Counter-example analysis and optimization.

1 files changed, 590 insertions, 0 deletions

diff --git a/src/sat/bmc/bmcCexTools.c b/src/sat/bmc/bmcCexTools.c
new file mode 100644
index 00000000..0cbb0e9a
--- /dev/null
+++ b/src/sat/bmc/bmcCexTools.c
@@ -0,0 +1,590 @@
+/**CFile****************************************************************
+
+  FileName    [bmcCexTools.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [SAT-based bounded model checking.]
+
+  Synopsis    [CEX analysis and optimization toolbox.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: bmcCexTools.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "bmc.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+static inline word Bmc_CexBitMask( int iBit )                                    { assert( iBit < 64 ); return ~(((word)1) << iBit); }
+static inline void Bmc_CexCopySim( Vec_Wrd_t * vSims, int iObjTo, int iObjFrom ) { Vec_WrdWriteEntry( vSims, iObjTo, iObjFrom );     }
+static inline void Bmc_CexAndSim( Vec_Wrd_t * vSims, int iObjTo, int i, int j )  { Vec_WrdWriteEntry( vSims, iObjTo, Vec_WrdEntry(vSims, i) & Vec_WrdEntry(vSims, j) ); }
+static inline void Bmc_CexOrSim( Vec_Wrd_t * vSims, int iObjTo, int i, int j )   { Vec_WrdWriteEntry( vSims, iObjTo, Vec_WrdEntry(vSims, i) | Vec_WrdEntry(vSims, j) ); }
+static inline int  Bmc_CexSim( Vec_Wrd_t * vSims, int iObj, int i )              { return (Vec_WrdEntry(vSims, iObj) >> i) & 1;      }
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Prints one counter-example.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Bmc_CexPrint( Abc_Cex_t * pCex, int nInputs )
+{
+    int i, k, Count, iBit = 0;
+    Abc_CexPrintStatsInputs( pCex, nInputs );
+    return;
+
+    for ( i = 0; i <= pCex->iFrame; i++ )
+    {
+        Count = 0;
+        printf( "%3d : ", i );
+        for ( k = 0; k < nInputs; k++ )
+        {
+            Count += Abc_InfoHasBit(pCex->pData, iBit);
+            printf( "%d", Abc_InfoHasBit(pCex->pData, iBit++) );
+        }
+        printf( " %3d ", Count );
+        Count = 0;
+        for (      ; k < pCex->nPis; k++ )
+        {
+            Count += Abc_InfoHasBit(pCex->pData, iBit);
+            printf( "%d", Abc_InfoHasBit(pCex->pData, iBit++) );
+        }
+        printf( " %3d\n", Count );
+    }
+    assert( iBit == pCex->nBits );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Verifies the care set of the counter-example.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Bmc_CexVerify( Gia_Man_t * p, Abc_Cex_t * pCex, Abc_Cex_t * pCexCare )
+{
+    Gia_Obj_t * pObj;
+    int i, k;
+    assert( pCex->nRegs > 0 );
+    assert( pCexCare->nRegs == 0 );
+    Gia_ObjTerSimSet0( Gia_ManConst0(p) );
+    Gia_ManForEachRi( p, pObj, k )
+        Gia_ObjTerSimSet0( pObj );
+    for ( i = 0; i <= pCex->iFrame; i++ )
+    {
+        Gia_ManForEachPi( p, pObj, k )
+        {
+            if ( !Abc_InfoHasBit( pCexCare->pData, i * pCexCare->nPis + k ) )
+                Gia_ObjTerSimSetX( pObj );
+            else if ( Abc_InfoHasBit( pCex->pData, pCex->nRegs + i * pCex->nPis + k ) )
+                Gia_ObjTerSimSet1( pObj );
