src/theory/quantifiers_engine.h

   1 /*********************                                                        */
   2 /*! \file quantifiers_engine.h
   3  ** \verbatim
   4  ** Original author: Morgan Deters
   5  ** Major contributors: Andrew Reynolds
   6  ** Minor contributors (to current version): Francois Bobot
   7  ** This file is part of the CVC4 project.
   8  ** Copyright (c) 2009-2014  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 Theory instantiator, Instantiation Engine classes
  13  **/
  14
  15 #include "cvc4_private.h"
  16
  17 #ifndef __CVC4__THEORY__QUANTIFIERS_ENGINE_H
  18 #define __CVC4__THEORY__QUANTIFIERS_ENGINE_H
  19
  20 #include "theory/theory.h"
  21 #include "util/hash.h"
  22 #include "theory/quantifiers/inst_match.h"
  23 #include "theory/quantifiers/quant_util.h"
  24 #include "expr/attribute.h"
  25
  26 #include "util/statistics_registry.h"
  27
  28 #include <ext/hash_set>
  29 #include <iostream>
  30 #include <map>
  31
  32 namespace CVC4 {
  33
  34 class TheoryEngine;
  35
  36 namespace theory {
  37
  38 class QuantifiersEngine;
  39
  40 class QuantifiersModule {
  41 protected:
  42   QuantifiersEngine* d_quantEngine;
  43 public:
  44   QuantifiersModule( QuantifiersEngine* qe ) : d_quantEngine( qe ){}
  45   virtual ~QuantifiersModule(){}
  46   //get quantifiers engine
  47   QuantifiersEngine* getQuantifiersEngine() { return d_quantEngine; }
  48   /** initialize */
  49   virtual void finishInit() {}
  50   /* whether this module needs to check this round */
  51   virtual bool needsCheck( Theory::Effort e ) { return e>=Theory::EFFORT_LAST_CALL; }
  52   /* reset at a round */
  53   virtual void reset_round( Theory::Effort e ){}
  54   /* Call during quantifier engine's check */
  55   virtual void check( Theory::Effort e, unsigned quant_e ) = 0;
  56   /* Called for new quantifiers */
  57   virtual void registerQuantifier( Node q ) = 0;
  58   virtual void assertNode( Node n ) = 0;
  59   virtual void propagate( Theory::Effort level ){}
  60   virtual Node getNextDecisionRequest() { return TNode::null(); }
  61   virtual Node explain(TNode n) { return TNode::null(); }
  62   /** Identify this module (for debugging, dynamic configuration, etc..) */
  63   virtual std::string identify() const = 0;
  64 };/* class QuantifiersModule */
  65
  66 namespace quantifiers {
  67   class TermDb;
  68   class FirstOrderModel;
  69   //modules
  70   class InstantiationEngine;
  71   class ModelEngine;
  72   class BoundedIntegers;
  73   class QuantConflictFind;
  74   class RewriteEngine;
  75   class RelevantDomain;
  76   class ConjectureGenerator;
  77   class CegInstantiation;
  78 }/* CVC4::theory::quantifiers */
  79
  80 namespace inst {
  81   class TriggerTrie;
  82 }/* CVC4::theory::inst */
  83
  84 //class EfficientEMatcher;
  85 class EqualityQueryQuantifiersEngine;
  86
  87 class QuantifiersEngine {
  88   friend class quantifiers::InstantiationEngine;
  89   friend class quantifiers::ModelEngine;
  90   friend class quantifiers::RewriteEngine;
  91   friend class quantifiers::QuantConflictFind;
  92   friend class inst::InstMatch;
  93 private:
  94   typedef context::CDHashMap< Node, bool, NodeHashFunction > BoolMap;
  95   /** reference to theory engine object */
  96   TheoryEngine* d_te;
  97   /** vector of modules for quantifiers */
  98   std::vector< QuantifiersModule* > d_modules;
  99   /** equality query class */
 100   EqualityQueryQuantifiersEngine* d_eq_query;
 101   /** for computing relevance of quantifiers */
 102   QuantRelevance * d_quant_rel;
 103   /** relevant domain */
 104   quantifiers::RelevantDomain* d_rel_dom;
