Example #1
0
//
// Return the conflict generated by a theory solver
//
void THandler::getConflict ( vec< Lit > & conflict, int & max_decision_level )
{
  // First of all, the explanation in a tsolver is
  // stored as conjunction of enodes e1,...,en
  // with associated polarities p1,...,pn. Since the sat-solver
  // wants a clause we store it in the form ( l1 | ... | ln )
  // where li is the literal corresponding with ei with polarity !pi
  vector< Enode * > & explanation = core_solver.getConflict( );
  assert( !explanation.empty( ) );

  if ( config.certification_level > 0 )
    verifyExplanationWithExternalTool( explanation );

#ifdef PRODUCE_PROOF
  max_decision_level = -1;
  for ( vector< Enode * >::iterator it = explanation.begin( )
      ; it != explanation.end( )
      ; ++ it )
  {
    Enode * ei  = *it;
    assert( ei->hasPolarity( ) );
    assert( ei->getPolarity( ) == l_True
         || ei->getPolarity( ) == l_False );
    bool negate = ei->getPolarity( ) == l_False;

    Var v = enodeToVar( ei );
#if PEDANTIC_DEBUG
    assert( isOnTrail( Lit( v, negate ) ) );
#endif
    Lit l = Lit( v, !negate );
    conflict.push( l );

    if ( max_decision_level < level[ v ] )
      max_decision_level = level[ v ];
  }
  if ( config.produce_inter == 0 )
    explanation.clear( );
#else
  max_decision_level = -1;
  while ( !explanation.empty( ) )
  {
    Enode * ei  = explanation.back( );
    explanation.pop_back( );
    assert( ei->hasPolarity( ) );
    assert( ei->getPolarity( ) == l_True
         || ei->getPolarity( ) == l_False );
    bool negate = ei->getPolarity( ) == l_False;

    Var v = enodeToVar( ei );
#if PEDANTIC_DEBUG
    assert( isOnTrail( Lit( v, negate ) ) );
#endif
    Lit l = Lit( v, !negate );
    conflict.push( l );

    if ( max_decision_level < level[ v ] )
      max_decision_level = level[ v ];
  }
#endif
}
Example #2
0
void THandler::backtrack( )
{
  // Undoes the state of theory atoms if needed
  while ( (int)stack.size( ) > trail.size( ) )
  {
    Enode * e = stack.back( );
    stack.pop_back( );

    // It was var_True or var_False
    if ( e == NULL )
      continue;

    if ( !e->isTAtom( ) )
      continue;

    core_solver.popBacktrackPoint( );

    assert( e->isTAtom( ) );
    assert( e->hasPolarity( ) );
    assert( e->getPolarity( ) == l_True
         || e->getPolarity( ) == l_False );
    // Reset polarity
    e->resetPolarity( );
    assert( !e->hasPolarity( ) );
  }
  checked_trail_size = stack.size( );
}
Example #3
0
ibex::SystemFactory * contractor_ibex_polytope::build_system_factory(
    vector<Enode *> const & vars, vector<shared_ptr<nonlinear_constraint>> const & ctrs) {
    DREAL_LOG_DEBUG << "build_system_factory:";
    ibex::SystemFactory * sf = new ibex::SystemFactory();
    map<string, ibex::ExprSymbol const *> var_map;  // Needed for translateEnodeToExprCtr

    // Construct System: add Variables
    for (Enode * e : vars) {
        string const & name = e->getCar()->getNameFull();
        DREAL_LOG_INFO << "build_system_factory: Add Variable " << name;
        auto var_it = m_var_cache.find(e);
        ibex::ExprSymbol const * var = nullptr;
        if (var_it == m_var_cache.end()) {
            // Not found
            var = &ibex::ExprSymbol::new_(name.c_str(), ibex::Dim::scalar());
            DREAL_LOG_INFO << "Added: var " << var << endl;
            m_var_cache.emplace(e, var);
        } else {
            // Found
            var = var_it->second;
        }
        var_map.emplace(name, var);
        sf->add_var(*var);
    }
    DREAL_LOG_DEBUG << "build_system_factory: Add Variable: DONE";

