Duplicating Glucose package.

28 files changed, 8080 insertions, 0 deletions

diff --git a/src/sat/glucose2/AbcGlucose2.cpp b/src/sat/glucose2/AbcGlucose2.cpp
new file mode 100644
index 00000000..dabaa6fb
--- /dev/null
+++ b/src/sat/glucose2/AbcGlucose2.cpp
@@ -0,0 +1,1388 @@
+/**CFile****************************************************************
+
+  FileName    [AbcGlucose.cpp]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [SAT solver Glucose 3.0 by Gilles Audemard and Laurent Simon.]
+
+  Synopsis    [Interface to Glucose.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - September 6, 2017.]
+
+  Revision    [$Id: AbcGlucose.cpp,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "sat/glucose2/System.h"
+#include "sat/glucose2/ParseUtils.h"
+#include "sat/glucose2/Options.h"
+#include "sat/glucose2/Dimacs.h"
+#include "sat/glucose2/SimpSolver.h"
+
+#include "sat/glucose2/AbcGlucose2.h"
+
+#include "base/abc/abc.h"
+#include "aig/gia/gia.h"
+#include "sat/cnf/cnf.h"
+#include "misc/extra/extra.h"
+
+ABC_NAMESPACE_IMPL_START
+
+using namespace Gluco2;
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+#define USE_SIMP_SOLVER 1
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+#ifdef USE_SIMP_SOLVER
+    
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gluco2::SimpSolver * glucose_solver_start()
+{
+    SimpSolver * S = new SimpSolver;
+    S->setIncrementalMode();
+    return S;
+}
+
+void glucose_solver_stop(Gluco2::SimpSolver* S)
+{
+    delete S;
+}
+
+void glucose_solver_reset(Gluco2::SimpSolver* S)
+{
+    S->reset();
+}
+
+int glucose_solver_addclause(Gluco2::SimpSolver* S, int * plits, int nlits)
+{
+    vec<Lit> lits;
+    for ( int i = 0; i < nlits; i++,plits++)
+    {
+        // note: Glucose uses the same var->lit conventiaon as ABC
+        while ((*plits)/2 >= S->nVars()) S->newVar();
+        assert((*plits)/2 < S->nVars()); // NOTE: since we explicitely use new function bmc_add_var
+        Lit p;
+        p.x = *plits;
+        lits.push(p);
+    }
+    return S->addClause(lits); // returns 0 if the problem is UNSAT
+}
+
+void glucose_solver_setcallback(Gluco2::SimpSolver* S, void * pman, int(*pfunc)(void*, int, int*))
+{
+    S->pCnfMan = pman;
+    S->pCnfFunc = pfunc;
+    S->nCallConfl = 1000;
+}
+
+int glucose_solver_solve(Gluco2::SimpSolver* S, int * plits, int nlits)
+{
+    vec<Lit> lits;
+    for (int i=0;i<nlits;i++,plits++)
+    {
+        Lit p;
+        p.x = *plits;
+        lits.push(p);
+    }
+    Gluco2::lbool res = S->solveLimited(lits, 0);
+    return (res == l_True ? 1 : res == l_False ? -1 : 0);
+}
+
+int glucose_solver_addvar(Gluco2::SimpSolver* S)
+{
+    S->newVar();
+    return S->nVars() - 1;
+}
+
+int * glucose_solver_read_cex(Gluco2::SimpSolver* S )
+{
+    return S->getCex();
+}
+
+int glucose_solver_read_cex_varvalue(Gluco2::SimpSolver* S, int ivar)
+{
+    return S->model[ivar] == l_True;
+}
+
+void glucose_solver_setstop(Gluco2::SimpSolver* S, int * pstop)
+{
+    S->pstop = pstop;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Wrapper APIs to calling from ABC.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+bmcg2_sat_solver * bmcg2_sat_solver_start() 
+{
+    return (bmcg2_sat_solver *)glucose_solver_start();
+}
+void bmcg2_sat_solver_stop(bmcg2_sat_solver* s)
+{
+    glucose_solver_stop((Gluco2::SimpSolver*)s);
+}
+void bmcg2_sat_solver_reset(bmcg2_sat_solver* s)
+{
+    glucose_solver_reset((Gluco2::SimpSolver*)s);
+}
+
+
+int bmcg2_sat_solver_addclause(bmcg2_sat_solver* s, int * plits, int nlits)
+{
+    return glucose_solver_addclause((Gluco2::SimpSolver*)s,plits,nlits);
+}
+
+void bmcg2_sat_solver_setcallback(bmcg2_sat_solver* s, void * pman, int(*pfunc)(void*, int, int*))
+{
+    glucose_solver_setcallback((Gluco2::SimpSolver*)s,pman,pfunc);
+}
+
+int bmcg2_sat_solver_solve(bmcg2_sat_solver* s, int * plits, int nlits)
+{
+    return glucose_solver_solve((Gluco2::SimpSolver*)s,plits,nlits);
+}
+
+int bmcg2_sat_solver_final(bmcg2_sat_solver* s, int ** ppArray)
+{
+    *ppArray = (int *)(Lit *)((Gluco2::SimpSolver*)s)->conflict;
+    return ((Gluco2::SimpSolver*)s)->conflict.size();
+}
+
+int bmcg2_sat_solver_addvar(bmcg2_sat_solver* s)
+{
+    return glucose_solver_addvar((Gluco2::SimpSolver*)s);
+}
+
+void bmcg2_sat_solver_set_nvars( bmcg2_sat_solver* s, int nvars )
+{
+    int i;
+    for ( i = bmcg2_sat_solver_varnum(s); i < nvars; i++ )
+        bmcg2_sat_solver_addvar(s);
+}
+
+int bmcg2_sat_solver_eliminate( bmcg2_sat_solver* s, int turn_off_elim )
+{
+//    return 1; 
+    return ((Gluco2::SimpSolver*)s)->eliminate(turn_off_elim != 0);
+}
+
+int bmcg2_sat_solver_var_is_elim( bmcg2_sat_solver* s, int v )
+{
+//    return 0; 
+    return ((Gluco2::SimpSolver*)s)->isEliminated(v);
+}
+
+void bmcg2_sat_solver_var_set_frozen( bmcg2_sat_solver* s, int v, int freeze )
+{
+    ((Gluco2::SimpSolver*)s)->setFrozen(v, freeze != 0);
+}
+
+int bmcg2_sat_solver_elim_varnum(bmcg2_sat_solver* s)
+{
+//    return 0; 
+    return ((Gluco2::SimpSolver*)s)->eliminated_vars;
+}
+
+int * bmcg2_sat_solver_read_cex(bmcg2_sat_solver* s)
+{
+    return glucose_solver_read_cex((Gluco2::SimpSolver*)s);
+}
+int bmcg2_sat_solver_read_cex_varvalue(bmcg2_sat_solver* s, int ivar)
+{
+    return glucose_solver_read_cex_varvalue((Gluco2::SimpSolver*)s, ivar);
+}
+
+void bmcg2_sat_solver_set_stop(bmcg2_sat_solver* s, int * pstop)
+{
+    glucose_solver_setstop((Gluco2::SimpSolver*)s, pstop);
+}
+
+abctime bmcg2_sat_solver_set_runtime_limit(bmcg2_sat_solver* s, abctime Limit)
+{
+    abctime nRuntimeLimit = ((Gluco2::SimpSolver*)s)->nRuntimeLimit;
+    ((Gluco2::SimpSolver*)s)->nRuntimeLimit = Limit;
+    return nRuntimeLimit;
+}
+
+void bmcg2_sat_solver_set_conflict_budget(bmcg2_sat_solver* s, int Limit)
+{
+    if ( Limit > 0 ) 
+        ((Gluco2::SimpSolver*)s)->setConfBudget( (int64_t)Limit );
+    else 
+        ((Gluco2::SimpSolver*)s)->budgetOff();
+}
+
+int bmcg2_sat_solver_varnum(bmcg2_sat_solver* s)
+{
+    return ((Gluco2::SimpSolver*)s)->nVars();
+}
+int bmcg2_sat_solver_clausenum(bmcg2_sat_solver* s)
+{
+    return ((Gluco2::SimpSolver*)s)->nClauses();
+}
+int bmcg2_sat_solver_learntnum(bmcg2_sat_solver* s)
+{
+    return ((Gluco2::SimpSolver*)s)->nLearnts();
+}
+int bmcg2_sat_solver_conflictnum(bmcg2_sat_solver* s)
+{
+    return ((Gluco2::SimpSolver*)s)->conflicts;
+}
+
+int bmcg2_sat_solver_minimize_assumptions( bmcg2_sat_solver * s, int * plits, int nlits, int pivot )
+{
+    vec<int>*array = &((Gluco2::SimpSolver*)s)->user_vec;
+    int i, nlitsL, nlitsR, nresL, nresR, status;
+    assert( pivot >= 0 );
+//    assert( nlits - pivot >= 2 );
+    assert( nlits - pivot >= 1 );
+    if ( nlits - pivot == 1 )
+    {
+        // since the problem is UNSAT, we try to solve it without assuming the last literal
+        // if the result is UNSAT, the last literal can be dropped; otherwise, it is needed
+        status = bmcg2_sat_solver_solve( s, plits, pivot );
+        return status != GLUCOSE_UNSAT; // return 1 if the problem is not UNSAT
+    }
+    assert( nlits - pivot >= 2 );
+    nlitsL = (nlits - pivot) / 2;
+    nlitsR = (nlits - pivot) - nlitsL;
+    assert( nlitsL + nlitsR == nlits - pivot );
+    // solve with these assumptions
+    status = bmcg2_sat_solver_solve( s, plits, pivot + nlitsL );
+    if ( status == GLUCOSE_UNSAT ) // these are enough
+        return bmcg2_sat_solver_minimize_assumptions( s, plits, pivot + nlitsL, pivot );
+    // these are not enough
+    // solve for the right lits
+//    nResL = nLitsR == 1 ? 1 : sat_solver_minimize_assumptions( s, pLits + nLitsL, nLitsR, nConfLimit );
+    nresL = nlitsR == 1 ? 1 : bmcg2_sat_solver_minimize_assumptions( s, plits, nlits, pivot + nlitsL );
+    // swap literals
+    array->clear();
+    for ( i = 0; i < nlitsL; i++ )
+        array->push(plits[pivot + i]);
+    for ( i = 0; i < nresL; i++ )
+        plits[pivot + i] = plits[pivot + nlitsL + i];
+    for ( i = 0; i < nlitsL; i++ )
+        plits[pivot + nresL + i] = (*array)[i];
+    // solve with these assumptions
+    status = bmcg2_sat_solver_solve( s, plits, pivot + nresL );
+    if ( status == GLUCOSE_UNSAT ) // these are enough
+        return nresL;
+    // solve for the left lits
+//    nResR = nLitsL == 1 ? 1 : sat_solver_minimize_assumptions( s, pLits + nResL, nLitsL, nConfLimit );
+    nresR = nlitsL == 1 ? 1 : bmcg2_sat_solver_minimize_assumptions( s, plits, pivot + nresL + nlitsL, pivot + nresL );
+    return nresL + nresR;
+}
+
+int bmcg2_sat_solver_add_and( bmcg2_sat_solver * s, int iVar, int iVar0, int iVar1, int fCompl0, int fCompl1, int fCompl )
+{
+    int Lits[3];
+
+    Lits[0] = Abc_Var2Lit( iVar, !fCompl );
+    Lits[1] = Abc_Var2Lit( iVar0, fCompl0 );
+    if ( !bmcg2_sat_solver_addclause( s, Lits, 2 ) )
+        return 0;
+
+    Lits[0] = Abc_Var2Lit( iVar, !fCompl );
+    Lits[1] = Abc_Var2Lit( iVar1, fCompl1 );
+    if ( !bmcg2_sat_solver_addclause( s, Lits, 2 ) )
+        return 0;
+
+    Lits[0] = Abc_Var2Lit( iVar,   fCompl );
+    Lits[1] = Abc_Var2Lit( iVar0, !fCompl0 );
+    Lits[2] = Abc_Var2Lit( iVar1, !fCompl1 );
+    if ( !bmcg2_sat_solver_addclause( s, Lits, 3 ) )
+        return 0;
+
+    return 1;
+}
+
+#else
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gluco2::Solver * glucose_solver_start()
+{
+    Solver * S = new Solver;
+    S->setIncrementalMode();
+    return S;
+}
+
+void glucose_solver_stop(Gluco2::Solver* S)
+{
+    delete S;
+}
+
+int glucose_solver_addclause(Gluco2::Solver* S, int * plits, int nlits)
+{
+    vec<Lit> lits;
+    for ( int i = 0; i < nlits; i++,plits++)
+    {
+        // note: Glucose uses the same var->lit conventiaon as ABC
+        while ((*plits)/2 >= S->nVars()) S->newVar();
+        assert((*plits)/2 < S->nVars()); // NOTE: since we explicitely use new function bmc_add_var
+        Lit p;
+        p.x = *plits;
+        lits.push(p);
+    }
+    return S->addClause(lits); // returns 0 if the problem is UNSAT
+}
+
+void glucose_solver_setcallback(Gluco2::Solver* S, void * pman, int(*pfunc)(void*, int, int*))
+{
+    S->pCnfMan = pman;
+    S->pCnfFunc = pfunc;
+    S->nCallConfl = 1000;
+}
+
+int glucose_solver_solve(Gluco2::Solver* S, int * plits, int nlits)
+{
+    vec<Lit> lits;
+    for (int i=0;i<nlits;i++,plits++)
+    {
+        Lit p;
+        p.x = *plits;
+        lits.push(p);
+    }
+    Gluco2::lbool res = S->solveLimited(lits);
+    return (res == l_True ? 1 : res == l_False ? -1 : 0);
+}
+
+int glucose_solver_addvar(Gluco2::Solver* S)
+{
+    S->newVar();
+    return S->nVars() - 1;
+}
+
+int * glucose_solver_read_cex(Gluco2::Solver* S )
+{
+    return S->getCex();
+}
+
+int glucose_solver_read_cex_varvalue(Gluco2::Solver* S, int ivar)
+{
+    return S->model[ivar] == l_True;
+}
+
+void glucose_solver_setstop(Gluco2::Solver* S, int * pstop)
+{
+    S->pstop = pstop;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Wrapper APIs to calling from ABC.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+bmcg2_sat_solver * bmcg2_sat_solver_start() 
+{
+    return (bmcg2_sat_solver *)glucose_solver_start();
+}
+void bmcg2_sat_solver_stop(bmcg2_sat_solver* s)
+{
+    glucose_solver_stop((Gluco2::Solver*)s);
+}
+
+int bmcg2_sat_solver_addclause(bmcg2_sat_solver* s, int * plits, int nlits)
+{
+    return glucose_solver_addclause((Gluco2::Solver*)s,plits,nlits);
+}
+
+void bmcg2_sat_solver_setcallback(bmcg2_sat_solver* s, void * pman, int(*pfunc)(void*, int, int*))
+{
+    glucose_solver_setcallback((Gluco2::Solver*)s,pman,pfunc);
+}
+
+int bmcg2_sat_solver_solve(bmcg2_sat_solver* s, int * plits, int nlits)
+{
+    return glucose_solver_solve((Gluco2::Solver*)s,plits,nlits);
+}
+
+int bmcg2_sat_solver_final(bmcg2_sat_solver* s, int ** ppArray)
+{
+    *ppArray = (int *)(Lit *)((Gluco2::Solver*)s)->conflict;
+    return ((Gluco2::Solver*)s)->conflict.size();
+}
+
+int bmcg2_sat_solver_addvar(bmcg2_sat_solver* s)
+{
+    return glucose_solver_addvar((Gluco2::Solver*)s);
+}
+
+void bmcg2_sat_solver_set_nvars( bmcg2_sat_solver* s, int nvars )
+{
+    int i;
+    for ( i = bmcg2_sat_solver_varnum(s); i < nvars; i++ )
+        bmcg2_sat_solver_addvar(s);
+}
+
+int bmcg2_sat_solver_eliminate( bmcg2_sat_solver* s, int turn_off_elim )
+{
+    return 1; 
+//    return ((Gluco2::SimpSolver*)s)->eliminate(turn_off_elim != 0);
+}
+
+int bmcg2_sat_solver_var_is_elim( bmcg2_sat_solver* s, int v )
+{
+    return 0; 
+//    return ((Gluco2::SimpSolver*)s)->isEliminated(v);
+}
+
+void bmcg2_sat_solver_var_set_frozen( bmcg2_sat_solver* s, int v, int freeze )
+{
+//    ((Gluco2::SimpSolver*)s)->setFrozen(v, freeze);
+}
+
+int bmcg2_sat_solver_elim_varnum(bmcg2_sat_solver* s)
+{
+    return 0;
+//    return ((Gluco2::SimpSolver*)s)->eliminated_vars;
+}
+
+int * bmcg2_sat_solver_read_cex(bmcg2_sat_solver* s)
+{
+    return glucose_solver_read_cex((Gluco2::Solver*)s);
+}
+
+int bmcg2_sat_solver_read_cex_varvalue(bmcg2_sat_solver* s, int ivar)
+{
+    return glucose_solver_read_cex_varvalue((Gluco2::Solver*)s, ivar);
+}
+
+void bmcg2_sat_solver_set_stop(bmcg2_sat_solver* s, int * pstop)
+{
+    glucose_solver_setstop((Gluco2::Solver*)s, pstop);
+}
+
+abctime bmcg2_sat_solver_set_runtime_limit(bmcg2_sat_solver* s, abctime Limit)
+{
+    abctime nRuntimeLimit = ((Gluco2::Solver*)s)->nRuntimeLimit;
+    ((Gluco2::Solver*)s)->nRuntimeLimit = Limit;
+    return nRuntimeLimit;
+}
+
+void bmcg2_sat_solver_set_conflict_budget(bmcg2_sat_solver* s, int Limit)
+{
+    if ( Limit > 0 ) 
+        ((Gluco2::Solver*)s)->setConfBudget( (int64_t)Limit );
+    else 
+        ((Gluco2::Solver*)s)->budgetOff();
+}
+
+int bmcg2_sat_solver_varnum(bmcg2_sat_solver* s)
+{
+    return ((Gluco2::Solver*)s)->nVars();
+}
+int bmcg2_sat_solver_clausenum(bmcg2_sat_solver* s)
+{
+    return ((Gluco2::Solver*)s)->nClauses();
+}
+int bmcg2_sat_solver_learntnum(bmcg2_sat_solver* s)
+{
+    return ((Gluco2::Solver*)s)->nLearnts();
+}
+int bmcg2_sat_solver_conflictnum(bmcg2_sat_solver* s)
+{
+    return ((Gluco2::Solver*)s)->conflicts;
+}
+
+int bmcg2_sat_solver_minimize_assumptions( bmcg2_sat_solver * s, int * plits, int nlits, int pivot )
+{
+    vec<int>*array = &((Gluco2::Solver*)s)->user_vec;
+    int i, nlitsL, nlitsR, nresL, nresR, status;
+    assert( pivot >= 0 );
+//    assert( nlits - pivot >= 2 );
+    assert( nlits - pivot >= 1 );
+    if ( nlits - pivot == 1 )
+    {
+        // since the problem is UNSAT, we try to solve it without assuming the last literal
+        // if the result is UNSAT, the last literal can be dropped; otherwise, it is needed
+        status = bmcg2_sat_solver_solve( s, plits, pivot );
+        return status != GLUCOSE_UNSAT; // return 1 if the problem is not UNSAT
+    }
+    assert( nlits - pivot >= 2 );
+    nlitsL = (nlits - pivot) / 2;
+    nlitsR = (nlits - pivot) - nlitsL;
+    assert( nlitsL + nlitsR == nlits - pivot );
+    // solve with these assumptions
+    status = bmcg2_sat_solver_solve( s, plits, pivot + nlitsL );
+    if ( status == GLUCOSE_UNSAT ) // these are enough
+        return bmcg2_sat_solver_minimize_assumptions( s, plits, pivot + nlitsL, pivot );
+    // these are not enough
+    // solve for the right lits
+//    nResL = nLitsR == 1 ? 1 : sat_solver_minimize_assumptions( s, pLits + nLitsL, nLitsR, nConfLimit );
+    nresL = nlitsR == 1 ? 1 : bmcg2_sat_solver_minimize_assumptions( s, plits, nlits, pivot + nlitsL );
+    // swap literals
+    array->clear();
+    for ( i = 0; i < nlitsL; i++ )
+        array->push(plits[pivot + i]);
+    for ( i = 0; i < nresL; i++ )
+        plits[pivot + i] = plits[pivot + nlitsL + i];
+    for ( i = 0; i < nlitsL; i++ )
+        plits[pivot + nresL + i] = (*array)[i];
+    // solve with these assumptions
+    status = bmcg2_sat_solver_solve( s, plits, pivot + nresL );
+    if ( status == GLUCOSE_UNSAT ) // these are enough
+        return nresL;
+    // solve for the left lits
+//    nResR = nLitsL == 1 ? 1 : sat_solver_minimize_assumptions( s, pLits + nResL, nLitsL, nConfLimit );
+    nresR = nlitsL == 1 ? 1 : bmcg2_sat_solver_minimize_assumptions( s, plits, pivot + nresL + nlitsL, pivot + nresL );
+    return nresL + nresR;
+}
+
+#endif
+
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void glucose_print_stats(SimpSolver& s, abctime clk)
+{
+    double cpu_time = (double)(unsigned)clk / CLOCKS_PER_SEC;
+    double mem_used = memUsed();
+    printf("c restarts              : %d (%d conflicts on average)\n",         (int)s.starts, s.starts > 0 ? (int)(s.conflicts/s.starts) : 0);
+    printf("c blocked restarts      : %d (multiple: %d) \n",                   (int)s.nbstopsrestarts, (int)s.nbstopsrestartssame);
+    printf("c last block at restart : %d\n",                                   (int)s.lastblockatrestart);
+    printf("c nb ReduceDB           : %-12d\n",                                (int)s.nbReduceDB);
+    printf("c nb removed Clauses    : %-12d\n",                                (int)s.nbRemovedClauses);
+    printf("c nb learnts DL2        : %-12d\n",                                (int)s.nbDL2);
+    printf("c nb learnts size 2     : %-12d\n",                                (int)s.nbBin);
+    printf("c nb learnts size 1     : %-12d\n",                                (int)s.nbUn);
+    printf("c conflicts             : %-12d  (%.0f /sec)\n",                   (int)s.conflicts,    s.conflicts   /cpu_time);
+    printf("c decisions             : %-12d  (%4.2f %% random) (%.0f /sec)\n", (int)s.decisions,    (float)s.rnd_decisions*100 / (float)s.decisions, s.decisions   /cpu_time);
+    printf("c propagations          : %-12d  (%.0f /sec)\n",                   (int)s.propagations, s.propagations/cpu_time);
+    printf("c conflict literals     : %-12d  (%4.2f %% deleted)\n",            (int)s.tot_literals, (s.max_literals - s.tot_literals)*100 / (double)s.max_literals);
+    printf("c nb reduced Clauses    : %-12d\n", (int)s.nbReducedClauses);
+    if (mem_used != 0) printf("Memory used           : %.2f MB\n", mem_used);
+    //printf("c CPU time              : %.2f sec\n", cpu_time);
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Glucose_ReadDimacs( char * pFileName, SimpSolver& s )
+{
+    vec<Lit> * lits = &s.user_lits;
+    char * pBuffer = Extra_FileReadContents( pFileName );
+    char * pTemp; int fComp, Var, VarMax = 0;
+    lits->clear();
+    for ( pTemp = pBuffer; *pTemp; pTemp++ )
+    {
+        if ( *pTemp == 'c' || *pTemp == 'p' ) {
+            while ( *pTemp != '\n' )
+                pTemp++;
+            continue;
+        }
+        while ( *pTemp == ' ' || *pTemp == '\t' || *pTemp == '\r' || *pTemp == '\n' )
+            pTemp++;
+        fComp = 0;
+        if ( *pTemp == '-' )
+            fComp = 1, pTemp++;
+        if ( *pTemp == '+' )
+            pTemp++;
+        Var = atoi( pTemp );
+        if ( Var == 0 ) {
+            if ( lits->size() > 0 ) {
+                s.addVar( VarMax );
+                s.addClause(*lits);
+                lits->clear();
+            }
+        }
+        else {
+            Var--;
+            VarMax = Abc_MaxInt( VarMax, Var );
+            lits->push( toLit(Abc_Var2Lit(Var, fComp)) );
+        }
+        while ( *pTemp >= '0' && *pTemp <= '9' )
+            pTemp++;
+    }
+    ABC_FREE( pBuffer );
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Glucose2_SolveCnf( char * pFileName, Glucose2_Pars * pPars )
+{
+    abctime clk = Abc_Clock();
+
+    SimpSolver  S;
+    S.verbosity = pPars->verb;
+    S.setConfBudget( pPars->nConfls > 0 ? (int64_t)pPars->nConfls : -1 );
+
+//    gzFile in = gzopen(pFilename, "rb");
+//    parse_DIMACS(in, S);
+//    gzclose(in);
+    Glucose_ReadDimacs( pFileName, S );
+
+    if ( pPars->verb )
+    {
+        printf("c ============================[ Problem Statistics ]=============================\n");
+        printf("c |                                                                             |\n");
+        printf("c |  Number of variables:  %12d                                         |\n", S.nVars());
+        printf("c |  Number of clauses:    %12d                                         |\n", S.nClauses());
+    }
+    
+    if ( pPars->pre ) 
+    {
+        S.eliminate(true);
+        printf( "c Simplication removed %d variables and %d clauses.  ", S.eliminated_vars, S.eliminated_clauses );
+        Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
+    }
+
+    vec<Lit> dummy;
+    lbool ret = S.solveLimited(dummy, 0);
+    if ( pPars->verb ) glucose_print_stats(S, Abc_Clock() - clk);
+    printf(ret == l_True ? "SATISFIABLE" : ret == l_False ? "UNSATISFIABLE" : "INDETERMINATE");
+    Abc_PrintTime( 1, "      Time", Abc_Clock() - clk );
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Int_t * Glucose_SolverFromAig( Gia_Man_t * p, SimpSolver& s )
+{
+    abctime clk = Abc_Clock();
+    vec<Lit> * lits = &s.user_lits;
+    Cnf_Dat_t * pCnf = (Cnf_Dat_t *)Mf_ManGenerateCnf( p, 8 /*nLutSize*/, 0 /*fCnfObjIds*/, 1/*fAddOrCla*/, 0, 0/*verbose*/ );
+    for ( int i = 0; i < pCnf->nClauses; i++ )
+    {
+        lits->clear();
+        for ( int * pLit = pCnf->pClauses[i]; pLit < pCnf->pClauses[i+1]; pLit++ )
+            lits->push( toLit(*pLit) ), s.addVar( *pLit >> 1 );
+        s.addClause(*lits);
+    }
+    Vec_Int_t * vCnfIds = Vec_IntAllocArrayCopy(pCnf->pVarNums,pCnf->nVars);
+    printf( "CNF stats: Vars = %6d. Clauses = %7d. Literals = %8d. ", pCnf->nVars, pCnf->nClauses, pCnf->nLiterals );
+    Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
+    Cnf_DataFree(pCnf);
+    return vCnfIds;
+}
+
+// procedure below does not work because glucose_solver_addclause() expects Solver
+Vec_Int_t * Glucose_SolverFromAig2( Gia_Man_t * p, SimpSolver& S ) 
+{
+    Cnf_Dat_t * pCnf = (Cnf_Dat_t *)Mf_ManGenerateCnf( p, 8 /*nLutSize*/, 0 /*fCnfObjIds*/, 1/*fAddOrCla*/, 0, 0/*verbose*/ );
+    for ( int i = 0; i < pCnf->nClauses; i++ )
+        if ( !glucose_solver_addclause( &S, pCnf->pClauses[i], pCnf->pClauses[i+1]-pCnf->pClauses[i] ) )
+            assert( 0 );
+    Vec_Int_t * vCnfIds = Vec_IntAllocArrayCopy(pCnf->pVarNums,pCnf->nVars);
+    //printf( "CNF stats: Vars = %6d. Clauses = %7d. Literals = %8d. ", pCnf->nVars, pCnf->nClauses, pCnf->nLiterals );
+    //Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
+    Cnf_DataFree(pCnf);
+    return vCnfIds;
+}
+
+
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Str_t * Glucose2_GenerateCubes( bmcg2_sat_solver * pSat[2], Vec_Int_t * vCiSatVars, Vec_Int_t * vVar2Index, int CubeLimit )
+{
+    int fCreatePrime = 1;
+    int nCubes, nSupp = Vec_IntSize(vCiSatVars);
+    Vec_Str_t * vSop  = Vec_StrAlloc( 1000 );
+    Vec_Int_t * vLits = Vec_IntAlloc( nSupp );
+    Vec_Str_t * vCube = Vec_StrAlloc( nSupp + 4 );
+    Vec_StrFill( vCube, nSupp, '-' );
+    Vec_StrPrintF( vCube, " 1\n\0" );
+    for ( nCubes = 0; !CubeLimit || nCubes < CubeLimit; nCubes++ )
+    {
+        int * pFinal, nFinal, iVar, i, k = 0;
+        // generate onset minterm
+        int status = bmcg2_sat_solver_solve( pSat[1], NULL, 0 );
+        if ( status == GLUCOSE_UNSAT )
+            break;
+        assert( status == GLUCOSE_SAT );
+        Vec_IntClear( vLits );
+        Vec_IntForEachEntry( vCiSatVars, iVar, i )
+            Vec_IntPush( vLits, Abc_Var2Lit(iVar, !bmcg2_sat_solver_read_cex_varvalue(pSat[1], iVar)) );
+        // expand against offset
+        if ( fCreatePrime )
+        {
+            nFinal = bmcg2_sat_solver_minimize_assumptions( pSat[0], Vec_IntArray(vLits), Vec_IntSize(vLits), 0 );
+            Vec_IntShrink( vLits, nFinal );
+            pFinal = Vec_IntArray( vLits );
+            for ( i = 0; i < nFinal; i++ )
+                pFinal[i] = Abc_LitNot(pFinal[i]);
+        }
+        else
+        {
+            status = bmcg2_sat_solver_solve( pSat[0], Vec_IntArray(vLits), Vec_IntSize(vLits) );
+            assert( status == GLUCOSE_UNSAT );
+            nFinal = bmcg2_sat_solver_final( pSat[0], &pFinal );
+        }
+        // print cube
+        Vec_StrFill( vCube, nSupp, '-' );
+        for ( i = 0; i < nFinal; i++ )
+        {
+            int Index = Vec_IntEntry(vVar2Index, Abc_Lit2Var(pFinal[i]));
+            if ( Index == -1 )
+                continue;
+            pFinal[k++] = pFinal[i];
+            assert( Index >= 0 && Index < nSupp );
+            Vec_StrWriteEntry( vCube, Index, (char)('0' + Abc_LitIsCompl(pFinal[i])) );
+        }
+        nFinal = k;
+        Vec_StrAppend( vSop, Vec_StrArray(vCube) );
+        //printf( "%s\n", Vec_StrArray(vCube) );
+        // add blocking clause
+        if ( !bmcg2_sat_solver_addclause( pSat[1], pFinal, nFinal ) )
+            break;
+    }
+    Vec_IntFree( vLits );
+    Vec_StrFree( vCube );
+    Vec_StrPush( vSop, '\0' );
+    return vSop;
+}
+Vec_Str_t * bmcg2_sat_solver_sop( Gia_Man_t * p, int CubeLimit )
+{
+    bmcg2_sat_solver * pSat[2] = { bmcg2_sat_solver_start(), bmcg2_sat_solver_start() };
+
+    // generate CNF for the on-set and off-set
+    Cnf_Dat_t * pCnf = (Cnf_Dat_t *)Mf_ManGenerateCnf( p, 8 /*nLutSize*/, 0 /*fCnfObjIds*/, 0/*fAddOrCla*/, 0, 0/*verbose*/ );
+    int i, n, nVars = Gia_ManCiNum(p), Lit;//, Count = 0;
+    int iFirstVar = pCnf->nVars - nVars;
+    assert( Gia_ManCoNum(p) == 1 );
+    for ( n = 0; n < 2; n++ )
+    {
+        bmcg2_sat_solver_set_nvars( pSat[n], pCnf->nVars );
+        Lit = Abc_Var2Lit( 1, !n );  // output variable is 1
+        for ( i = 0; i < pCnf->nClauses; i++ )
+            if ( !bmcg2_sat_solver_addclause( pSat[n], pCnf->pClauses[i], pCnf->pClauses[i+1]-pCnf->pClauses[i] ) )
+                assert( 0 );
+        if ( !bmcg2_sat_solver_addclause( pSat[n], &Lit, 1 ) )
+        {
+            Vec_Str_t * vSop = Vec_StrAlloc( 10 );
+            Vec_StrPrintF( vSop, " %d\n\0", !n );
+            Cnf_DataFree( pCnf );
+            return vSop;
+        }
+    }
+    Cnf_DataFree( pCnf );
+
+    // collect cube vars and map SAT vars into them
+    Vec_Int_t * vVars = Vec_IntAlloc( 100 ); 
+    Vec_Int_t * vVarMap = Vec_IntStartFull( iFirstVar + nVars ); 
+    for ( i = 0; i < nVars; i++ )
+    {
+        Vec_IntPush( vVars, iFirstVar+i );
+        Vec_IntWriteEntry( vVarMap, iFirstVar+i, i );
+    }
+
+    Vec_Str_t * vSop = Glucose2_GenerateCubes( pSat, vVars, vVarMap, CubeLimit );
+    Vec_IntFree( vVarMap );
+    Vec_IntFree( vVars );
+
+    bmcg2_sat_solver_stop( pSat[0] );
+    bmcg2_sat_solver_stop( pSat[1] );
+    return vSop;
+}
+void bmcg2_sat_solver_print_sop( Gia_Man_t * p )
+{
+    Vec_Str_t * vSop = bmcg2_sat_solver_sop( p, 0 );
+    printf( "%s", Vec_StrArray(vSop) );
+    Vec_StrFree( vSop );
+}
+void bmcg2_sat_solver_print_sop_lit( Gia_Man_t * p, int Lit )
+{
+    Vec_Int_t * vCisUsed = Vec_IntAlloc( 100 );
+    int i, ObjId, iNode = Abc_Lit2Var( Lit );
+    Gia_ManCollectCis( p, &iNode, 1, vCisUsed );
+    Vec_IntSort( vCisUsed, 0 );
+    Vec_IntForEachEntry( vCisUsed, ObjId, i )
+        Vec_IntWriteEntry( vCisUsed, i, Gia_ManIdToCioId(p, ObjId) );
+    Vec_IntPrint( vCisUsed );
+    Gia_Man_t * pNew = Gia_ManDupConeSupp( p, Lit, vCisUsed );
+    Vec_IntFree( vCisUsed );
+    bmcg2_sat_solver_print_sop( pNew );
+    Gia_ManStop( pNew );
+    printf( "\n" );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Computing d-literals.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+#define Gia_CubeForEachVar( pCube, Value, i )                                                      \
+    for ( i = 0; (pCube[i] != ' ') && (Value = pCube[i]); i++ )           
+#define Gia_SopForEachCube( pSop, nFanins, pCube )                                                 \
+    for ( pCube = (pSop); *pCube; pCube += (nFanins) + 3 )
+
+void bmcg2_sat_generate_dvars( Vec_Int_t * vCiVars, Vec_Str_t * vSop, Vec_Int_t * vDLits )
+{
+    int i, Lit, Counter, nCubes = 0;
+    char Value, * pCube, * pSop = Vec_StrArray( vSop );
+    Vec_Int_t * vCounts = Vec_IntStart( 2*Vec_IntSize(vCiVars) );
+    Vec_IntClear( vDLits );
+    Gia_SopForEachCube( pSop, Vec_IntSize(vCiVars), pCube )
+    {
+        nCubes++;
+        Gia_CubeForEachVar( pCube, Value, i )
+        {
+            if ( Value == '1' )
+                Vec_IntAddToEntry( vCounts, 2*i, 1 );
+            else if ( Value == '0' )
+                Vec_IntAddToEntry( vCounts, 2*i+1, 1 );
+        }
+    }
+    Vec_IntForEachEntry( vCounts, Counter, Lit )
+        if ( Counter == nCubes )
+            Vec_IntPush( vDLits, Abc_Var2Lit(Vec_IntEntry(vCiVars, Abc_Lit2Var(Lit)), Abc_LitIsCompl(Lit)) );
+    Vec_IntSort( vDLits, 0 );
+    Vec_IntFree( vCounts );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Performs SAT-based quantification.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int bmcg2_sat_solver_quantify2( Gia_Man_t * p, int iLit, int fHash, int(*pFuncCiToKeep)(void *, int), void * pData, Vec_Int_t * vDLits )
+{
+    int fSynthesize = 0;
+    extern Gia_Man_t * Abc_SopSynthesizeOne( char * pSop, int fClp );
+    Gia_Man_t * pMan, * pNew, * pTemp;  Vec_Str_t * vSop;
+    int i, CiId, ObjId, Res, nCubes = 0, nNodes, Count = 0, iNode = Abc_Lit2Var(iLit);
+    Vec_Int_t * vCisUsed = Vec_IntAlloc( 100 );
+    Gia_ManCollectCis( p, &iNode, 1, vCisUsed );
+    Vec_IntSort( vCisUsed, 0 );
+    if ( vDLits ) Vec_IntClear( vDLits );
+    if ( iLit < 2 )
+        return iLit;
+    // remap into CI Ids
+    Vec_IntForEachEntry( vCisUsed, ObjId, i )
+        Vec_IntWriteEntry( vCisUsed, i, Gia_ManIdToCioId(p, ObjId) );
+    // duplicate cone
+    pNew = Gia_ManDupConeSupp( p, iLit, vCisUsed );
+    assert( Gia_ManCiNum(pNew) == Vec_IntSize(vCisUsed) );
+    nNodes = Gia_ManAndNum(pNew);
+
+    // perform quantification one CI at a time
+    assert( pFuncCiToKeep );
+    Vec_IntForEachEntry( vCisUsed, CiId, i )
+        if ( !pFuncCiToKeep( pData, CiId ) )
+        {
+            //printf( "Quantifying %d.\n", CiId );
+            pNew = Gia_ManDupExist( pTemp = pNew, i );
+            Gia_ManStop( pTemp );
+            Count++;
+        }
+    if ( Gia_ManPoIsConst(pNew, 0) )
+    {