 105   /** phase requirements for each quantifier for each instantiation literal */
 106   std::map< Node, QuantPhaseReq* > d_phase_reqs;
 107   /** instantiation engine */
 108   quantifiers::InstantiationEngine* d_inst_engine;
 109   /** model engine */
 110   quantifiers::ModelEngine* d_model_engine;
 111   /** bounded integers utility */
 112   quantifiers::BoundedIntegers * d_bint;
 113   /** Conflict find mechanism for quantifiers */
 114   quantifiers::QuantConflictFind* d_qcf;
 115   /** rewrite rules utility */
 116   quantifiers::RewriteEngine * d_rr_engine;
 117   /** subgoal generator */
 118   quantifiers::ConjectureGenerator * d_sg_gen;
 119   /** ceg instantiation */
 120   quantifiers::CegInstantiation * d_ceg_inst;
 121 public: //effort levels
 122   enum {
 123     QEFFORT_CONFLICT,
 124     QEFFORT_STANDARD,
 125     QEFFORT_MODEL,
 126   };
 127 private:
 128   /** list of all quantifiers seen */
 129   std::vector< Node > d_quants;
 130   /** list of all lemmas produced */
 131   //std::map< Node, bool > d_lemmas_produced;
 132   BoolMap d_lemmas_produced_c;
 133   /** lemmas waiting */
 134   std::vector< Node > d_lemmas_waiting;
 135   /** phase requirements waiting */
 136   std::map< Node, bool > d_phase_req_waiting;
 137   /** has added lemma this round */
 138   bool d_hasAddedLemma;
 139   /** has a conflict been found */
 140   bool d_conflict;
 141   /** list of all instantiations produced for each quantifier */
 142   std::map< Node, inst::InstMatchTrie > d_inst_match_trie;
 143   std::map< Node, inst::CDInstMatchTrie* > d_c_inst_match_trie;
 144   /** quantifiers that have been skolemized */
 145   std::map< Node, bool > d_skolemized;
 146   /** term database */
 147   quantifiers::TermDb* d_term_db;
 148   /** all triggers will be stored in this trie */
 149   inst::TriggerTrie* d_tr_trie;
 150   /** extended model object */
 151   quantifiers::FirstOrderModel* d_model;
 152   /** statistics for debugging */
 153   std::map< Node, int > d_total_inst_debug;
 154   std::map< Node, int > d_temp_inst_debug;
 155   int d_total_inst_count_debug;
 156 private:
 157   KEEP_STATISTIC(TimerStat, d_time, "theory::QuantifiersEngine::time");
 158 public:
 159   QuantifiersEngine(context::Context* c, context::UserContext* u, TheoryEngine* te);
 160   ~QuantifiersEngine();
 161   /** get theory engine */
 162   TheoryEngine* getTheoryEngine() { return d_te; }
 163   /** get equality query object for the given type. The default is the
 164       generic one */
 165   EqualityQueryQuantifiersEngine* getEqualityQuery();
 166   /** get default sat context for quantifiers engine */
 167   context::Context* getSatContext();
 168   /** get default sat context for quantifiers engine */
 169   context::Context* getUserContext();
 170   /** get default output channel for the quantifiers engine */
 171   OutputChannel& getOutputChannel();
 172   /** get default valuation for the quantifiers engine */
 173   Valuation& getValuation();
 174   /** get relevant domain */
 175   quantifiers::RelevantDomain* getRelevantDomain() { return d_rel_dom; }
 176   /** get quantifier relevance */
 177   QuantRelevance* getQuantifierRelevance() { return d_quant_rel; }
 178   /** get phase requirement information */
 179   QuantPhaseReq* getPhaseRequirements( Node f ) { return d_phase_reqs.find( f )==d_phase_reqs.end() ? NULL : d_phase_reqs[f]; }
 180   /** get phase requirement terms */
 181   void getPhaseReqTerms( Node f, std::vector< Node >& nodes );
 182 public:  //modules
 183   /** get instantiation engine */
 184   quantifiers::InstantiationEngine* getInstantiationEngine() { return d_inst_engine; }