    // Construct System: add constraints
    for (shared_ptr<nonlinear_constraint> const ctr : ctrs) {
        if (ctr->is_neq()) {
            continue;
        }
        DREAL_LOG_INFO << "build_system_factory: Add Constraint: " << *ctr;
        Enode * e = ctr->get_enode();
        auto p = e->getPolarity();
        assert(p == l_True || p == l_False);
        auto & m_exprctr_cache = (p == l_True) ? m_exprctr_cache_pos : m_exprctr_cache_neg;
        auto exprctr_it = m_exprctr_cache.find(e);
        ibex::ExprCtr const * exprctr = nullptr;
        if (exprctr_it == m_exprctr_cache.end()) {
            // Not found
            exprctr = translate_enode_to_exprctr(var_map, e);
            m_exprctr_cache.emplace(e, exprctr);
            DREAL_LOG_INFO << "Added: exprctr " << p << " " << *exprctr << endl;
        } else {
            // Found
            exprctr = exprctr_it->second;
        }
        if (exprctr) {
            DREAL_LOG_INFO << "build_system_factory: Add Constraint: expr: " << *exprctr;
            sf->add_ctr(*exprctr);
        }
    }
    DREAL_LOG_DEBUG << "build_system_factory: Add Constraint: "
                    << "DONE";
    DREAL_LOG_DEBUG << "build_system_factory: DONE";
    return sf;
}
Example #4
0
ostream & ode_constraint::display(ostream & out) const {
    out << "ode_constraint(" << m_int << ")" << endl;
    for (shared_ptr<forallt_constraint> const & inv : m_invs) {
        Enode * e = inv->get_enodes()[0];
        if (e->hasPolarity() && e->getPolarity() == l_True) {
            out << *inv << endl;
        }
    }
    return out;
}
Example #5
0
void THandler::verifyExplanationWithExternalTool( vector< Enode * > & expl )
{
  // First stage: print declarations
  const char * name = "/tmp/verifyexp.smt2";
  std::ofstream dump_out( name );

  core_solver.dumpHeaderToFile( dump_out );

  dump_out << "(assert " << endl;
  dump_out << "(and" << endl;

  for ( size_t j = 0 ; j < expl.size( ) ; j ++ )
  {
    Enode * e = expl[ j ];
    assert( e->isTAtom( ) );
    assert( e->getPolarity( ) != l_Undef );
    bool negated = e->getPolarity( ) == l_False;
    if ( negated )
      dump_out << "(not ";
    e->print( dump_out );
    if ( negated )
      dump_out << ")";

    dump_out << endl;
  }

  dump_out << "))" << endl;
  dump_out << "(check-sat)" << endl;
  dump_out << "(exit)" << endl;
  dump_out.close( );
  // Third stage, check the formula
  const bool tool_res = callCertifyingSolver( name );