+            else
+                Gia_ObjTerSimSet0( pObj );
+        }
+        Gia_ManForEachRo( p, pObj, k )
+            Gia_ObjTerSimRo( p, pObj );
+        Gia_ManForEachAnd( p, pObj, k )
+            Gia_ObjTerSimAnd( pObj );
+        Gia_ManForEachCo( p, pObj, k )
+            Gia_ObjTerSimCo( pObj );
+    }
+    pObj = Gia_ManPo( p, pCex->iPo );
+    return Gia_ObjTerSimGet1(pObj);
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Computes internal states of the CEX.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Abc_Cex_t * Bmc_CexInnerStates( Gia_Man_t * p, Abc_Cex_t * pCex, Abc_Cex_t ** ppCexImpl )
+{
+    Abc_Cex_t * pNew, * pNew2;
+    Gia_Obj_t * pObj, * pObjRo, * pObjRi;
+    int fCompl0, fCompl1;
+    int i, k, iBit = 0;
+    assert( pCex->nRegs > 0 );
+    // start the counter-example
+    pNew = Abc_CexAlloc( 0, Gia_ManCiNum(p), pCex->iFrame + 1 );
+    pNew->iFrame = pCex->iFrame;
+    pNew->iPo    = pCex->iPo;
+    // start the counter-example
+    pNew2 = Abc_CexAlloc( 0, Gia_ManCiNum(p), pCex->iFrame + 1 );
+    pNew2->iFrame = pCex->iFrame;
+    pNew2->iPo    = pCex->iPo;
+    // set initial state
+    Gia_ManCleanMark01(p);
+    // set const0
+    Gia_ManConst0(p)->fMark0 = 0;
+    Gia_ManConst0(p)->fMark1 = 1;
+    // set init state
+    Gia_ManForEachRi( p, pObjRi, k )
+    {
+        pObjRi->fMark0 = Abc_InfoHasBit(pCex->pData, iBit++);
+        pObjRi->fMark1 = 1;
+    }
+    for ( i = 0; i <= pCex->iFrame; i++ )
+    {
+        Gia_ManForEachPi( p, pObj, k )
+            pObj->fMark0 = Abc_InfoHasBit(pCex->pData, iBit++);
+        Gia_ManForEachRiRo( p, pObjRi, pObjRo, k )
+        {
+            pObjRo->fMark0 = pObjRi->fMark0;
+            pObjRo->fMark1 = pObjRi->fMark1;
+        }
+        Gia_ManForEachCi( p, pObj, k )
+        {
+            if ( pObj->fMark0 )
+                Abc_InfoSetBit( pNew->pData, pNew->nPis * i + k );
+            if ( pObj->fMark1 )
+                Abc_InfoSetBit( pNew2->pData, pNew2->nPis * i + k );
+        }
+        Gia_ManForEachAnd( p, pObj, k )
+        {
+            fCompl0 = Gia_ObjFanin0(pObj)->fMark0 ^ Gia_ObjFaninC0(pObj);
+            fCompl1 = Gia_ObjFanin1(pObj)->fMark0 ^ Gia_ObjFaninC1(pObj);
+            pObj->fMark0 = fCompl0 & fCompl1;
+            if ( pObj->fMark0 )
+                pObj->fMark1 = Gia_ObjFanin0(pObj)->fMark1 & Gia_ObjFanin1(pObj)->fMark1;
+            else if ( !fCompl0 && !fCompl1 )
+                pObj->fMark1 = Gia_ObjFanin0(pObj)->fMark1 | Gia_ObjFanin1(pObj)->fMark1;
+            else if ( !fCompl0 )
+                pObj->fMark1 = Gia_ObjFanin0(pObj)->fMark1;
+            else if ( !fCompl1 )
+                pObj->fMark1 = Gia_ObjFanin1(pObj)->fMark1;
+            else assert( 0 );
+        }
+        Gia_ManForEachCo( p, pObj, k )
+        {
+            pObj->fMark0 = Gia_ObjFanin0(pObj)->fMark0 ^ Gia_ObjFaninC0(pObj);
+            pObj->fMark1 = Gia_ObjFanin0(pObj)->fMark1;
+        }
+
+/*
+        // print input/state/output
+        printf( "%3d : ", i );
+        Gia_ManForEachPi( p, pObj, k )