 185   /** get model engine */
 186   quantifiers::ModelEngine* getModelEngine() { return d_model_engine; }
 187   /** get bounded integers utility */
 188   quantifiers::BoundedIntegers * getBoundedIntegers() { return d_bint; }
 189   /** Conflict find mechanism for quantifiers */
 190   quantifiers::QuantConflictFind* getConflictFind() { return d_qcf; }
 191   /** rewrite rules utility */
 192   quantifiers::RewriteEngine * getRewriteEngine() { return d_rr_engine; }
 193   /** subgoal generator */
 194   quantifiers::ConjectureGenerator * getConjectureGenerator() { return d_sg_gen; }
 195   /** ceg instantiation */
 196   quantifiers::CegInstantiation * getCegInstantiation() { return d_ceg_inst; }
 197 private:
 198   /** owner of quantified formulas */
 199   std::map< Node, QuantifiersModule * > d_owner;
 200 public:
 201   /** get owner */
 202   QuantifiersModule * getOwner( Node q );
 203   /** set owner */
 204   void setOwner( Node q, QuantifiersModule * m );
 205   /** considers */
 206   bool hasOwnership( Node q, QuantifiersModule * m = NULL );
 207 public:
 208   /** initialize */
 209   void finishInit();
 210   /** check at level */
 211   void check( Theory::Effort e );
 212   /** register quantifier */
 213   void registerQuantifier( Node f );
 214   /** register quantifier */
 215   void registerPattern( std::vector<Node> & pattern);
 216   /** assert universal quantifier */
 217   void assertQuantifier( Node q, bool pol );
 218   /** propagate */
 219   void propagate( Theory::Effort level );
 220   /** get next decision request */
 221   Node getNextDecisionRequest();
 222 private:
 223   /** compute term vector */
 224   void computeTermVector( Node f, InstMatch& m, std::vector< Node >& vars, std::vector< Node >& terms );
 225   /** instantiate f with arguments terms */
 226   bool addInstantiation( Node f, std::vector< Node >& vars, std::vector< Node >& terms );
 227   /** set instantiation level attr */
 228   static void setInstantiationLevelAttr( Node n, Node qn, uint64_t level );
 229   /** flush lemmas */
 230   void flushLemmas();
 231 public:
 232   /** get instantiation */
 233   Node getInstantiation( Node f, std::vector< Node >& vars, std::vector< Node >& terms );
 234   /** get instantiation */
 235   Node getInstantiation( Node f, InstMatch& m );
 236   /** get instantiation */
 237   Node getInstantiation( Node f, std::vector< Node >& terms );
 238   /** do substitution */
 239   Node getSubstitute( Node n, std::vector< Node >& terms );
 240   /** exist instantiation ? */
 241   bool existsInstantiation( Node f, InstMatch& m, bool modEq = true, bool modInst = false );
 242   /** add lemma lem */
 243   bool addLemma( Node lem, bool doCache = true );
 244   /** add require phase */
 245   void addRequirePhase( Node lit, bool req );
 246   /** do instantiation specified by m */
 247   bool addInstantiation( Node f, InstMatch& m, bool mkRep = true, bool modEq = false, bool modInst = false );
 248   /** add instantiation */
 249   bool addInstantiation( Node f, std::vector< Node >& terms, bool mkRep = true, bool modEq = false, bool modInst = false );
 250   /** split on node n */
 251   bool addSplit( Node n, bool reqPhase = false, bool reqPhasePol = true );
 252   /** add split equality */
 253   bool addSplitEquality( Node n1, Node n2, bool reqPhase = false, bool reqPhasePol = true );
 254   /** has added lemma */
 255   bool hasAddedLemma() { return !d_lemmas_waiting.empty() || d_hasAddedLemma; }
 256   /** get number of waiting lemmas */
 257   int getNumLemmasWaiting() { return (int)d_lemmas_waiting.size(); }
 258   /** set instantiation level attr */