+        int RetValue = Gia_ManPoIsConst1(pNew, 0);
+        Vec_IntFree( vCisUsed );
+        Gia_ManStop( pNew );
+        return RetValue;
+    }
+
+    if ( fSynthesize )
+    {
+        vSop = bmcg2_sat_solver_sop( pNew, 0 );
+        Gia_ManStop( pNew );
+        pMan = Abc_SopSynthesizeOne( Vec_StrArray(vSop), 1 );
+        nCubes = Vec_StrCountEntry(vSop, '\n');
+        if ( vDLits )
+        {
+            // convert into object IDs
+            Vec_Int_t * vCisObjs = Vec_IntAlloc( Vec_IntSize(vCisUsed) );
+            Vec_IntForEachEntry( vCisUsed, CiId, i )
+                Vec_IntPush( vCisObjs, CiId + 1 );
+            bmcg2_sat_generate_dvars( vCisObjs, vSop, vDLits );
+            Vec_IntFree( vCisObjs );
+        }
+        Vec_StrFree( vSop );
+
+        if ( Gia_ManPoIsConst(pMan, 0) )
+        {
+            int RetValue = Gia_ManPoIsConst1(pMan, 0);
+            Vec_IntFree( vCisUsed );
+            Gia_ManStop( pMan );
+            return RetValue;
+        }
+    }
+    else
+    {
+        pMan = pNew;
+    }
+
+    Res = Gia_ManDupConeBack( p, pMan, vCisUsed );
+
+    // report the result
+    //printf( "Performed quantification with %5d nodes, %3d keep-vars, %3d quant-vars, resulting in %5d cubes and %5d nodes. ", 
+    //    nNodes, Vec_IntSize(vCisUsed) - Count, Count, nCubes, Gia_ManAndNum(pMan) );
+    //Abc_PrintTime( 1, "Time", Abc_Clock() - clkAll );
+
+    Vec_IntFree( vCisUsed );
+    Gia_ManStop( pMan );
+    return Res;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Performs SAT-based quantification.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Gia_ManSatAndCollect2_rec( Gia_Man_t * p, int iObj, Vec_Int_t * vObjsUsed, Vec_Int_t * vCiVars )
+{
+    Gia_Obj_t * pObj; int iVar;
+    if ( (iVar = Gia_ObjCopyArray(p, iObj)) >= 0 )
+        return iVar;
+    pObj = Gia_ManObj( p, iObj );
+    assert( Gia_ObjIsCand(pObj) );
+    if ( Gia_ObjIsAnd(pObj) )
+    {
+        Gia_ManSatAndCollect2_rec( p, Gia_ObjFaninId0(pObj, iObj), vObjsUsed, vCiVars );
+        Gia_ManSatAndCollect2_rec( p, Gia_ObjFaninId1(pObj, iObj), vObjsUsed, vCiVars );
+    }
+    iVar = Vec_IntSize( vObjsUsed );
+    Vec_IntPush( vObjsUsed, iObj );
+    Gia_ObjSetCopyArray( p, iObj, iVar );
+    if ( vCiVars && Gia_ObjIsCi(pObj) )
+        Vec_IntPush( vCiVars, iVar );
+    return iVar;
+}                             
+void Gia_ManQuantLoadCnf2( Gia_Man_t * p, Vec_Int_t * vObjsUsed, bmcg2_sat_solver * pSats[] )
+{
+    Gia_Obj_t * pObj; int i;
+    bmcg2_sat_solver_reset( pSats[0] );
+    if ( pSats[1] )
+    bmcg2_sat_solver_reset( pSats[1] );
+    bmcg2_sat_solver_set_nvars( pSats[0], Vec_IntSize(vObjsUsed) );
+    if ( pSats[1] )
+    bmcg2_sat_solver_set_nvars( pSats[1], Vec_IntSize(vObjsUsed) );
+    Gia_ManForEachObjVec( vObjsUsed, p, pObj, i ) 
+        if ( Gia_ObjIsAnd(pObj) )
+        {
+            int iObj  = Gia_ObjId( p, pObj );
+            int iVar  = Gia_ObjCopyArray(p, iObj);
+            int iVar0 = Gia_ObjCopyArray(p, Gia_ObjFaninId0(pObj, iObj));
+            int iVar1 = Gia_ObjCopyArray(p, Gia_ObjFaninId1(pObj, iObj));
+            bmcg2_sat_solver_add_and( pSats[0], iVar, iVar0, iVar1, Gia_ObjFaninC0(pObj), Gia_ObjFaninC1(pObj), 0 );
+            if ( pSats[1] )
+            bmcg2_sat_solver_add_and( pSats[1], iVar, iVar0, iVar1, Gia_ObjFaninC0(pObj), Gia_ObjFaninC1(pObj), 0 );
+        }
+        else if ( Gia_ObjIsConst0(pObj) )
+        {
+            int Lit = Abc_Var2Lit( Gia_ObjCopyArray(p, 0), 1 );
+            int RetValue = bmcg2_sat_solver_addclause( pSats[0], &Lit, 1 );
+            assert( RetValue );
+            if ( pSats[1] )
+            bmcg2_sat_solver_addclause( pSats[1], &Lit, 1 );
+            assert( Lit == 1 );
+        }
+}
+int Gia_ManFactorSop2( Gia_Man_t * p, Vec_Int_t * vCiObjIds, Vec_Str_t * vSop, int fHash )
+{
+    extern Gia_Man_t * Abc_SopSynthesizeOne( char * pSop, int fClp );
+    Gia_Man_t * pMan = Abc_SopSynthesizeOne( Vec_StrArray(vSop), 1 );
+    Gia_Obj_t * pObj; int i, Result;
+    assert( Gia_ManPiNum(pMan) == Vec_IntSize(vCiObjIds) );
+    Gia_ManConst0(pMan)->Value = 0;
+    Gia_ManForEachPi( pMan, pObj, i )
+        pObj->Value = Abc_Var2Lit( Vec_IntEntry(vCiObjIds, i), 0 );
+    Gia_ManForEachAnd( pMan, pObj, i )
+        if ( fHash )
+            pObj->Value = Gia_ManHashAnd( p, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+        else
+            pObj->Value = Gia_ManAppendAnd( p, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+    pObj = Gia_ManPo(pMan, 0);
+    Result = Gia_ObjFanin0Copy(pObj);
+    Gia_ManStop( pMan );
+    return Result;
+}
+int bmcg2_sat_solver_quantify( bmcg2_sat_solver * pSats[], Gia_Man_t * p, int iLit, int fHash, int(*pFuncCiToKeep)(void *, int), void * pData, Vec_Int_t * vDLits )
+{
+    Vec_Int_t * vObjsUsed = Vec_IntAlloc( 100 ); // GIA objs
+    Vec_Int_t * vCiVars = Vec_IntAlloc( 100 );   // CI SAT vars
+    Vec_Int_t * vVarMap = NULL; Vec_Str_t * vSop = NULL; 
+    int i, iVar, iVarLast, Lit, RetValue, Count = 0, Result = -1;
+    if ( vDLits ) Vec_IntClear( vDLits );
+    if ( iLit < 2 )
+        return iLit;
+    if ( Vec_IntSize(&p->vCopies) < Gia_ManObjNum(p) )
+        Vec_IntFillExtra( &p->vCopies, Gia_ManObjNum(p), -1 );
+    // assign variable number 0 to const0 node
+    iVar = Vec_IntSize(vObjsUsed); 
+    Vec_IntPush( vObjsUsed, 0 );
+    Gia_ObjSetCopyArray( p, 0, iVar );
+    assert( iVar == 0 );    
+
+    // collect other variables
+    iVarLast = Gia_ManSatAndCollect2_rec( p, Abc_Lit2Var(iLit), vObjsUsed, vCiVars );
+    Gia_ManQuantLoadCnf2( p, vObjsUsed, pSats );
+
+    // check constants
+    Lit = Abc_Var2Lit( iVarLast, !Abc_LitIsCompl(iLit) ); 
+    RetValue = bmcg2_sat_solver_addclause( pSats[0], &Lit, 1 ); // offset
+    if ( !RetValue || bmcg2_sat_solver_solve(pSats[0], NULL, 0) == GLUCOSE_UNSAT )
+    {
+        Result = 1;
+        goto cleanup;
+    }
+    Lit = Abc_Var2Lit( iVarLast, Abc_LitIsCompl(iLit) );
+    RetValue = bmcg2_sat_solver_addclause( pSats[1], &Lit, 1 ); // onset
+    if ( !RetValue || bmcg2_sat_solver_solve(pSats[1], NULL, 0) == GLUCOSE_UNSAT )
+    {
+        Result = 0;
+        goto cleanup;
+    }
+/*
+    // reorder CI SAT variables to have keep-vars first
+    Vec_Int_t * vCiVars2 = Vec_IntAlloc( 100 );   // CI SAT vars
+    Vec_IntForEachEntry( vCiVars, iVar, i )
+    {
+        Gia_Obj_t * pObj = Gia_ManObj( p, Vec_IntEntry(vObjsUsed, iVar) );
+        assert( Gia_ObjIsCi(pObj) );
+        if ( pFuncCiToKeep(pData, Gia_ObjCioId(pObj)) )
+            Vec_IntPush( vCiVars2, iVar );
+    }
+    Vec_IntForEachEntry( vCiVars, iVar, i )
+    {
+        Gia_Obj_t * pObj = Gia_ManObj( p, Vec_IntEntry(vObjsUsed, iVar) );
+        assert( Gia_ObjIsCi(pObj) );
+        if ( !pFuncCiToKeep(pData, Gia_ObjCioId(pObj)) )
+            Vec_IntPush( vCiVars2, iVar );
+    }
+    ABC_SWAP( Vec_Int_t *, vCiVars2, vCiVars );
+    Vec_IntFree( vCiVars2 );
+*/
+    // map CI SAT variables into their indexes used in the cubes
+    vVarMap = Vec_IntStartFull( Vec_IntSize(vObjsUsed) );
+    Vec_IntForEachEntry( vCiVars, iVar, i )
+    {
+        Gia_Obj_t * pObj = Gia_ManObj( p, Vec_IntEntry(vObjsUsed, iVar) );
+        assert( Gia_ObjIsCi(pObj) );
+        if ( pFuncCiToKeep(pData, Gia_ObjCioId(pObj)) )
+            Vec_IntWriteEntry( vVarMap, iVar, i ), Count++;
+    }
+    if ( Count == 0 || Count == Vec_IntSize(vCiVars) )
+    {
+        Result = Count == 0 ? 1 : iLit;
+        goto cleanup;
+    }
+    // generate cubes
+    vSop = Glucose2_GenerateCubes( pSats, vCiVars, vVarMap, 0 );
+    //printf( "%s", Vec_StrArray(vSop) );
+    // convert into object IDs
+    Vec_IntForEachEntry( vCiVars, iVar, i )
+        Vec_IntWriteEntry( vCiVars, i, Vec_IntEntry(vObjsUsed, iVar) );
+    // generate unate variables
+    if ( vDLits )
+        bmcg2_sat_generate_dvars( vCiVars, vSop, vDLits );
+    // convert into an AIG
+    RetValue = Gia_ManAndNum(p);
+    Result = Gia_ManFactorSop2( p, vCiVars, vSop, fHash );
+
+    // report the result
+//    printf( "Performed quantification with %5d nodes, %3d keep-vars, %3d quant-vars, resulting in %5d cubes and %5d nodes. ", 
+//        Vec_IntSize(vObjsUsed), Count, Vec_IntSize(vCiVars) - Count, Vec_StrCountEntry(vSop, '\n'), Gia_ManAndNum(p)-RetValue );
+//    Abc_PrintTime( 1, "Time", Abc_Clock() - clkAll );
+
+cleanup:
+    Vec_IntForEachEntry( vObjsUsed, iVar, i )
+        Gia_ObjSetCopyArray( p, iVar, -1 );
+    Vec_IntFree( vObjsUsed );
+    Vec_IntFree( vCiVars );
+    Vec_IntFreeP( &vVarMap );
+    Vec_StrFreeP( &vSop );
+    return Result;
+}
+int Gia_ManCiIsToKeep2( void * pData, int i )
+{
+    return i % 5 != 0;
+}
+void Glucose2_QuantifyAigTest( Gia_Man_t * p )
+{
+    bmcg2_sat_solver * pSats[3] = { bmcg2_sat_solver_start(), bmcg2_sat_solver_start(), bmcg2_sat_solver_start() };
+
+    abctime clk1 = Abc_Clock();
+    int iRes1 = bmcg2_sat_solver_quantify( pSats, p, Gia_ObjFaninLit0p(p, Gia_ManPo(p, 0)), 0, Gia_ManCiIsToKeep2, NULL, NULL );
+    abctime clk1d = Abc_Clock()-clk1;
+
+    abctime clk2 = Abc_Clock();
+    int iRes2 = bmcg2_sat_solver_quantify2( p, Gia_ObjFaninLit0p(p, Gia_ManPo(p, 0)), 0, Gia_ManCiIsToKeep2, NULL, NULL );
+    abctime clk2d = Abc_Clock()-clk2;
+
+    Abc_PrintTime( 1, "Time1", clk1d );
+    Abc_PrintTime( 1, "Time2", clk2d );
+
+    if ( bmcg2_sat_solver_equiv_overlap_check( pSats[2], p, iRes1, iRes2, 1 ) )
+        printf( "Verification passed.\n" );
+    else
+        printf( "Verification FAILED.\n" );
+
+    Gia_ManAppendCo( p, iRes1 );
+    Gia_ManAppendCo( p, iRes2 );
+
+    bmcg2_sat_solver_stop( pSats[0] );
+    bmcg2_sat_solver_stop( pSats[1] );
+    bmcg2_sat_solver_stop( pSats[2] );
+}
+int bmcg2_sat_solver_quantify_test( bmcg2_sat_solver * pSats[], Gia_Man_t * p, int iLit, int fHash, int(*pFuncCiToKeep)(void *, int), void * pData, Vec_Int_t * vDLits )
+{
+    extern int Gia_ManQuantExist( Gia_Man_t * p, int iLit, int(*pFuncCiToKeep)(void *, int), void * pData );
+    int Res1 = Gia_ManQuantExist( p, iLit, pFuncCiToKeep, pData );
+    int Res2 = bmcg2_sat_solver_quantify2( p, iLit, 1, pFuncCiToKeep, pData, NULL );
+
+    bmcg2_sat_solver * pSat = bmcg2_sat_solver_start();
+    if ( bmcg2_sat_solver_equiv_overlap_check( pSat, p, Res1, Res2, 1 ) )
+        printf( "Verification passed.\n" );
+    else
+    {
+        printf( "Verification FAILED.\n" );
+        bmcg2_sat_solver_print_sop_lit( p, Res1 );
+        bmcg2_sat_solver_print_sop_lit( p, Res2 );
+        printf( "\n" );
+    }
+    return Res1;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Checks equivalence or intersection of two nodes.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int bmcg2_sat_solver_equiv_overlap_check( bmcg2_sat_solver * pSat, Gia_Man_t * p, int iLit0, int iLit1, int fEquiv )
+{
+    bmcg2_sat_solver * pSats[2] = { pSat, NULL };
+    Vec_Int_t * vObjsUsed = Vec_IntAlloc( 100 ); 
+    int i, iVar, iSatVar[2], iSatLit[2], Lits[2], status;
+    if ( Vec_IntSize(&p->vCopies) < Gia_ManObjNum(p) )
+        Vec_IntFillExtra( &p->vCopies, Gia_ManObjNum(p), -1 );
+
+    // assign const0 variable number 0
+    iVar = Vec_IntSize(vObjsUsed);
+    Vec_IntPush( vObjsUsed, 0 );
+    Gia_ObjSetCopyArray( p, 0, iVar );
+    assert( iVar == 0 );
+
+    iSatVar[0] = Gia_ManSatAndCollect2_rec( p, Abc_Lit2Var(iLit0), vObjsUsed, NULL );
+    iSatVar[1] = Gia_ManSatAndCollect2_rec( p, Abc_Lit2Var(iLit1), vObjsUsed, NULL );
+
+    iSatLit[0] = Abc_Var2Lit( iSatVar[0], Abc_LitIsCompl(iLit0) );
+    iSatLit[1] = Abc_Var2Lit( iSatVar[1], Abc_LitIsCompl(iLit1) );
+    Gia_ManQuantLoadCnf2( p, vObjsUsed, pSats );
+    Vec_IntForEachEntry( vObjsUsed, iVar, i )
+        Gia_ObjSetCopyArray( p, iVar, -1 );
+    Vec_IntFree( vObjsUsed );
+
+    if ( fEquiv )
+    {
+        Lits[0] = iSatLit[0];
+        Lits[1] = Abc_LitNot(iSatLit[1]);
+        status  = bmcg2_sat_solver_solve( pSats[0], Lits, 2 );
+        if ( status == GLUCOSE_UNSAT )
+        {
+            Lits[0] = Abc_LitNot(iSatLit[0]);
+            Lits[1] = iSatLit[1];
+            status  = bmcg2_sat_solver_solve( pSats[0], Lits, 2 );
+        }
+        return status == GLUCOSE_UNSAT;
+    }
+    else
+    {
+        Lits[0] = iSatLit[0];
+        Lits[1] = iSatLit[1];
+        status  = bmcg2_sat_solver_solve( pSats[0], Lits, 2 );
+        return status == GLUCOSE_SAT;
+    }
+}
+void Glucose2_CheckTwoNodesTest( Gia_Man_t * p )
+{
+    int n, Res;
+    bmcg2_sat_solver * pSat = bmcg2_sat_solver_start();
+    for ( n = 0; n < 2; n++ )
+    {
+        Res = bmcg2_sat_solver_equiv_overlap_check( 
+            pSat, p, 
+            Gia_ObjFaninLit0p(p, Gia_ManPo(p, 0)), 
+            Gia_ObjFaninLit0p(p, Gia_ManPo(p, 1)), 
+            n );
+        bmcg2_sat_solver_reset( pSat );
+        printf( "%s %s.\n", n ? "Equivalence" : "Overlap", Res ? "holds" : "fails" );
+    }
+    bmcg2_sat_solver_stop( pSat );
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Glucose2_SolveAig(Gia_Man_t * p, Glucose2_Pars * pPars)
+{  
+    abctime clk = Abc_Clock();
+
+    SimpSolver S;
+    S.verbosity = pPars->verb;
+    S.verbEveryConflicts = 50000;
+    S.showModel = false;
+    //S.verbosity = 2;
+    S.setConfBudget( pPars->nConfls > 0 ? (int64_t)pPars->nConfls : -1 );
+
+    S.parsing = 1;
+    Vec_Int_t * vCnfIds = Glucose_SolverFromAig(p,S);
+    S.parsing = 0;
+
+    if (pPars->verb)
+    {
+        printf("c ============================[ Problem Statistics ]=============================\n");
+        printf("c |                                                                             |\n");
+        printf("c |  Number of variables:  %12d                                         |\n", S.nVars());
+        printf("c |  Number of clauses:    %12d                                         |\n", S.nClauses());
+    }
+
+    if (pPars->pre) 
+    {
+        S.eliminate(true);
+        printf( "c Simplication removed %d variables and %d clauses.  ", S.eliminated_vars, S.eliminated_clauses );
+        Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
+    }
+    
+    vec<Lit> dummy;
+    lbool ret = S.solveLimited(dummy, 0);
+
+    if ( pPars->verb ) glucose_print_stats(S, Abc_Clock() - clk);
+    printf(ret == l_True ? "SATISFIABLE" : ret == l_False ? "UNSATISFIABLE" : "INDETERMINATE");
+    Abc_PrintTime( 1, "      Time", Abc_Clock() - clk );
+
+    // port counterexample
+    if (ret == l_True)
+    {
+        Gia_Obj_t * pObj;  int i;
+        p->pCexComb = Abc_CexAlloc(0,Gia_ManCiNum(p),1);
+        Gia_ManForEachCi( p, pObj, i )
+        {
+            assert(Vec_IntEntry(vCnfIds,Gia_ObjId(p, pObj))!=-1);
+            if (S.model[Vec_IntEntry(vCnfIds,Gia_ObjId(p, pObj))] == l_True)
+                Abc_InfoSetBit( p->pCexComb->pData, i);
+        }
+    }
+    Vec_IntFree(vCnfIds);
+    return (ret == l_True ? 10 : ret == l_False ? 20 : 0);
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+ABC_NAMESPACE_IMPL_END
diff --git a/src/sat/glucose2/AbcGlucose2.h b/src/sat/glucose2/AbcGlucose2.h
new file mode 100644
index 00000000..8fc774cd
--- /dev/null
+++ b/src/sat/glucose2/AbcGlucose2.h
@@ -0,0 +1,111 @@
+/**CFile****************************************************************
+
+  FileName    [AbcGlucose.h]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [SAT solver Glucose 3.0 by Gilles Audemard and Laurent Simon.]
+
+  Synopsis    [Interface to Glucose.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - September 6, 2017.]
+
+  Revision    [$Id: AbcGlucose.h,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#ifndef ABC_SAT_GLUCOSE_H_
+#define ABC_SAT_GLUCOSE_H_
+
+////////////////////////////////////////////////////////////////////////
+///                          INCLUDES                                ///
+////////////////////////////////////////////////////////////////////////
+
+#include "aig/gia/gia.h"
+
+////////////////////////////////////////////////////////////////////////
+///                         PARAMETERS                               ///
+////////////////////////////////////////////////////////////////////////
+
+#define GLUCOSE_UNSAT -1
+#define GLUCOSE_SAT    1
+#define GLUCOSE_UNDEC  0
+
+
+ABC_NAMESPACE_HEADER_START
+
+////////////////////////////////////////////////////////////////////////
+///                         BASIC TYPES                              ///
+////////////////////////////////////////////////////////////////////////
+
+typedef struct Glucose2_Pars_ Glucose2_Pars;
+struct Glucose2_Pars_ {
+    int pre;     // preprocessing
+    int verb;    // verbosity
+    int cust;    // customizable
+    int nConfls; // conflict limit (0 = no limit)
+};
+
+static inline Glucose2_Pars Glucose_CreatePars(int p, int v, int c, int nConfls)
+{
+    Glucose2_Pars pars;
+    pars.pre     = p;
+    pars.verb    = v;
+    pars.cust    = c;
+    pars.nConfls = nConfls;
+    return pars;
+}
+
+typedef void bmcg2_sat_solver;
+
+////////////////////////////////////////////////////////////////////////
+///                      MACRO DEFINITIONS                           ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                    FUNCTION DECLARATIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+extern bmcg2_sat_solver * bmcg2_sat_solver_start();
+extern void              bmcg2_sat_solver_stop( bmcg2_sat_solver* s );
+extern void              bmcg2_sat_solver_reset( bmcg2_sat_solver* s );
+extern int               bmcg2_sat_solver_addclause( bmcg2_sat_solver* s, int * plits, int nlits );
+extern void              bmcg2_sat_solver_setcallback( bmcg2_sat_solver* s, void * pman, int(*pfunc)(void*, int, int*) );
+extern int               bmcg2_sat_solver_solve( bmcg2_sat_solver* s, int * plits, int nlits );
+extern int               bmcg2_sat_solver_final( bmcg2_sat_solver* s, int ** ppArray );
+extern int               bmcg2_sat_solver_addvar( bmcg2_sat_solver* s );
+extern void              bmcg2_sat_solver_set_nvars( bmcg2_sat_solver* s, int nvars );
+extern int               bmcg2_sat_solver_eliminate( bmcg2_sat_solver* s, int turn_off_elim );
+extern int               bmcg2_sat_solver_var_is_elim( bmcg2_sat_solver* s, int v );
+extern void              bmcg2_sat_solver_var_set_frozen( bmcg2_sat_solver* s, int v, int freeze );
+extern int               bmcg2_sat_solver_elim_varnum(bmcg2_sat_solver* s);
+extern int *             bmcg2_sat_solver_read_cex( bmcg2_sat_solver* s );
+extern int               bmcg2_sat_solver_read_cex_varvalue( bmcg2_sat_solver* s, int );
+extern void              bmcg2_sat_solver_set_stop( bmcg2_sat_solver* s, int * pstop );
+extern abctime           bmcg2_sat_solver_set_runtime_limit( bmcg2_sat_solver* s, abctime Limit );
+extern void              bmcg2_sat_solver_set_conflict_budget( bmcg2_sat_solver* s, int Limit );
+extern int               bmcg2_sat_solver_varnum( bmcg2_sat_solver* s );
+extern int               bmcg2_sat_solver_clausenum( bmcg2_sat_solver* s );
+extern int               bmcg2_sat_solver_learntnum( bmcg2_sat_solver* s );
+extern int               bmcg2_sat_solver_conflictnum( bmcg2_sat_solver* s );
+extern int               bmcg2_sat_solver_minimize_assumptions( bmcg2_sat_solver * s, int * plits, int nlits, int pivot );
+extern int               bmcg2_sat_solver_add_and( bmcg2_sat_solver * s, int iVar, int iVar0, int iVar1, int fCompl0, int fCompl1, int fCompl );
+extern int               bmcg2_sat_solver_quantify( bmcg2_sat_solver * s[], Gia_Man_t * p, int iLit, int fHash, int(*pFuncCiToKeep)(void *, int), void * pData, Vec_Int_t * vDLits );
+extern int               bmcg2_sat_solver_equiv_overlap_check( bmcg2_sat_solver * s, Gia_Man_t * p, int iLit0, int iLit1, int fEquiv );
+extern Vec_Str_t *       bmcg2_sat_solver_sop( Gia_Man_t * p, int CubeLimit );
+
+extern void              Glucose2_SolveCnf( char * pFilename, Glucose2_Pars * pPars );
+extern int               Glucose2_SolveAig( Gia_Man_t * p, Glucose2_Pars * pPars );
+
+ABC_NAMESPACE_HEADER_END
+
+#endif
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
diff --git a/src/sat/glucose2/AbcGlucoseCmd2.cpp b/src/sat/glucose2/AbcGlucoseCmd2.cpp
new file mode 100644
index 00000000..44288336
--- /dev/null
+++ b/src/sat/glucose2/AbcGlucoseCmd2.cpp
@@ -0,0 +1,149 @@
+/**CFile****************************************************************
+
+  FileName    [AbcGlucoseCmd.cpp]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [SAT solver Glucose 3.0 by Gilles Audemard and Laurent Simon.]
+
+  Synopsis    [Interface to Glucose.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - September 6, 2017.]
+
+  Revision    [$Id: AbcGlucoseCmd.cpp,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "aig/gia/gia.h"
+#include "base/main/mainInt.h"
+
+#include "sat/glucose2/AbcGlucose2.h"
+
+
+ABC_NAMESPACE_HEADER_START
+
+extern void Glucose2_Init( Abc_Frame_t *pAbc );
+extern void Glucose2_End( Abc_Frame_t * pAbc );
+
+ABC_NAMESPACE_HEADER_END
+
+ABC_NAMESPACE_IMPL_START
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+static int Abc_CommandGlucose( Abc_Frame_t * pAbc, int argc, char ** argv );
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+
+void Glucose2_Init(Abc_Frame_t *pAbc)
+{
+    Cmd_CommandAdd( pAbc, "ABC9", "&glucose",  Abc_CommandGlucose,  0 );
+}
+
+void Glucose2_End( Abc_Frame_t * pAbc )
+{
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Abc_CommandGlucose( Abc_Frame_t * pAbc, int argc, char ** argv )
+{
+    int c       = 0;
+    int pre     = 1;
+    int verb    = 0;
+    int nConfls = 0;
+
+    Glucose2_Pars pPars;
+    Extra_UtilGetoptReset();
+    while ( ( c = Extra_UtilGetopt( argc, argv, "Cpvh" ) ) != EOF )
+    {
+        switch ( c )
+        {
+            case 'C':
+                if ( globalUtilOptind >= argc )
+                {
+                    Abc_Print( -1, "Command line switch \"-C\" should be followed by an integer.\n" );
+                    goto usage;
+                }
+                nConfls = atoi(argv[globalUtilOptind]);
+                globalUtilOptind++;
+                if ( nConfls < 0 )
+                    goto usage;
+                break;
+            case 'p':
+                pre ^= 1;
+                break;
+            case 'v':
+                verb ^= 1;
+                break;
+            case 'h':
+                goto usage;
+            default:
+                goto usage;
+        }
+    }
+
+    pPars = Glucose_CreatePars(pre,verb,0,nConfls);
+
+    if ( argc == globalUtilOptind + 1 )
+    {
+        Glucose2_SolveCnf( argv[globalUtilOptind], &pPars );
+        return 0;
+    }
+
+    if ( pAbc->pGia == NULL )
+    {
+        Abc_Print( -1, "Abc_CommandGlucose(): There is no AIG.\n" );
+        return 1;
+    }
+    
+    if ( Glucose2_SolveAig( pAbc->pGia, &pPars ) == 10 )
+        Abc_FrameReplaceCex( pAbc, &pAbc->pGia->pCexComb );
+
+    return 0;
+    
+usage:
+    Abc_Print( -2, "usage: &glucose2 [-C num] [-pvh] <file.cnf>\n" );
+    Abc_Print( -2, "\t             run Glucose 3.0 by Gilles Audemard and Laurent Simon\n" );
+    Abc_Print( -2, "\t-C num     : conflict limit [default = %d]\n",  nConfls );
+    Abc_Print( -2, "\t-p         : enable preprocessing [default = %d]\n",pre);
+    Abc_Print( -2, "\t-v         : verbosity [default = %d]\n",verb);
+    Abc_Print( -2, "\t-h         : print the command usage\n");
+    Abc_Print( -2, "\t<file.cnf> : (optional) CNF file to solve\n");
+    return 1;
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+ABC_NAMESPACE_IMPL_END
diff --git a/src/sat/glucose2/Alg.h b/src/sat/glucose2/Alg.h
new file mode 100644
index 00000000..96f6ab70
--- /dev/null
+++ b/src/sat/glucose2/Alg.h
@@ -0,0 +1,88 @@
+/*******************************************************************************************[Alg.h]
+Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_Alg_h
+#define Glucose_Alg_h
+
+#include "sat/glucose2/Vec.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//=================================================================================================
+// Useful functions on vector-like types:
+
+//=================================================================================================
+// Removing and searching for elements:
+//
+
+template<class V, class T>
+static inline void remove(V& ts, const T& t)
+{
+    int j = 0;
+    for (; j < ts.size() && ts[j] != t; j++);
+    assert(j < ts.size());
+    for (; j < ts.size()-1; j++) ts[j] = ts[j+1];
+    ts.pop();
+}
+
+
+template<class V, class T>
+static inline bool find(V& ts, const T& t)
+{
+    int j = 0;
+    for (; j < ts.size() && ts[j] != t; j++);
+    return j < ts.size();
+}
+
+
+//=================================================================================================
+// Copying vectors with support for nested vector types:
+//
+
+// Base case:
+template<class T>
+static inline void copy(const T& from, T& to)
+{
+    to = from;
+}
+
+// Recursive case:
+template<class T>
+static inline void copy(const vec<T>& from, vec<T>& to, bool append = false)
+{
+    if (!append)
+        to.clear();
+    for (int i = 0; i < from.size(); i++){
+        to.push();
+        copy(from[i], to.last());
+    }
+}
+
+template<class T>
+static inline void append(const vec<T>& from, vec<T>& to){ copy(from, to, true); }
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/Alloc.h b/src/sat/glucose2/Alloc.h
new file mode 100644
index 00000000..b7bebaca
--- /dev/null
+++ b/src/sat/glucose2/Alloc.h
@@ -0,0 +1,136 @@
+/*****************************************************************************************[Alloc.h]
+Copyright (c) 2008-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+
+#ifndef Glucose_Alloc_h
+#define Glucose_Alloc_h
+
+#include "sat/glucose2/XAlloc.h"
+#include "sat/glucose2/Vec.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//=================================================================================================
+// Simple Region-based memory allocator:
+
+template<class T>
+class RegionAllocator
+{
+    T*        memory;
+    uint32_t  sz;
+    uint32_t  cap;
+    uint32_t  wasted_;
+
+    void capacity(uint32_t min_cap);
+
+ public:
+    // TODO: make this a class for better type-checking?
+    typedef uint32_t Ref;
+    enum { Ref_Undef = UINT32_MAX };
+    enum { Unit_Size = sizeof(uint32_t) };
+
+    explicit RegionAllocator(uint32_t start_cap = 1024*1024) : memory(NULL), sz(0), cap(0), wasted_(0){ capacity(start_cap); }
+    ~RegionAllocator()
+    {
+        if (memory != NULL)
+            ::free(memory);
+    }
+
+
+    uint32_t size      () const      { return sz; }
+    uint32_t wasted    () const      { return wasted_; }
+
+    Ref      alloc     (int size); 
+    void     free_     (int size)    { wasted_ += size; }
+    void     clear     ()            { sz = 0; wasted_=0; }
+
+    // Deref, Load Effective Address (LEA), Inverse of LEA (AEL):
+    T&       operator[](Ref r)       { assert(r >= 0 && r < sz); return memory[r]; }
+    const T& operator[](Ref r) const { assert(r >= 0 && r < sz); return memory[r]; }
+
+    T*       lea       (Ref r)       { assert(r >= 0 && r < sz); return &memory[r]; }
+    const T* lea       (Ref r) const { assert(r >= 0 && r < sz); return &memory[r]; }
+    Ref      ael       (const T* t)  { assert((void*)t >= (void*)&memory[0] && (void*)t < (void*)&memory[sz-1]);
+        return  (Ref)(t - &memory[0]); }
+
+    void     moveTo(RegionAllocator& to) {
+        if (to.memory != NULL) ::free(to.memory);
+        to.memory = memory;
+        to.sz = sz;
+        to.cap = cap;
+        to.wasted_ = wasted_;
+
+        memory = NULL;
+        sz = cap = wasted_ = 0;
+    }
+
+
+};
+
+template<class T>
+void RegionAllocator<T>::capacity(uint32_t min_cap)
+{
+    if (cap >= min_cap) return;
+
+    uint32_t prev_cap = cap;
+    while (cap < min_cap){
+        // NOTE: Multiply by a factor (13/8) without causing overflow, then add 2 and make the
+        // result even by clearing the least significant bit. The resulting sequence of capacities
+        // is carefully chosen to hit a maximum capacity that is close to the '2^32-1' limit when
+        // using 'uint32_t' as indices so that as much as possible of this space can be used.
+        uint32_t delta = ((cap >> 1) + (cap >> 3) + 2) & ~1;
+        cap += delta;
+
+        if (cap <= prev_cap)
+            throw OutOfMemoryException();
+    }
+    //printf(" .. (%p) cap = %u\n", this, cap);
+
+    assert(cap > 0);
+    memory = (T*)xrealloc(memory, sizeof(T)*cap);
+}
+
+
+template<class T>
+typename RegionAllocator<T>::Ref
+RegionAllocator<T>::alloc(int size)
+{ 
+    //printf("ALLOC called (this = %p, size = %d)\n", this, size); fflush(stdout);
+    assert(size > 0);
+    capacity(sz + size);
+
+    uint32_t prev_sz = sz;
+    sz += size;
+    
+    // Handle overflow:
+    if (sz < prev_sz)
+        throw OutOfMemoryException();
+
+    return prev_sz;
+}
+
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/BoundedQueue.h b/src/sat/glucose2/BoundedQueue.h
new file mode 100644
index 00000000..1a0d2148
--- /dev/null
+++ b/src/sat/glucose2/BoundedQueue.h
@@ -0,0 +1,114 @@
+/***********************************************************************************[BoundedQueue.h]
+ Glucose -- Copyright (c) 2009, Gilles Audemard, Laurent Simon
+                CRIL - Univ. Artois, France
+                LRI  - Univ. Paris Sud, France
+ 
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+ 
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+ 
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+
+#ifndef BoundedQueue_h
+#define BoundedQueue_h
+
+#include "sat/glucose2/Vec.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+//=================================================================================================
+
+namespace Gluco2 {
+
+template <class T>
+class bqueue {
+    vec<T>  elems;
+    int     first;
+    int        last;
+    uint64_t sumofqueue;
+    int     maxsize;
+    int     queuesize; // Number of current elements (must be < maxsize !)