+            printf( "%d", pObj->fMark0 );
+        printf( " " );
+        Gia_ManForEachRo( p, pObj, k )
+            printf( "%d", pObj->fMark0 );
+        printf( " " );
+        Gia_ManForEachPo( p, pObj, k )
+            printf( "%d", pObj->fMark0 );
+        printf( "\n" );
+*/
+    }
+    assert( iBit == pCex->nBits );
+    assert( Gia_ManPo(p, pCex->iPo)->fMark0 == 1 );
+
+    printf( "Inner states: " );
+    Bmc_CexPrint( pNew, Gia_ManPiNum(p) );
+    printf( "Implications: " );
+    Bmc_CexPrint( pNew2, Gia_ManPiNum(p) );
+    if ( ppCexImpl )
+        *ppCexImpl = pNew2;
+    else
+        Abc_CexFree( pNew2 );
+    return pNew;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Computes care bits of the CEX.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Bmc_CexCareBits_rec( Gia_Man_t * p, Gia_Obj_t * pObj )
+{
+    int fCompl0, fCompl1;
+    if ( Gia_ObjIsConst0(pObj) )
+        return;
+    if ( pObj->fMark1 )
+        return;
+    pObj->fMark1 = 1;
+    if ( Gia_ObjIsCi(pObj) )
+        return;
+    assert( Gia_ObjIsAnd(pObj) );
+    fCompl0 = Gia_ObjFanin0(pObj)->fMark0 ^ Gia_ObjFaninC0(pObj);
+    fCompl1 = Gia_ObjFanin1(pObj)->fMark0 ^ Gia_ObjFaninC1(pObj);
+    if ( pObj->fMark0 )
+    {
+        assert( fCompl0 == 1 && fCompl1 == 1 );
+        Bmc_CexCareBits_rec( p, Gia_ObjFanin0(pObj) );
+        Bmc_CexCareBits_rec( p, Gia_ObjFanin1(pObj) );
+    }
+    else
+    {
+        assert( fCompl0 == 0 || fCompl1 == 0 );
+        if ( fCompl0 == 0 )
+            Bmc_CexCareBits_rec( p, Gia_ObjFanin0(pObj) );
+        if ( fCompl1 == 0 )
+            Bmc_CexCareBits_rec( p, Gia_ObjFanin1(pObj) );
+    }
+}
+void Bmc_CexCareBits2_rec( Gia_Man_t * p, Gia_Obj_t * pObj )
+{
+    int fCompl0, fCompl1;
+    if ( Gia_ObjIsConst0(pObj) )
+        return;
+    if ( pObj->fMark1 )
+        return;
+    pObj->fMark1 = 1;
+    if ( Gia_ObjIsCi(pObj) )
+        return;
+    assert( Gia_ObjIsAnd(pObj) );
+    fCompl0 = Gia_ObjFanin0(pObj)->fMark0 ^ Gia_ObjFaninC0(pObj);
+    fCompl1 = Gia_ObjFanin1(pObj)->fMark0 ^ Gia_ObjFaninC1(pObj);
+    if ( pObj->fMark0 )
+    {
+        assert( fCompl0 == 1 && fCompl1 == 1 );
+        Bmc_CexCareBits2_rec( p, Gia_ObjFanin0(pObj) );
+        Bmc_CexCareBits2_rec( p, Gia_ObjFanin1(pObj) );
+    }
+    else
+    {
+        assert( fCompl0 == 0 || fCompl1 == 0 );
+        if ( fCompl0 == 0 )
+            Bmc_CexCareBits2_rec( p, Gia_ObjFanin0(pObj) );
+        /**/ 
+        else 
+        /**/ 
+        if ( fCompl1 == 0 )
+            Bmc_CexCareBits2_rec( p, Gia_ObjFanin1(pObj) );
+    }
+}
+Abc_Cex_t * Bmc_CexCareBits( Gia_Man_t * p, Abc_Cex_t * pCexState, Abc_Cex_t * pCexImpl, Abc_Cex_t * pCexEss, int fFindAll )
+{
+    Abc_Cex_t * pNew;
+    Gia_Obj_t * pObj;
+    int fCompl0, fCompl1;
+    int i, k, iBit;
+    assert( pCexState->nRegs == 0 );
+    // start the counter-example
+    pNew = Abc_CexAlloc( 0, Gia_ManCiNum(p), pCexState->iFrame + 1 );
+    pNew->iFrame = pCexState->iFrame;
+    pNew->iPo    = pCexState->iPo;
+    // set initial state
+    Gia_ManCleanMark01(p);
+    // set const0
+    Gia_ManConst0(p)->fMark0 = 0;
