*/
+    // compact literals
+    Vec_PtrClear( p->vTemp );
+    for ( i = k = pQue->iHead + 1; i < pQue->iTail; i++ )
+    {
+        pObj = pQue->pData[i];
+        if ( pObj->fPhase ) // unassigned - seen again
+            continue;
+        // assigned - seen first time
+        pObj->fPhase = 1;
+        Vec_PtrPush( p->vTemp, pObj );
+        // bump activity
+//        Id = Gia_ObjId( p->pAig, pObj );
+//        if ( p->pActivity[Id] == 0.0 )
+//            Vec_IntPush( p->vActiveVars, Id );
+//        p->pActivity[Id] += p->Pars.VarInc;
+        // check decision level
+        iLitLevel = Tas_VarDecLevel( p, pObj );
+        if ( iLitLevel < Level )
+        {
+            pQue->pData[k++] = pObj;
+            continue;
+        }
+        assert( iLitLevel == Level );
+        if ( Tas_VarHasReasonCls( p, pObj ) )
+        {
+            Tas_Cls_t * pCls = Tas_VarReasonCls( p, pObj );
+            pReason = Gia_ManObj( p->pAig, Gia_Lit2Var(pCls->pLits[0]) );
+            assert( pReason == pObj );
+            for ( j = 1; j < pCls->nLits; j++ )
+            {
+                pReason = Gia_ManObj( p->pAig, Gia_Lit2Var(pCls->pLits[j]) );
+                iLitLevel2 = Tas_VarDecLevel( p, pReason );
+                assert( Tas_VarIsAssigned( pReason ) );
+                assert( !Tas_LitIsTrue( pReason, pCls->pLits[j] ) );
+                Tas_QuePush( pQue, pReason );
+            }
+        }
+        else
+        {
+            pReason = Tas_VarReason0( p, pObj );
+            if ( pReason == pObj ) // no reason
+            {
+                assert( pQue->pData[pQue->iHead] == NULL || Level == 0 );
+                if ( pQue->pData[pQue->iHead] == NULL )
+                    pQue->pData[pQue->iHead] = pObj;
+                else
+                    Tas_QuePush( pQue, pObj );
+                continue;
+            }
+            Tas_QuePush( pQue, pReason );
+            pReason = Tas_VarReason1( p, pObj );
+            if ( pReason != pObj ) // second reason
+                Tas_QuePush( pQue, pReason );
+        }
+    }
+    assert( pQue->pData[pQue->iHead] != NULL );
+    if ( pQue->pData[pQue->iHead] == NULL )
+        printf( "Tas_ManDeriveReason(): Failed to derive the clause!!!\n" );
+    pQue->iTail = k;
+    // clear the marks
+    Vec_PtrForEachEntry( Gia_Obj_t *, p->vTemp, pObj, i )
+        pObj->fPhase = 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Returns conflict clause.]
+
+  Description [Performs conflict analysis.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Tas_ManAnalyze( Tas_Man_t * p, int Level, Gia_Obj_t * pVar, Gia_Obj_t * pFan0, Gia_Obj_t * pFan1 )
+{
+    Tas_Que_t * pQue = &(p->pClauses);
+    assert( Tas_VarIsAssigned(pVar) );
+    assert( Tas_VarIsAssigned(pFan0) );
+    assert( pFan1 == NULL || Tas_VarIsAssigned(pFan1) );
+    assert( Tas_QueIsEmpty( pQue ) );
+    Tas_QuePush( pQue, NULL );
+    Tas_QuePush( pQue, pVar );
+    Tas_QuePush( pQue, pFan0 );
+    if ( pFan1 )
+        Tas_QuePush( pQue, pFan1 );
+    Tas_ManDeriveReason( p, Level );
+    return Tas_QueFinish( pQue );
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Performs resolution of two clauses.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Tas_ManResolve( Tas_Man_t * p, int Level, int hClause0, int hClause1 )
+{
+    Tas_Que_t * pQue = &(p->pClauses);
+    Gia_Obj_t * pObj;
+    int i, LevelMax = -1, LevelCur;
+    assert( pQue->pData[hClause0] != NULL );
+    assert( pQue->pData[hClause0] == pQue->pData[hClause1] );
+/*
+    for ( i = hClause0 + 1; (pObj = pQue->pData[i]); i++ )
+        assert( pObj->fPhase == 0 );
+    for ( i = hClause1 + 1; (pObj = pQue->pData[i]); i++ )
+        assert( pObj->fPhase == 0 );
+*/
+    assert( Tas_QueIsEmpty( pQue ) );
+    Tas_QuePush( pQue, NULL );
+    for ( i = hClause0 + 1; (pObj = pQue->pData[i]); i++ )
+    {
+        if ( pObj->fPhase ) // unassigned - seen again
