src/theory/quantifiers/theory_quantifiers.cpp

   1 /*********************                                                        */
   2 /*! \file theory_quantifiers.cpp
   3  ** \verbatim
   4  ** Original author: Morgan Deters
   5  ** Major contributors: Andrew Reynolds
   6  ** Minor contributors (to current version): Dejan Jovanovic
   7  ** This file is part of the CVC4 project.
   8  ** Copyright (c) 2009-2013  New York University and The University of Iowa
   9  ** See the file COPYING in the top-level source directory for licensing
  10  ** information.\endverbatim
  11  **
  12  ** \brief Implementation of the theory of quantifiers
  13  **
  14  ** Implementation of the theory of quantifiers.
  15  **/
  16
  17
  18 #include "theory/quantifiers/theory_quantifiers.h"
  19 #include "theory/valuation.h"
  20 #include "theory/quantifiers_engine.h"
  21 #include "theory/quantifiers/instantiation_engine.h"
  22 #include "theory/quantifiers/model_engine.h"
  23 #include "expr/kind.h"
  24 #include "util/cvc4_assert.h"
  25 #include "theory/quantifiers/options.h"
  26 #include "theory/quantifiers/term_database.h"
  27 #include "theory/quantifiers/quantifiers_attributes.h"
  28
  29 using namespace std;
  30 using namespace CVC4;
  31 using namespace CVC4::kind;
  32 using namespace CVC4::context;
  33 using namespace CVC4::theory;
  34 using namespace CVC4::theory::quantifiers;
  35
  36 TheoryQuantifiers::TheoryQuantifiers(Context* c, context::UserContext* u, OutputChannel& out, Valuation valuation, const LogicInfo& logicInfo) :
  37   Theory(THEORY_QUANTIFIERS, c, u, out, valuation, logicInfo),
  38   d_numRestarts(0),
  39   d_masterEqualityEngine(0)
  40 {
  41   d_numInstantiations = 0;
  42   d_baseDecLevel = -1;
  43   out.handleUserAttribute( "axiom", this );
  44   out.handleUserAttribute( "conjecture", this );
  45 }
  46
  47 TheoryQuantifiers::~TheoryQuantifiers() {
  48 }
  49
  50 void TheoryQuantifiers::setMasterEqualityEngine(eq::EqualityEngine* eq) {
  51   d_masterEqualityEngine = eq;
  52 }
  53
  54 void TheoryQuantifiers::addSharedTerm(TNode t) {
  55   Debug("quantifiers-other") << "TheoryQuantifiers::addSharedTerm(): "
  56                      << t << endl;
  57 }
  58
  59
  60 void TheoryQuantifiers::notifyEq(TNode lhs, TNode rhs) {
  61   Debug("quantifiers-other") << "TheoryQuantifiers::notifyEq(): "
  62                      << lhs << " = " << rhs << endl;
  63
  64 }
  65
  66 void TheoryQuantifiers::preRegisterTerm(TNode n) {
  67   Debug("quantifiers-prereg") << "TheoryQuantifiers::preRegisterTerm() " << n << endl;
  68   if( n.getKind()==FORALL && !TermDb::hasInstConstAttr(n) ){
  69     getQuantifiersEngine()->registerQuantifier( n );
  70   }
  71 }
  72
  73
  74 void TheoryQuantifiers::presolve() {
  75   Debug("quantifiers-presolve") << "TheoryQuantifiers::presolve()" << endl;
  76 }
  77
  78 Node TheoryQuantifiers::getValue(TNode n) {
  79   //NodeManager* nodeManager = NodeManager::currentNM();
  80   switch(n.getKind()) {
  81   case FORALL:
  82   case EXISTS:
  83     bool value;
  84     if( d_valuation.hasSatValue( n, value ) ){
  85       return NodeManager::currentNM()->mkConst(value);
  86     }else{
  87       return NodeManager::currentNM()->mkConst(false);  //FIX_THIS?
