Version abc80510

3 files changed, 660 insertions, 0 deletions

diff --git a/src/aig/saig/module.make b/src/aig/saig/module.make
index c9172024..20428b36 100644
--- a/src/aig/saig/module.make
+++ b/src/aig/saig/module.make
@@ -1,4 +1,5 @@
 SRC +=    src/aig/saig/saig_.c \
+    src/aig/saig/saigInter.c \
     src/aig/saig/saigPhase.c \
     src/aig/saig/saigRetFwd.c \
     src/aig/saig/saigRetMin.c \
diff --git a/src/aig/saig/saig.h b/src/aig/saig/saig.h
index 7f6bb292..60db874b 100644
--- a/src/aig/saig/saig.h
+++ b/src/aig/saig/saig.h
@@ -75,6 +75,8 @@ static inline int          Saig_ObjIsLi( Aig_Man_t * p, Aig_Obj_t * pObj )    {
 ///                    FUNCTION DECLARATIONS                         ///
 ////////////////////////////////////////////////////////////////////////
 
+/*=== saigInter.c ==========================================================*/
+extern int               Saig_Interpolate( Aig_Man_t * pAig, int nConfLimit, int fVerbose, int * pDepth );
 /*=== saigPhase.c ==========================================================*/
 extern Aig_Man_t *       Saig_ManPhaseAbstract( Aig_Man_t * p, Vec_Int_t * vInits, int nFrames, int fIgnore, int fPrint, int fVerbose );
 /*=== saigRetFwd.c ==========================================================*/
diff --git a/src/aig/saig/saigInter.c b/src/aig/saig/saigInter.c
new file mode 100644
index 00000000..34069b03
--- /dev/null
+++ b/src/aig/saig/saigInter.c
@@ -0,0 +1,657 @@
+/**CFile****************************************************************
+
+  FileName    [saigInter.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Sequential AIG package.]
+
+  Synopsis    [Interplation for unbounded model checking.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: saigInter.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "saig.h"
+#include "fra.h"
+#include "cnf.h"
+#include "satStore.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+/* 
+    The interpolation algorithm implemented here was introduced in the paper:
+    K. L. McMillan. Interpolation and SAT-based model checking. CAV’03, pp. 1-13.
+*/
+
+
+// simulation manager
+typedef struct Saig_IntMan_t_ Saig_IntMan_t;
+struct Saig_IntMan_t_
+{
+    // AIG manager
+    Aig_Man_t *      pAig;         // the original AIG manager
+    Aig_Man_t *      pAigTrans;    // the transformed original AIG manager
+    Cnf_Dat_t *      pCnfAig;      // CNF for the original manager
+    // interpolant
+    Aig_Man_t *      pInter;       // the current interpolant
+    Cnf_Dat_t *      pCnfInter;    // CNF for the current interplant
+    // timeframes
+    Aig_Man_t *      pFrames;      // the timeframes      
+    Cnf_Dat_t *      pCnfFrames;   // CNF for the timeframes 
+    // other data
+    Vec_Int_t *      vVarsAB;      // the variables participating in 
+    // temporary place for the new interpolant
+    Aig_Man_t *      pInterNew;
+    // parameters
+    int              nFrames;      // the number of timeframes
+    int              nConfCur;     // the current number of conflicts
+    int              nConfLimit;   // the limit on the number of conflicts
+    int              fVerbose;     // the verbosiness flag
+    // runtime
+    int              timeRwr;
+    int              timeCnf;
+    int              timeSat;
+    int              timeInt;
+    int              timeEqu;
+    int              timeOther;
+    int              timeTotal;
+};
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Create trivial AIG manager for the init state.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Aig_Man_t * Saig_ManInit( int nRegs )
+{
+    Aig_Man_t * p;
+    Aig_Obj_t * pRes;
+    Aig_Obj_t ** ppInputs;
+    int i;
+    assert( nRegs > 0 );
+    ppInputs = ALLOC( Aig_Obj_t *, nRegs );
+    p = Aig_ManStart( nRegs );
+    for ( i = 0; i < nRegs; i++ )
+        ppInputs[i] = Aig_Not( Aig_ObjCreatePi(p) );
+    pRes = Aig_Multi( p, ppInputs, nRegs, AIG_OBJ_AND );
+    Aig_ObjCreatePo( p, pRes );
+    free( ppInputs );
+    return p;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Duplicate the AIG w/o POs.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Aig_Man_t * Saig_ManDuplicated( Aig_Man_t * p )