+            continue;
+        // assigned - seen first time
+        pObj->fPhase = 1;
+        Tas_QuePush( pQue, pObj );
+        LevelCur = Tas_VarDecLevel( p, pObj );
+        if ( LevelMax < LevelCur )
+            LevelMax = LevelCur;
+    }
+    for ( i = hClause1 + 1; (pObj = pQue->pData[i]); i++ )
+    {
+        if ( pObj->fPhase ) // unassigned - seen again
+            continue;
+        // assigned - seen first time
+        pObj->fPhase = 1;
+        Tas_QuePush( pQue, pObj );
+        LevelCur = Tas_VarDecLevel( p, pObj );
+        if ( LevelMax < LevelCur )
+            LevelMax = LevelCur;
+    }
+    for ( i = pQue->iHead + 1; i < pQue->iTail; i++ )
+        pQue->pData[i]->fPhase = 0;
+    Tas_ManDeriveReason( p, LevelMax );
+    return Tas_QueFinish( pQue );
+}
+
+
+
+/**Function*************************************************************
+
+  Synopsis    [Allocates clause of the given size.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline Tas_Cls_t * Tas_ManAllocCls( Tas_Man_t * p, int nSize )
+{
+    Tas_Cls_t * pCls;
+    if ( p->pStore.iCur + nSize > p->pStore.nSize )
+    {
+        p->pStore.nSize *= 2;
+        p->pStore.pData  = ABC_REALLOC( int, p->pStore.pData, p->pStore.nSize ); 
+    }
+    pCls = Tas_ClsFromHandle( p, p->pStore.iCur ); p->pStore.iCur += nSize;
+    memset( pCls, 0, sizeof(int) * nSize );
+    p->nClauses++;
+    return pCls;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Adds one clause to the watcher list.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Tas_ManWatchClause( Tas_Man_t * p, Tas_Cls_t * pClause, int Lit )
+{
+    assert( Gia_Lit2Var(Lit) < Gia_ManObjNum(p->pAig) );
+    assert( pClause->nLits >= 2 );
+    assert( pClause->pLits[0] == Lit || pClause->pLits[1] == Lit );
+    if ( pClause->pLits[0] == Lit )
+        pClause->iNext[0] = p->pWatches[Gia_LitNot(Lit)];  
+    else
+        pClause->iNext[1] = p->pWatches[Gia_LitNot(Lit)];  
+    if ( p->pWatches[Gia_LitNot(Lit)] == 0 )
+        Vec_IntPush( p->vWatchLits, Gia_LitNot(Lit) );
+    p->pWatches[Gia_LitNot(Lit)] = Tas_ClsHandle( p, pClause );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Creates clause of the given size.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline Tas_Cls_t * Tas_ManCreateCls( Tas_Man_t * p, int hClause )
+{
+    Tas_Cls_t * pClause;
+    Tas_Que_t * pQue = &(p->pClauses);
+    Gia_Obj_t * pObj;
+    int i, nLits = 0;
+    assert( Tas_QueIsEmpty( pQue ) );
+    assert( pQue->pData[hClause] != NULL );
+    for ( i = hClause; (pObj = pQue->pData[i]); i++ )
+        nLits++;
+    if ( nLits == 1 )
+        return NULL;
+    // create this clause
+    pClause = Tas_ManAllocCls( p, nLits + 3 );
+    pClause->nLits = nLits;
+    for ( i = hClause; (pObj = pQue->pData[i]); i++ )
+    {
+        assert( Tas_VarIsAssigned( pObj ) );
+        pClause->pLits[i-hClause] = Gia_LitNot( Tas_VarToLit(p, pObj) );
+    }
+    // add the clause as watched one
+    if ( nLits >= 2 )
+    {
+        Tas_ManWatchClause( p, pClause, pClause->pLits[0] );
+        Tas_ManWatchClause( p, pClause, pClause->pLits[1] );
+    }
+    // increment activity
+//    p->Pars.VarInc /= p->Pars.VarDecay;
+    return pClause;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Creates clause of the given size.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Tas_ManCreateFromCls( Tas_Man_t * p, Tas_Cls_t * pCls, int Level )
+{
+    Tas_Que_t * pQue = &(p->pClauses);
+    Gia_Obj_t * pObj;
+    int i;
+    assert( Tas_QueIsEmpty( pQue ) );
+    Tas_QuePush( pQue, NULL );
+    for ( i = 0; i < pCls->nLits; i++ )
+    {
+        pObj = Gia_ManObj( p->pAig, Gia_Lit2Var(pCls->pLits[i]) );
+        assert( Tas_VarIsAssigned(pObj) );
+        assert( !Tas_LitIsTrue( pObj, pCls->pLits[i] ) );
+        Tas_QuePush( pQue, pObj );
+    }
+    Tas_ManDeriveReason( p, Level );