+    Gia_ManConst0(p)->fMark1 = 1;
+    for ( i = pCexState->iFrame; i >= 0; i-- )
+    {
+        // set correct values
+        iBit = pCexState->nPis * i;
+        Gia_ManForEachCi( p, pObj, k )
+        {
+            pObj->fMark0 = Abc_InfoHasBit(pCexState->pData, iBit+k);
+            pObj->fMark1 = Abc_InfoHasBit(pCexImpl->pData, iBit+k);
+            if ( pCexEss )
+                pObj->fMark1 |= Abc_InfoHasBit(pCexEss->pData, iBit+k);
+        }
+        Gia_ManForEachAnd( p, pObj, k )
+        {
+            fCompl0 = Gia_ObjFanin0(pObj)->fMark0 ^ Gia_ObjFaninC0(pObj);
+            fCompl1 = Gia_ObjFanin1(pObj)->fMark0 ^ Gia_ObjFaninC1(pObj);
+            pObj->fMark0 = fCompl0 & fCompl1;
+            if ( pObj->fMark0 )
+                pObj->fMark1 = Gia_ObjFanin0(pObj)->fMark1 & Gia_ObjFanin1(pObj)->fMark1;
+            else if ( !fCompl0 && !fCompl1 )
+                pObj->fMark1 = Gia_ObjFanin0(pObj)->fMark1 | Gia_ObjFanin1(pObj)->fMark1;
+            else if ( !fCompl0 )
+                pObj->fMark1 = Gia_ObjFanin0(pObj)->fMark1;
+            else if ( !fCompl1 )
+                pObj->fMark1 = Gia_ObjFanin1(pObj)->fMark1;
+            else assert( 0 );
+        }
+        Gia_ManForEachCo( p, pObj, k )
+            pObj->fMark0 = Gia_ObjFanin0(pObj)->fMark0 ^ Gia_ObjFaninC0(pObj);
+        // move values from COs to CIs
+        if ( i == pCexState->iFrame )
+        {
+            assert( Gia_ManPo(p, pCexState->iPo)->fMark0 == 1 );
+            if ( fFindAll )
+                Bmc_CexCareBits_rec( p, Gia_ObjFanin0(Gia_ManPo(p, pCexState->iPo)) );
+            else
+                Bmc_CexCareBits2_rec( p, Gia_ObjFanin0(Gia_ManPo(p, pCexState->iPo)) );
+        }
+        else
+        {
+            Gia_ManForEachRi( p, pObj, k )
+                if ( Abc_InfoHasBit(pNew->pData, pNew->nPis * (i+1) + Gia_ManPiNum(p) + k) )
+                {
+                     if ( fFindAll )
+                         Bmc_CexCareBits_rec( p, Gia_ObjFanin0(pObj) );
+                     else
+                         Bmc_CexCareBits2_rec( p, Gia_ObjFanin0(pObj) );
+                }
+        }
+        // save the results
+        Gia_ManForEachCi( p, pObj, k )
+            if ( pObj->fMark1 )
+            {
+                pObj->fMark1 = 0;
+                if ( !Abc_InfoHasBit(pCexImpl->pData, pNew->nPis * i + k) )
+                    Abc_InfoSetBit(pNew->pData, pNew->nPis * i + k);
+            }
+    }
+    printf( "Care bits:    " );
+    Bmc_CexPrint( pNew, Gia_ManPiNum(p) );
+    return pNew;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Simulates one bit to check whether it is essential.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Abc_Cex_t * Bmc_CexEssentialBitOne( Gia_Man_t * p, Abc_Cex_t * pCexState, int iBit, Abc_Cex_t * pCexPrev, int * pfEqual )
+{
+    Abc_Cex_t * pNew;
+    Gia_Obj_t * pObj;
+    int i, k, fCompl0, fCompl1;
+    int iFrame  = iBit / pCexState->nPis;
+    int iNumber = iBit % pCexState->nPis;
+    assert( pCexState->nRegs == 0 );
+    assert( iBit < pCexState->nBits );
+    if ( pfEqual )
+        *pfEqual = 0;