 259   static void setInstantiationLevelAttr( Node n, uint64_t level );
 260   /** is term eligble for instantiation? */
 261   bool isTermEligibleForInstantiation( Node n, Node f, bool print = false );
 262 public:
 263   /** get number of quantifiers */
 264   int getNumQuantifiers() { return (int)d_quants.size(); }
 265   /** get quantifier */
 266   Node getQuantifier( int i ) { return d_quants[i]; }
 267 public:
 268   /** get model */
 269   quantifiers::FirstOrderModel* getModel() { return d_model; }
 270   /** get term database */
 271   quantifiers::TermDb* getTermDatabase() { return d_term_db; }
 272   /** get trigger database */
 273   inst::TriggerTrie* getTriggerDatabase() { return d_tr_trie; }
 274   /** add term to database */
 275   void addTermToDatabase( Node n, bool withinQuant = false );
 276   /** get the master equality engine */
 277   eq::EqualityEngine* getMasterEqualityEngine() ;
 278 public:
 279   /** print instantiations */
 280   void printInstantiations( std::ostream& out );
 281   /** statistics class */
 282   class Statistics {
 283   public:
 284     IntStat d_num_quant;
 285     IntStat d_instantiation_rounds;
 286     IntStat d_instantiation_rounds_lc;
 287     IntStat d_instantiations;
 288     IntStat d_inst_duplicate;
 289     IntStat d_inst_duplicate_eq;
 290     IntStat d_lit_phase_req;
 291     IntStat d_lit_phase_nreq;
 292     IntStat d_triggers;
 293     IntStat d_simple_triggers;
 294     IntStat d_multi_triggers;
 295     IntStat d_multi_trigger_instantiations;
 296     Statistics();
 297     ~Statistics();
 298   };/* class QuantifiersEngine::Statistics */
 299   Statistics d_statistics;
 300 };/* class QuantifiersEngine */
 301
 302
 303
 304 /** equality query object using theory engine */
 305 class EqualityQueryQuantifiersEngine : public EqualityQuery
 306 {
 307 private:
 308   /** pointer to theory engine */
 309   QuantifiersEngine* d_qe;
 310   /** internal representatives */
 311   std::map< Node, Node > d_int_rep;
 312   /** rep score */
 313   std::map< Node, int > d_rep_score;
 314   /** reset count */
 315   int d_reset_count;
 316
 317   bool d_liberal;
 318 private:
 319   /** node contains */
 320   Node getInstance( Node n, const std::vector< Node >& eqc, std::hash_map<TNode, Node, TNodeHashFunction>& cache );
 321   /** get score */
 322   int getRepScore( Node n, Node f, int index );
 323 public:
 324   EqualityQueryQuantifiersEngine( QuantifiersEngine* qe ) : d_qe( qe ), d_reset_count( 0 ), d_liberal( false ){}
 325   ~EqualityQueryQuantifiersEngine(){}
 326   /** reset */
 327   void reset();
 328   /** general queries about equality */
 329   bool hasTerm( Node a );
 330   Node getRepresentative( Node a );
 331   bool areEqual( Node a, Node b );
 332   bool areDisequal( Node a, Node b );
 333   eq::EqualityEngine* getEngine();
 334   void getEquivalenceClass( Node a, std::vector< Node >& eqc );
 335   /** getInternalRepresentative gets the current best representative in the equivalence class of a, based on some criteria.
 336       If cbqi is active, this will return a term in the equivalence class of "a" that does
 337       not contain instantiation constants, if such a term exists.
 338    */
 339   Node getInternalRepresentative( Node a, Node f, int index );
 340   /** flatten representatives */
 341   void flattenRepresentatives( std::map< TypeNode, std::vector< Node > >& reps );
 342
 343   void setLiberal( bool l ) { d_liberal = l; }
 344 }; /* EqualityQueryQuantifiersEngine */
 345
 346 }/* CVC4::theory namespace */
 347 }/* CVC4 namespace */
 348
 349 #endif /* __CVC4__THEORY__QUANTIFIERS_ENGINE_H */