+    bool expComputed;
+    double exp,value;
+public:
+ bqueue(void) : first(0), last(0), sumofqueue(0), maxsize(0), queuesize(0),expComputed(false) { } 
+    
+    void initSize(int size) {growTo(size);exp = 2.0/(size+1);} // Init size of bounded size queue
+    
+    void push(T x) {
+      expComputed = false;
+        if (queuesize==maxsize) {
+            assert(last==first); // The queue is full, next value to enter will replace oldest one
+            sumofqueue -= elems[last];
+            if ((++last) == maxsize) last = 0;
+        } else 
+            queuesize++;
+        sumofqueue += x;
+        elems[first] = x;
+        if ((++first) == maxsize) {first = 0;last = 0;}
+    }
+
+    T peek() { assert(queuesize>0); return elems[last]; }
+    void pop() {sumofqueue-=elems[last]; queuesize--; if ((++last) == maxsize) last = 0;}
+    
+    uint64_t getsum() const {return sumofqueue;}
+    unsigned int getavg() const {return (unsigned int)(sumofqueue/((uint64_t)queuesize));}
+    int maxSize() const {return maxsize;}
+    double getavgDouble() const {
+      double tmp = 0;
+      for(int i=0;i<elems.size();i++) {
+        tmp+=elems[i];
+      }
+      return tmp/elems.size();
+    }
+    int isvalid() const {return (queuesize==maxsize);}
+    
+    void growTo(int size) {
+        elems.growTo(size); 
+        first=0; maxsize=size; queuesize = 0;last = 0;
+        for(int i=0;i<size;i++) elems[i]=0; 
+    }
+    
+    double getAvgExp() {
+      if(expComputed) return value;
+      double a=exp;
+      value = elems[first];
+      for(int i  = first;i<maxsize;i++) {
+        value+=a*((double)elems[i]);
+        a=a*exp;
+      }
+      for(int i  = 0;i<last;i++) {
+        value+=a*((double)elems[i]);
+        a=a*exp;
+      }
+      value = value*(1-exp)/(1-a);
+      expComputed = true;
+      return value;
+      
+
+    }
+    void fastclear() {first = 0; last = 0; queuesize=0; sumofqueue=0;} // to be called after restarts... Discard the queue
+    
+    int  size(void)    { return queuesize; }
+
+    void clear(bool dealloc = false)   { elems.clear(dealloc); first = 0; maxsize=0; queuesize=0;sumofqueue=0;}
+
+
+};
+}
+//=================================================================================================
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/Constants.h b/src/sat/glucose2/Constants.h
new file mode 100644
index 00000000..4cccad24
--- /dev/null
+++ b/src/sat/glucose2/Constants.h
@@ -0,0 +1,33 @@
+/************************************************************************************[Constants.h]
+ Glucose -- Copyright (c) 2009, Gilles Audemard, Laurent Simon
+                CRIL - Univ. Artois, France
+                LRI  - Univ. Paris Sud, France
+  
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+ 
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+ 
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#define DYNAMICNBLEVEL
+#define CONSTANTREMOVECLAUSE
+#define UPDATEVARACTIVITY
+
+// Constants for clauses reductions
+#define RATIOREMOVECLAUSES 2
+
+
+
+// Constants for restarts
+#define LOWER_BOUND_FOR_BLOCKING_RESTART 10000
+
diff --git a/src/sat/glucose2/Dimacs.h b/src/sat/glucose2/Dimacs.h
new file mode 100644
index 00000000..1d6a0bed
--- /dev/null
+++ b/src/sat/glucose2/Dimacs.h
@@ -0,0 +1,93 @@
+/****************************************************************************************[Dimacs.h]
+Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_Dimacs_h
+#define Glucose_Dimacs_h
+
+#include <stdio.h>
+
+#include "sat/glucose2/ParseUtils.h"
+#include "sat/glucose2/SolverTypes.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//=================================================================================================
+// DIMACS Parser:
+
+template<class B, class Solver>
+static void readClause(B& in, Solver& S, vec<Lit>& lits) {
+    int     parsed_lit, var;
+    lits.clear();
+    for (;;){
+        parsed_lit = parseInt(in);
+        if (parsed_lit == 0) break;
+        var = abs(parsed_lit)-1;
+        while (var >= S.nVars()) S.newVar();
+        lits.push( (parsed_lit > 0) ? mkLit(var) : ~mkLit(var) );
+    }
+}
+
+template<class B, class Solver>
+static void parse_DIMACS_main(B& in, Solver& S) {
+    vec<Lit> lits;
+    int vars    = 0;
+    int clauses = 0;
+    int cnt     = 0;
+    for (;;){
+        skipWhitespace(in);
+        if (*in == EOF) break;
+        else if (*in == 'p'){
+            if (eagerMatch(in, "p cnf")){
+                vars    = parseInt(in);
+                clauses = parseInt(in);
+                // SATRACE'06 hack
+                // if (clauses > 4000000)
+                //     S.eliminate(true);
+            }else{
+                printf("PARSE ERROR! Unexpected char: %c\n", *in), exit(3);
+            }
+        } else if (*in == 'c' || *in == 'p')
+            skipLine(in);
+        else{
+            cnt++;
+            readClause(in, S, lits);
+            S.addClause_(lits); }
+    }
+    if (vars != S.nVars())
+        fprintf(stderr, "WARNING! DIMACS header mismatch: wrong number of variables.\n");
+    if (cnt  != clauses)
+        fprintf(stderr, "WARNING! DIMACS header mismatch: wrong number of clauses.\n");
+}
+
+// Inserts problem into solver.
+//
+template<class Solver>
+static void parse_DIMACS(gzFile input_stream, Solver& S) {
+    StreamBuffer in(input_stream);
+    parse_DIMACS_main(in, S); }
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/Glucose2.cpp b/src/sat/glucose2/Glucose2.cpp
new file mode 100644
index 00000000..00d8b57a
--- /dev/null
+++ b/src/sat/glucose2/Glucose2.cpp
@@ -0,0 +1,1503 @@
+/***************************************************************************************[Solver.cc]
+ Glucose -- Copyright (c) 2013, Gilles Audemard, Laurent Simon
+                                CRIL - Univ. Artois, France
+                                LRI  - Univ. Paris Sud, France
+ 
+Glucose sources are based on MiniSat (see below MiniSat copyrights). Permissions and copyrights of
+Glucose are exactly the same as Minisat on which it is based on. (see below).
+
+---------------
+
+Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#include <math.h>
+
+#include "sat/glucose2/Sort.h"
+#include "sat/glucose2/Solver.h"
+#include "sat/glucose2/Constants.h"
+#include "sat/glucose2/System.h"
+
+ABC_NAMESPACE_IMPL_START
+
+using namespace Gluco2;
+
+//=================================================================================================
+// Options:
+
+static const char* _cat = "CORE";
+static const char* _cr = "CORE -- RESTART";
+static const char* _cred = "CORE -- REDUCE";
+static const char* _cm = "CORE -- MINIMIZE";
+static const char* _certified = "CORE -- CERTIFIED UNSAT";
+
+
+
+
+static BoolOption    opt_incremental              (_cat,"incremental",             "Use incremental SAT solving",                                            false);
+static DoubleOption  opt_K                        (_cr, "K",                       "The constant used to force restart",                                     0.8,  DoubleRange(0, false, 1, false));           
+static DoubleOption  opt_R                        (_cr, "R",                       "The constant used to block restart",                                     1.4,  DoubleRange(1, false, 5, false));           
+static IntOption     opt_size_lbd_queue           (_cr, "szLBDQueue",              "The size of moving average for LBD (restarts)",                          50,   IntRange(10, INT32_MAX));
+static IntOption     opt_size_trail_queue         (_cr, "szTrailQueue",            "The size of moving average for trail (block restarts)",                  5000, IntRange(10, INT32_MAX));
+
+static IntOption     opt_first_reduce_db          (_cred, "firstReduceDB",         "The number of conflicts before the first reduce DB",                     2000, IntRange(0, INT32_MAX));
+static IntOption     opt_inc_reduce_db            (_cred, "incReduceDB",           "Increment for reduce DB",                                                300,  IntRange(0, INT32_MAX));
+static IntOption     opt_spec_inc_reduce_db       (_cred, "specialIncReduceDB",    "Special increment for reduce DB",                                        1000, IntRange(0, INT32_MAX));
+static IntOption     opt_lb_lbd_frozen_clause     (_cred, "minLBDFrozenClause",    "Protect clauses if their LBD decrease and is lower than (for one turn)", 30,   IntRange(0, INT32_MAX));
+
+static IntOption     opt_lb_size_minimzing_clause (_cm, "minSizeMinimizingClause", "The min size required to minimize clause",                               30, IntRange(3, INT32_MAX));
+static IntOption     opt_lb_lbd_minimzing_clause  (_cm, "minLBDMinimizingClause",  "The min LBD required to minimize clause",                                6, IntRange(3, INT32_MAX));
+
+
+static DoubleOption  opt_var_decay         (_cat, "var-decay",   "The variable activity decay factor",                                                       0.8,      DoubleRange(0, false, 1, false));
+static DoubleOption  opt_clause_decay      (_cat, "cla-decay",   "The clause activity decay factor",                                                         0.999,    DoubleRange(0, false, 1, false));
+static DoubleOption  opt_random_var_freq   (_cat, "rnd-freq",    "The frequency with which the decision heuristic tries to choose a random variable",        0, DoubleRange(0, true, 1, true));
+static DoubleOption  opt_random_seed       (_cat, "rnd-seed",    "Used by the random variable selection",                                                    91648253, DoubleRange(0, false, HUGE_VAL, false));
+static IntOption     opt_ccmin_mode        (_cat, "ccmin-mode",  "Controls conflict clause minimization (0=none, 1=basic, 2=deep)",                          2, IntRange(0, 2));
+static IntOption     opt_phase_saving      (_cat, "phase-saving", "Controls the level of phase saving (0=none, 1=limited, 2=full)",                          2, IntRange(0, 2));
+static BoolOption    opt_rnd_init_act      (_cat, "rnd-init",    "Randomize the initial activity",                                                           false);
+/*
+static IntOption     opt_restart_first     (_cat, "rfirst",      "The base restart interval",                                                                100, IntRange(1, INT32_MAX));
+static DoubleOption  opt_restart_inc       (_cat, "rinc",        "Restart interval increase factor",                                                         2, DoubleRange(1, false, HUGE_VAL, false));
+*/
+static DoubleOption  opt_garbage_frac      (_cat, "gc-frac",     "The fraction of wasted memory allowed before a garbage collection is triggered",           0.20, DoubleRange(0, false, HUGE_VAL, false));
+
+
+BoolOption    opt_certified_      (_certified, "certified",         "Certified UNSAT using DRUP format", false );
+StringOption  opt_certified_file_ (_certified, "certified-output",  "Certified UNSAT output file",       "NULL");
+
+
+//=================================================================================================
+// Constructor/Destructor:
+
+
+Solver::Solver() :
+
+    // Parameters (user settable):
+    //
+    SolverType(0)
+    , pCnfFunc(NULL)
+    , nCallConfl(1000)
+    , terminate_search_early(false)
+    , pstop(NULL)
+    , nRuntimeLimit(0)
+
+    , verbosity      (0)
+    , verbEveryConflicts(10000)
+    , showModel      (0)
+    , K              (opt_K)
+    , R              (opt_R)
+    , sizeLBDQueue   (opt_size_lbd_queue)
+    , sizeTrailQueue   (opt_size_trail_queue)
+    , firstReduceDB  (opt_first_reduce_db)
+    , incReduceDB    (opt_inc_reduce_db)
+    , specialIncReduceDB    (opt_spec_inc_reduce_db)
+    , lbLBDFrozenClause (opt_lb_lbd_frozen_clause)
+    , lbSizeMinimizingClause (opt_lb_size_minimzing_clause)
+    , lbLBDMinimizingClause (opt_lb_lbd_minimzing_clause)
+  , var_decay        (opt_var_decay)
+  , clause_decay     (opt_clause_decay)
+  , random_var_freq  (opt_random_var_freq)
+  , random_seed      (opt_random_seed)
+  , ccmin_mode       (opt_ccmin_mode)
+  , phase_saving     (opt_phase_saving)
+  , rnd_pol          (false)
+  , rnd_init_act     (opt_rnd_init_act)
+  , garbage_frac     (opt_garbage_frac)
+  , certifiedOutput  (NULL)
+  , certifiedUNSAT   (opt_certified_) 
+    // Statistics: (formerly in 'SolverStats')
+    //
+  ,  nbRemovedClauses(0),nbReducedClauses(0), nbDL2(0),nbBin(0),nbUn(0) , nbReduceDB(0)
+    , solves(0), starts(0), decisions(0), rnd_decisions(0), propagations(0),conflicts(0),conflictsRestarts(0),nbstopsrestarts(0),nbstopsrestartssame(0),lastblockatrestart(0)
+  , dec_vars(0), clauses_literals(0), learnts_literals(0), max_literals(0), tot_literals(0)
+    , curRestart(1)
+
+  , ok                 (true)
+  , cla_inc            (1)
+  , var_inc            (1)
+  , watches            (WatcherDeleted(ca))
+  , watchesBin            (WatcherDeleted(ca))
+  , qhead              (0)
+  , simpDB_assigns     (-1)
+  , simpDB_props       (0)
+  , order_heap         (VarOrderLt(activity))
+  , progress_estimate  (0)
+  , remove_satisfied   (true)
+
+    // Resource constraints:
+    //
+  , conflict_budget    (-1)
+  , propagation_budget (-1)
+  , asynch_interrupt   (false)
+  , incremental(opt_incremental)
+  , nbVarsInitialFormula(INT32_MAX)
+{
+  MYFLAG=0;  
+  // Initialize only first time. Useful for incremental solving, useless otherwise
+  lbdQueue.initSize(sizeLBDQueue);
+  trailQueue.initSize(sizeTrailQueue);
+  sumLBD = 0;
+  nbclausesbeforereduce = firstReduceDB;
+  totalTime4Sat=0;totalTime4Unsat=0;
+  nbSatCalls=0;nbUnsatCalls=0;
+
+
+  if(certifiedUNSAT) {
+    if(!strcmp(opt_certified_file_,"NULL")) {
+      certifiedOutput =  fopen("/dev/stdout", "wb");
+    } else {
+      certifiedOutput =  fopen(opt_certified_file_, "wb");           
+    }
+    //    fprintf(certifiedOutput,"o proof DRUP\n");
+  }
+}
+
+
+Solver::~Solver()
+{
+}
+
+
+/****************************************************************
+ Set the incremental mode
+****************************************************************/
+
+// This function set the incremental mode to true.
+// You can add special code for this mode here.
+
+void Solver::setIncrementalMode() {
+  incremental = true;
+}
+
+// Number of variables without selectors
+void Solver::initNbInitialVars(int nb) {
+  nbVarsInitialFormula = nb;
+}
+
+
+//=================================================================================================
+// Minor methods:
+
+
+// Creates a new SAT variable in the solver. If 'decision' is cleared, variable will not be
+// used as a decision variable (NOTE! This has effects on the meaning of a SATISFIABLE result).
+//
+Var Solver::newVar(bool sign, bool dvar)
+{
+    int v = nVars();
+    watches  .init(mkLit(v, false));
+    watches  .init(mkLit(v, true ));
+    watchesBin  .init(mkLit(v, false));
+    watchesBin  .init(mkLit(v, true ));
+    assigns  .push(l_Undef);
+    vardata  .push(mkVarData(CRef_Undef, 0));
+    //activity .push(0);
+    activity .push(rnd_init_act ? drand(random_seed) * 0.00001 : 0);
+    seen     .push(0);
+    permDiff .push(0);
+    polarity .push(sign);
+    decision .push();
+    trail    .capacity(v+1);
+    setDecisionVar(v, dvar);
+    return v;
+}
+
+
+
+bool Solver::addClause_(vec<Lit>& ps)
+{
+    assert(decisionLevel() == 0);
+    if (!ok) return false;
+
+    if ( 0 ) {
+        for ( int i = 0; i < ps.size(); i++ )
+            printf( "%s%d ", (toInt(ps[i]) & 1) ? "-":"", toInt(ps[i]) >> 1 );
+        printf( "\n" );
+    }
+
+    // Check if clause is satisfied and remove false/duplicate literals:
+    sort(ps);
+
+    vec<Lit>    oc;
+    oc.clear();
+
+    Lit p; int i, j, flag = 0;
+    if(certifiedUNSAT) {
+      for (i = j = 0, p = lit_Undef; i < ps.size(); i++) {
+        oc.push(ps[i]);
+        if (value(ps[i]) == l_True || ps[i] == ~p || value(ps[i]) == l_False)
+          flag = 1;
+      }
+    }
+
+    for (i = j = 0, p = lit_Undef; i < ps.size(); i++)
+      if (value(ps[i]) == l_True || ps[i] == ~p)
+        return true;
+      else if (value(ps[i]) != l_False && ps[i] != p)
+        ps[j++] = p = ps[i];
+    ps.shrink(i - j);
+
+    if ( 0 ) {
+        for ( int i = 0; i < ps.size(); i++ )
+            printf( "%s%d ", (toInt(ps[i]) & 1) ? "-":"", toInt(ps[i]) >> 1 );
+        printf( "\n" );
+    }
+    
+    if (flag && (certifiedUNSAT)) {
+      for (i = j = 0, p = lit_Undef; i < ps.size(); i++)
+        fprintf(certifiedOutput, "%i ", (var(ps[i]) + 1) * (-2 * sign(ps[i]) + 1));
+      fprintf(certifiedOutput, "0\n");
+
+      fprintf(certifiedOutput, "d ");
+      for (i = j = 0, p = lit_Undef; i < oc.size(); i++)
+        fprintf(certifiedOutput, "%i ", (var(oc[i]) + 1) * (-2 * sign(oc[i]) + 1));
+      fprintf(certifiedOutput, "0\n");
+    }
+
+    if (ps.size() == 0)
+        return ok = false;
+    else if (ps.size() == 1){
+        uncheckedEnqueue(ps[0]);
+        return ok = (propagate() == CRef_Undef);
+    }else{
+        CRef cr = ca.alloc(ps, false);
+        clauses.push(cr);
+        attachClause(cr);
+    }
+
+    return true;
+}
+
+
+void Solver::attachClause(CRef cr) {
+    const Clause& c = ca[cr];
+
+    assert(c.size() > 1);
+    if(c.size()==2) {
+      watchesBin[~c[0]].push(Watcher(cr, c[1]));
+      watchesBin[~c[1]].push(Watcher(cr, c[0]));
+    } else {
+      watches[~c[0]].push(Watcher(cr, c[1]));
+      watches[~c[1]].push(Watcher(cr, c[0]));
+    }
+    if (c.learnt()) learnts_literals += c.size();
+    else            clauses_literals += c.size(); }
+
+
+
+
+void Solver::detachClause(CRef cr, bool strict) {
+    const Clause& c = ca[cr];
+    
+    assert(c.size() > 1);
+    if(c.size()==2) {
+      if (strict){
+        remove(watchesBin[~c[0]], Watcher(cr, c[1]));
+        remove(watchesBin[~c[1]], Watcher(cr, c[0]));
+      }else{
+        // Lazy detaching: (NOTE! Must clean all watcher lists before garbage collecting this clause)
+        watchesBin.smudge(~c[0]);
+        watchesBin.smudge(~c[1]);
+      }
+    } else {
+      if (strict){
+        remove(watches[~c[0]], Watcher(cr, c[1]));
+        remove(watches[~c[1]], Watcher(cr, c[0]));
+      }else{
+        // Lazy detaching: (NOTE! Must clean all watcher lists before garbage collecting this clause)
+        watches.smudge(~c[0]);
+        watches.smudge(~c[1]);
+      }
+    }
+    if (c.learnt()) learnts_literals -= c.size();
+    else            clauses_literals -= c.size(); }
+
+
+void Solver::removeClause(CRef cr) {
+
+  Clause& c = ca[cr];
+
+  if (certifiedUNSAT) {
+    fprintf(certifiedOutput, "d ");
+    for (int i = 0; i < c.size(); i++)
+      fprintf(certifiedOutput, "%i ", (var(c[i]) + 1) * (-2 * sign(c[i]) + 1));
+    fprintf(certifiedOutput, "0\n");
+  }
+
+  detachClause(cr);
+  // Don't leave pointers to free'd memory!
+  if (locked(c)) vardata[var(c[0])].reason = CRef_Undef;
+  c.mark(1);
+  ca.free_(cr);
+}
+
+
+bool Solver::satisfied(const Clause& c) const {
+  if(incremental)  // Check clauses with many selectors is too time consuming
+    return (value(c[0]) == l_True) || (value(c[1]) == l_True);
+
+  // Default mode.
+    for (int i = 0; i < c.size(); i++)
+        if (value(c[i]) == l_True)
+            return true;
+    return false; 
+}
+
+/************************************************************
+ * Compute LBD functions
+ *************************************************************/
+
+inline unsigned int Solver::computeLBD(const vec<Lit> & lits,int end) {
+  int nblevels = 0;
+  MYFLAG++;
+
+  if(incremental) { // ----------------- INCREMENTAL MODE
+    if(end==-1) end = lits.size();
+    unsigned int nbDone = 0;
+    for(int i=0;i<lits.size();i++) {
+      if(nbDone>=end) break;
+      if(isSelector(var(lits[i]))) continue;
+      nbDone++;
+      int l = level(var(lits[i]));
+      if (permDiff[l] != MYFLAG) {
+        permDiff[l] = MYFLAG;
+        nblevels++;
+      }
+    }
+  } else { // -------- DEFAULT MODE. NOT A LOT OF DIFFERENCES... BUT EASIER TO READ
+    for(int i=0;i<lits.size();i++) {
+      int l = level(var(lits[i]));
+      if (permDiff[l] != MYFLAG) {
+        permDiff[l] = MYFLAG;
+        nblevels++;
+      }
+    }
+  }
+
+  return nblevels;
+}
+
+inline unsigned int Solver::computeLBD(const Clause &c) {
+  int nblevels = 0;
+  MYFLAG++;
+
+  if(incremental) { // ----------------- INCREMENTAL MODE
+     int nbDone = 0;
+    for(int i=0;i<c.size();i++) {
+      if(nbDone>=c.sizeWithoutSelectors()) break;
+      if(isSelector(var(c[i]))) continue;
+      nbDone++;
+      int l = level(var(c[i]));
+      if (permDiff[l] != MYFLAG) {
+        permDiff[l] = MYFLAG;
+        nblevels++;
+      }
+    }
+  } else { // -------- DEFAULT MODE. NOT A LOT OF DIFFERENCES... BUT EASIER TO READ
+    for(int i=0;i<c.size();i++) {
+      int l = level(var(c[i]));
+      if (permDiff[l] != MYFLAG) {
+        permDiff[l] = MYFLAG;
+        nblevels++;
+      }
+    }
+  }
+  return nblevels;
+}
+
+
+/******************************************************************
+ * Minimisation with binary reolution
+ ******************************************************************/
+void Solver::minimisationWithBinaryResolution(vec<Lit> &out_learnt) {
+  
+  // Find the LBD measure                                                                                                         
+  unsigned int lbd = computeLBD(out_learnt);
+  Lit p = ~out_learnt[0];
+  
+  if(lbd<=lbLBDMinimizingClause){
+    MYFLAG++;
+    
+    for(int i = 1;i<out_learnt.size();i++) {
+      permDiff[var(out_learnt[i])] = MYFLAG;
+    }
+
+    vec<Watcher>&  wbin  = watchesBin[p];
+    int nb = 0;
+    for(int k = 0;k<wbin.size();k++) {
+      Lit imp = wbin[k].blocker;
+      if(permDiff[var(imp)]==MYFLAG && value(imp)==l_True) {
+        nb++;
+        permDiff[var(imp)]= MYFLAG-1;
+      }
+      }
+    int l = out_learnt.size()-1;
+    if(nb>0) {
+      nbReducedClauses++;
+      for(int i = 1;i<out_learnt.size()-nb;i++) {
+        if(permDiff[var(out_learnt[i])]!=MYFLAG) {
+          Lit p = out_learnt[l];
+          out_learnt[l] = out_learnt[i];
+          out_learnt[i] = p;
+          l--;i--;
+        }
+      }
+      
+      out_learnt.shrink(nb);
+      
+    }
+  }
+}
+
+// Revert to the state at given level (keeping all assignment at 'level' but not beyond).
+//
+void Solver::cancelUntil(int level) {
+    if (decisionLevel() > level){
+        for (int c = trail.size()-1; c >= trail_lim[level]; c--){
+            Var      x  = var(trail[c]);
+            assigns [x] = l_Undef;
+            if (phase_saving > 1 || ((phase_saving == 1) && c > trail_lim.last()))
+                polarity[x] = sign(trail[c]);
+            insertVarOrder(x); }
+        qhead = trail_lim[level];
+        trail.shrink(trail.size() - trail_lim[level]);
+        trail_lim.shrink(trail_lim.size() - level);
+    } 
+}
+
+
+//=================================================================================================
+// Major methods:
+
+
+Lit Solver::pickBranchLit()
+{
+    Var next = var_Undef;
+
+    // Random decision:
+    if (drand(random_seed) < random_var_freq && !order_heap.empty()){
+        next = order_heap[irand(random_seed,order_heap.size())];
+        if (value(next) == l_Undef && decision[next])
+            rnd_decisions++; }
+
+    // Activity based decision:
+    while (next == var_Undef || value(next) != l_Undef || !decision[next])
+        if (order_heap.empty()){
+            next = var_Undef;
+            break;
+        }else
+            next = order_heap.removeMin();
+    
+    return next == var_Undef ? lit_Undef : mkLit(next, rnd_pol ? drand(random_seed) < 0.5 : (polarity[next] != 0));
+}
+
+
+/*_________________________________________________________________________________________________
+|
+|  analyze : (confl : Clause*) (out_learnt : vec<Lit>&) (out_btlevel : int&)  ->  [void]
+|  
+|  Description:
+|    Analyze conflict and produce a reason clause.
+|  
+|    Pre-conditions:
+|      * 'out_learnt' is assumed to be cleared.
+|      * Current decision level must be greater than root level.
+|  
+|    Post-conditions:
+|      * 'out_learnt[0]' is the asserting literal at level 'out_btlevel'.
+|      * If out_learnt.size() > 1 then 'out_learnt[1]' has the greatest decision level of the 
+|        rest of literals. There may be others from the same level though.
+|  
+|________________________________________________________________________________________________@*/
+void Solver::analyze(CRef confl, vec<Lit>& out_learnt,vec<Lit>&selectors, int& out_btlevel,unsigned int &lbd,unsigned int &szWithoutSelectors)
+{
+    int pathC = 0;
+    Lit p     = lit_Undef;
+
+    // Generate conflict clause:
+    //
+    out_learnt.push();      // (leave room for the asserting literal)
+    int index   = trail.size() - 1;
+
+    do{
+        assert(confl != CRef_Undef); // (otherwise should be UIP)
+        Clause& c = ca[confl];
+
+        // Special case for binary clauses
+        // The first one has to be SAT
+        if( p != lit_Undef && c.size()==2 && value(c[0])==l_False) {
+          
+          assert(value(c[1])==l_True);
+          Lit tmp = c[0];
+          c[0] =  c[1], c[1] = tmp;
+        }
+        
+        if (c.learnt()) 
+            claBumpActivity(c);
+
+#ifdef DYNAMICNBLEVEL               
+        // DYNAMIC NBLEVEL trick (see competition'09 companion paper)
+        if(c.learnt()  && c.lbd()>2) { 
+          unsigned int nblevels = computeLBD(c);
+          if(nblevels+1<c.lbd() ) { // improve the LBD
+            if(c.lbd()<=lbLBDFrozenClause) {
+              c.setCanBeDel(false); 
+            }
+            // seems to be interesting : keep it for the next round
+            c.setLBD(nblevels); // Update it
+          }
+        }
+#endif
+
+
+        for (int j = (p == lit_Undef) ? 0 : 1; j < c.size(); j++){
+            Lit q = c[j];
+
+            if (!seen[var(q)] && level(var(q)) > 0){
+              if(!isSelector(var(q)))
+                varBumpActivity(var(q));
+              seen[var(q)] = 1;
+              if (level(var(q)) >= decisionLevel()) {
+                pathC++;
+#ifdef UPDATEVARACTIVITY
+                // UPDATEVARACTIVITY trick (see competition'09 companion paper)
+                if(!isSelector(var(q)) && (reason(var(q))!= CRef_Undef)  && ca[reason(var(q))].learnt()) 
+                  lastDecisionLevel.push(q);
+#endif
+                
+              } else {
+                if(isSelector(var(q))) {
+                  assert(value(q) == l_False);
+                  selectors.push(q);
+                } else 
+                  out_learnt.push(q);
+              }
+            }
+        }
+        
+        // Select next clause to look at:
+        while (!seen[var(trail[index--])]);
+        p     = trail[index+1];
+        confl = reason(var(p));
+        seen[var(p)] = 0;
+        pathC--;
+
+    }while (pathC > 0);
+    out_learnt[0] = ~p;
+
+    // Simplify conflict clause:
+    //
+    int i, j;
+
+    for(i = 0;i<selectors.size();i++)  
+      out_learnt.push(selectors[i]);       
+
+    out_learnt.copyTo(analyze_toclear);
+    if (ccmin_mode == 2){
+        uint32_t abstract_level = 0;
+        for (i = 1; i < out_learnt.size(); i++)
+            abstract_level |= abstractLevel(var(out_learnt[i])); // (maintain an abstraction of levels involved in conflict)
+
+        for (i = j = 1; i < out_learnt.size(); i++)
+            if (reason(var(out_learnt[i])) == CRef_Undef || !litRedundant(out_learnt[i], abstract_level))
+                out_learnt[j++] = out_learnt[i];
+        
+    }else if (ccmin_mode == 1){
+        for (i = j = 1; i < out_learnt.size(); i++){
+            Var x = var(out_learnt[i]);
+
+            if (reason(x) == CRef_Undef)
+                out_learnt[j++] = out_learnt[i];
+            else{
+                Clause& c = ca[reason(var(out_learnt[i]))];
+                // Thanks to Siert Wieringa for this bug fix!
+                for (int k = ((c.size()==2) ? 0:1); k < c.size(); k++)
+                    if (!seen[var(c[k])] && level(var(c[k])) > 0){
+                        out_learnt[j++] = out_learnt[i];
+                        break; }
+            }
+        }
+    }else
+        i = j = out_learnt.size();
+
+    max_literals += out_learnt.size();
+    out_learnt.shrink(i - j);
+    tot_literals += out_learnt.size();
+
+
+    /* ***************************************
+      Minimisation with binary clauses of the asserting clause
+      First of all : we look for small clauses
+      Then, we reduce clauses with small LBD.
+      Otherwise, this can be useless
+     */
+    if(!incremental && out_learnt.size()<=lbSizeMinimizingClause) {
+      minimisationWithBinaryResolution(out_learnt);
+    }
+    // Find correct backtrack level:
+    //
+    if (out_learnt.size() == 1)
+        out_btlevel = 0;
+    else{
+        int max_i = 1;
+        // Find the first literal assigned at the next-highest level:
+        for (int i = 2; i < out_learnt.size(); i++)
+            if (level(var(out_learnt[i])) > level(var(out_learnt[max_i])))
+                max_i = i;
+        // Swap-in this literal at index 1:
+        Lit p             = out_learnt[max_i];
+        out_learnt[max_i] = out_learnt[1];
+        out_learnt[1]     = p;
+        out_btlevel       = level(var(p));
+    }
+
+
+    // Compute the size of the clause without selectors (incremental mode)
+    if(incremental) {
+      szWithoutSelectors = 0;
+      for(int i=0;i<out_learnt.size();i++) {
+        if(!isSelector(var((out_learnt[i])))) szWithoutSelectors++; 
+        else if(i>0) break;
+      }
+    } else 
+      szWithoutSelectors = out_learnt.size();
+    
+    // Compute LBD
+    lbd = computeLBD(out_learnt,out_learnt.size()-selectors.size());
+
+  
+#ifdef UPDATEVARACTIVITY
+  // UPDATEVARACTIVITY trick (see competition'09 companion paper)
+  if(lastDecisionLevel.size()>0) {
+    for(int i = 0;i<lastDecisionLevel.size();i++) {
+      if(ca[reason(var(lastDecisionLevel[i]))].lbd()<lbd)
+        varBumpActivity(var(lastDecisionLevel[i]));
+    }
+    lastDecisionLevel.clear();
+  } 
+#endif      
+
+
+
+  for (j = 0; j < analyze_toclear.size(); j++) seen[var(analyze_toclear[j])] = 0;    // ('seen[]' is now cleared)
+  for(j = 0 ; j<selectors.size() ; j++) seen[var(selectors[j])] = 0;  
+}
+
+
+// Check if 'p' can be removed. 'abstract_levels' is used to abort early if the algorithm is
+// visiting literals at levels that cannot be removed later.
+bool Solver::litRedundant(Lit p, uint32_t abstract_levels)
+{
+    analyze_stack.clear(); analyze_stack.push(p);
+    int top = analyze_toclear.size();
+    while (analyze_stack.size() > 0){
+        assert(reason(var(analyze_stack.last())) != CRef_Undef);
+        Clause& c = ca[reason(var(analyze_stack.last()))]; analyze_stack.pop();
+        if(c.size()==2 && value(c[0])==l_False) {
+          assert(value(c[1])==l_True);
+          Lit tmp = c[0];
+          c[0] =  c[1], c[1] = tmp;
+        }
+
+        for (int i = 1; i < c.size(); i++){
+            Lit p  = c[i];
+            if (!seen[var(p)] && level(var(p)) > 0){
+                if (reason(var(p)) != CRef_Undef && (abstractLevel(var(p)) & abstract_levels) != 0){
+                    seen[var(p)] = 1;
+                    analyze_stack.push(p);
+                    analyze_toclear.push(p);
+                }else{
+                    for (int j = top; j < analyze_toclear.size(); j++)
+                        seen[var(analyze_toclear[j])] = 0;
+                    analyze_toclear.shrink(analyze_toclear.size() - top);
+                    return false;
+                }
+            }
+        }
+    }
+
+    return true;
+}
+
+
+/*_________________________________________________________________________________________________
+|
+|  analyzeFinal : (p : Lit)  ->  [void]
+|  
+|  Description:
+|    Specialized analysis procedure to express the final conflict in terms of assumptions.
+|    Calculates the (possibly empty) set of assumptions that led to the assignment of 'p', and
+|    stores the result in 'out_conflict'.
+|________________________________________________________________________________________________@*/
+void Solver::analyzeFinal(Lit p, vec<Lit>& out_conflict)
+{
+    out_conflict.clear();
+    out_conflict.push(p);
+
+    if (decisionLevel() == 0)
+        return;
+
+    seen[var(p)] = 1;
+
+    for (int i = trail.size()-1; i >= trail_lim[0]; i--){
+        Var x = var(trail[i]);
+        if (seen[x]){
+            if (reason(x) == CRef_Undef){
+                assert(level(x) > 0);
+                out_conflict.push(~trail[i]);
+            }else{
+                Clause& c = ca[reason(x)];
+                //                for (int j = 1; j < c.size(); j++) Minisat (glucose 2.0) loop 
+                // Bug in case of assumptions due to special data structures for Binary.
+                // Many thanks to Sam Bayless (sbayless@cs.ubc.ca) for discover this bug.
+                for (int j = ((c.size()==2) ? 0:1); j < c.size(); j++)
+                    if (level(var(c[j])) > 0)
+                        seen[var(c[j])] = 1;
+            }  
+
+            seen[x] = 0;
+        }
+    }
+
+    seen[var(p)] = 0;
+}
+
+
+void Solver::uncheckedEnqueue(Lit p, CRef from)
+{
+    assert(value(p) == l_Undef);
+    assigns[var(p)] = lbool(!sign(p));
+    vardata[var(p)] = mkVarData(from, decisionLevel());
+    trail.push_(p);
+}
+
+
+/*_________________________________________________________________________________________________
+|
+|  propagate : [void]  ->  [Clause*]
+|  
+|  Description:
+|    Propagates all enqueued facts. If a conflict arises, the conflicting clause is returned,
+|    otherwise CRef_Undef.
+|  
+|    Post-conditions:
+|      * the propagation queue is empty, even if there was a conflict.
+|________________________________________________________________________________________________@*/
+CRef Solver::propagate()
+{
+    CRef    confl     = CRef_Undef;
+    int     num_props = 0;
+    watches.cleanAll();
+    watchesBin.cleanAll();
+    while (qhead < trail.size()){
+        Lit            p   = trail[qhead++];     // 'p' is enqueued fact to propagate.