+    // start the counter-example
+    pNew = Abc_CexAllocFull( 0, Gia_ManCiNum(p), pCexState->iFrame + 1 );
+    pNew->iFrame = pCexState->iFrame;
+    pNew->iPo    = pCexState->iPo;
+    // clean bit
+    Abc_InfoXorBit( pNew->pData, iBit );
+    // simulate the remaining frames
+    Gia_ManConst0(p)->fMark0 = 0;
+    Gia_ManConst0(p)->fMark1 = 1;
+    for ( i = iFrame; i <= pCexState->iFrame; i++ )
+    {
+        Gia_ManForEachCi( p, pObj, k )
+        {
+            pObj->fMark0 = Abc_InfoHasBit( pCexState->pData, i * pCexState->nPis + k );
+            pObj->fMark1 = Abc_InfoHasBit( pNew->pData,      i * pCexState->nPis + k );
+        }
+        Gia_ManForEachAnd( p, pObj, k )
+        {
+            fCompl0 = Gia_ObjFanin0(pObj)->fMark0 ^ Gia_ObjFaninC0(pObj);
+            fCompl1 = Gia_ObjFanin1(pObj)->fMark0 ^ Gia_ObjFaninC1(pObj);
+            pObj->fMark0 = fCompl0 & fCompl1;
+            if ( pObj->fMark0 )
+                pObj->fMark1 = Gia_ObjFanin0(pObj)->fMark1 & Gia_ObjFanin1(pObj)->fMark1;
+            else if ( !fCompl0 && !fCompl1 )
+                pObj->fMark1 = Gia_ObjFanin0(pObj)->fMark1 | Gia_ObjFanin1(pObj)->fMark1;
+            else if ( !fCompl0 )
+                pObj->fMark1 = Gia_ObjFanin0(pObj)->fMark1;
+            else if ( !fCompl1 )
+                pObj->fMark1 = Gia_ObjFanin1(pObj)->fMark1;
+            else assert( 0 );
+        }
+        Gia_ManForEachCo( p, pObj, k )
+        {
+            pObj->fMark0 = Gia_ObjFanin0(pObj)->fMark0 ^ Gia_ObjFaninC0(pObj);
+            pObj->fMark1 = Gia_ObjFanin0(pObj)->fMark1;
+        }
+        if ( i < pCexState->iFrame )
+        {
+            int fChanges  = 0;
+            int fEqual    = (pCexPrev != NULL);
+            int iBitShift = (i + 1) * pCexState->nPis + Gia_ManPiNum(p);
+            Gia_ManForEachRi( p, pObj, k )
+            {
+                if ( fEqual && pCexPrev && (int)pObj->fMark1 != Abc_InfoHasBit(pCexPrev->pData, iBitShift + k) )
+                    fEqual = 0;
+                if ( !pObj->fMark1 )
+                {
+                    fChanges = 1;
+                    Abc_InfoXorBit( pNew->pData, iBitShift + k );
+                }
+            }
+            if ( !fChanges || fEqual )
+            {
+                if ( pfEqual )
+                    *pfEqual = fEqual;
+                Abc_CexFree( pNew );
+                return NULL;
+            }
+        }
+/*
+        if ( i == 20 )
+        {
+            printf( "Frame %d : ", i );
+            Gia_ManForEachRi( p, pObj, k )
+                printf( "%d", pObj->fMark1 );
+            printf( "\n" );
+        }
+*/
+    }
+    return pNew;
+}
+void Bmc_CexEssentialBitTest( Gia_Man_t * p, Abc_Cex_t * pCexState )
+{
+    Abc_Cex_t * pNew;
+    int b;
+    for ( b = 0; b < pCexState->nBits; b++ )
+    {
+        if ( b % 100 )
+            continue;
+        pNew = Bmc_CexEssentialBitOne( p, pCexState, b, NULL, NULL );
+        Bmc_CexPrint( pNew, Gia_ManPiNum(p) );
+
+        if ( Gia_ManPo(p, pCexState->iPo)->fMark1 )
+            printf( "Not essential\n" );
+        else