  if ( tool_res == true )
    opensmt_error2( config.certifying_solver, " says this is not an explanation" );
}
Example #6
0
void CostSolver::check_status()
{
#ifndef NDEBUG
  for ( costfuns_t::iterator it = costfuns_.begin();
        it != costfuns_.end();
        ++it )
  {
    costfun & fun = **it;
    codomain slack = 0;
    for ( incurnode * n=fun.unassigned.head; n; n=n->next )
    {
      assert( !n->atom->hasPolarity() );
      if ( n->next )
      {
        assert( n != n->next );
        if ( n->cost > n->next->cost )
        {
          cout << n->cost << " > " << n->next->cost << endl;
        }
        assert( n->cost <= n->next->cost );
        assert( n->next->prev == n );
      }
      if ( n->prev )
      {
        assert( n->prev != n );
        assert( n->prev->next == n );
      }
      slack += get_incurred( n->atom );
    }
    assert( slack == fun.slack );
    {
      codomain incurred = 0;
      for ( costfun::nodes_t::iterator it = fun.assigned.begin();
            it != fun.assigned.end();
            ++it )
      {
        incurnode * node = *it;
        assert( node->atom->hasPolarity() );
        if ( node->atom->getPolarity() == l_True )
        {
          incurred += get_incurred( node->atom );
        }
      }
      if ( fun.incurred != incurred )
      {
        if ( conflict_ )
        {
          cout << "conflict = " << conflict_ << endl;
        }
        cout << "incurred = " << incurred << endl;
        print_status( cout, fun );
      }
      assert( fun.incurred == incurred );
    }
  }
  if ( conflict_ )
  {
    cout << "ct conflict " << conflict_ << endl;
    costfun & fun = *nodemap_.find( conflict_ )->second;
    codomain incurred = 0;
    Enode * upper_bound = 0;
    Enode * lower_bound = 0;
    for ( vector<Enode*>::iterator it = explanation.begin();
          it != explanation.end();
          ++it )
    {
      Enode * atom = *it;
      assert( atom->hasPolarity() );
      if ( atom->isCostIncur() )
      {
        if ( atom->getPolarity() == l_True )
        {
          incurred += get_incurred( atom );
        }
      }
      if ( atom->isCostBound() )
      {
        if ( atom->getPolarity() == l_True )
        {
          assert( !upper_bound );
          upper_bound = atom;
        }
        else
        {
          assert( !lower_bound );
          assert( atom->getPolarity() == l_False );
          lower_bound = atom;
        }
      }
    }
    if ( !fun.lowerbound.empty() && fun.upperbound.empty() )
    {
      assert( fun.incurred + fun.slack < get_bound( fun.lowerbound.top() ) );
    }
    if ( fun.lowerbound.empty() && !fun.upperbound.empty() )
    {
      assert( fun.incurred >= get_bound( fun.upperbound.top() ) );
      assert( incurred >= get_bound( upper_bound ) );
    }
  }
#endif
}
Example #7
0
void THandler::verifyInterpolantWithExternalTool( vector< Enode * > & expl
                                                , Enode * interp_list )
{
  uint64_t mask = 0xFFFFFFFFFFFFFFFEULL;
  for ( unsigned in = 1 ; in < core_solver.getNofPartitions( ) ; in ++ )
  {
    Enode * args = interp_list;
    // Advance in the interpolants list
    for ( unsigned i = 0 ; i < in - 1 ; i ++ )
      args = args->getCdr( );
    Enode * interp = args->getCar( );
    mask &= ~SETBIT( in );
    // Check A -> I, i.e., A & !I
    // First stage: print declarations
    const char * name = "/tmp/verifyinterp.smt2";
    std::ofstream dump_out( name );
    core_solver.dumpHeaderToFile( dump_out );
    // Print only A atoms
    dump_out << "(assert " << endl;
    dump_out << "(and" << endl;
    for ( size_t j = 0 ; j < expl.size( ) ; j ++ )
    {
      Enode * e = expl[ j ];
      assert( e->isTAtom( ) );
      assert( e->getPolarity( ) != l_Undef );
      assert( (core_solver.getIPartitions( e ) &  mask) != 0
           || (core_solver.getIPartitions( e ) & ~mask) != 0 );
      if ( (core_solver.getIPartitions( e ) & ~mask) != 0 )
      {
        bool negated = e->getPolarity( ) == l_False;
        if ( negated )
          dump_out << "(not ";
        e->print( dump_out );
        if ( negated )
          dump_out << ")";
        dump_out << endl;
      }
    }

    dump_out << "(not " << interp << ")" << endl;
    dump_out << "))" << endl;
    dump_out << "(check-sat)" << endl;
    dump_out << "(exit)" << endl;
    dump_out.close( );
    // Check !
    bool tool_res;
    if ( int pid = fork() )
    {
      int status;
      waitpid(pid, &status, 0);
      switch ( WEXITSTATUS( status ) )
      {
        case 0:
          tool_res = false;
          break;
        case 1:
          tool_res = true;
          break;
        default:
          perror( "Tool" );
          exit( EXIT_FAILURE );
      }
    }
    else
    {
      execlp( "tool_wrapper.sh", "tool_wrapper.sh", name, 0 );
      perror( "Tool" );
      exit( 1 );
    }