+        vec<Watcher>&  ws  = watches[p];
+        Watcher        *i, *j, *end;
+        num_props++;
+        
+        // First, Propagate binary clauses 
+        vec<Watcher>&  wbin  = watchesBin[p];
+        for(int k = 0;k<wbin.size();k++) {
+          Lit imp = wbin[k].blocker;
+          if(value(imp) == l_False) {
+            return wbin[k].cref;
+          }
+          if(value(imp) == l_Undef) {
+            uncheckedEnqueue(imp,wbin[k].cref);
+          }
+        }
+
+        for (i = j = (Watcher*)ws, end = i + ws.size();  i != end;){
+            // Try to avoid inspecting the clause:
+            Lit blocker = i->blocker;
+            if (value(blocker) == l_True){
+                *j++ = *i++; continue; }
+
+            // Make sure the false literal is data[1]:
+            CRef     cr        = i->cref;
+            Clause&  c         = ca[cr];
+            Lit      false_lit = ~p;
+            if (c[0] == false_lit)
+                c[0] = c[1], c[1] = false_lit;
+            assert(c[1] == false_lit);
+            i++;
+
+            // If 0th watch is true, then clause is already satisfied.
+            Lit     first = c[0];
+            Watcher w     = Watcher(cr, first);
+            if (first != blocker && value(first) == l_True){
+              *j++ = w; continue; }
+
+            // Look for new watch:
+            if(incremental) { // ----------------- INCREMENTAL MODE
+              int choosenPos = -1;
+              for (int k = 2; k < c.size(); k++) {
+                
+                if (value(c[k]) != l_False){
+                  if(decisionLevel()>assumptions.size()) {
+                    choosenPos = k;
+                    break;
+                  } else {
+                    choosenPos = k;
+                    
+                    if(value(c[k])==l_True || !isSelector(var(c[k]))) {
+                      break;
+                    }
+                  }
+
+                }
+              }
+              if(choosenPos!=-1) {
+                c[1] = c[choosenPos]; c[choosenPos] = false_lit;
+                watches[~c[1]].push(w);
+                goto NextClause; }
+            } else {  // ----------------- DEFAULT  MODE (NOT INCREMENTAL)
+              for (int k = 2; k < c.size(); k++) {
+                
+                if (value(c[k]) != l_False){
+                  c[1] = c[k]; c[k] = false_lit;
+                  watches[~c[1]].push(w);
+                  goto NextClause; }
+              }
+            }
+
+            // Did not find watch -- clause is unit under assignment:
+            *j++ = w;
+            if (value(first) == l_False){
+                confl = cr;
+                qhead = trail.size();
+                // Copy the remaining watches:
+                while (i < end)
+                    *j++ = *i++;
+            }else {
+                uncheckedEnqueue(first, cr);
+          
+                
+            }
+        NextClause:;
+        }
+        ws.shrink(i - j);
+    }
+    propagations += num_props;
+    simpDB_props -= num_props;
+    
+    return confl;
+}
+
+
+/*_________________________________________________________________________________________________
+|
+|  reduceDB : ()  ->  [void]
+|  
+|  Description:
+|    Remove half of the learnt clauses, minus the clauses locked by the current assignment. Locked
+|    clauses are clauses that are reason to some assignment. Binary clauses are never removed.
+|________________________________________________________________________________________________@*/
+struct reduceDB_lt { 
+    ClauseAllocator& ca;
+    reduceDB_lt(ClauseAllocator& ca_) : ca(ca_) {}
+    bool operator () (CRef x, CRef y) { 
+ 
+    // Main criteria... Like in MiniSat we keep all binary clauses
+    if(ca[x].size()> 2 && ca[y].size()==2) return 1;
+    
+    if(ca[y].size()> 2 && ca[x].size()==2) return 0;
+    if(ca[x].size()==2 && ca[y].size()==2) return 0;
+    
+    // Second one  based on literal block distance
+    if(ca[x].lbd()> ca[y].lbd()) return 1;
+    if(ca[x].lbd()< ca[y].lbd()) return 0;    
+    
+    // Finally we can use old activity or size, we choose the last one
+    return ca[x].activity() < ca[y].activity();
+    //return x->size() < y->size();
+    //return ca[x].size() > 2 && (ca[y].size() == 2 || ca[x].activity() < ca[y].activity()); } 
+    }    
+};
+
+void Solver::reduceDB()
+{ 
+  int i, j;
+  nbReduceDB++;
+  sort(learnts, reduceDB_lt(ca));
+
+  // We have a lot of "good" clauses, it is difficult to compare them. Keep more !
+  if(ca[learnts[learnts.size() / RATIOREMOVECLAUSES]].lbd()<=3) nbclausesbeforereduce +=specialIncReduceDB; 
+  // Useless :-)
+  if(ca[learnts.last()].lbd()<=5)  nbclausesbeforereduce +=specialIncReduceDB;   
+  
+  // Don't delete binary or locked clauses. From the rest, delete clauses from the first half
+  // Keep clauses which seem to be usefull (their lbd was reduce during this sequence)
+
+  int limit = learnts.size() / 2;
+  for (i = j = 0; i < learnts.size(); i++){
+    Clause& c = ca[learnts[i]];
+    if (c.lbd()>2 && c.size() > 2 && c.canBeDel() &&  !locked(c) && (i < limit)) {
+      removeClause(learnts[i]);
+      nbRemovedClauses++;
+    }
+    else {
+      if(!c.canBeDel()) limit++; //we keep c, so we can delete an other clause
+      c.setCanBeDel(true);       // At the next step, c can be delete
+      learnts[j++] = learnts[i];
+    }
+  }
+  learnts.shrink(i - j);
+  checkGarbage();
+}
+
+
+void Solver::removeSatisfied(vec<CRef>& cs)
+{
+    int i, j;
+    for (i = j = 0; i < cs.size(); i++){
+        Clause& c = ca[cs[i]];
+        if (satisfied(c)) 
+            removeClause(cs[i]);
+        else
+            cs[j++] = cs[i];
+    }
+    cs.shrink(i - j);
+}
+
+
+void Solver::rebuildOrderHeap()
+{
+    vec<Var> vs;
+    for (Var v = 0; v < nVars(); v++)
+        if (decision[v] && value(v) == l_Undef)
+            vs.push(v);
+    order_heap.build(vs);
+}
+
+
+/*_________________________________________________________________________________________________
+|
+|  simplify : [void]  ->  [bool]
+|  
+|  Description:
+|    Simplify the clause database according to the current top-level assigment. Currently, the only
+|    thing done here is the removal of satisfied clauses, but more things can be put here.
+|________________________________________________________________________________________________@*/
+bool Solver::simplify()
+{
+    assert(decisionLevel() == 0);
+
+    if (!ok || propagate() != CRef_Undef)
+        return ok = false;
+
+    if (nAssigns() == simpDB_assigns || (simpDB_props > 0))
+        return true;
+
+    // Remove satisfied clauses:
+    removeSatisfied(learnts);
+    if (remove_satisfied)        // Can be turned off.
+        removeSatisfied(clauses);
+
+    checkGarbage();
+
+    rebuildOrderHeap();
+
+    simpDB_assigns = nAssigns();
+    simpDB_props   = clauses_literals + learnts_literals;   // (shouldn't depend on stats really, but it will do for now)
+
+    return true;
+}
+
+
+/*_________________________________________________________________________________________________
+|
+|  search : (nof_conflicts : int) (params : const SearchParams&)  ->  [lbool]
+|  
+|  Description:
+|    Search for a model the specified number of conflicts. 
+|    NOTE! Use negative value for 'nof_conflicts' indicate infinity.
+|  
+|  Output:
+|    'l_True' if a partial assigment that is consistent with respect to the clauseset is found. If
+|    all variables are decision variables, this means that the clause set is satisfiable. 'l_False'
+|    if the clause set is unsatisfiable. 'l_Undef' if the bound on number of conflicts is reached.
+|________________________________________________________________________________________________@*/
+lbool Solver::search(int nof_conflicts)
+{
+    assert(ok);
+    int         backtrack_level;
+    int         conflictC = 0;
+    vec<Lit>    learnt_clause,selectors;
+    unsigned int nblevels,szWoutSelectors;
+    bool blocked=false;
+    starts++;
+    for (;;){
+        CRef confl = propagate();
+        if (confl != CRef_Undef){
+            // CONFLICT
+          conflicts++; conflictC++;conflictsRestarts++;
+          if(conflicts%5000==0 && var_decay<0.95)
+            var_decay += 0.01;
+
+          if (verbosity >= 1 && conflicts%verbEveryConflicts==0){
+            printf("c | %8d   %7d    %5d | %7d %8d %8d | %5d %8d   %6d %8d | %6.3f %% |\n", 
+                   (int)starts,(int)nbstopsrestarts, (int)(conflicts/starts), 
+                   (int)dec_vars - (trail_lim.size() == 0 ? trail.size() : trail_lim[0]), nClauses(), (int)clauses_literals, 
+                   (int)nbReduceDB, nLearnts(), (int)nbDL2,(int)nbRemovedClauses, progressEstimate()*100);
+          }
+          if (decisionLevel() == 0) {
+            return l_False;
+            
+          }
+
+          trailQueue.push(trail.size());
+          // BLOCK RESTART (CP 2012 paper)
+          if( conflictsRestarts>LOWER_BOUND_FOR_BLOCKING_RESTART && lbdQueue.isvalid()  && trail.size()>R*trailQueue.getavg()) {
+            lbdQueue.fastclear();
+            nbstopsrestarts++;
+            if(!blocked) {lastblockatrestart=starts;nbstopsrestartssame++;blocked=true;}
+          }
+
+            learnt_clause.clear();
+            selectors.clear();
+            analyze(confl, learnt_clause, selectors,backtrack_level,nblevels,szWoutSelectors);
+
+            lbdQueue.push(nblevels);
+            sumLBD += nblevels;
+ 
+            cancelUntil(backtrack_level);
+
+            if (certifiedUNSAT) {
+              for (int i = 0; i < learnt_clause.size(); i++)
+                fprintf(certifiedOutput, "%i " , (var(learnt_clause[i]) + 1) *
+                            (-2 * sign(learnt_clause[i]) + 1) );
+              fprintf(certifiedOutput, "0\n");
+            }
+
+            if (learnt_clause.size() == 1){
+              uncheckedEnqueue(learnt_clause[0]);nbUn++;
+            }else{
+                CRef cr = ca.alloc(learnt_clause, true);
+                ca[cr].setLBD(nblevels); 
+                ca[cr].setSizeWithoutSelectors(szWoutSelectors);
+                if(nblevels<=2) nbDL2++; // stats
+                if(ca[cr].size()==2) nbBin++; // stats
+                learnts.push(cr);
+                attachClause(cr);
+
+                claBumpActivity(ca[cr]);
+                uncheckedEnqueue(learnt_clause[0], cr);
+            }
+            varDecayActivity();
+            claDecayActivity();
+
+           
+        }else{
+
+          // Our dynamic restart, see the SAT09 competition compagnion paper 
+          if ( (conflictsRestarts && lbdQueue.isvalid() && lbdQueue.getavg()*K > sumLBD/conflictsRestarts) || (pstop && *pstop) ) {
+            lbdQueue.fastclear();
+            progress_estimate = progressEstimate();
+            int bt = 0;
+            if(incremental) { // DO NOT BACKTRACK UNTIL 0.. USELESS
+              bt = (decisionLevel()<assumptions.size()) ? decisionLevel() : assumptions.size();
+            }
+            cancelUntil(bt);
+            return l_Undef; 
+          }
+
+           // Simplify the set of problem clauses:
+          if (decisionLevel() == 0 && !simplify()) {
+            return l_False;
+          }
+            // Perform clause database reduction !
+            if(conflicts>=curRestart* nbclausesbeforereduce) 
+              {
+                  
+                assert(learnts.size()>0);
+                curRestart = (conflicts/ nbclausesbeforereduce)+1;
+                reduceDB();
+                nbclausesbeforereduce += incReduceDB;
+              }
+
+            Lit next = lit_Undef;
+            while (decisionLevel() < assumptions.size()){
+                // Perform user provided assumption:
+                Lit p = assumptions[decisionLevel()];
+                if (value(p) == l_True){
+                    // Dummy decision level:
+                    newDecisionLevel();
+                }else if (value(p) == l_False){
+                    analyzeFinal(~p, conflict);
+                    return l_False;
+                }else{
+                    next = p;
+                    break;
+                }
+            }
+
+            if (next == lit_Undef){
+                // New variable decision:
+                decisions++;
+                next = pickBranchLit();
+
+                if (next == lit_Undef){
+                  //printf("c last restart ## conflicts  :  %d %d \n",conflictC,decisionLevel());
+                  // Model found:
+                  return l_True;
+                }
+            }
+
+            // Increase decision level and enqueue 'next'
+            newDecisionLevel();
+            uncheckedEnqueue(next);
+        }
+    }
+}
+
+
+double Solver::progressEstimate() const
+{
+    double  progress = 0;
+    double  F = 1.0 / nVars();
+
+    for (int i = 0; i <= decisionLevel(); i++){
+        int beg = i == 0 ? 0 : trail_lim[i - 1];
+        int end = i == decisionLevel() ? trail.size() : trail_lim[i];
+        progress += pow(F, i) * (end - beg);
+    }
+
+    return progress / nVars();
+}
+
+void Solver::printIncrementalStats() {
+
+  printf("c---------- Glucose Stats -------------------------\n");
+  printf("c restarts              : %ld\n", starts);
+  printf("c nb ReduceDB           : %ld\n", nbReduceDB);
+  printf("c nb removed Clauses    : %ld\n", nbRemovedClauses);
+  printf("c nb learnts DL2        : %ld\n", nbDL2);
+  printf("c nb learnts size 2     : %ld\n", nbBin);
+  printf("c nb learnts size 1     : %ld\n", nbUn);
+
+  printf("c conflicts             : %ld\n", conflicts);
+  printf("c decisions             : %ld\n", decisions);
+  printf("c propagations          : %ld\n", propagations);
+
+  printf("c SAT Calls             : %d in %g seconds\n", nbSatCalls,   totalTime4Sat);
+  printf("c UNSAT Calls           : %d in %g seconds\n", nbUnsatCalls, totalTime4Unsat);
+  printf("c--------------------------------------------------\n");
+
+
+}
+
+
+// NOTE: assumptions passed in member-variable 'assumptions'.
+lbool Solver::solve_()
+{
+
+  if(incremental && certifiedUNSAT) {
+    printf("Can not use incremental and certified unsat in the same time\n");
+    exit(-1);
+  }
+    model.clear();
+    conflict.clear();
+    if (!ok) return l_False;
+    double curTime = cpuTime();
+
+    
+    solves++;
+            
+
+    
+    lbool   status        = l_Undef;
+    if(!incremental && verbosity>=1) {
+      printf("c ========================================[ MAGIC CONSTANTS ]==============================================\n");
+      printf("c | Constants are supposed to work well together :-)                                                      |\n");
+      printf("c | however, if you find better choices, please let us known...                                           |\n");
+      printf("c |-------------------------------------------------------------------------------------------------------|\n");
+    printf("c |                                |                                |                                     |\n"); 
+    printf("c | - Restarts:                    | - Reduce Clause DB:            | - Minimize Asserting:               |\n");
+    printf("c |   * LBD Queue    : %6d      |   * First     : %6d         |    * size < %3d                     |\n",lbdQueue.maxSize(),nbclausesbeforereduce,lbSizeMinimizingClause);
+    printf("c |   * Trail  Queue : %6d      |   * Inc       : %6d         |    * lbd  < %3d                     |\n",trailQueue.maxSize(),incReduceDB,lbLBDMinimizingClause);
+    printf("c |   * K            : %6.2f      |   * Special   : %6d         |                                     |\n",K,specialIncReduceDB);
+    printf("c |   * R            : %6.2f      |   * Protected :  (lbd)< %2d     |                                     |\n",R,lbLBDFrozenClause);
+    printf("c |                                |                                |                                     |\n"); 
+printf("c ==================================[ Search Statistics (every %6d conflicts) ]=========================\n",verbEveryConflicts);
+      printf("c |                                                                                                       |\n"); 
+
+      printf("c |          RESTARTS           |          ORIGINAL         |              LEARNT              | Progress |\n");
+      printf("c |       NB   Blocked  Avg Cfc |    Vars  Clauses Literals |   Red   Learnts    LBD2  Removed |          |\n");
+      printf("c =========================================================================================================\n");
+    }
+
+    // Search:
+    int curr_restarts = 0;
+    while (status == l_Undef){
+      status = search(0); // the parameter is useless in glucose, kept to allow modifications
+        if (!withinBudget() || terminate_search_early || (pstop && *pstop)) break;
+        if (nRuntimeLimit && Abc_Clock() > nRuntimeLimit)                   break;
+        curr_restarts++;
+    }
+
+    if (!incremental && verbosity >= 1)
+      printf("c =========================================================================================================\n");
+
+
+    if (certifiedUNSAT){ // Want certified output
+      if (status == l_False)
+        fprintf(certifiedOutput, "0\n");
+      fclose(certifiedOutput);
+    }
+
+
+    if (status == l_True){
+        // Extend & copy model:
+        model.growTo(nVars());
+        for (int i = 0; i < nVars(); i++) model[i] = value(i);
+    }else if (status == l_False && conflict.size() == 0)
+        ok = false;
+
+    cancelUntil(0);
+
+    double finalTime = cpuTime();
+    if(status==l_True) {
+      nbSatCalls++; 
+      totalTime4Sat +=(finalTime-curTime);
+    }
+    if(status==l_False) {
+      nbUnsatCalls++; 
+      totalTime4Unsat +=(finalTime-curTime);
+    }
+
+    // ABC callback
+    if (pCnfFunc && !terminate_search_early) {// hack to avoid calling callback twise if the solver was terminated early
+        int * pCex = NULL;
+        int message = (status == l_True ? 1 : status == l_False ? 0 : -1);
+        if (status == l_True) {
+            pCex = new int[nVars()];
+            for (int i = 0; i < nVars(); i++)
+                pCex[i] = (model[i] == l_True);
+        }
+        
+        int callback_result = pCnfFunc(pCnfMan, message, pCex);
+        assert(callback_result == 0);
+    }
+    else if (pCnfFunc)
+        terminate_search_early = false; // for next run
+
+    return status;
+}
+
+//=================================================================================================
+// Writing CNF to DIMACS:
+// 
+// FIXME: this needs to be rewritten completely.
+
+static Var mapVar(Var x, vec<Var>& map, Var& max)
+{
+    if (map.size() <= x || map[x] == -1){
+        map.growTo(x+1, -1);
+        map[x] = max++;
+    }
+    return map[x];
+}
+
+
+void Solver::toDimacs(FILE* f, Clause& c, vec<Var>& map, Var& max)
+{
+    if (satisfied(c)) return;
+
+    for (int i = 0; i < c.size(); i++)
+        if (value(c[i]) != l_False)
+            fprintf(f, "%s%d ", sign(c[i]) ? "-" : "", mapVar(var(c[i]), map, max)+1);
+    fprintf(f, "0\n");
+}
+
+
+void Solver::toDimacs(const char *file, const vec<Lit>& assumps)
+{
+    FILE* f = fopen(file, "wr");
+    if (f == NULL)
+        fprintf(stderr, "could not open file %s\n", file), exit(1);
+    toDimacs(f, assumps);
+    fclose(f);
+}
+
+
+void Solver::toDimacs(FILE* f, const vec<Lit>& assumps)
+{
+    // Handle case when solver is in contradictory state:
+    if (!ok){
+        fprintf(f, "p cnf 1 2\n1 0\n-1 0\n");
+        return; }
+
+    vec<Var> map; Var max = 0;
+
+    // Cannot use removeClauses here because it is not safe
+    // to deallocate them at this point. Could be improved.
+    int i, cnt = 0;
+    for (i = 0; i < clauses.size(); i++)
+        if (!satisfied(ca[clauses[i]]))
+            cnt++;
+        
+    for (i = 0; i < clauses.size(); i++)
+        if (!satisfied(ca[clauses[i]])){
+            Clause& c = ca[clauses[i]];
+            for (int j = 0; j < c.size(); j++)
+                if (value(c[j]) != l_False)
+                    mapVar(var(c[j]), map, max);
+        }
+
+    // Assumptions are added as unit clauses:
+    cnt += assumptions.size();
+
+    fprintf(f, "p cnf %d %d\n", max, cnt);
+
+    for (i = 0; i < assumptions.size(); i++){
+        assert(value(assumptions[i]) != l_False);
+        fprintf(f, "%s%d 0\n", sign(assumptions[i]) ? "-" : "", mapVar(var(assumptions[i]), map, max)+1);
+    }
+
+    for (i = 0; i < clauses.size(); i++)
+        toDimacs(f, ca[clauses[i]], map, max);
+
+    if (verbosity > 0)
+        printf("Wrote %d clauses with %d variables.\n", cnt, max);
+}
+
+
+//=================================================================================================
+// Garbage Collection methods:
+
+void Solver::relocAll(ClauseAllocator& to)
+{
+    int v, s, i, j;
+    // All watchers:
+    //
+    // for (int i = 0; i < watches.size(); i++)
+    watches.cleanAll();
+    watchesBin.cleanAll();
+    for (v = 0; v < nVars(); v++)
+        for (s = 0; s < 2; s++){
+            Lit p = mkLit(v, s != 0);
+            // printf(" >>> RELOCING: %s%d\n", sign(p)?"-":"", var(p)+1);
+            vec<Watcher>& ws = watches[p];
+            for (j = 0; j < ws.size(); j++)
+                ca.reloc(ws[j].cref, to);
+            vec<Watcher>& ws2 = watchesBin[p];
+            for (j = 0; j < ws2.size(); j++)
+                ca.reloc(ws2[j].cref, to);
+        }
+
+    // All reasons:
+    //
+    for (i = 0; i < trail.size(); i++){
+        Var v = var(trail[i]);
+
+        if (reason(v) != CRef_Undef && (ca[reason(v)].reloced() || locked(ca[reason(v)])))
+            ca.reloc(vardata[v].reason, to);
+    }
+
+    // All learnt:
+    //
+    for (i = 0; i < learnts.size(); i++)
+        ca.reloc(learnts[i], to);
+
+    // All original:
+    //
+    for (i = 0; i < clauses.size(); i++)
+        ca.reloc(clauses[i], to);
+}
+
+
+void Solver::garbageCollect()
+{
+    // Initialize the next region to a size corresponding to the estimated utilization degree. This
+    // is not precise but should avoid some unnecessary reallocations for the new region:
+    ClauseAllocator to(ca.size() - ca.wasted()); 
+
+    relocAll(to);
+    if (verbosity >= 2)
+        printf("|  Garbage collection:   %12d bytes => %12d bytes             |\n", 
+               ca.size()*ClauseAllocator::Unit_Size, to.size()*ClauseAllocator::Unit_Size);
+    to.moveTo(ca);
+}
+
+void Solver::reset() 
+{
+    // Reset everything
+    ok = true;
+    K = (double)opt_K;
+    R = (double)opt_R;
+    firstReduceDB = opt_first_reduce_db;
+    var_decay = (double)opt_var_decay;
+    //max_var_decay = opt_max_var_decay;
+    solves = starts = decisions = propagations = conflicts = conflictsRestarts = 0;
+    curRestart = 1;
+    cla_inc = var_inc = 1;
+    watches.clear(false); // We don't free the memory, new calls should be of the same size order.
+    watchesBin.clear(false); 
+    //unaryWatches.clear(false);
+    qhead = 0;
+    simpDB_assigns = -1;
+    simpDB_props = 0;
+    order_heap.clear(false);
+    progress_estimate = 0;
+    //lastLearntClause = CRef_Undef;
+    conflict_budget = -1;
+    propagation_budget = -1;
+    nbVarsInitialFormula = INT32_MAX;
+    totalTime4Sat = 0.;
+    totalTime4Unsat = 0.;
+    nbSatCalls = nbUnsatCalls = 0;
+    MYFLAG = 0;
+    lbdQueue.clear(false);
+    lbdQueue.initSize(sizeLBDQueue);
+    trailQueue.clear(false);
+    trailQueue.initSize(sizeTrailQueue);
+    sumLBD = 0;
+    nbclausesbeforereduce = firstReduceDB;
+    //stats.clear();
+    //stats.growTo(coreStatsSize, 0);
+    clauses.clear(false);
+    learnts.clear(false);
+    //permanentLearnts.clear(false);
+    //unaryWatchedClauses.clear(false);
+    model.clear(false);
+    conflict.clear(false);
+    activity.clear(false);
+    assigns.clear(false);
+    polarity.clear(false);
+    //forceUNSAT.clear(false);
+    decision.clear(false);
+    trail.clear(false);
+    nbpos.clear(false);
+    trail_lim.clear(false);
+    vardata.clear(false);
+    assumptions.clear(false);
+    permDiff.clear(false);
+    lastDecisionLevel.clear(false);
+    ca.clear();
+    seen.clear(false);
+    analyze_stack.clear(false);
+    analyze_toclear.clear(false);
+    add_tmp.clear(false);
+    assumptionPositions.clear(false);
+    initialPositions.clear(false);
+}
+
+ABC_NAMESPACE_IMPL_END
diff --git a/src/sat/glucose2/Heap.h b/src/sat/glucose2/Heap.h
new file mode 100644
index 00000000..9999fba5
--- /dev/null
+++ b/src/sat/glucose2/Heap.h
@@ -0,0 +1,154 @@
+/******************************************************************************************[Heap.h]
+Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_Heap_h
+#define Glucose_Heap_h
+
+#include "sat/glucose2/Vec.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//=================================================================================================
+// A heap implementation with support for decrease/increase key.
+
+
+template<class Comp>
+class Heap {
+    Comp     lt;       // The heap is a minimum-heap with respect to this comparator
+    vec<int> heap;     // Heap of integers
+    vec<int> indices;  // Each integers position (index) in the Heap
+
+    // Index "traversal" functions
+    static inline int left  (int i) { return i*2+1; }
+    static inline int right (int i) { return (i+1)*2; }
+    static inline int parent(int i) { return (i-1) >> 1; }
+
+
+    void percolateUp(int i)
+    {
+        int x  = heap[i];
+        int p  = parent(i);
+        
+        while (i != 0 && lt(x, heap[p])){
+            heap[i]          = heap[p];
+            indices[heap[p]] = i;
+            i                = p;
+            p                = parent(p);
+        }
+        heap   [i] = x;
+        indices[x] = i;
+    }
+
+
+    void percolateDown(int i)
+    {
+        int x = heap[i];
+        while (left(i) < heap.size()){
+            int child = right(i) < heap.size() && lt(heap[right(i)], heap[left(i)]) ? right(i) : left(i);
+            if (!lt(heap[child], x)) break;
+            heap[i]          = heap[child];
+            indices[heap[i]] = i;
+            i                = child;
+        }
+        heap   [i] = x;
+        indices[x] = i;
+    }
+
+
+  public:
+    Heap(const Comp& c) : lt(c) { }
+
+    int  size      ()          const { return heap.size(); }
+    bool empty     ()          const { return heap.size() == 0; }
+    bool inHeap    (int n)     const { return n < indices.size() && indices[n] >= 0; }
+    int  operator[](int index) const { assert(index < heap.size()); return heap[index]; }
+
+
+    void decrease  (int n) { assert(inHeap(n)); percolateUp  (indices[n]); }
+    void increase  (int n) { assert(inHeap(n)); percolateDown(indices[n]); }
+
+
+    // Safe variant of insert/decrease/increase:
+    void update(int n)
+    {
+        if (!inHeap(n))
+            insert(n);
+        else {
+            percolateUp(indices[n]);
+            percolateDown(indices[n]); }
+    }
+
+
+    void insert(int n)
+    {
+        indices.growTo(n+1, -1);
+        assert(!inHeap(n));
+
+        indices[n] = heap.size();
+        heap.push(n);
+        percolateUp(indices[n]); 
+    }
+
+
+    int  removeMin()
+    {
+        int x            = heap[0];
+        heap[0]          = heap.last();
+        indices[heap[0]] = 0;
+        indices[x]       = -1;
+        heap.pop();
+        if (heap.size() > 1) percolateDown(0);
+        return x; 
+    }
+
+
+    // Rebuild the heap from scratch, using the elements in 'ns':
+    void build(vec<int>& ns) {
+        int i;
+        for (i = 0; i < heap.size(); i++)
+            indices[heap[i]] = -1;
+        heap.clear();
+
+        for (i = 0; i < ns.size(); i++){
+            indices[ns[i]] = i;
+            heap.push(ns[i]); }
+
+        for (i = heap.size() / 2 - 1; i >= 0; i--)
+            percolateDown(i);
+    }
+
+    void clear(bool dealloc = false) 
+    { 
+        int i;
+        for (i = 0; i < heap.size(); i++)
+            indices[heap[i]] = -1;
+        heap.clear(dealloc); 
+    }
+};
+
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/IntTypes.h b/src/sat/glucose2/IntTypes.h
new file mode 100644
index 00000000..3f75862b
--- /dev/null
+++ b/src/sat/glucose2/IntTypes.h
@@ -0,0 +1,49 @@
+/**************************************************************************************[IntTypes.h]
+Copyright (c) 2009-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_IntTypes_h
+#define Glucose_IntTypes_h
+
+#ifdef __sun
+    // Not sure if there are newer versions that support C99 headers. The
+    // needed features are implemented in the headers below though:
+
+#   include <sys/int_types.h>
+#   include <sys/int_fmtio.h>
+#   include <sys/int_limits.h>
+
+#else
+
+#define __STDC_LIMIT_MACROS
+#   include "pstdint.h"
+//#   include <inttypes.h>
+
+#endif
+
+#include <limits.h>
+
+#ifndef PRIu64
+#define PRIu64 "lu"
+#define PRIi64 "ld"
+#endif
+//=================================================================================================
+
+#include <misc/util/abc_namespaces.h>
+
+#endif
diff --git a/src/sat/glucose2/Map.h b/src/sat/glucose2/Map.h
new file mode 100644
index 00000000..d9c31aae
--- /dev/null
+++ b/src/sat/glucose2/Map.h
@@ -0,0 +1,197 @@
+/*******************************************************************************************[Map.h]
+Copyright (c) 2006-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_Map_h
+#define Glucose_Map_h
+
+#include "sat/glucose2/IntTypes.h"
+#include "sat/glucose2/Vec.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//=================================================================================================
+// Default hash/equals functions
+//
+
+template<class K> struct Hash  { uint32_t operator()(const K& k)               const { return hash(k);  } };
+template<class K> struct Equal { bool     operator()(const K& k1, const K& k2) const { return k1 == k2; } };
+
+template<class K> struct DeepHash  { uint32_t operator()(const K* k)               const { return hash(*k);  } };
+template<class K> struct DeepEqual { bool     operator()(const K* k1, const K* k2) const { return *k1 == *k2; } };
+
+static inline uint32_t hash(uint32_t x){ return x; }
+static inline uint32_t hash(uint64_t x){ return (uint32_t)x; }
+static inline uint32_t hash(int32_t x) { return (uint32_t)x; }
+static inline uint32_t hash(int64_t x) { return (uint32_t)x; }
+
+
+//=================================================================================================
+// Some primes
+//
+
+static const int nprimes          = 25;
+static const int primes [nprimes] = { 31, 73, 151, 313, 643, 1291, 2593, 5233, 10501, 21013, 42073, 84181, 168451, 337219, 674701, 1349473, 2699299, 5398891, 10798093, 21596719, 43193641, 86387383, 172775299, 345550609, 691101253 };
+
+//=================================================================================================
+// Hash table implementation of Maps
+//
+
+template<class K, class D, class H = Hash<K>, class E = Equal<K> >
+class Map {
+ public:
+    struct Pair { K key; D data; };
+
+ private:
+    H          hash;
+    E          equals;
+
+    vec<Pair>* table;
+    int        cap;
+    int        size;
+
+    // Don't allow copying (error prone):
+    Map<K,D,H,E>&  operator = (Map<K,D,H,E>& other) { assert(0); }
+                   Map        (Map<K,D,H,E>& other) { assert(0); }
+
+    bool    checkCap(int new_size) const { return new_size > cap; }
+
+    int32_t index  (const K& k) const { return hash(k) % cap; }
+    void   _insert (const K& k, const D& d) { 
+        vec<Pair>& ps = table[index(k)];
+        ps.push(); ps.last().key = k; ps.last().data = d; }
+
+    void    rehash () {
+        const vec<Pair>* old = table;
+
+        int old_cap = cap;
+        int newsize = primes[0];
+        for (int i = 1; newsize <= cap && i < nprimes; i++)
+           newsize = primes[i];
+
+        table = new vec<Pair>[newsize];
+        cap   = newsize;
+
+        for (int i = 0; i < old_cap; i++){
+            for (int j = 0; j < old[i].size(); j++){
+                _insert(old[i][j].key, old[i][j].data); }}
+
+        delete [] old;
+
+        // printf(" --- rehashing, old-cap=%d, new-cap=%d\n", cap, newsize);
+    }
+
+    
+ public:
+
+    Map () : table(NULL), cap(0), size(0) {}
+    Map (const H& h, const E& e) : hash(h), equals(e), table(NULL), cap(0), size(0){}
+    ~Map () { delete [] table; }
+
+    // PRECONDITION: the key must already exist in the map.
+    const D& operator [] (const K& k) const
+    {
+        assert(size != 0);
+        const D*         res = NULL;
+        const vec<Pair>& ps  = table[index(k)];
+        for (int i = 0; i < ps.size(); i++)
+            if (equals(ps[i].key, k))
+                res = &ps[i].data;
+        assert(res != NULL);
+        return *res;
+    }
+
+    // PRECONDITION: the key must already exist in the map.
+    D& operator [] (const K& k)
+    {
+        assert(size != 0);
+        D*         res = NULL;
+        vec<Pair>& ps  = table[index(k)];
+        for (int i = 0; i < ps.size(); i++)
+            if (equals(ps[i].key, k))
+                res = &ps[i].data;
+        assert(res != NULL);
+        return *res;
+    }
+
+    // PRECONDITION: the key must *NOT* exist in the map.
+    void insert (const K& k, const D& d) { if (checkCap(size+1)) rehash(); _insert(k, d); size++; }
+    bool peek   (const K& k, D& d) const {
+        if (size == 0) return false;
+        const vec<Pair>& ps = table[index(k)];
+        for (int i = 0; i < ps.size(); i++)
+            if (equals(ps[i].key, k)){
+                d = ps[i].data;
+                return true; } 
+        return false;
+    }
+
+    bool has   (const K& k) const {
+        if (size == 0) return false;
+        const vec<Pair>& ps = table[index(k)];
+        for (int i = 0; i < ps.size(); i++)
+            if (equals(ps[i].key, k))
+                return true;
+        return false;
+    }
+
+    // PRECONDITION: the key must exist in the map.
+    void remove(const K& k) {
+        assert(table != NULL);
+        vec<Pair>& ps = table[index(k)];
+        int j = 0;
+        for (; j < ps.size() && !equals(ps[j].key, k); j++);
+        assert(j < ps.size());
+        ps[j] = ps.last();
+        ps.pop();
+        size--;
+    }
+
+    void clear  () {
+        cap = size = 0;
+        delete [] table;
+        table = NULL;
+    }
+
+    int  elems() const { return size; }
+    int  bucket_count() const { return cap; }
+
+    // NOTE: the hash and equality objects are not moved by this method:
+    void moveTo(Map& other){
+        delete [] other.table;
+
+        other.table = table;
+        other.cap   = cap;
+        other.size  = size;
+
+        table = NULL;
+        size = cap = 0;
+    }
+
+    // NOTE: given a bit more time, I could make a more C++-style iterator out of this:
+    const vec<Pair>& bucket(int i) const { return table[i]; }
+};
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/Options.h b/src/sat/glucose2/Options.h
new file mode 100644
index 00000000..f2d4d493
--- /dev/null
+++ b/src/sat/glucose2/Options.h
@@ -0,0 +1,392 @@
+/***************************************************************************************[Options.h]
+Copyright (c) 2008-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_Options_h
+#define Glucose_Options_h
+
+#define __STDC_FORMAT_MACROS
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <string.h>
+
+#include "sat/glucose2/IntTypes.h"
+#include "sat/glucose2/Vec.h"
+#include "sat/glucose2/ParseUtils.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//==================================================================================================
+// Top-level option parse/help functions:
+
+
+extern void parseOptions     (int& argc, char** argv, bool strict = false);
+extern void printUsageAndExit(int  argc, char** argv, bool verbose = false);
+extern void setUsageHelp     (const char* str);
+extern void setHelpPrefixStr (const char* str);
+
+
+//==================================================================================================
+// Options is an abstract class that gives the interface for all types options:
+
+
+class Option
+{
+ public:
+    const char* name;
+    const char* description;
+    const char* category;
+    const char* type_name;
+
+    static vec<Option*>& getOptionList () { static vec<Option*> options; return options; }
+    static const char*&  getUsageString() { static const char* usage_str; return usage_str; }
+    static const char*&  getHelpPrefixString() { static const char* help_prefix_str = ""; return help_prefix_str; }
+
+    struct OptionLt {
+        bool operator()(const Option* x, const Option* y) {
+            int test1 = strcmp(x->category, y->category);
+            return test1 < 0 || (test1 == 0 && strcmp(x->type_name, y->type_name) < 0);
+        }
+    };
+
+    Option(const char* name_, 
+           const char* desc_,
+           const char* cate_,
+           const char* type_) : 
+      name       (name_)
+    , description(desc_)
+    , category   (cate_)
+    , type_name  (type_)
+    { 
+        getOptionList().push(this); 
+    }
+
+ public:
+    virtual ~Option() {}
+
+    virtual bool parse             (const char* str)      = 0;
+    virtual void help              (bool verbose = false) = 0;
+
+    friend  void parseOptions      (int& argc, char** argv, bool strict);
+    friend  void printUsageAndExit (int  argc, char** argv, bool verbose);
+    friend  void setUsageHelp      (const char* str);
+    friend  void setHelpPrefixStr  (const char* str);
+};
+
+
+//==================================================================================================
+// Range classes with specialization for floating types:
+
+
+struct IntRange {
+    int begin;
+    int end;
+    IntRange(int b, int e) : begin(b), end(e) {}
+};
+
+struct Int64Range {
+    int64_t begin;
+    int64_t end;
+    Int64Range(int64_t b, int64_t e) : begin(b), end(e) {}
+};
+
+struct DoubleRange {
+    double begin;
+    double end;
+    bool  begin_inclusive;
+    bool  end_inclusive;
+    DoubleRange(double b, bool binc, double e, bool einc) : begin(b), end(e), begin_inclusive(binc), end_inclusive(einc) {}
+};
+
+
+//==================================================================================================
+// Double options:
+
+
+class DoubleOption : public Option
+{
+ protected:
+    DoubleRange range;
+    double      value;
+
+ public:
+    DoubleOption(const char* c, const char* n, const char* d, double def = double(), DoubleRange r = DoubleRange(-HUGE_VAL, false, HUGE_VAL, false))
+        : Option(n, d, c, "<double>"), range(r), value(def) {
+        // FIXME: set LC_NUMERIC to "C" to make sure that strtof/strtod parses decimal point correctly.