+{
+    Aig_Man_t * pNew;
+    Aig_Obj_t * pObj;
+    int i;
+    assert( Aig_ManRegNum(p) > 0 );
+    // create the new manager
+    pNew = Aig_ManStart( Aig_ManObjNumMax(p) );
+    pNew->pName = Aig_UtilStrsav( p->pName );
+    pNew->pSpec = Aig_UtilStrsav( p->pSpec );
+    // create the PIs
+    Aig_ManCleanData( p );
+    Aig_ManConst1(p)->pData = Aig_ManConst1(pNew);
+    Aig_ManForEachPi( p, pObj, i )
+        pObj->pData = Aig_ObjCreatePi( pNew );
+    // set registers
+    pNew->nRegs    = p->nRegs;
+    pNew->nTruePis = p->nTruePis;
+    pNew->nTruePos = 0;
+    // duplicate internal nodes
+    Aig_ManForEachNode( p, pObj, i )
+        pObj->pData = Aig_And( pNew, Aig_ObjChild0Copy(pObj), Aig_ObjChild1Copy(pObj) );
+    // create register inputs with MUXes
+    Saig_ManForEachLi( p, pObj, i )
+        Aig_ObjCreatePo( pNew, Aig_ObjChild0Copy(pObj) );
+    Aig_ManCleanup( pNew );
+    return pNew;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Duplicate the AIG w/o POs and transforms to transit into init state.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Aig_Man_t * Saig_ManTransformed( Aig_Man_t * p )
+{
+    Aig_Man_t * pNew;
+    Aig_Obj_t * pObj, * pObjLi, * pObjLo, * pCtrl;
+    int i;
+    assert( Aig_ManRegNum(p) > 0 );
+    // create the new manager
+    pNew = Aig_ManStart( Aig_ManObjNumMax(p) );
+    pNew->pName = Aig_UtilStrsav( p->pName );
+    pNew->pSpec = Aig_UtilStrsav( p->pSpec );
+    // create the PIs
+    Aig_ManCleanData( p );
+    Aig_ManConst1(p)->pData = Aig_ManConst1(pNew);
+    Aig_ManForEachPi( p, pObj, i )
+    {
+        if ( i == Saig_ManPiNum(p) )
+            pCtrl = Aig_ObjCreatePi( pNew );
+        pObj->pData = Aig_ObjCreatePi( pNew );
+    }
+    // set registers
+    pNew->nRegs    = p->nRegs;
+    pNew->nTruePis = p->nTruePis + 1;
+    pNew->nTruePos = 0;
+    // duplicate internal nodes
+    Aig_ManForEachNode( p, pObj, i )
+        pObj->pData = Aig_And( pNew, Aig_ObjChild0Copy(pObj), Aig_ObjChild1Copy(pObj) );
+    // create register inputs with MUXes
+    Saig_ManForEachLiLo( p, pObjLi, pObjLo, i )
+    {
+        pObj = Aig_Mux( pNew, pCtrl, pObjLo->pData, Aig_ObjChild0Copy(pObjLi) );
+        Aig_ObjCreatePo( pNew, pObj );
+    }
+    Aig_ManCleanup( pNew );
+    return pNew;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Create timeframes of the manager for interpolation.]
+
+  Description [The resulting manager is combinational. The primary inputs
+  corresponding to register outputs are ordered first. The only POs of the 
+  manager is the property output of the last timeframe.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Aig_Man_t * Saig_ManFramesInter( Aig_Man_t * pAig, int nFrames )
+{
+    Aig_Man_t * pFrames;
+    Aig_Obj_t * pObj, * pObjLi, * pObjLo;
+    int i, f;
+    assert( Saig_ManPoNum(pAig) == 1 );
+    // start the fraig package
+    pFrames = Aig_ManStart( Aig_ManNodeNum(pAig) * nFrames );
+    // map the constant node
+    Aig_ManConst1(pAig)->pData = Aig_ManConst1( pFrames );
+    // create variables for register outputs
+    Saig_ManForEachLo( pAig, pObj, i )
+        pObj->pData = Aig_ObjCreatePi( pFrames );
+    // add timeframes
+    for ( f = 0; f < nFrames; f++ )
+    {
+        // create PI nodes for this frame
+        Saig_ManForEachPi( pAig, pObj, i )
+            pObj->pData = Aig_ObjCreatePi( pFrames );
+        // add internal nodes of this frame
+        Aig_ManForEachNode( pAig, pObj, i )
+            pObj->pData = Aig_And( pFrames, Aig_ObjChild0Copy(pObj), Aig_ObjChild1Copy(pObj) );
+        if ( f == nFrames - 1 )
+            break;
+        // save register inputs
+        Saig_ManForEachLi( pAig, pObj, i )
+            pObj->pData = Aig_ObjChild0Copy(pObj);
+        // transfer to register outputs
+        Saig_ManForEachLiLo(  pAig, pObjLi, pObjLo, i )
+            pObjLo->pData = pObjLi->pData;
+    }
+    // create the only PO of the manager
+    pObj = Aig_ManPo( pAig, 0 );
+    Aig_ObjCreatePo( pFrames, Aig_ObjChild0Copy(pObj) );
+    Aig_ManCleanup( pFrames );
+    return pFrames;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Returns the SAT solver for one interpolation run.]