+    return Tas_QueFinish( pQue );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Propagate one assignment.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Tas_ManPropagateWatch( Tas_Man_t * p, int Level, int Lit )
+{
+    Gia_Obj_t * pObj;
+    Tas_Cls_t * pCur;
+    int * piPrev, iCur, iTemp;
+    int i, LitF = Gia_LitNot(Lit);
+    // iterate through the clauses
+    piPrev = p->pWatches + Lit;
+    for ( iCur = p->pWatches[Lit]; iCur; iCur = *piPrev )
+    {
+        pCur = Tas_ClsFromHandle( p, iCur );
+        // make sure the false literal is in the second literal of the clause
+        if ( pCur->pLits[0] == LitF )
+        {
+            pCur->pLits[0] = pCur->pLits[1];
+            pCur->pLits[1] = LitF;
+            iTemp = pCur->iNext[0];
+            pCur->iNext[0] = pCur->iNext[1];
+            pCur->iNext[1] = iTemp;
+        }
+        assert( pCur->pLits[1] == LitF );
+
+        // if the first literal is true, the clause is satisfied
+//        if ( pCur->pLits[0] == p->pAssigns[Gia_Lit2Var(pCur->pLits[0])] )
+        pObj = Gia_ManObj( p->pAig, Gia_Lit2Var(pCur->pLits[0]) );
+        if ( Tas_VarIsAssigned(pObj) && Tas_LitIsTrue( pObj, pCur->pLits[0] ) )
+        {
+            piPrev = &pCur->iNext[1];
+            continue;
+        }
+
+        // look for a new literal to watch
+        for ( i = 2; i < (int)pCur->nLits; i++ )
+        {
+            // skip the case when the literal is false
+//            if ( Gia_LitNot(pCur->pLits[i]) == p->pAssigns[Gia_Lit2Var(pCur->pLits[i])] )
+            pObj = Gia_ManObj( p->pAig, Gia_Lit2Var(pCur->pLits[i]) );
+            if ( Tas_VarIsAssigned(pObj) && !Tas_LitIsTrue( pObj, pCur->pLits[i] ) )
+                continue;
+            // the literal is either true or unassigned - watch it
+            pCur->pLits[1] = pCur->pLits[i];
+            pCur->pLits[i] = LitF;
+            // remove this clause from the watch list of Lit
+            *piPrev = pCur->iNext[1];
+            // add this clause to the watch list of pCur->pLits[i] (now it is pCur->pLits[1])
+            Tas_ManWatchClause( p, pCur, pCur->pLits[1] );
+            break;
+        }
+        if ( i < (int)pCur->nLits ) // found new watch
+            continue;
+
+        // clause is unit - enqueue new implication
+        pObj = Gia_ManObj( p->pAig, Gia_Lit2Var(pCur->pLits[0]) );
+        if ( !Tas_VarIsAssigned(pObj) )
+        {
+/*
+            {
+                int iLitLevel, iPlace;
+                for ( i = 1; i < (int)pCur->nLits; i++ )
+                {
+                    pObj = Gia_ManObj( p->pAig, Gia_Lit2Var(pCur->pLits[i]) );
+                    iLitLevel = Tas_VarDecLevel( p, pObj );
+                    iPlace = pObj->Value;
+                    printf( "Lit = %d. Level = %d. Place = %d.\n", pCur->pLits[i], iLitLevel, iPlace );
+                    i = i;
+                }
+            }
+*/
+            Tas_ManAssign( p, Gia_ObjFromLit(p->pAig, pCur->pLits[0]), Level, NULL, (Gia_Obj_t *)pCur );
+            piPrev = &pCur->iNext[1];
+            continue;
+        }
+        // conflict detected - return the conflict clause
+        assert( !Tas_LitIsTrue( pObj, pCur->pLits[0] ) );
+        return Tas_ManCreateFromCls( p, pCur, Level );
+    }
+    return 0;
+}
+
+
+
+/**Function*************************************************************
+
+  Synopsis    [Propagates a variable.]
+
+  Description [Returns clause handle if conflict; 0 if no conflict.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Tas_ManPropagateOne( Tas_Man_t * p, Gia_Obj_t * pVar, int Level )
+{
+    int Value0, Value1, hClause;
+    assert( !Gia_IsComplement(pVar) );
+    assert( Tas_VarIsAssigned(pVar) );
+    s_Counter3++;
+    if ( (hClause = Tas_ManPropagateWatch( p, Level, Tas_VarToLit(p, pVar) )) )
+        return hClause;
+    if ( Gia_ObjIsCi(pVar) )
+        return 0;
+/*
+    if ( pVar->iDiff0 == 570869 && pVar->iDiff1 == 546821 && Level == 3 )