+    }
+
+    operator      double   (void) const { return value; }
+    operator      double&  (void)       { return value; }
+    DoubleOption& operator=(double x)   { value = x; return *this; }
+
+    virtual bool parse(const char* str){
+        const char* span = str; 
+
+        if (!match(span, "-") || !match(span, name) || !match(span, "="))
+            return false;
+
+        char*  end;
+        double tmp = strtod(span, &end);
+
+        if (end == NULL) 
+            return false;
+        else if (tmp >= range.end && (!range.end_inclusive || tmp != range.end)){
+            fprintf(stderr, "ERROR! value <%s> is too large for option \"%s\".\n", span, name);
+            exit(1);
+        }else if (tmp <= range.begin && (!range.begin_inclusive || tmp != range.begin)){
+            fprintf(stderr, "ERROR! value <%s> is too small for option \"%s\".\n", span, name);
+            exit(1); }
+
+        value = tmp;
+        // fprintf(stderr, "READ VALUE: %g\n", value);
+
+        return true;
+    }
+
+    virtual void help (bool verbose = false){
+        fprintf(stderr, "  -%-12s = %-8s %c%4.2g .. %4.2g%c (default: %g)\n", 
+                name, type_name, 
+                range.begin_inclusive ? '[' : '(', 
+                range.begin,
+                range.end,
+                range.end_inclusive ? ']' : ')', 
+                value);
+        if (verbose){
+            fprintf(stderr, "\n        %s\n", description);
+            fprintf(stderr, "\n");
+        }
+    }
+};
+
+
+//==================================================================================================
+// Int options:
+
+
+class IntOption : public Option
+{
+ protected:
+    IntRange range;
+    int32_t  value;
+
+ public:
+    IntOption(const char* c, const char* n, const char* d, int32_t def = int32_t(), IntRange r = IntRange(INT32_MIN, INT32_MAX))
+        : Option(n, d, c, "<int32>"), range(r), value(def) {}
+ 
+    operator   int32_t   (void) const { return value; }
+    operator   int32_t&  (void)       { return value; }
+    IntOption& operator= (int32_t x)  { value = x; return *this; }
+
+    virtual bool parse(const char* str){
+        const char* span = str; 
+
+        if (!match(span, "-") || !match(span, name) || !match(span, "="))
+            return false;
+
+        char*   end;
+        int32_t tmp = strtol(span, &end, 10);
+
+        if (end == NULL) 
+            return false;
+        else if (tmp > range.end){
+            fprintf(stderr, "ERROR! value <%s> is too large for option \"%s\".\n", span, name);
+            exit(1);
+        }else if (tmp < range.begin){
+            fprintf(stderr, "ERROR! value <%s> is too small for option \"%s\".\n", span, name);
+            exit(1); }
+
+        value = tmp;
+
+        return true;
+    }
+
+    virtual void help (bool verbose = false){
+        fprintf(stderr, "  -%-12s = %-8s [", name, type_name);
+        if (range.begin == INT32_MIN)
+            fprintf(stderr, "imin");
+        else
+            fprintf(stderr, "%4d", range.begin);
+
+        fprintf(stderr, " .. ");
+        if (range.end == INT32_MAX)
+            fprintf(stderr, "imax");
+        else
+            fprintf(stderr, "%4d", range.end);
+
+        fprintf(stderr, "] (default: %d)\n", value);
+        if (verbose){
+            fprintf(stderr, "\n        %s\n", description);
+            fprintf(stderr, "\n");
+        }
+    }
+};
+
+
+// Leave this out for visual C++ until Microsoft implements C99 and gets support for strtoll.
+#ifndef _MSC_VER
+
+class Int64Option : public Option
+{
+ protected:
+    Int64Range range;
+    int64_t  value;
+
+ public:
+    Int64Option(const char* c, const char* n, const char* d, int64_t def = int64_t(), Int64Range r = Int64Range(INT64_MIN, INT64_MAX))
+        : Option(n, d, c, "<int64>"), range(r), value(def) {}
+ 
+    operator     int64_t   (void) const { return value; }
+    operator     int64_t&  (void)       { return value; }
+    Int64Option& operator= (int64_t x)  { value = x; return *this; }
+
+    virtual bool parse(const char* str){
+        const char* span = str; 
+
+        if (!match(span, "-") || !match(span, name) || !match(span, "="))
+            return false;
+
+        char*   end;
+        int64_t tmp = strtoll(span, &end, 10);
+
+        if (end == NULL) 
+            return false;
+        else if (tmp > range.end){
+            fprintf(stderr, "ERROR! value <%s> is too large for option \"%s\".\n", span, name);
+            exit(1);
+        }else if (tmp < range.begin){
+            fprintf(stderr, "ERROR! value <%s> is too small for option \"%s\".\n", span, name);
+            exit(1); }
+
+        value = tmp;
+
+        return true;
+    }
+
+    virtual void help (bool verbose = false){
+        fprintf(stderr, "  -%-12s = %-8s [", name, type_name);
+        if (range.begin == INT64_MIN)
+            fprintf(stderr, "imin");
+        else
+            fprintf(stderr, "%4d", (int)range.begin);
+
+        fprintf(stderr, " .. ");
+        if (range.end == INT64_MAX)
+            fprintf(stderr, "imax");
+        else
+            fprintf(stderr, "%4d", (int)range.end);
+
+        fprintf(stderr, "] (default: %d)\n", (int)value);
+        if (verbose){
+            fprintf(stderr, "\n        %s\n", description);
+            fprintf(stderr, "\n");
+        }
+    }
+};
+#endif
+
+//==================================================================================================
+// String option:
+
+
+class StringOption : public Option
+{
+    const char* value;
+ public:
+    StringOption(const char* c, const char* n, const char* d, const char* def = NULL) 
+        : Option(n, d, c, "<string>"), value(def) {}
+
+    operator      const char*  (void) const     { return value; }
+    operator      const char*& (void)           { return value; }
+    StringOption& operator=    (const char* x)  { value = x; return *this; }
+
+    virtual bool parse(const char* str){
+        const char* span = str; 
+
+        if (!match(span, "-") || !match(span, name) || !match(span, "="))
+            return false;
+
+        value = span;
+        return true;
+    }
+
+    virtual void help (bool verbose = false){
+        fprintf(stderr, "  -%-10s = %8s\n", name, type_name);
+        if (verbose){
+            fprintf(stderr, "\n        %s\n", description);
+            fprintf(stderr, "\n");
+        }
+    }    
+};
+
+
+//==================================================================================================
+// Bool option:
+
+
+class BoolOption : public Option
+{
+    bool value;
+
+ public:
+    BoolOption(const char* c, const char* n, const char* d, bool v) 
+        : Option(n, d, c, "<bool>"), value(v) {}
+
+    operator    bool     (void) const { return value; }
+    operator    bool&    (void)       { return value; }
+    BoolOption& operator=(bool b)     { value = b; return *this; }
+
+    virtual bool parse(const char* str){
+        const char* span = str; 
+        
+        if (match(span, "-")){
+            bool b = !match(span, "no-");
+
+            if (strcmp(span, name) == 0){
+                value = b;
+                return true; }
+        }
+
+        return false;
+    }
+
+    virtual void help (bool verbose = false){
+
+        fprintf(stderr, "  -%s, -no-%s", name, name);
+
+        for (uint32_t i = 0; i < 32 - strlen(name)*2; i++)
+            fprintf(stderr, " ");
+
+        fprintf(stderr, " ");
+        fprintf(stderr, "(default: %s)\n", value ? "on" : "off");
+        if (verbose){
+            fprintf(stderr, "\n        %s\n", description);
+            fprintf(stderr, "\n");
+        }
+    }
+};
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/Options2.cpp b/src/sat/glucose2/Options2.cpp
new file mode 100644
index 00000000..b419e054
--- /dev/null
+++ b/src/sat/glucose2/Options2.cpp
@@ -0,0 +1,95 @@
+/**************************************************************************************[Options.cc]
+Copyright (c) 2008-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#include "sat/glucose2/Sort.h"
+#include "sat/glucose2/Options.h"
+#include "sat/glucose2/ParseUtils.h"
+
+ABC_NAMESPACE_IMPL_START
+
+using namespace Gluco2;
+
+void Gluco2::parseOptions(int& argc, char** argv, bool strict)
+{
+    int i, j;
+    for (i = j = 1; i < argc; i++){
+        const char* str = argv[i];
+        if (match(str, "--") && match(str, Option::getHelpPrefixString()) && match(str, "help")){
+            if (*str == '\0')
+                printUsageAndExit(argc, argv);
+            else if (match(str, "-verb"))
+                printUsageAndExit(argc, argv, true);
+        } else {
+            bool parsed_ok = false;
+        
+            for (int k = 0; !parsed_ok && k < Option::getOptionList().size(); k++){
+                parsed_ok = Option::getOptionList()[k]->parse(argv[i]);
+
+                // fprintf(stderr, "checking %d: %s against flag <%s> (%s)\n", i, argv[i], Option::getOptionList()[k]->name, parsed_ok ? "ok" : "skip");
+            }
+
+            if (!parsed_ok) {
+                if (strict && match(argv[i], "-"))
+                    fprintf(stderr, "ERROR! Unknown flag \"%s\". Use '--%shelp' for help.\n", argv[i], Option::getHelpPrefixString()), exit(1);
+                else
+                    argv[j++] = argv[i];
+            }
+        }
+    }
+
+    argc -= (i - j);
+}
+
+
+void Gluco2::setUsageHelp      (const char* str){ Option::getUsageString() = str; }
+void Gluco2::setHelpPrefixStr  (const char* str){ Option::getHelpPrefixString() = str; }
+void Gluco2::printUsageAndExit (int argc, char** argv, bool verbose)
+{
+    const char* usage = Option::getUsageString();
+    if (usage != NULL)
+        fprintf(stderr, usage, argv[0]);
+
+    sort(Option::getOptionList(), Option::OptionLt());
+
+    const char* prev_cat  = NULL;
+    const char* prev_type = NULL;
+
+    for (int i = 0; i < Option::getOptionList().size(); i++){
+        const char* cat  = Option::getOptionList()[i]->category;
+        const char* type = Option::getOptionList()[i]->type_name;
+
+        if (cat != prev_cat)
+            fprintf(stderr, "\n%s OPTIONS:\n\n", cat);
+        else if (type != prev_type)
+            fprintf(stderr, "\n");
+
+        Option::getOptionList()[i]->help(verbose);
+
+        prev_cat  = Option::getOptionList()[i]->category;
+        prev_type = Option::getOptionList()[i]->type_name;
+    }
+
+    fprintf(stderr, "\nHELP OPTIONS:\n\n");
+    fprintf(stderr, "  --%shelp        Print help message.\n", Option::getHelpPrefixString());
+    fprintf(stderr, "  --%shelp-verb   Print verbose help message.\n", Option::getHelpPrefixString());
+    fprintf(stderr, "\n");
+    exit(0);
+}
+
+ABC_NAMESPACE_IMPL_END
diff --git a/src/sat/glucose2/ParseUtils.h b/src/sat/glucose2/ParseUtils.h
new file mode 100644
index 00000000..54a139b1
--- /dev/null
+++ b/src/sat/glucose2/ParseUtils.h
@@ -0,0 +1,155 @@
+/************************************************************************************[ParseUtils.h]
+Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose2_ParseUtils_h
+#define Glucose2_ParseUtils_h
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+
+#include "misc/zlib/zlib.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//-------------------------------------------------------------------------------------------------
+// A simple buffered character stream class:
+
+static const int buffer_size = 1048576;
+
+
+class StreamBuffer {
+    gzFile        in;
+    unsigned char buf[buffer_size];
+    int           pos;
+    int           size;
+
+    void assureLookahead() {
+        if (pos >= size) {
+            pos  = 0;
+            size = gzread(in, buf, sizeof(buf)); } }
+
+public:
+    explicit StreamBuffer(gzFile i) : in(i), pos(0), size(0) { assureLookahead(); }
+
+    int  operator *  () const { return (pos >= size) ? EOF : buf[pos]; }
+    void operator ++ ()       { pos++; assureLookahead(); }
+    int  position    () const { return pos; }
+};
+
+
+//-------------------------------------------------------------------------------------------------
+// End-of-file detection functions for StreamBuffer and char*:
+
+
+static inline bool isEof(StreamBuffer& in) { return *in == EOF;  }
+static inline bool isEof(const char*   in) { return *in == '\0'; }
+
+//-------------------------------------------------------------------------------------------------
+// Generic parse functions parametrized over the input-stream type.
+
+
+template<class B>
+static void skipWhitespace(B& in) {
+    while ((*in >= 9 && *in <= 13) || *in == 32)
+        ++in; }
+
+
+template<class B>
+static void skipLine(B& in) {
+    for (;;){
+        if (isEof(in)) return;
+        if (*in == '\n') { ++in; return; }
+        ++in; } }
+
+template<class B>
+static double parseDouble(B& in) { // only in the form X.XXXXXe-XX
+    bool    neg= false;
+    double accu = 0.0;
+    double currentExponent = 1;
+    int exponent;
+    
+    skipWhitespace(in);
+    if(*in == EOF) return 0;
+    if      (*in == '-') neg = true, ++in;
+    else if (*in == '+') ++in;
+    if (*in < '1' || *in > '9') printf("PARSE ERROR! Unexpected char: %c\n", *in), exit(3);
+    accu = (double)(*in - '0');
+    ++in;
+    if (*in != '.') printf("PARSE ERROR! Unexpected char: %c\n", *in),exit(3);
+    ++in; // skip dot
+    currentExponent = 0.1;
+    while (*in >= '0' && *in <= '9')
+        accu = accu + currentExponent * ((double)(*in - '0')),
+        currentExponent /= 10,
+        ++in;
+    if (*in != 'e') printf("PARSE ERROR! Unexpected char: %c\n", *in),exit(3);
+    ++in; // skip dot
+    exponent = parseInt(in); // read exponent
+    accu *= pow(10,exponent);
+    return neg ? -accu:accu;
+}
+
+
+template<class B>
+static int parseInt(B& in) {
+    int     val = 0;
+    bool    neg = false;
+    skipWhitespace(in);
+    if      (*in == '-') neg = true, ++in;
+    else if (*in == '+') ++in;
+    if (*in < '0' || *in > '9') fprintf(stderr, "PARSE ERROR! Unexpected char: %c\n", *in), exit(3);
+    while (*in >= '0' && *in <= '9')
+        val = val*10 + (*in - '0'),
+        ++in;
+    return neg ? -val : val; }
+
+
+// String matching: in case of a match the input iterator will be advanced the corresponding
+// number of characters.
+template<class B>
+static bool match(B& in, const char* str) {
+    int i;
+    for (i = 0; str[i] != '\0'; i++)
+        if (in[i] != str[i])
+            return false;
+
+    in += i;
+
+    return true; 
+}
+
+// String matching: consumes characters eagerly, but does not require random access iterator.
+template<class B>
+static bool eagerMatch(B& in, const char* str) {
+    for (; *str != '\0'; ++str, ++in)
+        if (*str != *in)
+            return false;
+    return true; }
+
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/Queue.h b/src/sat/glucose2/Queue.h
new file mode 100644
index 00000000..2328fdf9
--- /dev/null
+++ b/src/sat/glucose2/Queue.h
@@ -0,0 +1,73 @@
+/*****************************************************************************************[Queue.h]
+Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_Queue_h
+#define Glucose_Queue_h
+
+#include "sat/glucose2/Vec.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//=================================================================================================
+
+template<class T>
+class Queue {
+    vec<T>  buf;
+    int     first;
+    int     end;
+
+public:
+    typedef T Key;
+
+    Queue() : buf(1), first(0), end(0) {}
+
+    void clear (bool dealloc = false) { buf.clear(dealloc); buf.growTo(1); first = end = 0; }
+    int  size  () const { return (end >= first) ? end - first : end - first + buf.size(); }
+
+    const T& operator [] (int index) const  { assert(index >= 0); assert(index < size()); return buf[(first + index) % buf.size()]; }
+    T&       operator [] (int index)        { assert(index >= 0); assert(index < size()); return buf[(first + index) % buf.size()]; }
+
+    T    peek  () const { assert(first != end); return buf[first]; }
+    void pop   () { assert(first != end); first++; if (first == buf.size()) first = 0; }
+    void insert(T elem) {   // INVARIANT: buf[end] is always unused
+        buf[end++] = elem;
+        if (end == buf.size()) end = 0;
+        if (first == end){  // Resize:
+            vec<T>  tmp((buf.size()*3 + 1) >> 1);
+            //**/printf("queue alloc: %d elems (%.1f MB)\n", tmp.size(), tmp.size() * sizeof(T) / 1000000.0);
+            int j, i = 0;
+            for (j = first; j < buf.size(); j++) tmp[i++] = buf[j];
+            for (j = 0    ; j < end       ; j++) tmp[i++] = buf[j];
+            first = 0;
+            end   = buf.size();
+            tmp.moveTo(buf);
+        }
+    }
+};
+
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/SimpSolver.h b/src/sat/glucose2/SimpSolver.h
new file mode 100644
index 00000000..dbb80434
--- /dev/null
+++ b/src/sat/glucose2/SimpSolver.h
@@ -0,0 +1,207 @@
+/************************************************************************************[SimpSolver.h]
+Copyright (c) 2006,      Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_SimpSolver_h
+#define Glucose_SimpSolver_h
+
+#include "sat/glucose2/Queue.h"
+#include "sat/glucose2/Solver.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//=================================================================================================
+
+
+class SimpSolver : public Solver {
+ public:
+    // Constructor/Destructor:
+    //
+    SimpSolver();
+    ~SimpSolver();
+
+    // Problem specification:
+    //
+    Var     newVar    (bool polarity = true, bool dvar = true);
+    void    addVar    (Var v);               
+    bool    addClause (const vec<Lit>& ps);
+    bool    addEmptyClause();                // Add the empty clause to the solver.
+    bool    addClause (Lit p);               // Add a unit clause to the solver.
+    bool    addClause (Lit p, Lit q);        // Add a binary clause to the solver.
+    bool    addClause (Lit p, Lit q, Lit r); // Add a ternary clause to the solver.
+    bool    addClause_(      vec<Lit>& ps);
+    bool    substitute(Var v, Lit x);  // Replace all occurences of v with x (may cause a contradiction).
+
+    // Variable mode:
+    // 
+    void    setFrozen (Var v, bool b); // If a variable is frozen it will not be eliminated.
+    bool    isEliminated(Var v) const;
+
+    // Solving:
+    //
+    bool    solve       (const vec<Lit>& assumps, bool do_simp = true, bool turn_off_simp = false);
+    lbool   solveLimited(const vec<Lit>& assumps, bool do_simp = true, bool turn_off_simp = false);
+    bool    solve       (                     bool do_simp = true, bool turn_off_simp = false);
+    bool    solve       (Lit p       ,        bool do_simp = true, bool turn_off_simp = false);       
+    bool    solve       (Lit p, Lit q,        bool do_simp = true, bool turn_off_simp = false);
+    bool    solve       (Lit p, Lit q, Lit r, bool do_simp = true, bool turn_off_simp = false);
+    bool    eliminate   (bool turn_off_elim = false);  // Perform variable elimination based simplification. 
+
+    // Memory managment:
+    //
+    virtual void reset();
+    virtual void garbageCollect();
+
+
+    // Generate a (possibly simplified) DIMACS file:
+    //
+#if 0
+    void    toDimacs  (const char* file, const vec<Lit>& assumps);
+    void    toDimacs  (const char* file);
+    void    toDimacs  (const char* file, Lit p);
+    void    toDimacs  (const char* file, Lit p, Lit q);
+    void    toDimacs  (const char* file, Lit p, Lit q, Lit r);
+#endif
+
+    // Mode of operation:
+    //
+    int     parsing;
+    int     grow;              // Allow a variable elimination step to grow by a number of clauses (default to zero).
+    int     clause_lim;        // Variables are not eliminated if it produces a resolvent with a length above this limit.
+                               // -1 means no limit.
+    int     subsumption_lim;   // Do not check if subsumption against a clause larger than this. -1 means no limit.
+    double  simp_garbage_frac; // A different limit for when to issue a GC during simplification (Also see 'garbage_frac').
+
+    bool    use_asymm;         // Shrink clauses by asymmetric branching.
+    bool    use_rcheck;        // Check if a clause is already implied. Prett costly, and subsumes subsumptions :)
+    bool    use_elim;          // Perform variable elimination.
+
+    // Statistics:
+    //
+    int     merges;
+    int     asymm_lits;
+    int     eliminated_vars;
+    int     eliminated_clauses;
+
+ protected:
+
+    // Helper structures:
+    //
+    struct ElimLt {
+        const vec<int>& n_occ;
+        explicit ElimLt(const vec<int>& no) : n_occ(no) {}
+
+        // TODO: are 64-bit operations here noticably bad on 32-bit platforms? Could use a saturating
+        // 32-bit implementation instead then, but this will have to do for now.
+        uint64_t cost  (Var x)        const { return (uint64_t)n_occ[toInt(mkLit(x))] * (uint64_t)n_occ[toInt(~mkLit(x))]; }
+        bool operator()(Var x, Var y) const { return cost(x) < cost(y); }
+        
+        // TODO: investigate this order alternative more.
+        // bool operator()(Var x, Var y) const { 
+        //     int c_x = cost(x);
+        //     int c_y = cost(y);
+        //     return c_x < c_y || c_x == c_y && x < y; }
+    };
+
+    struct ClauseDeleted {
+        const ClauseAllocator& ca;
+        explicit ClauseDeleted(const ClauseAllocator& _ca) : ca(_ca) {}
+        bool operator()(const CRef& cr) const { return ca[cr].mark() == 1; } };
+
+    // Solver state:
+    //
+    int                 elimorder;
+    bool                use_simplification;
+    vec<uint32_t>       elimclauses;
+    vec<char>           touched;
+    OccLists<Var, vec<CRef>, ClauseDeleted>
+                        occurs;
+    vec<int>            n_occ;
+    Heap<ElimLt>        elim_heap;
+    Queue<CRef>         subsumption_queue;
+    vec<char>           frozen;
+    vec<char>           eliminated;
+    int                 bwdsub_assigns;
+    int                 n_touched;
+
+    // Temporaries:
+    //
+    CRef                bwdsub_tmpunit;
+
+    // Main internal methods:
+    //
+    lbool         solve_                   (bool do_simp = true, bool turn_off_simp = false);
+    bool          asymm                    (Var v, CRef cr);
+    bool          asymmVar                 (Var v);
+    void          updateElimHeap           (Var v);
+    void          gatherTouchedClauses     ();
+    bool          merge                    (const Clause& _ps, const Clause& _qs, Var v, vec<Lit>& out_clause);
+    bool          merge                    (const Clause& _ps, const Clause& _qs, Var v, int& size);
+    bool          backwardSubsumptionCheck (bool verbose = false);
+    bool          eliminateVar             (Var v);
+    void          extendModel              ();
+
+    void          removeClause             (CRef cr);
+    bool          strengthenClause         (CRef cr, Lit l);
+    void          cleanUpClauses           ();
+    bool          implied                  (const vec<Lit>& c);
+    void          relocAll                 (ClauseAllocator& to);
+};
+
+
+//=================================================================================================
+// Implementation of inline methods:
+
+
+//inline bool SimpSolver::isEliminated (Var v) const { return eliminated[v]; }
+inline bool SimpSolver::isEliminated (Var v) const { return eliminated.size() > 0 ? eliminated[v] != 0 : 0; }
+inline void SimpSolver::updateElimHeap(Var v) {
+    assert(use_simplification);
+    // if (!frozen[v] && !isEliminated(v) && value(v) == l_Undef)
+    if (elim_heap.inHeap(v) || (!frozen[v] && !isEliminated(v) && value(v) == l_Undef))
+        elim_heap.update(v); }
+
+
+inline bool SimpSolver::addClause    (const vec<Lit>& ps)  { ps.copyTo(add_tmp); return addClause_(add_tmp); }
+inline bool SimpSolver::addEmptyClause()                   { add_tmp.clear(); return addClause_(add_tmp); }
+inline bool SimpSolver::addClause    (Lit p)               { add_tmp.clear(); add_tmp.push(p); return addClause_(add_tmp); }
+inline bool SimpSolver::addClause    (Lit p, Lit q)        { add_tmp.clear(); add_tmp.push(p); add_tmp.push(q); return addClause_(add_tmp); }
+inline bool SimpSolver::addClause    (Lit p, Lit q, Lit r) { add_tmp.clear(); add_tmp.push(p); add_tmp.push(q); add_tmp.push(r); return addClause_(add_tmp); }
+inline void SimpSolver::setFrozen    (Var v, bool b) { frozen[v] = (char)b; if (use_simplification && !b) { updateElimHeap(v); } }
+
+inline bool SimpSolver::solve        (                     bool do_simp, bool turn_off_simp)  { budgetOff(); assumptions.clear(); return solve_(do_simp, turn_off_simp) == l_True; }
+inline bool SimpSolver::solve        (Lit p       ,        bool do_simp, bool turn_off_simp)  { budgetOff(); assumptions.clear(); assumptions.push(p); return solve_(do_simp, turn_off_simp) == l_True; }
+inline bool SimpSolver::solve        (Lit p, Lit q,        bool do_simp, bool turn_off_simp)  { budgetOff(); assumptions.clear(); assumptions.push(p); assumptions.push(q); return solve_(do_simp, turn_off_simp) == l_True; }
+inline bool SimpSolver::solve        (Lit p, Lit q, Lit r, bool do_simp, bool turn_off_simp)  { budgetOff(); assumptions.clear(); assumptions.push(p); assumptions.push(q); assumptions.push(r); return solve_(do_simp, turn_off_simp) == l_True; }
+inline bool SimpSolver::solve        (const vec<Lit>& assumps, bool do_simp, bool turn_off_simp){ 
+    budgetOff(); assumps.copyTo(assumptions); return solve_(do_simp, turn_off_simp) == l_True; }
+
+inline lbool SimpSolver::solveLimited (const vec<Lit>& assumps, bool do_simp, bool turn_off_simp){ 
+    assumps.copyTo(assumptions); return solve_(do_simp, turn_off_simp); }
+
+inline void SimpSolver::addVar(Var v) { while (v >= nVars()) newVar(); }
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/SimpSolver2.cpp b/src/sat/glucose2/SimpSolver2.cpp
new file mode 100644
index 00000000..70240cb1
--- /dev/null
+++ b/src/sat/glucose2/SimpSolver2.cpp
@@ -0,0 +1,776 @@
+/***********************************************************************************[SimpSolver.cc]
+Copyright (c) 2006,      Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#include "sat/glucose2/Sort.h"
+#include "sat/glucose2/SimpSolver.h"
+#include "sat/glucose2/System.h"
+
+ABC_NAMESPACE_IMPL_START
+
+using namespace Gluco2;
+
+//=================================================================================================
+// Options:
+
+
+static const char* _cat = "SIMP";
+
+static BoolOption   opt_use_asymm        (_cat, "asymm",        "Shrink clauses by asymmetric branching.", false);
+static BoolOption   opt_use_rcheck       (_cat, "rcheck",       "Check if a clause is already implied. (costly)", false);
+static BoolOption   opt_use_elim         (_cat, "elim",         "Perform variable elimination.", true);
+static IntOption    opt_grow             (_cat, "grow",         "Allow a variable elimination step to grow by a number of clauses.", 0);
+static IntOption    opt_clause_lim       (_cat, "cl-lim",       "Variables are not eliminated if it produces a resolvent with a length above this limit. -1 means no limit", 20,   IntRange(-1, INT32_MAX));
+static IntOption    opt_subsumption_lim  (_cat, "sub-lim",      "Do not check if subsumption against a clause larger than this. -1 means no limit.", 1000, IntRange(-1, INT32_MAX));
+static DoubleOption opt_simp_garbage_frac(_cat, "simp-gc-frac", "The fraction of wasted memory allowed before a garbage collection is triggered during simplification.",  0.5, DoubleRange(0, false, HUGE_VAL, false));
+
+
+//=================================================================================================
+// Constructor/Destructor:
+
+
+SimpSolver::SimpSolver() :
+    grow               (opt_grow)
+  , clause_lim         (opt_clause_lim)
+  , subsumption_lim    (opt_subsumption_lim)
+  , simp_garbage_frac  (opt_simp_garbage_frac)
+  , use_asymm          (opt_use_asymm)
+  , use_rcheck         (opt_use_rcheck)
+  , use_elim           (opt_use_elim)
+  , merges             (0)
+  , asymm_lits         (0)
+  , eliminated_vars    (0)
+  , eliminated_clauses (0)
+  , elimorder          (1)
+  , use_simplification (true)
+  , occurs             (ClauseDeleted(ca))
+  , elim_heap          (ElimLt(n_occ))
+  , bwdsub_assigns     (0)
+  , n_touched          (0)
+{
+    vec<Lit> dummy(1,lit_Undef);
+    ca.extra_clause_field = true; // NOTE: must happen before allocating the dummy clause below.
+    bwdsub_tmpunit        = ca.alloc(dummy);
+    remove_satisfied      = false;
+}
+
+
+SimpSolver::~SimpSolver()
+{
+}
+
+
+Var SimpSolver::newVar(bool sign, bool dvar) {
+    Var v = Solver::newVar(sign, dvar);
+
+    frozen    .push((char)false);
+    eliminated.push((char)false);
+
+    if (use_simplification){
+        n_occ     .push(0);
+        n_occ     .push(0);
+        occurs    .init(v);
+        touched   .push(0);
+        elim_heap .insert(v);
+    }
+    return v; }
+
+
+
+lbool SimpSolver::solve_(bool do_simp, bool turn_off_simp)
+{
+    vec<Var> extra_frozen;
+    lbool    result = l_True;
+
+    do_simp &= use_simplification;
+
+    if (do_simp){
+        // Assumptions must be temporarily frozen to run variable elimination:
+        for (int i = 0; i < assumptions.size(); i++){
+            Var v = var(assumptions[i]);
+
+            // If an assumption has been eliminated, remember it.
+            assert(!isEliminated(v));
+
+            if (!frozen[v]){
+                // Freeze and store.
+                setFrozen(v, true);
+                extra_frozen.push(v);
+            } }
+
+        result = lbool(eliminate(turn_off_simp));
+    }
+
+    if (result == l_True)
+        result = Solver::solve_();
+    else if (verbosity >= 1)
+        printf("===============================================================================\n");
+
+    if (result == l_True)
+        extendModel();
+
+    if (do_simp)
+        // Unfreeze the assumptions that were frozen:
+        for (int i = 0; i < extra_frozen.size(); i++)
+            setFrozen(extra_frozen[i], false);
+
+    return result;
+}
+
+
+
+bool SimpSolver::addClause_(vec<Lit>& ps)
+{
+#ifndef NDEBUG
+    for (int i = 0; i < ps.size(); i++)
+        assert(!isEliminated(var(ps[i])));
+#endif
+    int nclauses = clauses.size();
+
+    if (use_rcheck && implied(ps))
+        return true;
+
+    if (!Solver::addClause_(ps))
+        return false;
+
+    if(!parsing && certifiedUNSAT) {
+      for (int i = 0; i < ps.size(); i++)
+        fprintf(certifiedOutput, "%i " , (var(ps[i]) + 1) * (-2 * sign(ps[i]) + 1) );
+      fprintf(certifiedOutput, "0\n");
+    }
+
+    if (use_simplification && clauses.size() == nclauses + 1){
+        CRef          cr = clauses.last();
+        const Clause& c  = ca[cr];
+
+        // NOTE: the clause is added to the queue immediately and then
+        // again during 'gatherTouchedClauses()'. If nothing happens
+        // in between, it will only be checked once. Otherwise, it may
+        // be checked twice unnecessarily. This is an unfortunate
+        // consequence of how backward subsumption is used to mimic
+        // forward subsumption.
+        subsumption_queue.insert(cr);
+        for (int i = 0; i < c.size(); i++){
+            occurs[var(c[i])].push(cr);
+            n_occ[toInt(c[i])]++;
+            touched[var(c[i])] = 1;
+            n_touched++;
+            if (elim_heap.inHeap(var(c[i])))
+                elim_heap.increase(var(c[i]));
+        }
+    }
+
+    return true;
+}
+
+
+void SimpSolver::removeClause(CRef cr)
+{
+    const Clause& c = ca[cr];
+
+    if (use_simplification)
+        for (int i = 0; i < c.size(); i++){
+            n_occ[toInt(c[i])]--;
+            updateElimHeap(var(c[i]));
+            occurs.smudge(var(c[i]));
+        }
+
+    Solver::removeClause(cr);
+}
+
+
+bool SimpSolver::strengthenClause(CRef cr, Lit l)
+{
+    Clause& c = ca[cr];
+    assert(decisionLevel() == 0);
+    assert(use_simplification);
+
+    // FIX: this is too inefficient but would be nice to have (properly implemented)
+    // if (!find(subsumption_queue, &c))
+    subsumption_queue.insert(cr);
+
+    if (certifiedUNSAT) {
+      for (int i = 0; i < c.size(); i++)
+        if (c[i] != l) fprintf(certifiedOutput, "%i " , (var(c[i]) + 1) * (-2 * sign(c[i]) + 1) );
+      fprintf(certifiedOutput, "0\n");
+    }
+
+    if (c.size() == 2){
+        removeClause(cr);
+        c.strengthen(l);
+    }else{
+        if (certifiedUNSAT) {
+          fprintf(certifiedOutput, "d ");
+          for (int i = 0; i < c.size(); i++)
+            fprintf(certifiedOutput, "%i " , (var(c[i]) + 1) * (-2 * sign(c[i]) + 1) );
+          fprintf(certifiedOutput, "0\n");
+        }
+
+        detachClause(cr, true);
+        c.strengthen(l);
+        attachClause(cr);
+        remove(occurs[var(l)], cr);
+        n_occ[toInt(l)]--;
+        updateElimHeap(var(l));
+    }
+
+    return c.size() == 1 ? enqueue(c[0]) && propagate() == CRef_Undef : true;
+}
+
+
+// Returns FALSE if clause is always satisfied ('out_clause' should not be used).
+bool SimpSolver::merge(const Clause& _ps, const Clause& _qs, Var v, vec<Lit>& out_clause)
+{
+    merges++;
+    out_clause.clear();
+
+    bool  ps_smallest = _ps.size() < _qs.size();
+    const Clause& ps  =  ps_smallest ? _qs : _ps;
+    const Clause& qs  =  ps_smallest ? _ps : _qs;
+
+    int i, j;
+    for (i = 0; i < qs.size(); i++){
+        if (var(qs[i]) != v){
+            for (j = 0; j < ps.size(); j++)
+                if (var(ps[j]) == var(qs[i])) {
+                    if (ps[j] == ~qs[i])
+                        return false;
+                    else
+                        goto next;
+                }
+            out_clause.push(qs[i]);
+        }
+        next:;
+    }
+
+    for (i = 0; i < ps.size(); i++)
+        if (var(ps[i]) != v)
+            out_clause.push(ps[i]);
+
+    return true;
+}
+
+
+// Returns FALSE if clause is always satisfied.