    if ( tool_res == true )
      opensmt_error2( config.certifying_solver, " says A -> I does not hold" );
    // Now check B & I
    dump_out.open( name );
    core_solver.dumpHeaderToFile( dump_out );
    // Print only B atoms
    dump_out << "(assert " << endl;
    dump_out << "(and" << endl;
    for ( size_t j = 0 ; j < expl.size( ) ; j ++ )
    {
      Enode * e = expl[ j ];
      assert( e->isTAtom( ) );
      assert( e->getPolarity( ) != l_Undef );
      assert( (core_solver.getIPartitions( e ) &  mask) != 0
           || (core_solver.getIPartitions( e ) & ~mask) != 0 );
      if ( (core_solver.getIPartitions( e ) & mask) != 0 )
      {
        bool negated = e->getPolarity( ) == l_False;
        if ( negated )
          dump_out << "(not ";
        e->print( dump_out );
        if ( negated )
          dump_out << ")";
        dump_out << endl;
      }
    }
    dump_out << interp << endl;
    dump_out << "))" << endl;
    dump_out << "(check-sat)" << endl;
    dump_out << "(exit)" << endl;
    dump_out.close( );
    // Check !
    tool_res;
    if ( int pid = fork() )
    {
      int status;
      waitpid(pid, &status, 0);
      switch ( WEXITSTATUS( status ) )
      {
        case 0:
          tool_res = false;
          break;
        case 1:
          tool_res = true;
          break;
        default:
          perror( "Tool" );
          exit( EXIT_FAILURE );
      }
    }
    else
    {
      execlp( "tool_wrapper.sh", "tool_wrapper.sh", name, 0 );
      perror( "Tool" );
      exit( 1 );
    }
    if ( tool_res == true )
      opensmt_error2( config.certifying_solver, " says B & I does not hold" );
  }
}
Example #8
0
void THandler::getReason( Lit l, vec< Lit > & reason )
{
#if LAZY_COMMUNICATION
  assert( checked_trail_size == stack.size( ) );
  assert( static_cast< int >( checked_trail_size ) == trail.size( ) );
#else
#endif

  Var v = var(l);
  Enode * e = varToEnode( v );

  // It must be a TAtom and already disabled
  assert( e->isTAtom( ) );
  assert( !e->hasPolarity( ) );
  assert( e->isDeduced( ) );
  assert( e->getDeduced( ) != l_Undef );           // Last assigned deduction
#if LAZY_COMMUNICATION
  assert( e->getPolarity( ) != l_Undef );          // Last assigned polarity
  assert( e->getPolarity( ) == e->getDeduced( ) ); // The two coincide
#else
#endif

  core_solver.pushBacktrackPoint( );

  // Assign reversed polarity temporairly
  e->setPolarity( e->getDeduced( ) == l_True ? l_False : l_True );
  // Compute reason in whatever solver
  const bool res = core_solver.assertLit( e, true ) &&
                   core_solver.check( true );
  // Result must be false
  if ( res )
  {
    cout << endl << "unknown" << endl;
    exit( 1 );
  }

  // Get Explanation
  vector< Enode * > & explanation = core_solver.getConflict( true );

  if ( config.certification_level > 0 )
    verifyExplanationWithExternalTool( explanation );

  // Reserve room for implied lit
  reason.push( lit_Undef );
  // Copy explanation

  while ( !explanation.empty( ) )
  {
    Enode * ei  = explanation.back( );
    explanation.pop_back( );
    assert( ei->hasPolarity( ) );
    assert( ei->getPolarity( ) == l_True
         || ei->getPolarity( ) == l_False );
    bool negate = ei->getPolarity( ) == l_False;
    Var v = enodeToVar( ei );

    // Toggle polarity for deduced literal
    if ( e == ei )
    {
      assert( e->getDeduced( ) != l_Undef );           // But still holds the deduced polarity
      // The deduced literal must have been pushed
      // with the the same polarity that has been deduced
      reason[ 0 ] = Lit( v, !negate );
    }
    else
    {
      assert( ei->hasPolarity( ) );                    // Lit in explanation is active
      // This assertion might fail if in your theory solver
      // you do not skip deduced literals during assertLit
      //
      // TODO: check ! It could be deduced: by another solver
      // For instance BV found conflict and ei was deduced by EUF solver
      //
      // assert( !ei->isDeduced( ) );                     // and not deduced
      Lit l = Lit( v, !negate );
      reason.push( l );
    }
  }

  core_solver.popBacktrackPoint( );

  // Resetting polarity
  e->resetPolarity( );
}