+
+  Description [pInter is the previous interpolant. pAig is one time frame.
+  pFrames is the unrolled time frames.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+sat_solver * Saig_DeriveSatSolver( 
+    Aig_Man_t * pInter, Cnf_Dat_t * pCnfInter, 
+    Aig_Man_t * pAig, Cnf_Dat_t * pCnfAig, 
+    Aig_Man_t * pFrames, Cnf_Dat_t * pCnfFrames, 
+    Vec_Int_t * vVarsAB )
+{
+    sat_solver * pSat;
+    Aig_Obj_t * pObj, * pObj2;
+    int i, Lits[2];
+
+    // sanity checks
+    assert( Aig_ManRegNum(pInter) == 0 );
+    assert( Aig_ManRegNum(pAig) > 0 );
+    assert( Aig_ManRegNum(pFrames) == 0 );
+    assert( Aig_ManPoNum(pInter) == 1 );
+    assert( Aig_ManPoNum(pFrames) == 1 );
+    assert( Aig_ManPiNum(pInter) == Aig_ManRegNum(pAig) );
+    assert( (Aig_ManPiNum(pFrames) - Aig_ManRegNum(pAig)) % Saig_ManPiNum(pAig) == 0 );
+
+    // prepare CNFs
+    Cnf_DataLift( pCnfAig,   pCnfFrames->nVars );
+    Cnf_DataLift( pCnfInter, pCnfFrames->nVars + pCnfAig->nVars );
+
+    // start the solver
+    pSat = sat_solver_new();
+    sat_solver_store_alloc( pSat );
+    sat_solver_setnvars( pSat, pCnfInter->nVars + pCnfAig->nVars + pCnfFrames->nVars );
+
+    // add clauses of A
+    // interpolant
+    for ( i = 0; i < pCnfInter->nClauses; i++ )
+    {
+        if ( !sat_solver_addclause( pSat, pCnfInter->pClauses[i], pCnfInter->pClauses[i+1] ) )
+            assert( 0 );
+    }
+    // connector clauses
+    Aig_ManForEachPi( pInter, pObj, i )
+    {
+        pObj2 = Saig_ManLo( pAig, i );
+        Lits[0] = toLitCond( pCnfInter->pVarNums[pObj->Id], 0 );
+        Lits[1] = toLitCond( pCnfAig->pVarNums[pObj2->Id], 1 );
+        if ( !sat_solver_addclause( pSat, Lits, Lits+2 ) )
+            assert( 0 );
+        Lits[0] = toLitCond( pCnfInter->pVarNums[pObj->Id], 1 );
+        Lits[1] = toLitCond( pCnfAig->pVarNums[pObj2->Id], 0 );
+        if ( !sat_solver_addclause( pSat, Lits, Lits+2 ) )
+            assert( 0 );
+    }
+    // one timeframe
+    for ( i = 0; i < pCnfAig->nClauses; i++ )
+    {
+        if ( !sat_solver_addclause( pSat, pCnfAig->pClauses[i], pCnfAig->pClauses[i+1] ) )
+            assert( 0 );
+    }
+    // connector clauses
+    Vec_IntClear( vVarsAB );
+    Aig_ManForEachPi( pFrames, pObj, i )
+    {
+        if ( i == Aig_ManRegNum(pAig) )
+            break;
+        Vec_IntPush( vVarsAB, pCnfFrames->pVarNums[pObj->Id] );
+
+        pObj2 = Saig_ManLi( pAig, i );
+        Lits[0] = toLitCond( pCnfFrames->pVarNums[pObj->Id], 0 );
+        Lits[1] = toLitCond( pCnfAig->pVarNums[pObj2->Id], 1 );
+        if ( !sat_solver_addclause( pSat, Lits, Lits+2 ) )
+            assert( 0 );
+        Lits[0] = toLitCond( pCnfFrames->pVarNums[pObj->Id], 1 );
+        Lits[1] = toLitCond( pCnfAig->pVarNums[pObj2->Id], 0 );
+        if ( !sat_solver_addclause( pSat, Lits, Lits+2 ) )
+            assert( 0 );
+    }
+    // add clauses of B
+    sat_solver_store_mark_clauses_a( pSat );
+    for ( i = 0; i < pCnfFrames->nClauses; i++ )
+    {
+        if ( !sat_solver_addclause( pSat, pCnfFrames->pClauses[i], pCnfFrames->pClauses[i+1] ) )
+            assert( 0 );
+    }
+    sat_solver_store_mark_roots( pSat );
+    // return clauses to the original state
+    Cnf_DataLift( pCnfAig, -pCnfFrames->nVars );
+    return pSat;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Performs one SAT run with interpolation.]