+    {
+        Gia_Obj_t * pFan0 = Gia_ObjFanin0(pVar);
+        Gia_Obj_t * pFan1 = Gia_ObjFanin1(pVar);
+        int s = 0;
+    }
+*/
+    assert( Gia_ObjIsAnd(pVar) );
+    Value0 = Tas_VarFanin0Value(pVar);
+    Value1 = Tas_VarFanin1Value(pVar);
+    if ( Tas_VarValue(pVar) )
+    { // value is 1
+        if ( Value0 == 0 || Value1 == 0 ) // one is 0
+        {
+            if ( Value0 == 0 && Value1 != 0 )
+                return Tas_ManAnalyze( p, Level, pVar, Gia_ObjFanin0(pVar), NULL );
+            if ( Value0 != 0 && Value1 == 0 )
+                return Tas_ManAnalyze( p, Level, pVar, Gia_ObjFanin1(pVar), NULL );
+            assert( Value0 == 0 && Value1 == 0 );
+            return Tas_ManAnalyze( p, Level, pVar, Gia_ObjFanin0(pVar), Gia_ObjFanin1(pVar) );
+        }
+        if ( Value0 == 2 ) // first is unassigned
+            Tas_ManAssign( p, Gia_ObjChild0(pVar), Level, pVar, NULL );
+        if ( Value1 == 2 ) // first is unassigned
+            Tas_ManAssign( p, Gia_ObjChild1(pVar), Level, pVar, NULL );
+        return 0;
+    }
+    // value is 0
+    if ( Value0 == 0 || Value1 == 0 ) // one is 0
+        return 0;
+    if ( Value0 == 1 && Value1 == 1 ) // both are 1
+        return Tas_ManAnalyze( p, Level, pVar, Gia_ObjFanin0(pVar), Gia_ObjFanin1(pVar) );
+    if ( Value0 == 1 || Value1 == 1 ) // one is 1 
+    {
+        if ( Value0 == 2 ) // first is unassigned
+            Tas_ManAssign( p, Gia_Not(Gia_ObjChild0(pVar)), Level, pVar, Gia_ObjFanin1(pVar) );
+        if ( Value1 == 2 ) // second is unassigned
+            Tas_ManAssign( p, Gia_Not(Gia_ObjChild1(pVar)), Level, pVar, Gia_ObjFanin0(pVar) );
+        return 0;
+    }
+    assert( Tas_VarIsJust(pVar) );
+    assert( !Tas_QueHasNode( &p->pJust, pVar ) );
+    Tas_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 Tas_ManPropagateTwo( Tas_Man_t * p, Gia_Obj_t * pVar, int Level )
+{
+    int Value0, Value1;
+    s_Counter4++;
+    assert( !Gia_IsComplement(pVar) );
+    assert( Gia_ObjIsAnd(pVar) );
+    assert( Tas_VarIsAssigned(pVar) );
+    assert( !Tas_VarValue(pVar) );
+    Value0 = Tas_VarFanin0Value(pVar);
+    Value1 = Tas_VarFanin1Value(pVar);
+    // value is 0
+    if ( Value0 == 0 || Value1 == 0 ) // one is 0
+        return 0;
+    if ( Value0 == 1 && Value1 == 1 ) // both are 1
+        return Tas_ManAnalyze( p, Level, pVar, Gia_ObjFanin0(pVar), Gia_ObjFanin1(pVar) );
+    assert( Value0 == 1 || Value1 == 1 );
+    if ( Value0 == 2 ) // first is unassigned
+        Tas_ManAssign( p, Gia_Not(Gia_ObjChild0(pVar)), Level, pVar, Gia_ObjFanin1(pVar) );
+    if ( Value1 == 2 ) // first is unassigned
+        Tas_ManAssign( p, Gia_Not(Gia_ObjChild1(pVar)), Level, pVar, Gia_ObjFanin0(pVar) );
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Propagates all variables.]
+
+  Description [Returns 1 if conflict; 0 if no conflict.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Tas_ManPropagate( Tas_Man_t * p, int Level )
+{
+    int hClause;
+    Gia_Obj_t * pVar;
+    int i, k, nIter = 0;
+    while ( 1 )
+    {
+//        nIter++;
+        Tas_QueForEachEntry( p->pProp, pVar, i )
+        {
+            if ( (hClause = Tas_ManPropagateOne( p, pVar, Level )) )
+                return hClause;
+        }
+        p->pProp.iHead = p->pProp.iTail;
+        k = p->pJust.iHead;
+        Tas_QueForEachEntry( p->pJust, pVar, i )
+        {
+            if ( Tas_VarIsJust( pVar ) )
+                p->pJust.pData[k++] = pVar;
+            else if ( (hClause = Tas_ManPropagateTwo( p, pVar, Level )) )
+                return hClause;
+        }
+        if ( k == p->pJust.iTail )
+            break;
+        p->pJust.iTail = k;
+    }
+//    printf( "%d ", nIter );
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Solve the problem recursively.]
+
+  Description [Returns learnt clause if unsat, NULL if sat or undecided.]