+            printf( "Essential\n" );
+
+        Abc_CexFree( pNew );
+    }
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Computes essential bits of the CEX.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Abc_Cex_t * Bmc_CexEssentialBits( Gia_Man_t * p, Abc_Cex_t * pCexState, Abc_Cex_t * pCexCare )
+{
+    Abc_Cex_t * pNew, * pTemp, * pPrev = NULL;
+    int b, fEqual = 0, fPrevStatus = 0;
+    clock_t clk = clock();
+    assert( pCexState->nBits == pCexCare->nBits );
+    // start the counter-example
+    pNew = Abc_CexAlloc( 0, Gia_ManCiNum(p), pCexState->iFrame + 1 );
+    pNew->iFrame = pCexState->iFrame;
+    pNew->iPo    = pCexState->iPo;
+    // iterate through care-bits
+    for ( b = 0; b < pCexState->nBits; b++ )
+    {
+        // skip don't-care bits
+        if ( !Abc_InfoHasBit(pCexCare->pData, b) )
+            continue;
+
+        // skip state bits
+        if ( b % pCexCare->nPis >= Gia_ManPiNum(p) )
+        {
+            Abc_InfoSetBit( pNew->pData, b );
+            continue;
+        }
+
+        // check if this is an essential bit
+        pTemp = Bmc_CexEssentialBitOne( p, pCexState, b, pPrev, &fEqual );
+//        pTemp = Bmc_CexEssentialBitOne( p, pCexState, b, NULL, &fEqual );
+        if ( pTemp == NULL )
+        {
+            if ( fEqual && fPrevStatus )
+                Abc_InfoSetBit( pNew->pData, b );
+            continue;
+        }
+//        Bmc_CexPrint( pTemp, Gia_ManPiNum(p) );
+        Abc_CexFree( pPrev );
+        pPrev = pTemp;
+
+        // record essential bit
+        fPrevStatus = !Gia_ManPo(p, pCexState->iPo)->fMark1;
+        if ( !Gia_ManPo(p, pCexState->iPo)->fMark1 )
+            Abc_InfoSetBit( pNew->pData, b );
+    }
+    Abc_CexFreeP( &pPrev );
+    Abc_PrintTime( 1, "Time", clock() - clk );
+    printf( "Essentials:   " );
+    Bmc_CexPrint( pNew, Gia_ManPiNum(p) );
+    return pNew;
+}
+ 
+
+
+/**Function*************************************************************
+
+  Synopsis    [Computes essential bits of the CEX.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Bmc_CexTest( Gia_Man_t * p, Abc_Cex_t * pCex )
+{
+    Abc_Cex_t * pCexImpl = NULL;
+    Abc_Cex_t * pCexStates = Bmc_CexInnerStates( p, pCex, &pCexImpl );
+    Abc_Cex_t * pCexCare = Bmc_CexCareBits( p, pCexStates, pCexImpl, NULL, 1 );
+    Abc_Cex_t * pCexEss, * pCexMin;
+
+    if ( !Bmc_CexVerify( p, pCex, pCexCare ) )
+        printf( "Counter-example care-set verification has failed.\n" );
+
+//    Bmc_CexEssentialBitTest( p, pCexStates );
+    pCexEss = Bmc_CexEssentialBits( p, pCexStates, pCexCare );
+
+    pCexMin = Bmc_CexCareBits( p, pCexStates, pCexImpl, pCexEss, 0 );
+
+    if ( !Bmc_CexVerify( p, pCex, pCexMin ) )
+        printf( "Counter-example care-set verification has failed.\n" );
+
+//    if ( !Bmc_CexVerify( p, pCex, pCexEss ) )
+//        printf( "Counter-example care-set verification has failed.\n" );
+
+    Abc_CexFreeP( &pCexStates );
+    Abc_CexFreeP( &pCexImpl );
+    Abc_CexFreeP( &pCexCare );
+    Abc_CexFreeP( &pCexEss );
+    Abc_CexFreeP( &pCexMin );
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+