+
+  Description [Returns 1 if proven. 0 if failed. -1 if undecided.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Saig_PerformOneStep( Saig_IntMan_t * p )
+{
+    sat_solver * pSat;
+    void * pSatCnf = NULL;
+    Inta_Man_t * pManInter; 
+    int clk, status, RetValue;
+    assert( p->pInterNew == NULL );
+
+    // derive the SAT solver
+    pSat = Saig_DeriveSatSolver( p->pInter, p->pCnfInter, p->pAigTrans, p->pCnfAig, p->pFrames, p->pCnfFrames, p->vVarsAB );
+Sat_SolverWriteDimacs( pSat, "test.cnf", NULL, NULL, 1 );
+    // solve the problem
+clk = clock();
+    status = sat_solver_solve( pSat, NULL, NULL, (sint64)p->nConfLimit, (sint64)0, (sint64)0, (sint64)0 );
+    p->nConfCur = pSat->stats.conflicts;
+p->timeSat += clock() - clk;
+    if ( status == l_False )
+    {
+        pSatCnf = sat_solver_store_release( pSat );
+        RetValue = 1;
+    }
+    else if ( status == l_True )
+    {
+        RetValue = 0;
+    }
+    else
+    {
+        RetValue = -1;
+    }
+    sat_solver_delete( pSat );
+    if ( pSatCnf == NULL )
+        return RetValue;
+
+    // create the resulting manager
+clk = clock();
+    pManInter = Inta_ManAlloc();
+    p->pInterNew = Inta_ManInterpolate( pManInter, pSatCnf, p->vVarsAB, 0 );
+    Inta_ManFree( pManInter );
+p->timeInt += clock() - clk;
+    Sto_ManFree( pSatCnf );
+    return RetValue;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Checks constainment of two interpolants.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Saig_ManCheckContainment( Aig_Man_t * pNew, Aig_Man_t * pOld )
+{
+    Aig_Man_t * pMiter, * pAigTemp;
+    int RetValue;
+    pMiter = Aig_ManCreateMiter( pNew, pOld, 1 );
+    pMiter = Dar_ManRwsat( pAigTemp = pMiter, 1, 0 );
+    Aig_ManStop( pAigTemp );
+    RetValue = Fra_FraigMiterStatus( pMiter );
+    if ( RetValue == -1 )
+    {
+        pAigTemp = Fra_FraigEquivence( pMiter, 1000000, 1 );
+        RetValue = Fra_FraigMiterStatus( pAigTemp );
+        Aig_ManStop( pAigTemp );
+    }
+    assert( RetValue != -1 );
+    Aig_ManStop( pMiter );
+    return RetValue;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Frees the interpolation manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Saig_ManagerClean( Saig_IntMan_t * p )
+{
+    if ( p->pCnfInter )
+        Cnf_DataFree( p->pCnfInter );
+    if ( p->pCnfFrames )
+        Cnf_DataFree( p->pCnfFrames );
+    if ( p->pInter )
+        Aig_ManStop( p->pInter );
+    if ( p->pFrames )
+        Aig_ManStop( p->pFrames );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Frees the interpolation manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Saig_ManagerFree( Saig_IntMan_t * p )
+{
+    if ( p->fVerbose )
+    {
+        p->timeOther = p->timeTotal-p->timeRwr-p->timeCnf-p->timeSat-p->timeInt-p->timeEqu;
+        printf( "Runtime statistics:\n" );
+        PRTP( "Rewriting  ", p->timeRwr,   p->timeTotal );
+        PRTP( "CNF mapping", p->timeCnf,   p->timeTotal );
+        PRTP( "SAT solving", p->timeSat,   p->timeTotal );
+        PRTP( "Interpol   ", p->timeInt,   p->timeTotal );