  88     }
  89     break;
  90   default:
  91     Unhandled(n.getKind());
  92   }
  93 }
  94
  95 void TheoryQuantifiers::collectModelInfo(TheoryModel* m, bool fullModel) {
  96   if(fullModel) {
  97     for(assertions_iterator i = facts_begin(); i != facts_end(); ++i) {
  98       if((*i).assertion.getKind() == kind::NOT) {
  99         Debug("quantifiers::collectModelInfo") << "got quant FALSE: " << (*i).assertion[0] << endl;
 100         m->assertPredicate((*i).assertion[0], false);
 101       } else {
 102         Debug("quantifiers::collectModelInfo") << "got quant TRUE : " << *i << endl;
 103         m->assertPredicate(*i, true);
 104       }
 105     }
 106   }
 107 }
 108
 109 void TheoryQuantifiers::check(Effort e) {
 110   CodeTimer codeTimer(d_theoryTime);
 111
 112   Debug("quantifiers-check") << "quantifiers::check(" << e << ")" << std::endl;
 113   while(!done()) {
 114     Node assertion = get();
 115     Debug("quantifiers-assert") << "quantifiers::assert(): " << assertion << std::endl;
 116     switch(assertion.getKind()) {
 117     case kind::FORALL:
 118       assertUniversal( assertion );
 119       break;
 120     case kind::NOT:
 121       {
 122         switch( assertion[0].getKind()) {
 123         case kind::FORALL:
 124           assertExistential( assertion );
 125           break;
 126         default:
 127           Unhandled(assertion[0].getKind());
 128           break;
 129         }
 130       }
 131       break;
 132     default:
 133       Unhandled(assertion.getKind());
 134       break;
 135     }
 136   }
 137   // call the quantifiers engine to check
 138   getQuantifiersEngine()->check( e );
 139 }
 140
 141 void TheoryQuantifiers::propagate(Effort level){
 142   //CodeTimer codeTimer(d_theoryTime);
 143   //getQuantifiersEngine()->propagate( level );
 144 }
 145
 146 Node TheoryQuantifiers::getNextDecisionRequest(){
 147   return getQuantifiersEngine()->getNextDecisionRequest();
 148 }
 149
 150 void TheoryQuantifiers::assertUniversal( Node n ){
 151   Assert( n.getKind()==FORALL );
 152   if( options::recurseCbqi() || !TermDb::hasInstConstAttr(n) ){
 153     getQuantifiersEngine()->registerQuantifier( n );
 154     getQuantifiersEngine()->assertNode( n );
 155   }
 156 }
 157
 158 void TheoryQuantifiers::assertExistential( Node n ){
 159   Assert( n.getKind()== NOT && n[0].getKind()==FORALL );
 160   if( options::recurseCbqi() || !TermDb::hasInstConstAttr(n[0]) ){
 161     if( d_skolemized.find( n )==d_skolemized.end() ){
 162       Node body = getQuantifiersEngine()->getTermDatabase()->getSkolemizedBody( n[0] );
 163       NodeBuilder<> nb(kind::OR);
 164       nb << n[0] << body.notNode();
 165       Node lem = nb;
 166       Trace("quantifiers-sk") << "Skolemize lemma : " << lem << std::endl;
 167       d_out->lemma( lem, false, true );
 168       d_skolemized[n] = true;
 169     }
 170   }
 171 }
 172
 173 bool TheoryQuantifiers::flipDecision(){
 174   //Debug("quantifiers-flip") << "No instantiation given, flip decision, level = " << d_valuation.getDecisionLevel() << std::endl;
 175   //for( int i=1; i<=(int)d_valuation.getDecisionLevel(); i++ ){
 176   //  Debug("quantifiers-flip") << "   " << d_valuation.getDecision( i ) << std::endl;
 177   //}
 178   //if( d_valuation.getDecisionLevel()>0 ){
 179   //  double r = double(rand())/double(RAND_MAX);
 180   //  unsigned decisionLevel = (unsigned)(r*d_valuation.getDecisionLevel());
 181   //  d_out->flipDecision( decisionLevel );
 182   //  return true;
 183   //}else{
 184   //  return false;
 185   //}
 186
 187   if( !d_out->flipDecision() ){
 188     return restart();
 189   }
 190   return true;
 191 }
 192
 193 bool TheoryQuantifiers::restart(){
 194   static const int restartLimit = 0;
 195   if( d_numRestarts==restartLimit ){
 196     Debug("quantifiers-flip") << "No more restarts." << std::endl;
 197     return false;
 198   }else{
 199     d_numRestarts++;
 200     Debug("quantifiers-flip") << "Do restart." << std::endl;
 201     return true;
 202   }
 203 }
 204
 205 void TheoryQuantifiers::setUserAttribute( const std::string& attr, Node n ){
 206   QuantifiersAttributes::setUserAttribute( attr, n );
 207 }