+               
+  SideEffects []
+
+  SeeAlso     []
+ 
+***********************************************************************/
+int Tas_ManSolve_rec( Tas_Man_t * p, int Level )
+{ 
+    Tas_Que_t * pQue = &(p->pClauses);
+    Gia_Obj_t * pVar, * pDecVar;
+    int hClause, hLearn0, hLearn1;
+    int iPropHead, iJustHead, iJustTail;
+    // propagate assignments
+    assert( !Tas_QueIsEmpty(&p->pProp) );
+    if ( (hClause = Tas_ManPropagate( p, Level )) )
+    {
+        Tas_ManCreateCls( p, hClause );
+        return hClause;
+    }
+    // check for satisfying assignment
+    assert( Tas_QueIsEmpty(&p->pProp) );
+    if ( Tas_QueIsEmpty(&p->pJust) )
+        return 0;
+    // quit using resource limits
+    p->Pars.nJustThis = ABC_MAX( p->Pars.nJustThis, p->pJust.iTail - p->pJust.iHead );
+    if ( Tas_ManCheckLimits( p ) )
+        return 0;
+    // remember the state before branching
+    iPropHead = p->pProp.iHead;
+    Tas_QueStore( &p->pJust, &iJustHead, &iJustTail );
+    // find the decision variable
+    if ( p->Pars.fUseActive )
+        pVar = NULL, pDecVar = Tas_ManFindActive( p );
+    else if ( p->Pars.fUseHighest )
+//        pVar = NULL, pDecVar = Tas_ManDecideHighestFanin( p );
+        pVar = Tas_ManDecideHighest( p );
+    else if ( p->Pars.fUseLowest )
+        pVar = Tas_ManDecideLowest( p );
+    else if ( p->Pars.fUseMaxFF )
+        pVar = Tas_ManDecideMaxFF( p );
+    else assert( 0 );
+    // chose decision variable using fanout count
+    if ( pVar != NULL )
+    {
+        assert( Tas_VarIsJust( pVar ) );
+        if ( Gia_ObjRefs(p->pAig, Gia_ObjFanin0(pVar)) > Gia_ObjRefs(p->pAig, Gia_ObjFanin1(pVar)) )
+            pDecVar = Gia_Not(Gia_ObjChild0(pVar));
+        else
+            pDecVar = Gia_Not(Gia_ObjChild1(pVar));
+//        pDecVar = Gia_NotCond( pDecVar, Gia_Regular(pDecVar)->fMark1 ^ !Gia_IsComplement(pDecVar) );
+    }
+    // decide on first fanin
+    Tas_ManAssign( p, pDecVar, Level+1, NULL, NULL );
+    if ( !(hLearn0 = Tas_ManSolve_rec( p, Level+1 )) )
+        return 0;
+    if ( pQue->pData[hLearn0] != Gia_Regular(pDecVar) )
+        return hLearn0;
+    Tas_ManCancelUntil( p, iPropHead );
+    Tas_QueRestore( &p->pJust, iJustHead, iJustTail );
+    // decide on second fanin
+    Tas_ManAssign( p, Gia_Not(pDecVar), Level+1, NULL, NULL );
+    if ( !(hLearn1 = Tas_ManSolve_rec( p, Level+1 )) )
+        return 0;
+    if ( pQue->pData[hLearn1] != Gia_Regular(pDecVar) )
+        return hLearn1;
+    hClause = Tas_ManResolve( p, Level, hLearn0, hLearn1 );
+    Tas_ManCreateCls( p, hClause );
+//    Tas_ManPrintClauseNew( p, Level, hClause );
+//    if ( Level > Tas_ClauseDecLevel(p, hClause) )
+//        p->Pars.nBTThisNc++;
+    p->Pars.nBTThis++;
+    return hClause;
+}
+
+/**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 Tas_ManSolve( Tas_Man_t * p, Gia_Obj_t * pObj, Gia_Obj_t * pObj2 )
+{
+    int i, Entry, RetValue = 0;
+    s_Counter2 = 0;
+    Vec_IntClear( p->vModel );
+    if ( pObj == Gia_ManConst0(p->pAig) || pObj2 == Gia_ManConst0(p->pAig) || pObj == Gia_Not(pObj2) )
+        return 1;
+    if ( pObj == Gia_ManConst1(p->pAig) && (pObj2 == NULL || pObj2 == Gia_ManConst1(p->pAig)) )
+        return 0;
+    assert( !p->pProp.iHead && !p->pProp.iTail );
+    assert( !p->pJust.iHead && !p->pJust.iTail );
+    assert( p->pClauses.iHead == 1 && p->pClauses.iTail == 1 );
+    p->Pars.nBTThis = p->Pars.nJustThis = p->Pars.nBTThisNc = 0;
+    Tas_ManAssign( p, pObj, 0, NULL, NULL );
+    if ( pObj2 && !Tas_VarIsAssigned(Gia_Regular(pObj2)) )
+        Tas_ManAssign( p, pObj2, 0, NULL, NULL );
+    if ( !Tas_ManSolve_rec(p, 0) && !Tas_ManCheckLimits(p) )
+        Tas_ManSaveModel( p, p->vModel );
+    else
+        RetValue = 1;
+    Tas_ManCancelUntil( p, 0 );
+    p->pJust.iHead = p->pJust.iTail = 0;
+    p->pClauses.iHead = p->pClauses.iTail = 1;
+    // clauses
+    if ( p->nClauses > 0 )
+    {
+        p->pStore.iCur = 16;
+        Vec_IntForEachEntry( p->vWatchLits, Entry, i )
+            p->pWatches[Entry] = 0;
+        Vec_IntClear( p->vWatchLits );
+        p->nClauses = 0;