+bool SimpSolver::merge(const Clause& _ps, const Clause& _qs, Var v, int& size)
+{
+    merges++;
+
+    bool  ps_smallest = _ps.size() < _qs.size();
+    const Clause& ps  =  ps_smallest ? _qs : _ps;
+    const Clause& qs  =  ps_smallest ? _ps : _qs;
+    const Lit*  __ps  = (const Lit*)ps;
+    const Lit*  __qs  = (const Lit*)qs;
+
+    size = ps.size()-1;
+
+    for (int i = 0; i < qs.size(); i++){
+        if (var(__qs[i]) != v){
+            for (int j = 0; j < ps.size(); j++)
+                if (var(__ps[j]) == var(__qs[i])) {
+                    if (__ps[j] == ~__qs[i])
+                        return false;
+                    else
+                        goto next;
+                }
+            size++;
+        }
+        next:;
+    }
+
+    return true;
+}
+
+
+void SimpSolver::gatherTouchedClauses()
+{
+    if (n_touched == 0) return;
+
+    int i,j;
+    for (i = j = 0; i < subsumption_queue.size(); i++)
+        if (ca[subsumption_queue[i]].mark() == 0)
+            ca[subsumption_queue[i]].mark(2);
+
+    for (i = 0; i < touched.size(); i++)
+        if (touched[i]){
+            const vec<CRef>& cs = occurs.lookup(i);
+            for (j = 0; j < cs.size(); j++)
+                if (ca[cs[j]].mark() == 0){
+                    subsumption_queue.insert(cs[j]);
+                    ca[cs[j]].mark(2);
+                }
+            touched[i] = 0;
+        }
+
+    for (i = 0; i < subsumption_queue.size(); i++)
+        if (ca[subsumption_queue[i]].mark() == 2)
+            ca[subsumption_queue[i]].mark(0);
+
+    n_touched = 0;
+}
+
+
+bool SimpSolver::implied(const vec<Lit>& c)
+{
+    assert(decisionLevel() == 0);
+
+    trail_lim.push(trail.size());
+    for (int i = 0; i < c.size(); i++)
+        if (value(c[i]) == l_True){
+            cancelUntil(0);
+            return false;
+        }else if (value(c[i]) != l_False){
+            assert(value(c[i]) == l_Undef);
+            uncheckedEnqueue(~c[i]);
+        }
+
+    bool result = propagate() != CRef_Undef;
+    cancelUntil(0);
+    return result;
+}
+
+
+// Backward subsumption + backward subsumption resolution
+bool SimpSolver::backwardSubsumptionCheck(bool verbose)
+{
+    int cnt = 0;
+    int subsumed = 0;
+    int deleted_literals = 0;
+    assert(decisionLevel() == 0);
+
+    while (subsumption_queue.size() > 0 || bwdsub_assigns < trail.size()){
+
+        // Empty subsumption queue and return immediately on user-interrupt:
+        if (asynch_interrupt){
+            subsumption_queue.clear();
+            bwdsub_assigns = trail.size();
+            break; }
+
+        // Check top-level assignments by creating a dummy clause and placing it in the queue:
+        if (subsumption_queue.size() == 0 && bwdsub_assigns < trail.size()){
+            Lit l = trail[bwdsub_assigns++];
+            ca[bwdsub_tmpunit][0] = l;
+            ca[bwdsub_tmpunit].calcAbstraction();
+            subsumption_queue.insert(bwdsub_tmpunit); }
+
+        CRef    cr = subsumption_queue.peek(); subsumption_queue.pop();
+        Clause& c  = ca[cr];
+
+        if (c.mark()) continue;
+
+        if (verbose && verbosity >= 2 && cnt++ % 1000 == 0)
+            printf("subsumption left: %10d (%10d subsumed, %10d deleted literals)\r", subsumption_queue.size(), subsumed, deleted_literals);
+
+        assert(c.size() > 1 || value(c[0]) == l_True);    // Unit-clauses should have been propagated before this point.
+
+        // Find best variable to scan:
+        Var best = var(c[0]);
+        for (int i = 1; i < c.size(); i++)
+            if (occurs[var(c[i])].size() < occurs[best].size())
+                best = var(c[i]);
+
+        // Search all candidates:
+        vec<CRef>& _cs = occurs.lookup(best);
+        CRef*       cs = (CRef*)_cs;
+
+        for (int j = 0; j < _cs.size(); j++)
+            if (c.mark())
+                break;
+            else if (!ca[cs[j]].mark() &&  cs[j] != cr && (subsumption_lim == -1 || ca[cs[j]].size() < subsumption_lim)){
+                Lit l = c.subsumes(ca[cs[j]]);
+
+                if (l == lit_Undef)
+                    subsumed++, removeClause(cs[j]);
+                else if (l != lit_Error){
+                    deleted_literals++;
+
+                    if (!strengthenClause(cs[j], ~l))
+                        return false;
+
+                    // Did current candidate get deleted from cs? Then check candidate at index j again:
+                    if (var(l) == best)
+                        j--;
+                }
+            }
+    }
+
+    return true;
+}
+
+
+bool SimpSolver::asymm(Var v, CRef cr)
+{
+    Clause& c = ca[cr];
+    assert(decisionLevel() == 0);
+
+    if (c.mark() || satisfied(c)) return true;
+
+    trail_lim.push(trail.size());
+    Lit l = lit_Undef;
+    for (int i = 0; i < c.size(); i++)
+        if (var(c[i]) != v && value(c[i]) != l_False)
+            uncheckedEnqueue(~c[i]);
+        else
+            l = c[i];
+
+    if (propagate() != CRef_Undef){
+        cancelUntil(0);
+        asymm_lits++;
+        if (!strengthenClause(cr, l))
+            return false;
+    }else
+        cancelUntil(0);
+
+    return true;
+}
+
+
+bool SimpSolver::asymmVar(Var v)
+{
+    assert(use_simplification);
+
+    const vec<CRef>& cls = occurs.lookup(v);
+
+    if (value(v) != l_Undef || cls.size() == 0)
+        return true;
+
+    for (int i = 0; i < cls.size(); i++)
+        if (!asymm(v, cls[i]))
+            return false;
+
+    return backwardSubsumptionCheck();
+}
+
+
+static void mkElimClause(vec<uint32_t>& elimclauses, Lit x)
+{
+    elimclauses.push(toInt(x));
+    elimclauses.push(1);
+}
+
+
+static void mkElimClause(vec<uint32_t>& elimclauses, Var v, Clause& c)
+{
+    int first = elimclauses.size();
+    int v_pos = -1;
+
+    // Copy clause to elimclauses-vector. Remember position where the
+    // variable 'v' occurs:
+    for (int i = 0; i < c.size(); i++){
+        elimclauses.push(toInt(c[i]));
+        if (var(c[i]) == v)
+            v_pos = i + first;
+    }
+    assert(v_pos != -1);
+
+    // Swap the first literal with the 'v' literal, so that the literal
+    // containing 'v' will occur first in the clause:
+    uint32_t tmp = elimclauses[v_pos];
+    elimclauses[v_pos] = elimclauses[first];
+    elimclauses[first] = tmp;
+
+    // Store the length of the clause last:
+    elimclauses.push(c.size());
+}
+
+
+
+bool SimpSolver::eliminateVar(Var v)
+{
+    int i, j;
+    assert(!frozen[v]);
+    assert(!isEliminated(v));
+    assert(value(v) == l_Undef);
+
+    // Split the occurrences into positive and negative:
+    //
+    const vec<CRef>& cls = occurs.lookup(v);
+    vec<CRef>        pos, neg;
+    for (i = 0; i < cls.size(); i++)
+        (find(ca[cls[i]], mkLit(v)) ? pos : neg).push(cls[i]);
+
+    // Check wether the increase in number of clauses stays within the allowed ('grow'). Moreover, no
+    // clause must exceed the limit on the maximal clause size (if it is set):
+    //
+    int cnt         = 0;
+    int clause_size = 0;
+
+    for (i = 0; i < pos.size(); i++)
+        for (j = 0; j < neg.size(); j++)
+            if (merge(ca[pos[i]], ca[neg[j]], v, clause_size) && 
+                (++cnt > cls.size() + grow || (clause_lim != -1 && clause_size > clause_lim)))
+                return true;
+
+    // Delete and store old clauses:
+    eliminated[v] = true;
+    setDecisionVar(v, false);
+    eliminated_vars++;
+
+    if (pos.size() > neg.size()){
+        for (i = 0; i < neg.size(); i++)
+            mkElimClause(elimclauses, v, ca[neg[i]]);
+        mkElimClause(elimclauses, mkLit(v));
+        eliminated_clauses += neg.size();
+    }else{
+        for (i = 0; i < pos.size(); i++)
+            mkElimClause(elimclauses, v, ca[pos[i]]);
+        mkElimClause(elimclauses, ~mkLit(v));
+        eliminated_clauses += pos.size();
+    }
+
+
+    // Produce clauses in cross product:
+    vec<Lit>& resolvent = add_tmp;
+    for (i = 0; i < pos.size(); i++)
+        for (j = 0; j < neg.size(); j++)
+            if (merge(ca[pos[i]], ca[neg[j]], v, resolvent) && !addClause_(resolvent))
+                return false;
+
+    for (i = 0; i < cls.size(); i++)
+        removeClause(cls[i]);
+
+    // Free occurs list for this variable:
+    occurs[v].clear(true);
+
+    // Free watchers lists for this variable, if possible:
+    if (watches[ mkLit(v)].size() == 0) watches[ mkLit(v)].clear(true);
+    if (watches[~mkLit(v)].size() == 0) watches[~mkLit(v)].clear(true);
+
+    return backwardSubsumptionCheck();
+}
+
+
+bool SimpSolver::substitute(Var v, Lit x)
+{
+    assert(!frozen[v]);
+    assert(!isEliminated(v));
+    assert(value(v) == l_Undef);
+
+    if (!ok) return false;
+
+    eliminated[v] = true;
+    setDecisionVar(v, false);
+    const vec<CRef>& cls = occurs.lookup(v);
+    
+    vec<Lit>& subst_clause = add_tmp;
+    for (int i = 0; i < cls.size(); i++){
+        Clause& c = ca[cls[i]];
+
+        subst_clause.clear();
+        for (int j = 0; j < c.size(); j++){
+            Lit p = c[j];
+            subst_clause.push(var(p) == v ? x ^ sign(p) : p);
+        }
+
+ 
+        if (!addClause_(subst_clause))
+            return ok = false;
+
+       removeClause(cls[i]);
+ 
+   }
+
+    return true;
+}
+
+
+void SimpSolver::extendModel()
+{
+    int i, j;
+    Lit x;
+
+    for (i = elimclauses.size()-1; i > 0; i -= j){
+        for (j = elimclauses[i--]; j > 1; j--, i--)
+            if (modelValue(toLit(elimclauses[i])) != l_False)
+                goto next;
+
+        x = toLit(elimclauses[i]);
+        model[var(x)] = lbool(!sign(x));
+    next:;
+    }
+}
+
+
+bool SimpSolver::eliminate(bool turn_off_elim)
+{
+    //abctime clk = Abc_Clock();
+    if (!simplify())
+        return false;
+    else if (!use_simplification)
+        return true;
+
+    // Main simplification loop:
+    //
+
+    int toPerform = clauses.size()<=4800000;
+    
+    if(!toPerform) {
+      printf("c Too many clauses... No preprocessing\n");
+    }
+
+    while (toPerform && (n_touched > 0 || bwdsub_assigns < trail.size() || elim_heap.size() > 0)){
+
+        gatherTouchedClauses();
+        // printf("  ## (time = %6.2f s) BWD-SUB: queue = %d, trail = %d\n", cpuTime(), subsumption_queue.size(), trail.size() - bwdsub_assigns);
+        if ((subsumption_queue.size() > 0 || bwdsub_assigns < trail.size()) && 
+            !backwardSubsumptionCheck(true)){
+            ok = false; goto cleanup; }
+
+        // Empty elim_heap and return immediately on user-interrupt:
+        if (asynch_interrupt){
+            assert(bwdsub_assigns == trail.size());
+            assert(subsumption_queue.size() == 0);
+            assert(n_touched == 0);
+            elim_heap.clear();
+            goto cleanup; }
+
+        // printf("  ## (time = %6.2f s) ELIM: vars = %d\n", cpuTime(), elim_heap.size());
+        for (int cnt = 0; !elim_heap.empty(); cnt++){
+            Var elim = elim_heap.removeMin();
+            
+            if (asynch_interrupt) break;
+
+            if (isEliminated(elim) || value(elim) != l_Undef) continue;
+
+            if (verbosity >= 2 && cnt % 100 == 0)
+                printf("elimination left: %10d\r", elim_heap.size());
+
+            if (use_asymm){
+                // Temporarily freeze variable. Otherwise, it would immediately end up on the queue again:
+                bool was_frozen = frozen[elim] != 0;
+                frozen[elim] = true;
+                if (!asymmVar(elim)){
+                    ok = false; goto cleanup; }
+                frozen[elim] = was_frozen; }
+
+            // At this point, the variable may have been set by assymetric branching, so check it
+            // again. Also, don't eliminate frozen variables:
+            if (use_elim && value(elim) == l_Undef && !frozen[elim] && !eliminateVar(elim)){
+                ok = false; goto cleanup; }
+
+            checkGarbage(simp_garbage_frac);
+        }
+
+        assert(subsumption_queue.size() == 0);
+    }
+ cleanup:
+
+    // If no more simplification is needed, free all simplification-related data structures:
+    if (turn_off_elim){
+        touched  .clear(true);
+        occurs   .clear(true);
+        n_occ    .clear(true);
+        elim_heap.clear(true);
+        subsumption_queue.clear(true);
+
+        use_simplification    = false;
+        remove_satisfied      = true;
+        ca.extra_clause_field = false;
+
+        // Force full cleanup (this is safe and desirable since it only happens once):
+        rebuildOrderHeap();
+        garbageCollect();
+    }else{
+        // Cheaper cleanup:
+        cleanUpClauses(); // TODO: can we make 'cleanUpClauses()' not be linear in the problem size somehow?
+        checkGarbage();
+    }
+
+    if (verbosity >= 1 && elimclauses.size() > 0)
+        printf("c |  Eliminated clauses:     %10.2f Mb                                                                |\n", 
+               double(elimclauses.size() * sizeof(uint32_t)) / (1024*1024));
+    return ok;
+}
+
+
+void SimpSolver::cleanUpClauses()
+{
+    occurs.cleanAll();
+    int i,j;
+    for (i = j = 0; i < clauses.size(); i++)
+        if (ca[clauses[i]].mark() == 0)
+            clauses[j++] = clauses[i];
+    clauses.shrink(i - j);
+}
+
+
+//=================================================================================================
+// Garbage Collection methods:
+
+
+void SimpSolver::relocAll(ClauseAllocator& to)
+{
+    int i;
+    if (!use_simplification) return;
+
+    // All occurs lists:
+    //
+    for (i = 0; i < nVars(); i++){
+        vec<CRef>& cs = occurs[i];
+        for (int j = 0; j < cs.size(); j++)
+            ca.reloc(cs[j], to);
+    }
+
+    // Subsumption queue:
+    //
+    for (i = 0; i < subsumption_queue.size(); i++)
+        ca.reloc(subsumption_queue[i], to);
+
+    // Temporary clause:
+    //
+    ca.reloc(bwdsub_tmpunit, to);
+}
+
+
+void SimpSolver::garbageCollect()
+{
+    // Initialize the next region to a size corresponding to the estimated utilization degree. This
+    // is not precise but should avoid some unnecessary reallocations for the new region:
+    ClauseAllocator to(ca.size() - ca.wasted()); 
+
+    cleanUpClauses();
+    to.extra_clause_field = ca.extra_clause_field; // NOTE: this is important to keep (or lose) the extra fields.
+    relocAll(to);
+    Solver::relocAll(to);
+    if (verbosity >= 2)
+        printf("|  Garbage collection:   %12d bytes => %12d bytes             |\n", 
+               ca.size()*ClauseAllocator::Unit_Size, to.size()*ClauseAllocator::Unit_Size);
+    to.moveTo(ca);
+}
+
+void SimpSolver::reset() 
+{
+    Solver::reset();
+    grow = opt_grow;
+    asymm_lits = eliminated_vars = bwdsub_assigns = n_touched = 0;
+    elimclauses.clear(false);
+    touched.clear(false);
+    occurs.clear(false);
+    n_occ.clear(false);
+    elim_heap.clear(false);
+    subsumption_queue.clear(false);
+    frozen.clear(false);
+    eliminated.clear(false);
+    vec<Lit> dummy(1,lit_Undef);
+    ca.extra_clause_field = true; // NOTE: must happen before allocating the dummy clause below.
+    bwdsub_tmpunit        = ca.alloc(dummy);
+    remove_satisfied      = false;
+}
+
+ABC_NAMESPACE_IMPL_END
diff --git a/src/sat/glucose2/Solver.h b/src/sat/glucose2/Solver.h
new file mode 100644
index 00000000..3beb60e0
--- /dev/null
+++ b/src/sat/glucose2/Solver.h
@@ -0,0 +1,496 @@
+/****************************************************************************************[Solver.h]
+ Glucose -- Copyright (c) 2009, Gilles Audemard, Laurent Simon
+                CRIL - Univ. Artois, France
+                LRI  - Univ. Paris Sud, France
+ 
+Glucose sources are based on MiniSat (see below MiniSat copyrights). Permissions and copyrights of
+Glucose are exactly the same as Minisat on which it is based on. (see below).
+
+---------------
+Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_Solver_h
+#define Glucose_Solver_h
+
+#include "sat/glucose2/Vec.h"
+#include "sat/glucose2/Heap.h"
+#include "sat/glucose2/Alg.h"
+#include "sat/glucose2/Options.h"
+#include "sat/glucose2/SolverTypes.h"
+#include "sat/glucose2/BoundedQueue.h"
+#include "sat/glucose2/Constants.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//=================================================================================================
+// Solver -- the main class:
+
+class Solver {
+public:
+
+    int SolverType; // ABC identifies Glucose's type as 0
+
+    // Constructor/Destructor:
+    //
+    Solver();
+    virtual ~Solver();
+
+    // ABC callbacks
+    void * pCnfMan;                      // external CNF manager
+    int(*pCnfFunc)(void * p, int, int*); // external callback. messages: 0: unsat; 1: sat; -1: still working
+    int nCallConfl;                      // callback will be called every this number of conflicts
+    bool terminate_search_early;         // used to stop the solver early if it as instructed by an external caller
+    int * pstop;                         // another callback
+    uint64_t nRuntimeLimit;              // runtime limit
+    vec<int> user_vec;
+    vec<Lit> user_lits;
+
+    // Problem specification:
+    //
+    Var     newVar    (bool polarity = true, bool dvar = true); // Add a new variable with parameters specifying variable mode.
+    void    addVar    (Var v);                                  // Add enough variables to make sure there is variable v.
+
+    bool    addClause (const vec<Lit>& ps);                     // Add a clause to the solver. 
+    bool    addEmptyClause();                                   // Add the empty clause, making the solver contradictory.
+    bool    addClause (Lit p);                                  // Add a unit clause to the solver. 
+    bool    addClause (Lit p, Lit q);                           // Add a binary clause to the solver. 
+    bool    addClause (Lit p, Lit q, Lit r);                    // Add a ternary clause to the solver. 
+    bool    addClause_(      vec<Lit>& ps);                     // Add a clause to the solver without making superflous internal copy. Will
+                                                                // change the passed vector 'ps'.
+
+    // Solving:
+    //
+    bool    simplify     ();                        // Removes already satisfied clauses.
+    bool    solve        (const vec<Lit>& assumps); // Search for a model that respects a given set of assumptions.
+    lbool   solveLimited (const vec<Lit>& assumps); // Search for a model that respects a given set of assumptions (With resource constraints).
+    bool    solve        ();                        // Search without assumptions.
+    bool    solve        (Lit p);                   // Search for a model that respects a single assumption.
+    bool    solve        (Lit p, Lit q);            // Search for a model that respects two assumptions.
+    bool    solve        (Lit p, Lit q, Lit r);     // Search for a model that respects three assumptions.
+    bool    okay         () const;                  // FALSE means solver is in a conflicting state
+
+    void    toDimacs     (FILE* f, const vec<Lit>& assumps);            // Write CNF to file in DIMACS-format.
+    void    toDimacs     (const char *file, const vec<Lit>& assumps);
+    void    toDimacs     (FILE* f, Clause& c, vec<Var>& map, Var& max);
+    void printLit(Lit l);
+    void printClause(CRef c);
+    void printInitialClause(CRef c);
+    // Convenience versions of 'toDimacs()':
+    void    toDimacs     (const char* file);
+    void    toDimacs     (const char* file, Lit p);
+    void    toDimacs     (const char* file, Lit p, Lit q);
+    void    toDimacs     (const char* file, Lit p, Lit q, Lit r);
+    
+    // Variable mode:
+    // 
+    void    setPolarity    (Var v, bool b); // Declare which polarity the decision heuristic should use for a variable. Requires mode 'polarity_user'.
+    void    setDecisionVar (Var v, bool b); // Declare if a variable should be eligible for selection in the decision heuristic.
+
+    // Read state:
+    //
+    lbool   value      (Var x) const;       // The current value of a variable.
+    lbool   value      (Lit p) const;       // The current value of a literal.
+    lbool   modelValue (Var x) const;       // The value of a variable in the last model. The last call to solve must have been satisfiable.
+    lbool   modelValue (Lit p) const;       // The value of a literal in the last model. The last call to solve must have been satisfiable.
+    int     nAssigns   ()      const;       // The current number of assigned literals.
+    int     nClauses   ()      const;       // The current number of original clauses.
+    int     nLearnts   ()      const;       // The current number of learnt clauses.
+    int     nVars      ()      const;       // The current number of variables.
+    int     nFreeVars  ()      const;
+    int *   getCex     ()      const;
+
+    // Incremental mode
+    void setIncrementalMode();
+    void initNbInitialVars(int nb);
+    void printIncrementalStats();
+
+    // Resource contraints:
+    //
+    void    setConfBudget(int64_t x);
+    void    setPropBudget(int64_t x);
+    void    budgetOff();
+    void    interrupt();          // Trigger a (potentially asynchronous) interruption of the solver.
+    void    clearInterrupt();     // Clear interrupt indicator flag.
+
+    // Memory managment:
+    //
+    virtual void reset();
+    virtual void garbageCollect(); // virtuality causes segfault for some reason
+    void    checkGarbage(double gf);
+    void    checkGarbage();
+
+
+
+
+    // Extra results: (read-only member variable)
+    //
+    vec<lbool> model;             // If problem is satisfiable, this vector contains the model (if any).
+    vec<Lit>   conflict;          // If problem is unsatisfiable (possibly under assumptions),
+                                  // this vector represent the final conflict clause expressed in the assumptions.
+
+    // Mode of operation:
+    //
+    int       verbosity;
+    int       verbEveryConflicts;
+    int       showModel;
+    // Constants For restarts
+    double    K;
+    double    R;
+    double    sizeLBDQueue;
+    double    sizeTrailQueue;
+
+    // Constants for reduce DB
+    int firstReduceDB;
+    int incReduceDB;
+    int specialIncReduceDB;
+    unsigned int lbLBDFrozenClause;
+
+    // Constant for reducing clause
+    int lbSizeMinimizingClause;
+    unsigned int lbLBDMinimizingClause;
+
+    double    var_decay;
+    double    clause_decay;
+    double    random_var_freq;
+    double    random_seed;
+    int       ccmin_mode;         // Controls conflict clause minimization (0=none, 1=basic, 2=deep).
+    int       phase_saving;       // Controls the level of phase saving (0=none, 1=limited, 2=full).
+    bool      rnd_pol;            // Use random polarities for branching heuristics.
+    bool      rnd_init_act;       // Initialize variable activities with a small random value.
+    double    garbage_frac;       // The fraction of wasted memory allowed before a garbage collection is triggered.
+
+    // Certified UNSAT ( Thanks to Marijn Heule)
+    FILE*               certifiedOutput;
+    bool                certifiedUNSAT;
+
+    
+    // Statistics: (read-only member variable)
+    //
+    int64_t nbRemovedClauses,nbReducedClauses,nbDL2,nbBin,nbUn,nbReduceDB,solves, starts, decisions, rnd_decisions, propagations, conflicts,conflictsRestarts,nbstopsrestarts,nbstopsrestartssame,lastblockatrestart;
+    int64_t dec_vars, clauses_literals, learnts_literals, max_literals, tot_literals;
+
+protected:
+    long curRestart;
+    // Helper structures:
+    //
+    struct VarData { CRef reason; int level; };
+    static inline VarData mkVarData(CRef cr, int l){ VarData d = {cr, l}; return d; }
+
+    struct Watcher {
+        CRef cref;
+        Lit  blocker;
+        Watcher(CRef cr, Lit p) : cref(cr), blocker(p) {}
+        bool operator==(const Watcher& w) const { return cref == w.cref; }
+        bool operator!=(const Watcher& w) const { return cref != w.cref; }
+    };
+
+    struct WatcherDeleted
+    {
+        const ClauseAllocator& ca;
+        WatcherDeleted(const ClauseAllocator& _ca) : ca(_ca) {}
+        bool operator()(const Watcher& w) const { return ca[w.cref].mark() == 1; }
+    };
+
+    struct VarOrderLt {
+        const vec<double>&  activity;
+        bool operator () (Var x, Var y) const { return activity[x] > activity[y]; }
+        VarOrderLt(const vec<double>&  act) : activity(act) { }
+    };
+
+
+    // Solver state:
+    //
+    int lastIndexRed;
+    bool                ok;               // If FALSE, the constraints are already unsatisfiable. No part of the solver state may be used!
+    double              cla_inc;          // Amount to bump next clause with.
+    vec<double>         activity;         // A heuristic measurement of the activity of a variable.
+    double              var_inc;          // Amount to bump next variable with.
+    OccLists<Lit, vec<Watcher>, WatcherDeleted>
+                        watches;          // 'watches[lit]' is a list of constraints watching 'lit' (will go there if literal becomes true).
+    OccLists<Lit, vec<Watcher>, WatcherDeleted>
+                        watchesBin;          // 'watches[lit]' is a list of constraints watching 'lit' (will go there if literal becomes true).
+    vec<CRef>           clauses;          // List of problem clauses.
+    vec<CRef>           learnts;          // List of learnt clauses.
+
+    vec<lbool>          assigns;          // The current assignments.
+    vec<char>           polarity;         // The preferred polarity of each variable.
+    vec<char>           decision;         // Declares if a variable is eligible for selection in the decision heuristic.
+    vec<Lit>            trail;            // Assignment stack; stores all assigments made in the order they were made.
+    vec<int>            nbpos;
+    vec<int>            trail_lim;        // Separator indices for different decision levels in 'trail'.
+    vec<VarData>        vardata;          // Stores reason and level for each variable.
+    int                 qhead;            // Head of queue (as index into the trail -- no more explicit propagation queue in MiniSat).
+    int                 simpDB_assigns;   // Number of top-level assignments since last execution of 'simplify()'.
+    int64_t             simpDB_props;     // Remaining number of propagations that must be made before next execution of 'simplify()'.
+    vec<Lit>            assumptions;      // Current set of assumptions provided to solve by the user.
+    Heap<VarOrderLt>    order_heap;       // A priority queue of variables ordered with respect to the variable activity.
+    double              progress_estimate;// Set by 'search()'.
+    bool                remove_satisfied; // Indicates whether possibly inefficient linear scan for satisfied clauses should be performed in 'simplify'.
+    vec<unsigned int> permDiff;      // permDiff[var] contains the current conflict number... Used to count the number of  LBD
+    
+#ifdef UPDATEVARACTIVITY
+    // UPDATEVARACTIVITY trick (see competition'09 companion paper)
+    vec<Lit> lastDecisionLevel; 
+#endif
+
+    ClauseAllocator     ca;
+
+    int nbclausesbeforereduce;            // To know when it is time to reduce clause database
+    
+    bqueue<unsigned int> trailQueue,lbdQueue; // Bounded queues for restarts.
+    float sumLBD; // used to compute the global average of LBD. Restarts...
+    int sumAssumptions;
+
+
+    // Temporaries (to reduce allocation overhead). Each variable is prefixed by the method in which it is
+    // used, exept 'seen' wich is used in several places.
+    //
+    vec<char>           seen;
+    vec<Lit>            analyze_stack;
+    vec<Lit>            analyze_toclear;
+    vec<Lit>            add_tmp;
+    unsigned int  MYFLAG;
+
+
+    double              max_learnts;
+    double              learntsize_adjust_confl;
+    int                 learntsize_adjust_cnt;
+
+    // Resource contraints:
+    //
+    int64_t             conflict_budget;    // -1 means no budget.
+    int64_t             propagation_budget; // -1 means no budget.
+    bool                asynch_interrupt;
+
+
+    // Variables added for incremental mode
+    int incremental; // Use incremental SAT Solver
+    int nbVarsInitialFormula; // nb VAR in formula without assumptions (incremental SAT)
+    double totalTime4Sat,totalTime4Unsat;
+    int nbSatCalls,nbUnsatCalls;
+    vec<int> assumptionPositions,initialPositions;
+
+
+    // Main internal methods:
+    //
+    void     insertVarOrder   (Var x);                                                 // Insert a variable in the decision order priority queue.
+    Lit      pickBranchLit    ();                                                      // Return the next decision variable.
+    void     newDecisionLevel ();                                                      // Begins a new decision level.
+    void     uncheckedEnqueue (Lit p, CRef from = CRef_Undef);                         // Enqueue a literal. Assumes value of literal is undefined.
+    bool     enqueue          (Lit p, CRef from = CRef_Undef);                         // Test if fact 'p' contradicts current state, enqueue otherwise.
+    CRef     propagate        ();                                                      // Perform unit propagation. Returns possibly conflicting clause.
+    void     cancelUntil      (int level);                                             // Backtrack until a certain level.
+    void     analyze          (CRef confl, vec<Lit>& out_learnt, vec<Lit> & selectors, int& out_btlevel,unsigned int &nblevels,unsigned int &szWithoutSelectors);    // (bt = backtrack)
+    void     analyzeFinal     (Lit p, vec<Lit>& out_conflict);                         // COULD THIS BE IMPLEMENTED BY THE ORDINARIY "analyze" BY SOME REASONABLE GENERALIZATION?
+    bool     litRedundant     (Lit p, uint32_t abstract_levels);                       // (helper method for 'analyze()')
+    lbool    search           (int nof_conflicts);                                     // Search for a given number of conflicts.
+    lbool    solve_           ();                                                      // Main solve method (assumptions given in 'assumptions').
+    void     reduceDB         ();                                                      // Reduce the set of learnt clauses.
+    void     removeSatisfied  (vec<CRef>& cs);                                         // Shrink 'cs' to contain only non-satisfied clauses.
+    void     rebuildOrderHeap ();
+
+    // Maintaining Variable/Clause activity:
+    //
+    void     varDecayActivity ();                      // Decay all variables with the specified factor. Implemented by increasing the 'bump' value instead.
+    void     varBumpActivity  (Var v, double inc);     // Increase a variable with the current 'bump' value.
+    void     varBumpActivity  (Var v);                 // Increase a variable with the current 'bump' value.
+    void     claDecayActivity ();                      // Decay all clauses with the specified factor. Implemented by increasing the 'bump' value instead.
+    void     claBumpActivity  (Clause& c);             // Increase a clause with the current 'bump' value.
+
+    // Operations on clauses:
+    //
+    void     attachClause     (CRef cr);               // Attach a clause to watcher lists.
+    void     detachClause     (CRef cr, bool strict = false); // Detach a clause to watcher lists.
+    void     removeClause     (CRef cr);               // Detach and free a clause.
+    bool     locked           (const Clause& c) const; // Returns TRUE if a clause is a reason for some implication in the current state.
+    bool     satisfied        (const Clause& c) const; // Returns TRUE if a clause is satisfied in the current state.
+
+    unsigned int computeLBD(const vec<Lit> & lits,int end=-1);
+    unsigned int computeLBD(const Clause &c);
+    void minimisationWithBinaryResolution(vec<Lit> &out_learnt);
+
+    void     relocAll         (ClauseAllocator& to);
+
+    // Misc:
+    //
+    int      decisionLevel    ()      const; // Gives the current decisionlevel.
+    uint32_t abstractLevel    (Var x) const; // Used to represent an abstraction of sets of decision levels.
+    CRef     reason           (Var x) const;
+    int      level            (Var x) const;
+    double   progressEstimate ()      const; // DELETE THIS ?? IT'S NOT VERY USEFUL ...
+    bool     withinBudget     ()      const;
+    inline bool isSelector(Var v) {return (incremental && v>nbVarsInitialFormula);}
+
+    // Static helpers:
+    //
+
+    // Returns a random float 0 <= x < 1. Seed must never be 0.
+    static inline double drand(double& seed) {
+        seed *= 1389796;
+        int q = (int)(seed / 2147483647);
+        seed -= (double)q * 2147483647;
+        return seed / 2147483647; }
+
+    // Returns a random integer 0 <= x < size. Seed must never be 0.
+    static inline int irand(double& seed, int size) {
+        return (int)(drand(seed) * size); }
+};
+
+
+//=================================================================================================
+// Implementation of inline methods:
+
+inline CRef Solver::reason(Var x) const { return vardata[x].reason; }
+inline int  Solver::level (Var x) const { return vardata[x].level; }
+
+inline void Solver::insertVarOrder(Var x) {
+    if (!order_heap.inHeap(x) && decision[x]) order_heap.insert(x); }
+
+inline void Solver::varDecayActivity() { var_inc *= (1 / var_decay); }
+inline void Solver::varBumpActivity(Var v) { varBumpActivity(v, var_inc); }
+inline void Solver::varBumpActivity(Var v, double inc) {
+    if ( (activity[v] += inc) > 1e100 ) {
+        // Rescale:
+        for (int i = 0; i < nVars(); i++)
+            activity[i] *= 1e-100;
+        var_inc *= 1e-100; }
+
+    // Update order_heap with respect to new activity:
+    if (order_heap.inHeap(v))
+        order_heap.decrease(v); }
+
+inline void Solver::claDecayActivity() { cla_inc *= (1 / clause_decay); }
+inline void Solver::claBumpActivity (Clause& c) {
+        if ( (c.activity() += cla_inc) > 1e20 ) {
+            // Rescale:
+            for (int i = 0; i < learnts.size(); i++)
+                ca[learnts[i]].activity() *= (float)1e-20;
+            cla_inc *= 1e-20; } }
+
+inline void Solver::checkGarbage(void){ checkGarbage(garbage_frac); }
+inline void Solver::checkGarbage(double gf){
+    if (ca.wasted() > ca.size() * gf)
+        garbageCollect();}
+
+// NOTE: enqueue does not set the ok flag! (only public methods do)
+inline bool     Solver::enqueue         (Lit p, CRef from)      { return value(p) != l_Undef ? value(p) != l_False : (uncheckedEnqueue(p, from), true); }
+inline bool     Solver::addClause       (const vec<Lit>& ps)    { ps.copyTo(add_tmp); return addClause_(add_tmp); }
+inline bool     Solver::addEmptyClause  ()                      { add_tmp.clear(); return addClause_(add_tmp); }
+inline bool     Solver::addClause       (Lit p)                 { add_tmp.clear(); add_tmp.push(p); return addClause_(add_tmp); }
+inline bool     Solver::addClause       (Lit p, Lit q)          { add_tmp.clear(); add_tmp.push(p); add_tmp.push(q); return addClause_(add_tmp); }
+inline bool     Solver::addClause       (Lit p, Lit q, Lit r)   { add_tmp.clear(); add_tmp.push(p); add_tmp.push(q); add_tmp.push(r); return addClause_(add_tmp); }
+inline bool     Solver::locked          (const Clause& c) const { 
+   if(c.size()>2) 
+     return value(c[0]) == l_True && reason(var(c[0])) != CRef_Undef && ca.lea(reason(var(c[0]))) == &c; 
+   return 
+     (value(c[0]) == l_True && reason(var(c[0])) != CRef_Undef && ca.lea(reason(var(c[0]))) == &c)
+     || 
+     (value(c[1]) == l_True && reason(var(c[1])) != CRef_Undef && ca.lea(reason(var(c[1]))) == &c);
+ }
+inline void     Solver::newDecisionLevel()                      { trail_lim.push(trail.size()); }
+
+inline int      Solver::decisionLevel ()      const   { return trail_lim.size(); }
+inline uint32_t Solver::abstractLevel (Var x) const   { return 1 << (level(x) & 31); }
+inline lbool    Solver::value         (Var x) const   { return assigns[x]; }
+inline lbool    Solver::value         (Lit p) const   { return assigns[var(p)] ^ sign(p); }
+inline lbool    Solver::modelValue    (Var x) const   { return model[x]; }
+inline lbool    Solver::modelValue    (Lit p) const   { return model[var(p)] ^ sign(p); }
+inline int      Solver::nAssigns      ()      const   { return trail.size(); }
+inline int      Solver::nClauses      ()      const   { return clauses.size(); }
+inline int      Solver::nLearnts      ()      const   { return learnts.size(); }
+inline int      Solver::nVars         ()      const   { return vardata.size(); }
+inline int      Solver::nFreeVars     ()      const   { return (int)dec_vars - (trail_lim.size() == 0 ? trail.size() : trail_lim[0]); }
+inline int *    Solver::getCex        ()      const   { return NULL; }
+inline void     Solver::setPolarity   (Var v, bool b) { polarity[v] = b; }
+inline void     Solver::setDecisionVar(Var v, bool b) 
+{ 
+    if      ( b && !decision[v]) dec_vars++;
+    else if (!b &&  decision[v]) dec_vars--;
+
+    decision[v] = b;
+    insertVarOrder(v);
+}
+inline void     Solver::setConfBudget(int64_t x){ conflict_budget    = conflicts    + x; }
+inline void     Solver::setPropBudget(int64_t x){ propagation_budget = propagations + x; }
+inline void     Solver::interrupt(){ asynch_interrupt = true; }
+inline void     Solver::clearInterrupt(){ asynch_interrupt = false; }
+inline void     Solver::budgetOff(){ conflict_budget = propagation_budget = -1; }
+inline bool     Solver::withinBudget() const {
+    return !asynch_interrupt &&
+           (conflict_budget    < 0 || conflicts < (uint64_t)conflict_budget) &&
+           (propagation_budget < 0 || propagations < (uint64_t)propagation_budget); }
+
+// FIXME: after the introduction of asynchronous interrruptions the solve-versions that return a
+// pure bool do not give a safe interface. Either interrupts must be possible to turn off here, or
+// all calls to solve must return an 'lbool'. I'm not yet sure which I prefer.