+        PRTP( "Containment", p->timeEqu,   p->timeTotal );
+        PRTP( "Other      ", p->timeOther, p->timeTotal );
+        PRTP( "TOTAL      ", p->timeTotal, p->timeTotal );
+    }
+
+    if ( p->pCnfAig )
+        Cnf_DataFree( p->pCnfAig );
+    if ( p->pCnfFrames )
+        Cnf_DataFree( p->pCnfFrames );
+    if ( p->pCnfInter )
+        Cnf_DataFree( p->pCnfInter );
+    Vec_IntFree( p->vVarsAB );
+    if ( p->pAigTrans )
+        Aig_ManStop( p->pAigTrans );
+    if ( p->pFrames )
+        Aig_ManStop( p->pFrames );
+    if ( p->pInter )
+        Aig_ManStop( p->pInter );
+    if ( p->pInterNew )
+        Aig_ManStop( p->pInterNew );
+    free( p );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Interplates while the number of conflicts is not exceeded.]
+
+  Description [Returns 1 if proven. 0 if failed. -1 if undecided.]
+               
+  SideEffects [Does not check the property in 0-th frame.]
+
+  SeeAlso     []
+
+***********************************************************************/
+int Saig_Interpolate( Aig_Man_t * pAig, int nConfLimit, int fVerbose, int * pDepth )
+{
+    int fUseTransRel = 0;
+    Saig_IntMan_t * p;
+    Aig_Man_t * pAigTemp;
+    int s, i, RetValue, Status, clk, clk2, clkTotal = clock();
+
+    // sanity checks
+    assert( Saig_ManRegNum(pAig) > 0 );
+    assert( Saig_ManPiNum(pAig) > 0 );
+    assert( Saig_ManPoNum(pAig) == 1 );
+
+    // create interpolation manager
+    p = ALLOC( Saig_IntMan_t, 1 );
+    memset( p, 0, sizeof(Saig_IntMan_t) );
+    p->vVarsAB = Vec_IntAlloc( Aig_ManRegNum(pAig) );
+    p->nFrames = 1;
+    p->nConfLimit = nConfLimit;
+    p->fVerbose = fVerbose;
+    // can perform SAT sweeping and/or rewriting of this AIG...
+    p->pAig = pAig;      
+    if ( fUseTransRel )
+        p->pAigTrans = Saig_ManTransformed( pAig );
+    else
+        p->pAigTrans = Saig_ManDuplicated( pAig );
+    // derive CNF for the transformed AIG
+clk = clock();
+    p->pCnfAig = Cnf_Derive( p->pAigTrans, Aig_ManRegNum(p->pAigTrans) ); 
+p->timeCnf += clock() - clk;    
+    if ( fVerbose )
+    {
+        printf( "AIG: PI/PO/Reg = %d/%d/%d. And = %d. Lev = %d.  CNF: Var/Cla = %d/%d.\n",
+            Aig_ManPiNum(pAig), Aig_ManPoNum(pAig), Aig_ManRegNum(pAig), 
+            Aig_ManAndNum(pAig), Aig_ManLevelNum(pAig),
+            p->pCnfAig->nVars, p->pCnfAig->nClauses );
+    }
+
+    // derive interpolant
+    *pDepth = -1;
+    for ( s = 0; ; s++ )
+    {
+clk2 = clock();
+        // initial state
+        p->pInter = Saig_ManInit( Aig_ManRegNum(pAig) );
+clk = clock();
+        p->pCnfInter = Cnf_Derive( p->pInter, 0 );  
+p->timeCnf += clock() - clk;    
+        // timeframes
+        p->pFrames = Saig_ManFramesInter( pAig, p->nFrames );
+clk = clock();
+//        p->pFrames = Dar_ManRwsat( pAigTemp = p->pFrames, 1, 0 );
+//        Aig_ManStop( pAigTemp );
+//        p->pFrames = Fra_FraigEquivence( pAigTemp = p->pFrames, 100, 0 );
+//        Aig_ManStop( pAigTemp );
+p->timeRwr += clock() - clk;
+        // can also do SAT sweeping on the timeframes...