+    }
+    // activity
+    Vec_IntForEachEntry( p->vActiveVars, Entry, i )
+        p->pActivity[Entry] = 0.0;
+    Vec_IntClear( p->vActiveVars );
+    // statistics
+    p->Pars.nBTTotal += p->Pars.nBTThis;
+    p->Pars.nJustTotal = ABC_MAX( p->Pars.nJustTotal, p->Pars.nJustThis );
+    if ( Tas_ManCheckLimits( p ) )
+        RetValue = -1;
+    return RetValue;
+}
+
+/**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 Tas_ManSolveArray( Tas_Man_t * p, Vec_Ptr_t * vObjs )
+{
+    Gia_Obj_t * pObj;
+    int i, Entry, RetValue = 0;
+    s_Counter2 = 0;
+    s_Counter3 = 0;
+    s_Counter4 = 0;
+    Vec_IntClear( p->vModel );
+    Vec_PtrForEachEntry( Gia_Obj_t *, vObjs, pObj, i )
+        if ( pObj == Gia_ManConst0(p->pAig) )
+            return 1;
+    assert( !p->pProp.iHead && !p->pProp.iTail );
+    assert( !p->pJust.iHead && !p->pJust.iTail );
+    assert( p->pClauses.iHead == 1 && p->pClauses.iTail == 1 );
+    p->Pars.nBTThis = p->Pars.nJustThis = p->Pars.nBTThisNc = 0;
+    Vec_PtrForEachEntry( Gia_Obj_t *, vObjs, pObj, i )
+        if ( pObj != Gia_ManConst1(p->pAig) && !Tas_VarIsAssigned(Gia_Regular(pObj)) )
+            Tas_ManAssign( p, pObj, 0, NULL, NULL );
+    if ( !Tas_ManSolve_rec(p, 0) && !Tas_ManCheckLimits(p) )
+        Tas_ManSaveModel( p, p->vModel );
+    else
+        RetValue = 1;
+    Tas_ManCancelUntil( p, 0 );
+    p->pJust.iHead = p->pJust.iTail = 0;
+    p->pClauses.iHead = p->pClauses.iTail = 1;
+    // clauses
+    if ( p->nClauses > 0 )
+    {
+        p->pStore.iCur = 16;
+        Vec_IntForEachEntry( p->vWatchLits, Entry, i )
+            p->pWatches[Entry] = 0;
+        Vec_IntClear( p->vWatchLits );
+        p->nClauses = 0;
+    }
+    // activity
+    Vec_IntForEachEntry( p->vActiveVars, Entry, i )
+        p->pActivity[Entry] = 0.0;
+    Vec_IntClear( p->vActiveVars );
+    // statistics
+    p->Pars.nBTTotal += p->Pars.nBTThis;
+    p->Pars.nJustTotal = ABC_MAX( p->Pars.nJustTotal, p->Pars.nJustThis );
+    if ( Tas_ManCheckLimits( p ) )
+        RetValue = -1;
+
+//    printf( "%d ", Gia_ManObjNum(p->pAig) );
+//    printf( "%d ", p->Pars.nBTThis );
+//    printf( "%d ", p->Pars.nJustThis );
+//    printf( "%d ", s_Counter2 );
+//    printf( "%d ", s_Counter3 );
+//    printf( "%d  ", s_Counter4 );
+    return RetValue;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Prints statistics of the manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Tas_ManSatPrintStats( Tas_Man_t * p )
+{
+    printf( "CO = %8d  ", Gia_ManCoNum(p->pAig) );
+    printf( "AND = %8d  ", Gia_ManAndNum(p->pAig) );
+    printf( "Conf = %6d  ", p->Pars.nBTLimit );
+    printf( "JustMax = %5d  ", p->Pars.nJustLimit );
+    printf( "\n" );
+    printf( "Unsat calls %6d  (%6.2f %%)   Ave conf = %8.1f   ", 
+        p->nSatUnsat, p->nSatTotal? 100.0*p->nSatUnsat/p->nSatTotal :0.0, p->nSatUnsat? 1.0*p->nConfUnsat/p->nSatUnsat :0.0 );
+    ABC_PRTP( "Time", p->timeSatUnsat, p->timeTotal );
+    printf( "Sat   calls %6d  (%6.2f %%)   Ave conf = %8.1f   ", 
+        p->nSatSat,   p->nSatTotal? 100.0*p->nSatSat/p->nSatTotal :0.0, p->nSatSat? 1.0*p->nConfSat/p->nSatSat : 0.0 );
+    ABC_PRTP( "Time", p->timeSatSat,   p->timeTotal );
+    printf( "Undef calls %6d  (%6.2f %%)   Ave conf = %8.1f   ", 
+        p->nSatUndec, p->nSatTotal? 100.0*p->nSatUndec/p->nSatTotal :0.0, p->nSatUndec? 1.0*p->nConfUndec/p->nSatUndec : 0.0 );
+    ABC_PRTP( "Time", p->timeSatUndec, p->timeTotal );
+    ABC_PRT( "Total time", p->timeTotal );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Procedure to test the new SAT solver.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Int_t * Tas_ManSolveMiterNc( Gia_Man_t * pAig, int nConfs, Vec_Str_t ** pvStatus, int fVerbose )
+{
+    extern void Gia_ManCollectTest( Gia_Man_t * pAig );
+    extern void Cec_ManSatAddToStore( Vec_Int_t * vCexStore, Vec_Int_t * vCex, int Out );
+    Tas_Man_t * p; 
+    Vec_Int_t * vCex, * vVisit, * vCexStore;
+    Vec_Str_t * vStatus;
+    Gia_Obj_t * pRoot;//, * pRootCopy; 
+//    Gia_Man_t * pAigCopy = Gia_ManDup( pAig ), * pAigTemp;
+