+inline bool     Solver::solve         ()                    { budgetOff(); assumptions.clear(); return solve_() == l_True; }
+inline bool     Solver::solve         (Lit p)               { budgetOff(); assumptions.clear(); assumptions.push(p); return solve_() == l_True; }
+inline bool     Solver::solve         (Lit p, Lit q)        { budgetOff(); assumptions.clear(); assumptions.push(p); assumptions.push(q); return solve_() == l_True; }
+inline bool     Solver::solve         (Lit p, Lit q, Lit r) { budgetOff(); assumptions.clear(); assumptions.push(p); assumptions.push(q); assumptions.push(r); return solve_() == l_True; }
+inline bool     Solver::solve         (const vec<Lit>& assumps){ budgetOff(); assumps.copyTo(assumptions); return solve_() == l_True; }
+inline lbool    Solver::solveLimited  (const vec<Lit>& assumps){ assumps.copyTo(assumptions); return solve_(); }
+inline bool     Solver::okay          ()      const   { return ok; }
+
+inline void     Solver::toDimacs      (const char* file){ vec<Lit> as; toDimacs(file, as); }
+inline void     Solver::toDimacs      (const char* file, Lit p){ vec<Lit> as; as.push(p); toDimacs(file, as); }
+inline void     Solver::toDimacs      (const char* file, Lit p, Lit q){ vec<Lit> as; as.push(p); as.push(q); toDimacs(file, as); }
+inline void     Solver::toDimacs      (const char* file, Lit p, Lit q, Lit r){ vec<Lit> as; as.push(p); as.push(q); as.push(r); toDimacs(file, as); }
+
+inline void     Solver::addVar(Var v) { while (v >= nVars()) newVar(); }
+
+//=================================================================================================
+// Debug etc:
+
+
+inline void Solver::printLit(Lit l)
+{
+    printf("%s%d:%c", sign(l) ? "-" : "", var(l)+1, value(l) == l_True ? '1' : (value(l) == l_False ? '0' : 'X'));
+}
+
+
+inline void Solver::printClause(CRef cr)
+{
+  Clause &c = ca[cr];
+    for (int i = 0; i < c.size(); i++){
+        printLit(c[i]);
+        printf(" ");
+    }
+}
+
+inline void Solver::printInitialClause(CRef cr)
+{
+  Clause &c = ca[cr];
+    for (int i = 0; i < c.size(); i++){
+      if(!isSelector(var(c[i]))) {
+    printLit(c[i]);
+        printf(" ");
+      }
+    }
+}
+
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/SolverTypes.h b/src/sat/glucose2/SolverTypes.h
new file mode 100644
index 00000000..b15c887f
--- /dev/null
+++ b/src/sat/glucose2/SolverTypes.h
@@ -0,0 +1,437 @@
+/***********************************************************************************[SolverTypes.h]
+ Glucose -- Copyright (c) 2009, Gilles Audemard, Laurent Simon
+                CRIL - Univ. Artois, France
+                LRI  - Univ. Paris Sud, France
+ 
+Glucose sources are based on MiniSat (see below MiniSat copyrights). Permissions and copyrights of
+Glucose are exactly the same as Minisat on which it is based on. (see below).
+
+---------------
+Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+
+#ifndef Glucose_SolverTypes_h
+#define Glucose_SolverTypes_h
+
+#include <assert.h>
+
+#include "sat/glucose2/IntTypes.h"
+#include "sat/glucose2/Alg.h"
+#include "sat/glucose2/Vec.h"
+#include "sat/glucose2/Map.h"
+#include "sat/glucose2/Alloc.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//=================================================================================================
+// Variables, literals, lifted booleans, clauses:
+
+
+// NOTE! Variables are just integers. No abstraction here. They should be chosen from 0..N,
+// so that they can be used as array indices.
+
+typedef int Var;
+#define var_Undef (-1)
+
+
+struct Lit {
+    int     x;
+
+    // Use this as a constructor:
+    friend Lit mkLit(Var var, bool sign);
+    bool operator == (Lit p) const { return x == p.x; }
+    bool operator != (Lit p) const { return x != p.x; }
+    bool operator <  (Lit p) const { return x < p.x;  } // '<' makes p, ~p adjacent in the ordering.
+};
+
+
+inline  Lit  mkLit     (Var var, bool sign = false) { Lit p; p.x = var + var + (int)sign; return p; }
+inline  Lit  operator ~(Lit p)              { Lit q; q.x = p.x ^ 1; return q; }
+inline  Lit  operator ^(Lit p, bool b)      { Lit q; q.x = p.x ^ (unsigned int)b; return q; }
+inline  bool sign      (Lit p)              { return p.x & 1; }
+inline  int  var       (Lit p)              { return p.x >> 1; }
+
+// Mapping Literals to and from compact integers suitable for array indexing:
+inline  int  toInt     (Var v)              { return v; } 
+inline  int  toInt     (Lit p)              { return p.x; } 
+inline  Lit  toLit     (int i)              { Lit p; p.x = i; return p; } 
+
+//const Lit lit_Undef = mkLit(var_Undef, false);  // }- Useful special constants.
+//const Lit lit_Error = mkLit(var_Undef, true );  // }
+
+const Lit lit_Undef = { -2 };  // }- Useful special constants.
+const Lit lit_Error = { -1 };  // }
+
+
+//=================================================================================================
+// Lifted booleans:
+//
+// NOTE: this implementation is optimized for the case when comparisons between values are mostly
+//       between one variable and one constant. Some care had to be taken to make sure that gcc 
+//       does enough constant propagation to produce sensible code, and this appears to be somewhat
+//       fragile unfortunately.
+
+#define l_True  (Gluco2::lbool((uint8_t)0)) // gcc does not do constant propagation if these are real constants.
+#define l_False (Gluco2::lbool((uint8_t)1))
+#define l_Undef (Gluco2::lbool((uint8_t)2))
+
+class lbool {
+    uint8_t value;
+
+public:
+    explicit lbool(uint8_t v) : value(v) { }
+
+    lbool()       : value(0) { }
+    explicit lbool(bool x) : value(!x) { }
+
+    bool  operator == (lbool b) const { return (((b.value&2) & (value&2)) | (!(b.value&2)&(value == b.value))) != 0; }
+    bool  operator != (lbool b) const { return !(*this == b); }
+    lbool operator ^  (bool  b) const { return lbool((uint8_t)(value^(uint8_t)b)); }
+
+    lbool operator && (lbool b) const { 
+        uint8_t sel = (this->value << 1) | (b.value << 3);
+        uint8_t v   = (0xF7F755F4 >> sel) & 3;
+        return lbool(v); }
+
+    lbool operator || (lbool b) const {
+        uint8_t sel = (this->value << 1) | (b.value << 3);
+        uint8_t v   = (0xFCFCF400 >> sel) & 3;
+        return lbool(v); }
+
+    friend int   toInt  (lbool l);
+    friend lbool toLbool(int   v);
+};
+inline int   toInt  (lbool l) { return l.value; }
+inline lbool toLbool(int   v) { return lbool((uint8_t)v);  }
+
+//=================================================================================================
+// Clause -- a simple class for representing a clause:
+
+class Clause;
+typedef RegionAllocator<uint32_t>::Ref CRef;
+
+class Clause {
+    struct {
+      unsigned mark      : 2;
+      unsigned learnt    : 1;
+      unsigned has_extra : 1;
+      unsigned reloced   : 1;
+      unsigned lbd       : 26;
+      unsigned canbedel  : 1;
+      unsigned size      : 32;
+      unsigned szWithoutSelectors : 32;
+
+    }                            header;
+    union { Lit lit; float act; uint32_t abs; CRef rel; } data[0];
+
+    friend class ClauseAllocator;
+
+    // NOTE: This constructor cannot be used directly (doesn't allocate enough memory).
+    template<class V>
+    Clause(const V& ps, bool use_extra, bool learnt) {
+        header.mark      = 0;
+        header.learnt    = learnt;
+        header.has_extra = use_extra;
+        header.reloced   = 0;
+        header.size      = ps.size();
+    header.lbd = 0;
+    header.canbedel = 1;
+        for (int i = 0; i < ps.size(); i++) 
+            data[i].lit = ps[i];
+    
+        if (header.has_extra){
+      if (header.learnt) 
+                data[header.size].act = 0; 
+            else 
+                calcAbstraction(); }
+    }
+
+public:
+    void calcAbstraction() {
+        assert(header.has_extra);
+        uint32_t abstraction = 0;
+        for (int i = 0; i < size(); i++)
+            abstraction |= 1 << (var(data[i].lit) & 31);
+        data[header.size].abs = abstraction;  }
+
+
+    int          size        ()      const   { return header.size; }
+    void         shrink      (int i)         { assert(i <= size()); if (header.has_extra) data[header.size-i] = data[header.size]; header.size -= i; }
+    void         pop         ()              { shrink(1); }
+    bool         learnt      ()      const   { return header.learnt; }
+    bool         has_extra   ()      const   { return header.has_extra; }
+    uint32_t     mark        ()      const   { return header.mark; }
+    void         mark        (uint32_t m)    { header.mark = m; }
+    const Lit&   last        ()      const   { return data[header.size-1].lit; }
+
+    bool         reloced     ()      const   { return header.reloced; }
+    CRef         relocation  ()      const   { return data[0].rel; }
+    void         relocate    (CRef c)        { header.reloced = 1; data[0].rel = c; }
+
+    // NOTE: somewhat unsafe to change the clause in-place! Must manually call 'calcAbstraction' afterwards for
+    //       subsumption operations to behave correctly.
+    Lit&         operator [] (int i)         { return data[i].lit; }
+    Lit          operator [] (int i) const   { return data[i].lit; }
+    operator const Lit* (void) const         { return (Lit*)data; }
+
+    float&       activity    ()              { assert(header.has_extra); return data[header.size].act; }
+    uint32_t     abstraction () const        { assert(header.has_extra); return data[header.size].abs; }
+
+    Lit          subsumes    (const Clause& other) const;
+    void         strengthen  (Lit p);
+    void         setLBD(int i)  {header.lbd = i;} 
+    // unsigned int&       lbd    ()              { return header.lbd; }
+    unsigned int        lbd    () const        { return header.lbd; }
+    void setCanBeDel(bool b) {header.canbedel = b;}
+    bool canBeDel() {return header.canbedel;}
+    void setSizeWithoutSelectors   (unsigned int n)              {header.szWithoutSelectors = n; }
+    unsigned int        sizeWithoutSelectors   () const        { return header.szWithoutSelectors; }
+
+};
+
+
+//=================================================================================================
+// ClauseAllocator -- a simple class for allocating memory for clauses:
+
+
+const CRef CRef_Undef = RegionAllocator<uint32_t>::Ref_Undef;
+class ClauseAllocator : public RegionAllocator<uint32_t>
+{
+    static int clauseWord32Size(int size, bool has_extra){
+        return (sizeof(Clause) + (sizeof(Lit) * (size + (int)has_extra))) / sizeof(uint32_t); }
+ public:
+    bool extra_clause_field;
+
+    ClauseAllocator(uint32_t start_cap) : RegionAllocator<uint32_t>(start_cap), extra_clause_field(false){}
+    ClauseAllocator() : extra_clause_field(false){}
+
+    void moveTo(ClauseAllocator& to){
+        to.extra_clause_field = extra_clause_field;
+        RegionAllocator<uint32_t>::moveTo(to); }
+
+    template<class Lits>
+    CRef alloc(const Lits& ps, bool learnt = false)
+    {
+        assert(sizeof(Lit)      == sizeof(uint32_t));
+        assert(sizeof(float)    == sizeof(uint32_t));
+        bool use_extra = learnt | extra_clause_field;
+
+        CRef cid = RegionAllocator<uint32_t>::alloc(clauseWord32Size(ps.size(), use_extra));
+        new (lea(cid)) Clause(ps, use_extra, learnt);
+
+        return cid;
+    }
+
+    // Deref, Load Effective Address (LEA), Inverse of LEA (AEL):
+    Clause&       operator[](Ref r)       { return (Clause&)RegionAllocator<uint32_t>::operator[](r); }
+    const Clause& operator[](Ref r) const { return (Clause&)RegionAllocator<uint32_t>::operator[](r); }
+    Clause*       lea       (Ref r)       { return (Clause*)RegionAllocator<uint32_t>::lea(r); }
+    const Clause* lea       (Ref r) const { return (Clause*)RegionAllocator<uint32_t>::lea(r); }
+    Ref           ael       (const Clause* t){ return RegionAllocator<uint32_t>::ael((uint32_t*)t); }
+
+    void free_(CRef cid)
+    {
+        Clause& c = operator[](cid);
+        RegionAllocator<uint32_t>::free_(clauseWord32Size(c.size(), c.has_extra()));
+    }
+
+    void reloc(CRef& cr, ClauseAllocator& to)
+    {
+        Clause& c = operator[](cr);
+        
+        if (c.reloced()) { cr = c.relocation(); return; }
+        
+        cr = to.alloc(c, c.learnt());
+        c.relocate(cr);
+        
+        // Copy extra data-fields: 
+        // (This could be cleaned-up. Generalize Clause-constructor to be applicable here instead?)
+        to[cr].mark(c.mark());
+        if (to[cr].learnt())        {
+      to[cr].activity() = c.activity();
+      to[cr].setLBD(c.lbd());
+      to[cr].setSizeWithoutSelectors(c.sizeWithoutSelectors());
+      to[cr].setCanBeDel(c.canBeDel());
+    }
+        else if (to[cr].has_extra()) to[cr].calcAbstraction();
+    }
+};
+
+
+//=================================================================================================
+// OccLists -- a class for maintaining occurence lists with lazy deletion:
+
+template<class Idx, class Vec, class Deleted>
+class OccLists
+{
+    vec<Vec>  occs;
+    vec<char> dirty;
+    vec<Idx>  dirties;
+    Deleted   deleted;
+
+ public:
+    OccLists(const Deleted& d) : deleted(d) {}
+    
+    void  init      (const Idx& idx){ occs.growTo(toInt(idx)+1); dirty.growTo(toInt(idx)+1, 0); }
+    // Vec&  operator[](const Idx& idx){ return occs[toInt(idx)]; }
+    Vec&  operator[](const Idx& idx){ return occs[toInt(idx)]; }
+    Vec&  lookup    (const Idx& idx){ if (dirty[toInt(idx)]) clean(idx); return occs[toInt(idx)]; }
+
+    void  cleanAll  ();
+    void  clean     (const Idx& idx);
+    void  smudge    (const Idx& idx){
+        if (dirty[toInt(idx)] == 0){
+            dirty[toInt(idx)] = 1;
+            dirties.push(idx);
+        }
+    }
+
+    void  clear(bool free = true){
+        occs   .clear(free);
+        dirty  .clear(free);
+        dirties.clear(free);
+    }
+};
+
+
+template<class Idx, class Vec, class Deleted>
+void OccLists<Idx,Vec,Deleted>::cleanAll()
+{
+    for (int i = 0; i < dirties.size(); i++)
+        // Dirties may contain duplicates so check here if a variable is already cleaned:
+        if (dirty[toInt(dirties[i])])
+            clean(dirties[i]);
+    dirties.clear();
+}
+
+
+template<class Idx, class Vec, class Deleted>
+void OccLists<Idx,Vec,Deleted>::clean(const Idx& idx)
+{
+    Vec& vec = occs[toInt(idx)];
+    int  i, j;
+    for (i = j = 0; i < vec.size(); i++)
+        if (!deleted(vec[i]))
+            vec[j++] = vec[i];
+    vec.shrink(i - j);
+    dirty[toInt(idx)] = 0;
+}
+
+
+//=================================================================================================
+// CMap -- a class for mapping clauses to values:
+
+
+template<class T>
+class CMap
+{
+    struct CRefHash {
+        uint32_t operator()(CRef cr) const { return (uint32_t)cr; } };
+
+    typedef Map<CRef, T, CRefHash> HashTable;
+    HashTable map;
+        
+ public:
+    // Size-operations:
+    void     clear       ()                           { map.clear(); }
+    int      size        ()                const      { return map.elems(); }
+
+    
+    // Insert/Remove/Test mapping:
+    void     insert      (CRef cr, const T& t){ map.insert(cr, t); }
+    void     growTo      (CRef cr, const T& t){ map.insert(cr, t); } // NOTE: for compatibility
+    void     remove      (CRef cr)            { map.remove(cr); }
+    bool     has         (CRef cr, T& t)      { return map.peek(cr, t); }
+
+    // Vector interface (the clause 'c' must already exist):
+    const T& operator [] (CRef cr) const      { return map[cr]; }
+    T&       operator [] (CRef cr)            { return map[cr]; }
+
+    // Iteration (not transparent at all at the moment):
+    int  bucket_count() const { return map.bucket_count(); }
+    const vec<typename HashTable::Pair>& bucket(int i) const { return map.bucket(i); }
+
+    // Move contents to other map:
+    void moveTo(CMap& other){ map.moveTo(other.map); }
+
+    // TMP debug:
+    void debug(){
+        printf(" --- size = %d, bucket_count = %d\n", size(), map.bucket_count()); }
+};
+
+
+/*_________________________________________________________________________________________________
+|
+|  subsumes : (other : const Clause&)  ->  Lit
+|  
+|  Description:
+|       Checks if clause subsumes 'other', and at the same time, if it can be used to simplify 'other'
+|       by subsumption resolution.
+|  
+|    Result:
+|       lit_Error  - No subsumption or simplification
+|       lit_Undef  - Clause subsumes 'other'
+|       p          - The literal p can be deleted from 'other'
+|________________________________________________________________________________________________@*/
+inline Lit Clause::subsumes(const Clause& other) const
+{
+    //if (other.size() < size() || (extra.abst & ~other.extra.abst) != 0)
+    //if (other.size() < size() || (!learnt() && !other.learnt() && (extra.abst & ~other.extra.abst) != 0))
+    assert(!header.learnt);   assert(!other.header.learnt);
+    assert(header.has_extra); assert(other.header.has_extra);
+    if (other.header.size < header.size || (data[header.size].abs & ~other.data[other.header.size].abs) != 0)
+        return lit_Error;
+
+    Lit        ret = lit_Undef;
+    const Lit* c   = (const Lit*)(*this);
+    const Lit* d   = (const Lit*)other;
+
+    for (unsigned i = 0; i < header.size; i++) {
+        // search for c[i] or ~c[i]
+        for (unsigned j = 0; j < other.header.size; j++)
+            if (c[i] == d[j])
+                goto ok;
+            else if (ret == lit_Undef && c[i] == ~d[j]){
+                ret = c[i];
+                goto ok;
+            }
+
+        // did not find it
+        return lit_Error;
+    ok:;
+    }
+
+    return ret;
+}
+
+inline void Clause::strengthen(Lit p)
+{
+    remove(*this, p);
+    calcAbstraction();
+}
+ 
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/Sort.h b/src/sat/glucose2/Sort.h
new file mode 100644
index 00000000..6be112ca
--- /dev/null
+++ b/src/sat/glucose2/Sort.h
@@ -0,0 +1,101 @@
+/******************************************************************************************[Sort.h]
+Copyright (c) 2003-2007, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_Sort_h
+#define Glucose_Sort_h
+
+#include "sat/glucose2/Vec.h"
+
+//=================================================================================================
+// Some sorting algorithms for vec's
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+template<class T>
+struct LessThan_default {
+    bool operator () (T x, T y) { return x < y; }
+};
+
+
+template <class T, class LessThan>
+void selectionSort(T* array, int size, LessThan lt)
+{
+    int     i, j, best_i;
+    T       tmp;
+
+    for (i = 0; i < size-1; i++){
+        best_i = i;
+        for (j = i+1; j < size; j++){
+            if (lt(array[j], array[best_i]))
+                best_i = j;
+        }
+        tmp = array[i]; array[i] = array[best_i]; array[best_i] = tmp;
+    }
+}
+template <class T> static inline void selectionSort(T* array, int size) {
+    selectionSort(array, size, LessThan_default<T>()); }
+
+template <class T, class LessThan>
+void sort(T* array, int size, LessThan lt)
+{
+    if (size <= 15)
+        selectionSort(array, size, lt);
+
+    else{
+        T           pivot = array[size / 2];
+        T           tmp;
+        int         i = -1;
+        int         j = size;
+
+        for(;;){
+            do i++; while(lt(array[i], pivot));
+            do j--; while(lt(pivot, array[j]));
+
+            if (i >= j) break;
+
+            tmp = array[i]; array[i] = array[j]; array[j] = tmp;
+        }
+
+        sort(array    , i     , lt);
+        sort(&array[i], size-i, lt);
+    }
+}
+template <class T> static inline void sort(T* array, int size) {
+    sort(array, size, LessThan_default<T>()); }
+
+
+//=================================================================================================
+// For 'vec's:
+
+
+template <class T, class LessThan> void sort(vec<T>& v, LessThan lt) {
+    sort((T*)v, v.size(), lt); }
+template <class T> void sort(vec<T>& v) {
+    sort(v, LessThan_default<T>()); }
+
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/System.h b/src/sat/glucose2/System.h
new file mode 100644
index 00000000..088bada5
--- /dev/null
+++ b/src/sat/glucose2/System.h
@@ -0,0 +1,73 @@
+/****************************************************************************************[System.h]
+Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_System_h
+#define Glucose_System_h
+
+#if defined(__linux__)
+//#include <fpu_control.h>
+#endif
+
+#include "sat/glucose2/IntTypes.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+//-------------------------------------------------------------------------------------------------
+
+namespace Gluco2 {
+
+static inline double cpuTime(void); // CPU-time in seconds.
+extern double memUsed();            // Memory in mega bytes (returns 0 for unsupported architectures).
+extern double memUsedPeak();        // Peak-memory in mega bytes (returns 0 for unsupported architectures).
+
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+//-------------------------------------------------------------------------------------------------
+// Implementation of inline functions:
+
+#if defined(_MSC_VER) || defined(__MINGW32__)
+#include <time.h>
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+static inline double Gluco2::cpuTime(void) { return (double)clock() / CLOCKS_PER_SEC; }
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+
+#else
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <unistd.h>
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+static inline double Gluco2::cpuTime(void) {
+    struct rusage ru;
+    getrusage(RUSAGE_SELF, &ru);
+    return (double)ru.ru_utime.tv_sec + (double)ru.ru_utime.tv_usec / 1000000; }
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
+
+#endif
diff --git a/src/sat/glucose2/System2.cpp b/src/sat/glucose2/System2.cpp
new file mode 100644
index 00000000..844220a0
--- /dev/null
+++ b/src/sat/glucose2/System2.cpp
@@ -0,0 +1,116 @@
+/***************************************************************************************[System.cc]
+Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#include "sat/glucose2/System.h"
+
+#if defined(__linux__)
+
+#include <stdio.h>
+#include <stdlib.h>
+
+ABC_NAMESPACE_IMPL_START
+
+using namespace Gluco2;
+
+// TODO: split the memory reading functions into two: one for reading high-watermark of RSS, and
+// one for reading the current virtual memory size.
+
+static inline int memReadStat(int field)
+{
+    char  name[256];
+    pid_t pid = getpid();
+    int   value;
+
+    sprintf(name, "/proc/%d/statm", pid);
+    FILE* in = fopen(name, "rb");
+    if (in == NULL) return 0;
+
+    for (; field >= 0; field--)
+        if (fscanf(in, "%d", &value) != 1)
+            printf("ERROR! Failed to parse memory statistics from \"/proc\".\n"), exit(1);
+    fclose(in);
+    return value;
+}
+
+
+static inline int memReadPeak(void)
+{
+    char  name[256];
+    pid_t pid = getpid();
+
+    sprintf(name, "/proc/%d/status", pid);
+    FILE* in = fopen(name, "rb");
+    if (in == NULL) return 0;
+
+    // Find the correct line, beginning with "VmPeak:":
+    int peak_kb = 0;
+    while (!feof(in) && fscanf(in, "VmPeak: %d kB", &peak_kb) != 1)
+        while (!feof(in) && fgetc(in) != '\n')
+            ;
+    fclose(in);
+
+    return peak_kb;
+}
+
+double Gluco2::memUsed() { return (double)memReadStat(0) * (double)getpagesize() / (1024*1024); }
+double Gluco2::memUsedPeak() { 
+    double peak = memReadPeak() / 1024;
+    return peak == 0 ? memUsed() : peak; }
+
+ABC_NAMESPACE_IMPL_END
+
+#elif defined(__FreeBSD__)
+
+ABC_NAMESPACE_IMPL_START
+
+using namespace Gluco2;
+
+double Gluco2::memUsed(void) {
+    struct rusage ru;
+    getrusage(RUSAGE_SELF, &ru);
+    return (double)ru.ru_maxrss / 1024; }
+double memUsedPeak(void) { return memUsed(); }
+
+ABC_NAMESPACE_IMPL_END
+
+#elif defined(__APPLE__)
+
+#include <malloc/malloc.h>
+
+ABC_NAMESPACE_IMPL_START
+
+double Gluco2::memUsed(void) {
+    malloc_statistics_t t;
+    malloc_zone_statistics(NULL, &t);
+    return (double)t.max_size_in_use / (1024*1024); }
+
+ABC_NAMESPACE_IMPL_END
+
+#else
+
+ABC_NAMESPACE_IMPL_START
+
+double Gluco2::memUsed() { 
+    return 0; }
+
+ABC_NAMESPACE_IMPL_END
+
+#endif
+
diff --git a/src/sat/glucose2/Vec.h b/src/sat/glucose2/Vec.h
new file mode 100644
index 00000000..4b60e13c
--- /dev/null
+++ b/src/sat/glucose2/Vec.h
@@ -0,0 +1,134 @@
+/*******************************************************************************************[Vec.h]
+Copyright (c) 2003-2007, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+#ifndef Glucose_Vec_h
+#define Glucose_Vec_h
+
+#include <assert.h>
+#include <new>
+
+#include "sat/glucose2/IntTypes.h"
+#include "sat/glucose2/XAlloc.h"
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//=================================================================================================
+// Automatically resizable arrays
+//
+// NOTE! Don't use this vector on datatypes that cannot be re-located in memory (with realloc)
+
+template<class T>
+class vec {
+    T*  data;
+    int sz;
+    int cap;
+
+    // Don't allow copying (error prone):
+    vec<T>&  operator = (vec<T>& other) { assert(0); return *this; }
+             vec        (vec<T>& other) { assert(0); }
+             
+    // Helpers for calculating next capacity:
+    static inline int  imax   (int x, int y) { int mask = (y-x) >> (sizeof(int)*8-1); return (x&mask) + (y&(~mask)); }
+    //static inline void nextCap(int& cap){ cap += ((cap >> 1) + 2) & ~1; }
+    static inline void nextCap(int& cap){ cap += ((cap >> 1) + 2) & ~1; }
+
+public:
+    // Constructors:
+    vec()                       : data(NULL) , sz(0)   , cap(0)    { }
+    explicit vec(int size)      : data(NULL) , sz(0)   , cap(0)    { growTo(size); }
+    vec(int size, const T& pad) : data(NULL) , sz(0)   , cap(0)    { growTo(size, pad); }
+   ~vec()                                                          { clear(true); }
+
+    // Pointer to first element:
+    operator T*       (void)           { return data; }
+
+    // Size operations:
+    int      size     (void) const     { return sz; }
+    void     shrink   (int nelems)     { assert(nelems <= sz); for (int i = 0; i < nelems; i++) sz--, data[sz].~T(); }
+    void     shrink_  (int nelems)     { assert(nelems <= sz); sz -= nelems; }
+    int      capacity (void) const     { return cap; }
+    void     capacity (int min_cap);
+    void     growTo   (int size);
+    void     growTo   (int size, const T& pad);
+    void     clear    (bool dealloc = false);
+
+    // Stack interface:
+    void     push  (void)              { if (sz == cap) capacity(sz+1); new (&data[sz]) T(); sz++; }
+    void     push  (const T& elem)     { if (sz == cap) capacity(sz+1); data[sz++] = elem; }
+    void     push_ (const T& elem)     { assert(sz < cap); data[sz++] = elem; }
+    void     pop   (void)              { assert(sz > 0); sz--, data[sz].~T(); }
+    // NOTE: it seems possible that overflow can happen in the 'sz+1' expression of 'push()', but
+    // in fact it can not since it requires that 'cap' is equal to INT_MAX. This in turn can not
+    // happen given the way capacities are calculated (below). Essentially, all capacities are
+    // even, but INT_MAX is odd.
+
+    const T& last  (void) const        { return data[sz-1]; }
+    T&       last  (void)              { return data[sz-1]; }
+
+    // Vector interface:
+    const T& operator [] (int index) const { return data[index]; }
+    T&       operator [] (int index)       { return data[index]; }
+
+    // Duplicatation (preferred instead):
+    void copyTo(vec<T>& copy) const { copy.clear(); copy.growTo(sz); for (int i = 0; i < sz; i++) copy[i] = data[i]; }
+    void moveTo(vec<T>& dest) { dest.clear(true); dest.data = data; dest.sz = sz; dest.cap = cap; data = NULL; sz = 0; cap = 0; }
+};
+
+
+template<class T>
+void vec<T>::capacity(int min_cap) {
+    if (cap >= min_cap) return;
+    int add = imax((min_cap - cap + 1) & ~1, ((cap >> 1) + 2) & ~1);   // NOTE: grow by approximately 3/2
+    if (add > INT_MAX - cap || (((data = (T*)::realloc(data, (cap += add) * sizeof(T))) == NULL) && errno == ENOMEM))
+        throw OutOfMemoryException();
+ }
+
+
+template<class T>
+void vec<T>::growTo(int size, const T& pad) {
+    if (sz >= size) return;
+    capacity(size);
+    for (int i = sz; i < size; i++) data[i] = pad;
+    sz = size; }
+
+
+template<class T>
+void vec<T>::growTo(int size) {
+    if (sz >= size) return;
+    capacity(size);
+    for (int i = sz; i < size; i++) new (&data[i]) T();
+    sz = size; }
+
+
+template<class T>
+void vec<T>::clear(bool dealloc) {
+    if (data != NULL){
+        for (int i = 0; i < sz; i++) data[i].~T();
+        sz = 0;
+        if (dealloc) free(data), data = NULL, cap = 0; } }
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/XAlloc.h b/src/sat/glucose2/XAlloc.h
new file mode 100644
index 00000000..716643ef
--- /dev/null
+++ b/src/sat/glucose2/XAlloc.h
@@ -0,0 +1,53 @@
+/****************************************************************************************[XAlloc.h]
+Copyright (c) 2009-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+associated documentation files (the "Software"), to deal in the Software without restriction,
+including without limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or
+substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
+OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+**************************************************************************************************/
+
+
+#ifndef Glucose_XAlloc_h
+#define Glucose_XAlloc_h
+
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <misc/util/abc_namespaces.h>
+
+ABC_NAMESPACE_CXX_HEADER_START
+
+namespace Gluco2 {
+
+//=================================================================================================
+// Simple layer on top of malloc/realloc to catch out-of-memory situtaions and provide some typing:
+
+class OutOfMemoryException{};
+static inline void* xrealloc(void *ptr, size_t size)
+{
+    void* mem = realloc(ptr, size);
+    if (mem == NULL && errno == ENOMEM){
+        throw OutOfMemoryException();
+    }else {
+        return mem;
+    }
+}
+
+//=================================================================================================
+}
+
+ABC_NAMESPACE_CXX_HEADER_END
+
+#endif
diff --git a/src/sat/glucose2/license b/src/sat/glucose2/license
new file mode 100644
index 00000000..04ed174b
--- /dev/null
+++ b/src/sat/glucose2/license
@@ -0,0 +1,32 @@
+---------------
+
+Glucose -- Copyright (c) 2013, Gilles Audemard, Laurent Simon
+                               CRIL - Univ. Artois, France
+                               LRI  - Univ. Paris Sud, France
+
+Glucose sources are based on MiniSat (see below MiniSat copyrights). Permissions
+and copyrights of Glucose are exactly the same as Minisat on which it is based
+on. (see below).
+
+---------------
+
+Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
+Copyright (c) 2007-2010, Niklas Sorensson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*******************************************************************************/
\ No newline at end of file
diff --git a/src/sat/glucose2/module.make b/src/sat/glucose2/module.make
new file mode 100644
index 00000000..c23cdc53
--- /dev/null
+++ b/src/sat/glucose2/module.make
@@ -0,0 +1,6 @@
+SRC +=    src/sat/glucose2/AbcGlucose2.cpp \
+    src/sat/glucose2/AbcGlucoseCmd2.cpp \
+    src/sat/glucose2/Glucose2.cpp \
+    src/sat/glucose2/Options2.cpp \
+    src/sat/glucose2/SimpSolver2.cpp \
+    src/sat/glucose2/System2.cpp
diff --git a/src/sat/glucose2/pstdint.h b/src/sat/glucose2/pstdint.h
new file mode 100644
index 00000000..989d0169
--- /dev/null
+++ b/src/sat/glucose2/pstdint.h
@@ -0,0 +1,919 @@
+/*  A portable stdint.h
+ ****************************************************************************
+ *  BSD License:
+ ****************************************************************************
+ *
+ *  Copyright (c) 2005-2016 Paul Hsieh
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. The name of the author may not be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************
+ *
+ *  Version 0.1.16.0
+ *
+ *  The ANSI C standard committee, for the C99 standard, specified the
+ *  inclusion of a new standard include file called stdint.h.  This is
+ *  a very useful and long desired include file which contains several
+ *  very precise definitions for integer scalar types that is critically
+ *  important for making several classes of applications portable
+ *  including cryptography, hashing, variable length integer libraries
+ *  and so on.  But for most developers its likely useful just for
+ *  programming sanity.
+ *
+ *  The problem is that some compiler vendors chose to ignore the C99
+ *  standard and some older compilers have no opportunity to be updated.
+ *  Because of this situation, simply including stdint.h in your code
+ *  makes it unportable.
+ *
+ *  So that's what this file is all about.  It's an attempt to build a
+ *  single universal include file that works on as many platforms as
+ *  possible to deliver what stdint.h is supposed to.  Even compilers
+ *  that already come with stdint.h can use this file instead without
+ *  any loss of functionality.  A few things that should be noted about
+ *  this file:
+ *
+ *    1) It is not guaranteed to be portable and/or present an identical
+ *       interface on all platforms.  The extreme variability of the
+ *       ANSI C standard makes this an impossibility right from the
+ *       very get go. Its really only meant to be useful for the vast
+ *       majority of platforms that possess the capability of
+ *       implementing usefully and precisely defined, standard sized
+ *       integer scalars.  Systems which are not intrinsically 2s
+ *       complement may produce invalid constants.
+ *
+ *    2) There is an unavoidable use of non-reserved symbols.
+ *
+ *    3) Other standard include files are invoked.
+ *
+ *    4) This file may come in conflict with future platforms that do
+ *       include stdint.h.  The hope is that one or the other can be
+ *       used with no real difference.
+ *
+ *    5) In the current version, if your platform can't represent
+ *       int32_t, int16_t and int8_t, it just dumps out with a compiler
+ *       error.
+ *
+ *    6) 64 bit integers may or may not be defined.  Test for their
+ *       presence with the test: #ifdef INT64_MAX or #ifdef UINT64_MAX.
+ *       Note that this is different from the C99 specification which
+ *       requires the existence of 64 bit support in the compiler.  If
+ *       this is not defined for your platform, yet it is capable of
+ *       dealing with 64 bits then it is because this file has not yet
+ *       been extended to cover all of your system's capabilities.
+ *
+ *    7) (u)intptr_t may or may not be defined.  Test for its presence
+ *       with the test: #ifdef PTRDIFF_MAX.  If this is not defined
+ *       for your platform, then it is because this file has not yet
+ *       been extended to cover all of your system's capabilities, not
+ *       because its optional.