+clk = clock();
+        p->pCnfFrames = Cnf_Derive( p->pFrames, 0 );  
+p->timeCnf += clock() - clk;    
+        // report statistics
+        if ( fVerbose )
+        {
+            printf( "Step = %2d. Frames = 1 + %d. And = %5d. Lev = %5d.  ", 
+                s+1, p->nFrames, Aig_ManNodeNum(p->pFrames), Aig_ManLevelNum(p->pFrames) );
+            PRT( "Time", clock() - clk2 );
+        }
+        // iterate the interpolation procedure
+        for ( i = 0; ; i++ )
+        {
+            // perform interplation
+            clk = clock();
+            RetValue = Saig_PerformOneStep( p );
+            if ( fVerbose )
+            {
+                printf( "   I = %2d. Bmc =%3d. IntAnd =%6d. IntLev =%4d. Conf =%6d.  ", 
+                    i+1, i + 1 + p->nFrames, Aig_ManNodeNum(p->pInter), Aig_ManLevelNum(p->pInter), p->nConfCur );
+                PRT( "Time", clock() - clk );
+                if ( Aig_ManNodeNum(p->pInter) == 0 )
+                {
+                    Aig_Obj_t * pObj = Aig_ManPo(p->pInter, 0);
+                    Aig_Obj_t * pObjR = Aig_Regular(pObj);
+                    int x = 0;
+                }
+            }
+            if ( RetValue == 0 ) // found a (spurious?) counter-example
+            {
+                if ( i == 0 ) // real counterexample
+                {
+                    if ( fVerbose )
+                        printf( "Found a real counterexample in the first frame.\n" );
+                    p->timeTotal = clock() - clkTotal;
+                    *pDepth = p->nFrames + 1;
+                    Saig_ManagerFree( p );
+                    return 0;
+                }
+                // likely spurious counter-example
+                p->nFrames += i;
+                Saig_ManagerClean( p );
+                break;
+            }
+            else if ( RetValue == -1 ) // timed out
+            {
+                if ( fVerbose )
+                    printf( "Reached limit (%d) on the number of conflicts.\n", p->nConfLimit );
+                assert( p->nConfCur >= p->nConfLimit );
+                p->timeTotal = clock() - clkTotal;
+                Saig_ManagerFree( p );
+                return -1;
+            }
+            assert( RetValue == 1 ); // found new interpolant
+            // compress the interpolant
+clk = clock();
+            p->pInterNew = Dar_ManRwsat( pAigTemp = p->pInterNew, 1, 0 );
+            Aig_ManStop( pAigTemp );
+p->timeRwr += clock() - clk;
+            // check containment of interpolants
+clk = clock();
+            Status = Saig_ManCheckContainment( p->pInterNew, p->pInter );
+p->timeEqu += clock() - clk;
+            if ( Status ) // contained
+            {
+                if ( fVerbose )
+                    printf( "Proved containment of interpolants.\n" );
+                p->timeTotal = clock() - clkTotal;
+                Saig_ManagerFree( p );
+                return 1;
+            }
+            // save interpolant and convert it into CNF
+            if ( fUseTransRel )
+            {
+                Aig_ManStop( p->pInter );
+                p->pInter = p->pInterNew; 
+            }
+            else
+            {
+                p->pInter = Aig_ManCreateMiter( pAigTemp = p->pInter, p->pInterNew, 2 );
+                Aig_ManStop( pAigTemp );
+                Aig_ManStop( p->pInterNew );
+                // compress the interpolant
+clk = clock();
+                p->pInter = Dar_ManRwsat( pAigTemp = p->pInter, 1, 0 );
+                Aig_ManStop( pAigTemp );
+p->timeRwr += clock() - clk;
+            }
+            p->pInterNew = NULL;
+            Cnf_DataFree( p->pCnfInter );
+clk = clock();
+            p->pCnfInter = Cnf_Derive( p->pInter, 0 );  
+p->timeCnf += clock() - clk;
+        }
+    }
+    assert( 0 );
+    return RetValue;
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+