+    int i, status, clk, clkTotal = clock();
+    assert( Gia_ManRegNum(pAig) == 0 );
+//    Gia_ManCollectTest( pAig );
+    // prepare AIG
+    Gia_ManCreateRefs( pAig );
+    Gia_ManCleanMark0( pAig );
+    Gia_ManCleanMark1( pAig );
+    Gia_ManFillValue( pAig ); // maps nodes into trail ids
+    Gia_ManCleanPhase( pAig ); // maps nodes into trail ids
+    // create logic network
+    p = Tas_ManAlloc( pAig, nConfs );
+    p->pAig   = pAig;
+    // create resulting data-structures
+    vStatus   = Vec_StrAlloc( Gia_ManPoNum(pAig) );
+    vCexStore = Vec_IntAlloc( 10000 );
+    vVisit    = Vec_IntAlloc( 100 );
+    vCex      = Tas_ReadModel( p );
+    // solve for each output
+    Gia_ManForEachCo( pAig, pRoot, i )
+    {
+//        printf( "%d=", i );
+
+        Vec_IntClear( vCex );
+        if ( Gia_ObjIsConst0(Gia_ObjFanin0(pRoot)) )
+        {
+            if ( Gia_ObjFaninC0(pRoot) )
+            {
+//                printf( "Constant 1 output of SRM!!!\n" );
+                Cec_ManSatAddToStore( vCexStore, vCex, i ); // trivial counter-example
+                Vec_StrPush( vStatus, 0 );
+            }
+            else
+            {
+//                printf( "Constant 0 output of SRM!!!\n" );
+                Vec_StrPush( vStatus, 1 );
+            }
+            continue;
+        } 
+        clk = clock();
+//        p->Pars.fUseActive  = 1;
+        p->Pars.fUseHighest = 1;
+        p->Pars.fUseLowest  = 0;
+        status = Tas_ManSolve( p, Gia_ObjChild0(pRoot), NULL );
+//        printf( "\n" );
+/*
+        if ( status == -1 )
+        {
+            p->Pars.fUseHighest = 0;
+            p->Pars.fUseLowest  = 1;
+            status = Tas_ManSolve( p, Gia_ObjChild0(pRoot) );
+        }
+*/
+        Vec_StrPush( vStatus, (char)status );
+        if ( status == -1 )
+        {
+//            printf( "Unsolved %d.\n", i );
+
+            p->nSatUndec++;
+            p->nConfUndec += p->Pars.nBTThis;
+            Cec_ManSatAddToStore( vCexStore, NULL, i ); // timeout
+            p->timeSatUndec += clock() - clk;
+            continue;
+        }
+
+//        pRootCopy = Gia_ManCo( pAigCopy, i );
+//        pRootCopy->iDiff0 = Gia_ObjId( pAigCopy, pRootCopy );
+//        pRootCopy->fCompl0 = 0;
+
+        if ( status == 1 )
+        {
+            p->nSatUnsat++;
+            p->nConfUnsat += p->Pars.nBTThis;
+            p->timeSatUnsat += clock() - clk;
+            continue;
+        }
+        p->nSatSat++;
+        p->nConfSat += p->Pars.nBTThis;
+//        Gia_SatVerifyPattern( pAig, pRoot, vCex, vVisit );
+        Cec_ManSatAddToStore( vCexStore, vCex, i );
+        p->timeSatSat += clock() - clk;
+
+//        printf( "%d ", Vec_IntSize(vCex) );
+    }
+//    pAigCopy = Gia_ManCleanup( pAigTemp = pAigCopy );
+//    Gia_ManStop( pAigTemp );
+//    Gia_DumpAiger( pAigCopy, "test", 0, 2 );
+//    Gia_ManStop( pAigCopy );
+
+    Vec_IntFree( vVisit );
+    p->nSatTotal = Gia_ManPoNum(pAig);
+    p->timeTotal = clock() - clkTotal;
+    if ( fVerbose )
+        Tas_ManSatPrintStats( p );
+//    printf( "RecCalls = %8d.  RecClause = %8d.  RecNonChro = %8d.\n", p->nRecCall, p->nRecClause, p->nRecNonChro );
+    Tas_ManStop( p );
+    *pvStatus = vStatus;
+
+//    printf( "Total number of cex literals = %d. (Ave = %d)\n", 
+//         Vec_IntSize(vCexStore)-2*p->nSatUndec-2*p->nSatSat, 
+//        (Vec_IntSize(vCexStore)-2*p->nSatUndec-2*p->nSatSat)/p->nSatSat );
+    return vCexStore;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Packs patterns into array of simulation info.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+*************************************`**********************************/
+int Tas_StorePatternTry( Vec_Ptr_t * vInfo, Vec_Ptr_t * vPres, int iBit, int * pLits, int nLits )
+{
+    unsigned * pInfo, * pPres;
+    int i;
+    for ( i = 0; i < nLits; i++ )
+    {
+        pInfo = (unsigned *)Vec_PtrEntry(vInfo, Gia_Lit2Var(pLits[i]));
+        pPres = (unsigned *)Vec_PtrEntry(vPres, Gia_Lit2Var(pLits[i]));
+        if ( Gia_InfoHasBit( pPres, iBit ) && 
+             Gia_InfoHasBit( pInfo, iBit ) == Gia_LitIsCompl(pLits[i]) )