+ *
+ *    8) The following might not been defined even if your platform is
+ *       capable of defining it:
+ *
+ *       WCHAR_MIN
+ *       WCHAR_MAX
+ *       (u)int64_t
+ *       PTRDIFF_MIN
+ *       PTRDIFF_MAX
+ *       (u)intptr_t
+ *
+ *    9) The following have not been defined:
+ *
+ *       WINT_MIN
+ *       WINT_MAX
+ *
+ *   10) The criteria for defining (u)int_least(*)_t isn't clear,
+ *       except for systems which don't have a type that precisely
+ *       defined 8, 16, or 32 bit types (which this include file does
+ *       not support anyways). Default definitions have been given.
+ *
+ *   11) The criteria for defining (u)int_fast(*)_t isn't something I
+ *       would trust to any particular compiler vendor or the ANSI C
+ *       committee.  It is well known that "compatible systems" are
+ *       commonly created that have very different performance
+ *       characteristics from the systems they are compatible with,
+ *       especially those whose vendors make both the compiler and the
+ *       system.  Default definitions have been given, but its strongly
+ *       recommended that users never use these definitions for any
+ *       reason (they do *NOT* deliver any serious guarantee of
+ *       improved performance -- not in this file, nor any vendor's
+ *       stdint.h).
+ *
+ *   12) The following macros:
+ *
+ *       PRINTF_INTMAX_MODIFIER
+ *       PRINTF_INT64_MODIFIER
+ *       PRINTF_INT32_MODIFIER
+ *       PRINTF_INT16_MODIFIER
+ *       PRINTF_LEAST64_MODIFIER
+ *       PRINTF_LEAST32_MODIFIER
+ *       PRINTF_LEAST16_MODIFIER
+ *       PRINTF_INTPTR_MODIFIER
+ *
+ *       are strings which have been defined as the modifiers required
+ *       for the "d", "u" and "x" printf formats to correctly output
+ *       (u)intmax_t, (u)int64_t, (u)int32_t, (u)int16_t, (u)least64_t,
+ *       (u)least32_t, (u)least16_t and (u)intptr_t types respectively.
+ *       PRINTF_INTPTR_MODIFIER is not defined for some systems which
+ *       provide their own stdint.h.  PRINTF_INT64_MODIFIER is not
+ *       defined if INT64_MAX is not defined.  These are an extension
+ *       beyond what C99 specifies must be in stdint.h.
+ *
+ *       In addition, the following macros are defined:
+ *
+ *       PRINTF_INTMAX_HEX_WIDTH
+ *       PRINTF_INT64_HEX_WIDTH
+ *       PRINTF_INT32_HEX_WIDTH
+ *       PRINTF_INT16_HEX_WIDTH
+ *       PRINTF_INT8_HEX_WIDTH
+ *       PRINTF_INTMAX_DEC_WIDTH
+ *       PRINTF_INT64_DEC_WIDTH
+ *       PRINTF_INT32_DEC_WIDTH
+ *       PRINTF_INT16_DEC_WIDTH
+ *       PRINTF_UINT8_DEC_WIDTH
+ *       PRINTF_UINTMAX_DEC_WIDTH
+ *       PRINTF_UINT64_DEC_WIDTH
+ *       PRINTF_UINT32_DEC_WIDTH
+ *       PRINTF_UINT16_DEC_WIDTH
+ *       PRINTF_UINT8_DEC_WIDTH
+ *
+ *       Which specifies the maximum number of characters required to
+ *       print the number of that type in either hexadecimal or decimal.
+ *       These are an extension beyond what C99 specifies must be in
+ *       stdint.h.
+ *
+ *  Compilers tested (all with 0 warnings at their highest respective
+ *  settings): Borland Turbo C 2.0, WATCOM C/C++ 11.0 (16 bits and 32
+ *  bits), Microsoft Visual C++ 6.0 (32 bit), Microsoft Visual Studio
+ *  .net (VC7), Intel C++ 4.0, GNU gcc v3.3.3
+ *
+ *  This file should be considered a work in progress.  Suggestions for
+ *  improvements, especially those which increase coverage are strongly
+ *  encouraged.
+ *
+ *  Acknowledgements
+ *
+ *  The following people have made significant contributions to the
+ *  development and testing of this file:
+ *
+ *  Chris Howie
+ *  John Steele Scott
+ *  Dave Thorup
+ *  John Dill
+ *  Florian Wobbe
+ *  Christopher Sean Morrison
+ *  Mikkel Fahnoe Jorgensen
+ *
+ */
+
+#include <stddef.h>
+#include <limits.h>
+#include <signal.h>
+
+/*
+ *  For gcc with _STDINT_H, fill in the PRINTF_INT*_MODIFIER macros, and
+ *  do nothing else.  On the Mac OS X version of gcc this is _STDINT_H_.
+ */
+
+#if ((defined(__SUNPRO_C) && __SUNPRO_C >= 0x570) || (defined(_MSC_VER) && _MSC_VER >= 1600) || (defined(__STDC__) && __STDC__ && defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) || (defined (__WATCOMC__) && (defined (_STDINT_H_INCLUDED) || __WATCOMC__ >= 1250)) || (defined(__GNUC__) && (__GNUC__ > 3 || defined(_STDINT_H) || defined(_STDINT_H_) || defined (__UINT_FAST64_TYPE__)) )) && !defined (_PSTDINT_H_INCLUDED)
+#include <stdint.h>
+#define _PSTDINT_H_INCLUDED
+# if defined(__GNUC__) && (defined(__x86_64__) || defined(__ppc64__)) && !(defined(__APPLE__) && defined(__MACH__))
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "l"
+#  endif
+#  ifndef PRINTF_INT32_MODIFIER
+#   define PRINTF_INT32_MODIFIER ""
+#  endif
+# else
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "ll"
+#  endif
+#  ifndef PRINTF_INT32_MODIFIER
+#   if (UINT_MAX == UINT32_MAX)
+#    define PRINTF_INT32_MODIFIER ""
+#   else
+#    define PRINTF_INT32_MODIFIER "l"
+#   endif
+#  endif
+# endif
+# ifndef PRINTF_INT16_MODIFIER
+#  define PRINTF_INT16_MODIFIER "h"
+# endif
+# ifndef PRINTF_INTMAX_MODIFIER
+#  define PRINTF_INTMAX_MODIFIER PRINTF_INT64_MODIFIER
+# endif
+# ifndef PRINTF_INT64_HEX_WIDTH
+#  define PRINTF_INT64_HEX_WIDTH "16"
+# endif
+# ifndef PRINTF_UINT64_HEX_WIDTH
+#  define PRINTF_UINT64_HEX_WIDTH "16"
+# endif
+# ifndef PRINTF_INT32_HEX_WIDTH
+#  define PRINTF_INT32_HEX_WIDTH "8"
+# endif
+# ifndef PRINTF_UINT32_HEX_WIDTH
+#  define PRINTF_UINT32_HEX_WIDTH "8"
+# endif
+# ifndef PRINTF_INT16_HEX_WIDTH
+#  define PRINTF_INT16_HEX_WIDTH "4"
+# endif
+# ifndef PRINTF_UINT16_HEX_WIDTH
+#  define PRINTF_UINT16_HEX_WIDTH "4"
+# endif
+# ifndef PRINTF_INT8_HEX_WIDTH
+#  define PRINTF_INT8_HEX_WIDTH "2"
+# endif
+# ifndef PRINTF_UINT8_HEX_WIDTH
+#  define PRINTF_UINT8_HEX_WIDTH "2"
+# endif
+# ifndef PRINTF_INT64_DEC_WIDTH
+#  define PRINTF_INT64_DEC_WIDTH "19"
+# endif
+# ifndef PRINTF_UINT64_DEC_WIDTH
+#  define PRINTF_UINT64_DEC_WIDTH "20"
+# endif
+# ifndef PRINTF_INT32_DEC_WIDTH
+#  define PRINTF_INT32_DEC_WIDTH "10"
+# endif
+# ifndef PRINTF_UINT32_DEC_WIDTH
+#  define PRINTF_UINT32_DEC_WIDTH "10"
+# endif
+# ifndef PRINTF_INT16_DEC_WIDTH
+#  define PRINTF_INT16_DEC_WIDTH "5"
+# endif
+# ifndef PRINTF_UINT16_DEC_WIDTH
+#  define PRINTF_UINT16_DEC_WIDTH "5"
+# endif
+# ifndef PRINTF_INT8_DEC_WIDTH
+#  define PRINTF_INT8_DEC_WIDTH "3"
+# endif
+# ifndef PRINTF_UINT8_DEC_WIDTH
+#  define PRINTF_UINT8_DEC_WIDTH "3"
+# endif
+# ifndef PRINTF_INTMAX_HEX_WIDTH
+#  define PRINTF_INTMAX_HEX_WIDTH PRINTF_UINT64_HEX_WIDTH
+# endif
+# ifndef PRINTF_UINTMAX_HEX_WIDTH
+#  define PRINTF_UINTMAX_HEX_WIDTH PRINTF_UINT64_HEX_WIDTH
+# endif
+# ifndef PRINTF_INTMAX_DEC_WIDTH
+#  define PRINTF_INTMAX_DEC_WIDTH PRINTF_UINT64_DEC_WIDTH
+# endif
+# ifndef PRINTF_UINTMAX_DEC_WIDTH
+#  define PRINTF_UINTMAX_DEC_WIDTH PRINTF_UINT64_DEC_WIDTH
+# endif
+
+/*
+ *  Something really weird is going on with Open Watcom.  Just pull some of
+ *  these duplicated definitions from Open Watcom's stdint.h file for now.
+ */
+
+# if defined (__WATCOMC__) && __WATCOMC__ >= 1250
+#  if !defined (INT64_C)
+#   define INT64_C(x)   (x + (INT64_MAX - INT64_MAX))
+#  endif
+#  if !defined (UINT64_C)
+#   define UINT64_C(x)  (x + (UINT64_MAX - UINT64_MAX))
+#  endif
+#  if !defined (INT32_C)
+#   define INT32_C(x)   (x + (INT32_MAX - INT32_MAX))
+#  endif
+#  if !defined (UINT32_C)
+#   define UINT32_C(x)  (x + (UINT32_MAX - UINT32_MAX))
+#  endif
+#  if !defined (INT16_C)
+#   define INT16_C(x)   (x)
+#  endif
+#  if !defined (UINT16_C)
+#   define UINT16_C(x)  (x)
+#  endif
+#  if !defined (INT8_C)
+#   define INT8_C(x)   (x)
+#  endif
+#  if !defined (UINT8_C)
+#   define UINT8_C(x)  (x)
+#  endif
+#  if !defined (UINT64_MAX)
+#   define UINT64_MAX  18446744073709551615ULL
+#  endif
+#  if !defined (INT64_MAX)
+#   define INT64_MAX  9223372036854775807LL
+#  endif
+#  if !defined (UINT32_MAX)
+#   define UINT32_MAX  4294967295UL
+#  endif
+#  if !defined (INT32_MAX)
+#   define INT32_MAX  2147483647L
+#  endif
+#  if !defined (INTMAX_MAX)
+#   define INTMAX_MAX INT64_MAX
+#  endif
+#  if !defined (INTMAX_MIN)
+#   define INTMAX_MIN INT64_MIN
+#  endif
+# endif
+#endif
+
+/*
+ *  I have no idea what is the truly correct thing to do on older Solaris.
+ *  From some online discussions, this seems to be what is being
+ *  recommended.  For people who actually are developing on older Solaris,
+ *  what I would like to know is, does this define all of the relevant
+ *  macros of a complete stdint.h?  Remember, in pstdint.h 64 bit is
+ *  considered optional.
+ */
+
+#if (defined(__SUNPRO_C) && __SUNPRO_C >= 0x420) && !defined(_PSTDINT_H_INCLUDED)
+#include <sys/inttypes.h>
+#define _PSTDINT_H_INCLUDED
+#endif
+
+#ifndef _PSTDINT_H_INCLUDED
+#define _PSTDINT_H_INCLUDED
+
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t)-1)
+#endif
+
+/*
+ *  Deduce the type assignments from limits.h under the assumption that
+ *  integer sizes in bits are powers of 2, and follow the ANSI
+ *  definitions.
+ */
+
+#ifndef UINT8_MAX
+# define UINT8_MAX 0xff
+#endif
+#if !defined(uint8_t) && !defined(_UINT8_T) && !defined(vxWorks)
+# if (UCHAR_MAX == UINT8_MAX) || defined (S_SPLINT_S)
+    typedef unsigned char uint8_t;
+#   define UINT8_C(v) ((uint8_t) v)
+# else
+#   error "Platform not supported"
+# endif
+#endif
+
+#ifndef INT8_MAX
+# define INT8_MAX 0x7f
+#endif
+#ifndef INT8_MIN
+# define INT8_MIN INT8_C(0x80)
+#endif
+#if !defined(int8_t) && !defined(_INT8_T) && !defined(vxWorks)
+# if (SCHAR_MAX == INT8_MAX) || defined (S_SPLINT_S)
+    typedef signed char int8_t;
+#   define INT8_C(v) ((int8_t) v)
+# else
+#   error "Platform not supported"
+# endif
+#endif
+
+#ifndef UINT16_MAX
+# define UINT16_MAX 0xffff
+#endif
+#if !defined(uint16_t) && !defined(_UINT16_T) && !defined(vxWorks)
+#if (UINT_MAX == UINT16_MAX) || defined (S_SPLINT_S)
+  typedef unsigned int uint16_t;
+# ifndef PRINTF_INT16_MODIFIER
+#  define PRINTF_INT16_MODIFIER ""
+# endif
+# define UINT16_C(v) ((uint16_t) (v))
+#elif (USHRT_MAX == UINT16_MAX)
+  typedef unsigned short uint16_t;
+# define UINT16_C(v) ((uint16_t) (v))
+# ifndef PRINTF_INT16_MODIFIER
+#  define PRINTF_INT16_MODIFIER "h"
+# endif
+#else
+#error "Platform not supported"
+#endif
+#endif
+
+#ifndef INT16_MAX
+# define INT16_MAX 0x7fff
+#endif
+#ifndef INT16_MIN
+# define INT16_MIN INT16_C(0x8000)
+#endif
+#if !defined(int16_t) && !defined(_INT16_T) && !defined(vxWorks)
+#if (INT_MAX == INT16_MAX) || defined (S_SPLINT_S)
+  typedef signed int int16_t;
+# define INT16_C(v) ((int16_t) (v))
+# ifndef PRINTF_INT16_MODIFIER
+#  define PRINTF_INT16_MODIFIER ""
+# endif
+#elif (SHRT_MAX == INT16_MAX)
+  typedef signed short int16_t;
+# define INT16_C(v) ((int16_t) (v))
+# ifndef PRINTF_INT16_MODIFIER
+#  define PRINTF_INT16_MODIFIER "h"
+# endif
+#else
+#error "Platform not supported"
+#endif
+#endif
+
+#ifndef UINT32_MAX
+# define UINT32_MAX (0xffffffffUL)
+#endif
+#if !defined(uint32_t) && !defined(_UINT32_T) && !defined(vxWorks)
+#if (ULONG_MAX == UINT32_MAX) || defined (S_SPLINT_S)
+  typedef unsigned long uint32_t;
+# define UINT32_C(v) v ## UL
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER "l"
+# endif
+#elif (UINT_MAX == UINT32_MAX)
+  typedef unsigned int uint32_t;
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER ""
+# endif
+# define UINT32_C(v) v ## U
+#elif (USHRT_MAX == UINT32_MAX)
+  typedef unsigned short uint32_t;
+# define UINT32_C(v) ((unsigned short) (v))
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER ""
+# endif
+#else
+#error "Platform not supported"
+#endif
+#endif
+
+#ifndef INT32_MAX
+# define INT32_MAX (0x7fffffffL)
+#endif
+#ifndef INT32_MIN
+# define INT32_MIN INT32_C(0x80000000)
+#endif
+#if !defined(int32_t) && !defined(_INT32_T) && !defined(vxWorks)
+#if (LONG_MAX == INT32_MAX) || defined (S_SPLINT_S)
+  typedef signed long int32_t;
+# define INT32_C(v) v ## L
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER "l"
+# endif
+#elif (INT_MAX == INT32_MAX)
+  typedef signed int int32_t;
+# define INT32_C(v) v
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER ""
+# endif
+#elif (SHRT_MAX == INT32_MAX)
+  typedef signed short int32_t;
+# define INT32_C(v) ((short) (v))
+# ifndef PRINTF_INT32_MODIFIER
+#  define PRINTF_INT32_MODIFIER ""
+# endif
+#else
+#error "Platform not supported"
+#endif
+#endif
+
+/*
+ *  The macro stdint_int64_defined is temporarily used to record
+ *  whether or not 64 integer support is available.  It must be
+ *  defined for any 64 integer extensions for new platforms that are
+ *  added.
+ */
+
+#undef stdint_int64_defined
+#if (defined(__STDC__) && defined(__STDC_VERSION__)) || defined (S_SPLINT_S)
+# if (__STDC__ && __STDC_VERSION__ >= 199901L) || defined (S_SPLINT_S)
+#  define stdint_int64_defined
+   typedef long long int64_t;
+   typedef unsigned long long uint64_t;
+#  define UINT64_C(v) v ## ULL
+#  define  INT64_C(v) v ## LL
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "ll"
+#  endif
+# endif
+#endif
+
+#if !defined (stdint_int64_defined)
+# if defined(__GNUC__) && !defined(vxWorks)
+#  define stdint_int64_defined
+   __extension__ typedef long long int64_t;
+   __extension__ typedef unsigned long long uint64_t;
+#  define UINT64_C(v) v ## ULL
+#  define  INT64_C(v) v ## LL
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "ll"
+#  endif
+# elif defined(__MWERKS__) || defined (__SUNPRO_C) || defined (__SUNPRO_CC) || defined (__APPLE_CC__) || defined (_LONG_LONG) || defined (_CRAYC) || defined (S_SPLINT_S)
+#  define stdint_int64_defined
+   typedef long long int64_t;
+   typedef unsigned long long uint64_t;
+#  define UINT64_C(v) v ## ULL
+#  define  INT64_C(v) v ## LL
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "ll"
+#  endif
+# elif (defined(__WATCOMC__) && defined(__WATCOM_INT64__)) || (defined(_MSC_VER) && _INTEGRAL_MAX_BITS >= 64) || (defined (__BORLANDC__) && __BORLANDC__ > 0x460) || defined (__alpha) || defined (__DECC)
+#  define stdint_int64_defined
+   typedef __int64 int64_t;
+   typedef unsigned __int64 uint64_t;
+#  define UINT64_C(v) v ## UI64
+#  define  INT64_C(v) v ## I64
+#  ifndef PRINTF_INT64_MODIFIER
+#   define PRINTF_INT64_MODIFIER "I64"
+#  endif
+# endif
+#endif
+
+#if !defined (LONG_LONG_MAX) && defined (INT64_C)
+# define LONG_LONG_MAX INT64_C (9223372036854775807)
+#endif
+#ifndef ULONG_LONG_MAX
+# define ULONG_LONG_MAX UINT64_C (18446744073709551615)
+#endif
+
+#if !defined (INT64_MAX) && defined (INT64_C)
+# define INT64_MAX INT64_C (9223372036854775807)
+#endif
+#if !defined (INT64_MIN) && defined (INT64_C)
+# define INT64_MIN INT64_C (-9223372036854775808)
+#endif
+#if !defined (UINT64_MAX) && defined (INT64_C)
+# define UINT64_MAX UINT64_C (18446744073709551615)
+#endif
+
+/*
+ *  Width of hexadecimal for number field.
+ */
+
+#ifndef PRINTF_INT64_HEX_WIDTH
+# define PRINTF_INT64_HEX_WIDTH "16"
+#endif
+#ifndef PRINTF_INT32_HEX_WIDTH
+# define PRINTF_INT32_HEX_WIDTH "8"
+#endif
+#ifndef PRINTF_INT16_HEX_WIDTH
+# define PRINTF_INT16_HEX_WIDTH "4"
+#endif
+#ifndef PRINTF_INT8_HEX_WIDTH
+# define PRINTF_INT8_HEX_WIDTH "2"
+#endif
+#ifndef PRINTF_INT64_DEC_WIDTH
+# define PRINTF_INT64_DEC_WIDTH "19"
+#endif
+#ifndef PRINTF_INT32_DEC_WIDTH
+# define PRINTF_INT32_DEC_WIDTH "10"
+#endif
+#ifndef PRINTF_INT16_DEC_WIDTH
+# define PRINTF_INT16_DEC_WIDTH "5"
+#endif
+#ifndef PRINTF_INT8_DEC_WIDTH
+# define PRINTF_INT8_DEC_WIDTH "3"
+#endif
+#ifndef PRINTF_UINT64_DEC_WIDTH
+# define PRINTF_UINT64_DEC_WIDTH "20"
+#endif
+#ifndef PRINTF_UINT32_DEC_WIDTH
+# define PRINTF_UINT32_DEC_WIDTH "10"
+#endif
+#ifndef PRINTF_UINT16_DEC_WIDTH
+# define PRINTF_UINT16_DEC_WIDTH "5"
+#endif
+#ifndef PRINTF_UINT8_DEC_WIDTH
+# define PRINTF_UINT8_DEC_WIDTH "3"
+#endif
+
+/*
+ *  Ok, lets not worry about 128 bit integers for now.  Moore's law says
+ *  we don't need to worry about that until about 2040 at which point
+ *  we'll have bigger things to worry about.
+ */
+
+#ifdef stdint_int64_defined
+  typedef int64_t intmax_t;
+  typedef uint64_t uintmax_t;
+# define  INTMAX_MAX   INT64_MAX
+# define  INTMAX_MIN   INT64_MIN
+# define UINTMAX_MAX  UINT64_MAX
+# define UINTMAX_C(v) UINT64_C(v)
+# define  INTMAX_C(v)  INT64_C(v)
+# ifndef PRINTF_INTMAX_MODIFIER
+#   define PRINTF_INTMAX_MODIFIER PRINTF_INT64_MODIFIER
+# endif
+# ifndef PRINTF_INTMAX_HEX_WIDTH
+#  define PRINTF_INTMAX_HEX_WIDTH PRINTF_INT64_HEX_WIDTH
+# endif
+# ifndef PRINTF_INTMAX_DEC_WIDTH
+#  define PRINTF_INTMAX_DEC_WIDTH PRINTF_INT64_DEC_WIDTH
+# endif
+#else
+  typedef int32_t intmax_t;
+  typedef uint32_t uintmax_t;
+# define  INTMAX_MAX   INT32_MAX
+# define UINTMAX_MAX  UINT32_MAX
+# define UINTMAX_C(v) UINT32_C(v)
+# define  INTMAX_C(v)  INT32_C(v)
+# ifndef PRINTF_INTMAX_MODIFIER
+#   define PRINTF_INTMAX_MODIFIER PRINTF_INT32_MODIFIER
+# endif
+# ifndef PRINTF_INTMAX_HEX_WIDTH
+#  define PRINTF_INTMAX_HEX_WIDTH PRINTF_INT32_HEX_WIDTH
+# endif
+# ifndef PRINTF_INTMAX_DEC_WIDTH
+#  define PRINTF_INTMAX_DEC_WIDTH PRINTF_INT32_DEC_WIDTH
+# endif
+#endif
+
+/*
+ *  Because this file currently only supports platforms which have
+ *  precise powers of 2 as bit sizes for the default integers, the
+ *  least definitions are all trivial.  Its possible that a future
+ *  version of this file could have different definitions.
+ */
+
+#ifndef stdint_least_defined
+  typedef   int8_t   int_least8_t;
+  typedef  uint8_t  uint_least8_t;
+  typedef  int16_t  int_least16_t;
+  typedef uint16_t uint_least16_t;
+  typedef  int32_t  int_least32_t;
+  typedef uint32_t uint_least32_t;
+# define PRINTF_LEAST32_MODIFIER PRINTF_INT32_MODIFIER
+# define PRINTF_LEAST16_MODIFIER PRINTF_INT16_MODIFIER
+# define  UINT_LEAST8_MAX  UINT8_MAX
+# define   INT_LEAST8_MAX   INT8_MAX
+# define UINT_LEAST16_MAX UINT16_MAX
+# define  INT_LEAST16_MAX  INT16_MAX
+# define UINT_LEAST32_MAX UINT32_MAX
+# define  INT_LEAST32_MAX  INT32_MAX
+# define   INT_LEAST8_MIN   INT8_MIN
+# define  INT_LEAST16_MIN  INT16_MIN
+# define  INT_LEAST32_MIN  INT32_MIN
+# ifdef stdint_int64_defined
+    typedef  int64_t  int_least64_t;
+    typedef uint64_t uint_least64_t;
+#   define PRINTF_LEAST64_MODIFIER PRINTF_INT64_MODIFIER
+#   define UINT_LEAST64_MAX UINT64_MAX
+#   define  INT_LEAST64_MAX  INT64_MAX
+#   define  INT_LEAST64_MIN  INT64_MIN
+# endif
+#endif
+#undef stdint_least_defined
+
+/*
+ *  The ANSI C committee has defined *int*_fast*_t types as well.  This,
+ *  of course, defies rationality -- you can't know what will be fast
+ *  just from the type itself.  Even for a given architecture, compatible
+ *  implementations might have different performance characteristics.
+ *  Developers are warned to stay away from these types when using this
+ *  or any other stdint.h.
+ */
+
+typedef   int_least8_t   int_fast8_t;
+typedef  uint_least8_t  uint_fast8_t;
+typedef  int_least16_t  int_fast16_t;
+typedef uint_least16_t uint_fast16_t;
+typedef  int_least32_t  int_fast32_t;
+typedef uint_least32_t uint_fast32_t;
+#define  UINT_FAST8_MAX  UINT_LEAST8_MAX
+#define   INT_FAST8_MAX   INT_LEAST8_MAX
+#define UINT_FAST16_MAX UINT_LEAST16_MAX
+#define  INT_FAST16_MAX  INT_LEAST16_MAX
+#define UINT_FAST32_MAX UINT_LEAST32_MAX
+#define  INT_FAST32_MAX  INT_LEAST32_MAX
+#define   INT_FAST8_MIN   INT_LEAST8_MIN
+#define  INT_FAST16_MIN  INT_LEAST16_MIN
+#define  INT_FAST32_MIN  INT_LEAST32_MIN
+#ifdef stdint_int64_defined
+  typedef  int_least64_t  int_fast64_t;
+  typedef uint_least64_t uint_fast64_t;
+# define UINT_FAST64_MAX UINT_LEAST64_MAX
+# define  INT_FAST64_MAX  INT_LEAST64_MAX
+# define  INT_FAST64_MIN  INT_LEAST64_MIN
+#endif
+
+#undef stdint_int64_defined
+
+/*
+ *  Whatever piecemeal, per compiler thing we can do about the wchar_t
+ *  type limits.
+ */
+
+#if defined(__WATCOMC__) || defined(_MSC_VER) || defined (__GNUC__) && !defined(vxWorks)
+# include <wchar.h>
+# ifndef WCHAR_MIN
+#  define WCHAR_MIN 0
+# endif
+# ifndef WCHAR_MAX
+#  define WCHAR_MAX ((wchar_t)-1)
+# endif
+#endif
+
+/*
+ *  Whatever piecemeal, per compiler/platform thing we can do about the
+ *  (u)intptr_t types and limits.
+ */
+
+#if (defined (_MSC_VER) && defined (_UINTPTR_T_DEFINED)) || defined (_UINTPTR_T)
+# define STDINT_H_UINTPTR_T_DEFINED
+#endif
+
+#ifndef STDINT_H_UINTPTR_T_DEFINED
+# if defined (__alpha__) || defined (__ia64__) || defined (__x86_64__) || defined (_WIN64) || defined (__ppc64__)
+#  define stdint_intptr_bits 64
+# elif defined (__WATCOMC__) || defined (__TURBOC__)
+#  if defined(__TINY__) || defined(__SMALL__) || defined(__MEDIUM__)
+#    define stdint_intptr_bits 16
+#  else
+#    define stdint_intptr_bits 32
+#  endif
+# elif defined (__i386__) || defined (_WIN32) || defined (WIN32) || defined (__ppc64__)
+#  define stdint_intptr_bits 32
+# elif defined (__INTEL_COMPILER)
+/* TODO -- what did Intel do about x86-64? */
+# else
+/* #error "This platform might not be supported yet" */
+# endif
+
+# ifdef stdint_intptr_bits
+#  define stdint_intptr_glue3_i(a,b,c)  a##b##c
+#  define stdint_intptr_glue3(a,b,c)    stdint_intptr_glue3_i(a,b,c)
+#  ifndef PRINTF_INTPTR_MODIFIER
+#    define PRINTF_INTPTR_MODIFIER      stdint_intptr_glue3(PRINTF_INT,stdint_intptr_bits,_MODIFIER)
+#  endif
+#  ifndef PTRDIFF_MAX
+#    define PTRDIFF_MAX                 stdint_intptr_glue3(INT,stdint_intptr_bits,_MAX)
+#  endif
+#  ifndef PTRDIFF_MIN
+#    define PTRDIFF_MIN                 stdint_intptr_glue3(INT,stdint_intptr_bits,_MIN)
+#  endif
+#  ifndef UINTPTR_MAX
+#    define UINTPTR_MAX                 stdint_intptr_glue3(UINT,stdint_intptr_bits,_MAX)
+#  endif
+#  ifndef INTPTR_MAX
+#    define INTPTR_MAX                  stdint_intptr_glue3(INT,stdint_intptr_bits,_MAX)
+#  endif
+#  ifndef INTPTR_MIN
+#    define INTPTR_MIN                  stdint_intptr_glue3(INT,stdint_intptr_bits,_MIN)
+#  endif
+#  ifndef INTPTR_C
+#    define INTPTR_C(x)                 stdint_intptr_glue3(INT,stdint_intptr_bits,_C)(x)
+#  endif
+#  ifndef UINTPTR_C
+#    define UINTPTR_C(x)                stdint_intptr_glue3(UINT,stdint_intptr_bits,_C)(x)
+#  endif
+  typedef stdint_intptr_glue3(uint,stdint_intptr_bits,_t) uintptr_t;
+  typedef stdint_intptr_glue3( int,stdint_intptr_bits,_t)  intptr_t;
+# else
+/* TODO -- This following is likely wrong for some platforms, and does
+   nothing for the definition of uintptr_t. */
+  typedef ptrdiff_t intptr_t;
+# endif
+# define STDINT_H_UINTPTR_T_DEFINED
+#endif
+
+/*
+ *  Assumes sig_atomic_t is signed and we have a 2s complement machine.
+ */
+
+#ifndef SIG_ATOMIC_MAX
+# define SIG_ATOMIC_MAX ((((sig_atomic_t) 1) << (sizeof (sig_atomic_t)*CHAR_BIT-1)) - 1)
+#endif
+
+#endif
+
+#if defined (__TEST_PSTDINT_FOR_CORRECTNESS)
+
+/*
+ *  Please compile with the maximum warning settings to make sure macros are
+ *  not defined more than once.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#define glue3_aux(x,y,z) x ## y ## z
+#define glue3(x,y,z) glue3_aux(x,y,z)
+
+#define DECLU(bits) glue3(uint,bits,_t) glue3(u,bits,) = glue3(UINT,bits,_C) (0);
+#define DECLI(bits) glue3(int,bits,_t) glue3(i,bits,) = glue3(INT,bits,_C) (0);
+
+#define DECL(us,bits) glue3(DECL,us,) (bits)
+
+#define TESTUMAX(bits) glue3(u,bits,) = ~glue3(u,bits,); if (glue3(UINT,bits,_MAX) != glue3(u,bits,)) printf ("Something wrong with UINT%d_MAX\n", bits)
+
+#define REPORTERROR(msg) { err_n++; if (err_first <= 0) err_first = __LINE__; printf msg; }
+
+#define X_SIZE_MAX ((size_t)-1)
+
+int main () {
+    int err_n = 0;
+    int err_first = 0;
+    DECL(I,8)
+    DECL(U,8)
+    DECL(I,16)
+    DECL(U,16)
+    DECL(I,32)
+    DECL(U,32)
+#ifdef INT64_MAX
+    DECL(I,64)
+    DECL(U,64)
+#endif
+    intmax_t imax = INTMAX_C(0);
+    uintmax_t umax = UINTMAX_C(0);
+    char str0[256], str1[256];
+
+    sprintf (str0, "%" PRINTF_INT32_MODIFIER "d", INT32_C(2147483647));
+    if (0 != strcmp (str0, "2147483647")) REPORTERROR (("Something wrong with PRINTF_INT32_MODIFIER : %s\n", str0));
+    if (atoi(PRINTF_INT32_DEC_WIDTH) != (int) strlen(str0)) REPORTERROR (("Something wrong with PRINTF_INT32_DEC_WIDTH : %s\n", PRINTF_INT32_DEC_WIDTH));
+    sprintf (str0, "%" PRINTF_INT32_MODIFIER "u", UINT32_C(4294967295));
+    if (0 != strcmp (str0, "4294967295")) REPORTERROR (("Something wrong with PRINTF_INT32_MODIFIER : %s\n", str0));
+    if (atoi(PRINTF_UINT32_DEC_WIDTH) != (int) strlen(str0)) REPORTERROR (("Something wrong with PRINTF_UINT32_DEC_WIDTH : %s\n", PRINTF_UINT32_DEC_WIDTH));
+#ifdef INT64_MAX
+    sprintf (str1, "%" PRINTF_INT64_MODIFIER "d", INT64_C(9223372036854775807));
+    if (0 != strcmp (str1, "9223372036854775807")) REPORTERROR (("Something wrong with PRINTF_INT32_MODIFIER : %s\n", str1));
+    if (atoi(PRINTF_INT64_DEC_WIDTH) != (int) strlen(str1)) REPORTERROR (("Something wrong with PRINTF_INT64_DEC_WIDTH : %s, %d\n", PRINTF_INT64_DEC_WIDTH, (int) strlen(str1)));
+    sprintf (str1, "%" PRINTF_INT64_MODIFIER "u", UINT64_C(18446744073709550591));
+    if (0 != strcmp (str1, "18446744073709550591")) REPORTERROR (("Something wrong with PRINTF_INT32_MODIFIER : %s\n", str1));
+    if (atoi(PRINTF_UINT64_DEC_WIDTH) != (int) strlen(str1)) REPORTERROR (("Something wrong with PRINTF_UINT64_DEC_WIDTH : %s, %d\n", PRINTF_UINT64_DEC_WIDTH, (int) strlen(str1)));
+#endif
+
+    sprintf (str0, "%d %x\n", 0, ~0);
+
+    sprintf (str1, "%d %x\n",  i8, ~0);
+    if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with i8 : %s\n", str1));
+    sprintf (str1, "%u %x\n",  u8, ~0);
+    if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with u8 : %s\n", str1));
+    sprintf (str1, "%d %x\n",  i16, ~0);
+    if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with i16 : %s\n", str1));
+    sprintf (str1, "%u %x\n",  u16, ~0);
+    if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with u16 : %s\n", str1));
+    sprintf (str1, "%" PRINTF_INT32_MODIFIER "d %x\n",  i32, ~0);
+    if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with i32 : %s\n", str1));
+    sprintf (str1, "%" PRINTF_INT32_MODIFIER "u %x\n",  u32, ~0);
+    if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with u32 : %s\n", str1));
+#ifdef INT64_MAX
+    sprintf (str1, "%" PRINTF_INT64_MODIFIER "d %x\n",  i64, ~0);
+    if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with i64 : %s\n", str1));
+#endif
+    sprintf (str1, "%" PRINTF_INTMAX_MODIFIER "d %x\n",  imax, ~0);
+    if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with imax : %s\n", str1));
+    sprintf (str1, "%" PRINTF_INTMAX_MODIFIER "u %x\n",  umax, ~0);
+    if (0 != strcmp (str0, str1)) REPORTERROR (("Something wrong with umax : %s\n", str1));
+
+    TESTUMAX(8);
+    TESTUMAX(16);
+    TESTUMAX(32);
+#ifdef INT64_MAX
+    TESTUMAX(64);
+#endif
+
+#define STR(v) #v
+#define Q(v) printf ("sizeof " STR(v) " = %u\n", (unsigned) sizeof (v));
+    if (err_n) {
+        printf ("pstdint.h is not correct.  Please use sizes below to correct it:\n");
+    }
+
+    Q(int)
+    Q(unsigned)
+    Q(long int)
+    Q(short int)
+    Q(int8_t)
+    Q(int16_t)
+    Q(int32_t)
+#ifdef INT64_MAX
+    Q(int64_t)
+#endif
+
+#if UINT_MAX < X_SIZE_MAX
+    printf ("UINT_MAX < X_SIZE_MAX\n");
+#else
+    printf ("UINT_MAX >= X_SIZE_MAX\n");
+#endif
+    printf ("%" PRINTF_INT64_MODIFIER "u vs %" PRINTF_INT64_MODIFIER "u\n", UINT_MAX, X_SIZE_MAX);
+
+    return EXIT_SUCCESS;
+}
+
+#endif