+             return 0;
+    }
+    for ( i = 0; i < nLits; i++ )
+    {
+        pInfo = (unsigned *)Vec_PtrEntry(vInfo, Gia_Lit2Var(pLits[i]));
+        pPres = (unsigned *)Vec_PtrEntry(vPres, Gia_Lit2Var(pLits[i]));
+        Gia_InfoSetBit( pPres, iBit );
+        if ( Gia_InfoHasBit( pInfo, iBit ) == Gia_LitIsCompl(pLits[i]) )
+            Gia_InfoXorBit( pInfo, iBit );
+    }
+    return 1;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Procedure to test the new SAT solver.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Tas_StorePattern( Vec_Ptr_t * vSimInfo, Vec_Ptr_t * vPres, Vec_Int_t * vCex )
+{
+    int k;
+    for ( k = 1; k < 32; k++ )
+        if ( Tas_StorePatternTry( vSimInfo, vPres, k, (int *)Vec_IntArray(vCex), Vec_IntSize(vCex) ) )
+            break;
+    return (int)(k < 32);
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Procedure to test the new SAT solver.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Tas_ManSolveMiterNc2( Gia_Man_t * pAig, int nConfs, Gia_Man_t * pAigOld, Vec_Ptr_t * vOldRoots, Vec_Ptr_t * vSimInfo )
+{
+    int nPatMax = 1000;
+    int fVerbose = 1;
+    extern void Gia_ManCollectTest( Gia_Man_t * pAig );
+    extern void Cec_ManSatAddToStore( Vec_Int_t * vCexStore, Vec_Int_t * vCex, int Out );
+    Tas_Man_t * p; 
+    Vec_Ptr_t * vPres;
+    Vec_Int_t * vCex, * vVisit, * vCexStore;
+    Vec_Str_t * vStatus;
+    Gia_Obj_t * pRoot, * pOldRoot; 
+    int i, status, clk, clkTotal = clock();
+    int Tried = 0, Stored = 0, Step = Gia_ManCoNum(pAig) / nPatMax;
+    assert( Gia_ManRegNum(pAig) == 0 );
+//    Gia_ManCollectTest( pAig );
+    // prepare AIG
+    Gia_ManCreateRefs( pAig );
+    Gia_ManCleanMark0( pAig );
+    Gia_ManCleanMark1( pAig );
+    Gia_ManFillValue( pAig ); // maps nodes into trail ids
+    Gia_ManCleanPhase( pAig ); // maps nodes into trail ids
+    // create logic network
+    p = Tas_ManAlloc( pAig, nConfs );
+    p->pAig   = pAig;
+    // create resulting data-structures
+    vStatus   = Vec_StrAlloc( Gia_ManPoNum(pAig) );
+    vCexStore = Vec_IntAlloc( 10000 );
+    vVisit    = Vec_IntAlloc( 100 );
+    vCex      = Tas_ReadModel( p );
+    // solve for each output
+    vPres = Vec_PtrAllocSimInfo( Gia_ManCiNum(pAig), 1 );
+    Vec_PtrCleanSimInfo( vPres, 0, 1 );
+    
+    Gia_ManForEachCo( pAig, pRoot, i )
+    {
+        assert( !Gia_ObjIsConst0(Gia_ObjFanin0(pRoot)) );
+        Vec_IntClear( vCex );
+        clk = clock();
+        p->Pars.fUseHighest = 1;
+        p->Pars.fUseLowest  = 0;
+        status = Tas_ManSolve( p, Gia_ObjChild0(pRoot), NULL );
+        Vec_StrPush( vStatus, (char)status );
+        if ( status == -1 )
+        {
+            p->nSatUndec++;
+            p->nConfUndec += p->Pars.nBTThis;
+//            Cec_ManSatAddToStore( vCexStore, NULL, i ); // timeout
+            p->timeSatUndec += clock() - clk;
+
+            i += Step;
+            continue;
+        }
+        if ( status == 1 )
+        {
+            p->nSatUnsat++;
+            p->nConfUnsat += p->Pars.nBTThis;
+            p->timeSatUnsat += clock() - clk;
+            // record proved
+            pOldRoot = (Gia_Obj_t *)Vec_PtrEntry( vOldRoots, i );
+            assert( !Gia_ObjProved( pAigOld, Gia_ObjId(pAigOld, pOldRoot) ) );
+            Gia_ObjSetProved( pAigOld, Gia_ObjId(pAigOld, pOldRoot) );
+
+            i += Step;
+            continue;
+        }
+        p->nSatSat++;
+        p->nConfSat += p->Pars.nBTThis;
+//        Gia_SatVerifyPattern( pAig, pRoot, vCex, vVisit );
+//        Cec_ManSatAddToStore( vCexStore, vCex, i );
+
+        // save pattern
+        Tried++;
+        Stored += Tas_StorePattern( vSimInfo, vPres, vCex );
+        p->timeSatSat += clock() - clk;
+        i += Step;
+    }
+    printf( "Tried = %d  Stored = %d\n", Tried, Stored );
+    Vec_IntFree( vVisit );
+    p->nSatTotal = Gia_ManPoNum(pAig);
+    p->timeTotal = clock() - clkTotal;
+    if ( fVerbose )
+        Tas_ManSatPrintStats( p );
+    Tas_ManStop( p );
+    Vec_PtrFree( vPres );
+}
+
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+