src/theory/quantifiers_engine.h

   1 /*********************                                                        */
   2 /*! \file quantifiers_engine.h
   3  ** \verbatim
   4  ** Top contributors (to current version):
   5  **   Andrew Reynolds, Morgan Deters, Tim King
   6  ** This file is part of the CVC4 project.
   7  ** Copyright (c) 2009-2016 by the authors listed in the file AUTHORS
   8  ** in the top-level source directory) and their institutional affiliations.
   9  ** All rights reserved.  See the file COPYING in the top-level source
  10  ** directory for licensing 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 <ext/hash_set>
  21 #include <iostream>
  22 #include <map>
  23
  24 #include "context/cdchunk_list.h"
  25 #include "context/cdhashset.h"
  26 #include "expr/attribute.h"
  27 #include "options/quantifiers_modes.h"
  28 #include "theory/quantifiers/inst_match.h"
  29 #include "theory/quantifiers/quant_util.h"
  30 #include "theory/theory.h"
  31 #include "util/hash.h"
  32 #include "util/statistics_registry.h"
  33
  34 namespace CVC4 {
  35
  36 class TheoryEngine;
  37
  38 namespace theory {
  39
  40 class QuantifiersEngine;
  41
  42 namespace quantifiers {
  43   class TermDb;
  44   class TermDbSygus;
  45 }
  46
  47 class InstantiationNotify {
  48 public:
  49   InstantiationNotify(){}
  50   virtual ~InstantiationNotify() {}
  51   virtual bool notifyInstantiation( unsigned quant_e, Node q, Node lem, std::vector< Node >& terms, Node body ) = 0;
  52   virtual void filterInstantiations() = 0;
  53 };
  54
  55 namespace quantifiers {
  56   class FirstOrderModel;
  57   //modules
  58   class InstantiationEngine;
  59   class ModelEngine;
  60   class BoundedIntegers;
  61   class QuantConflictFind;
  62   class RewriteEngine;
  63   class RelevantDomain;
  64   class QModelBuilder;
  65   class ConjectureGenerator;
  66   class CegInstantiation;
  67   class LtePartialInst;
  68   class AlphaEquivalence;
  69   class FunDefEngine;
  70   class QuantEqualityEngine;
  71   class FullSaturation;
  72   class InstStrategyCbqi;
  73   class InstStrategyCegqi;
  74   class QuantDSplit;
  75   class QuantAntiSkolem;
  76   class EqualityInference;
  77   class InstPropagator;
  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::InstStrategyCbqi;
  90   friend class quantifiers::InstStrategyCegqi;
  91   friend class quantifiers::ModelEngine;
  92   friend class quantifiers::RewriteEngine;
  93   friend class quantifiers::QuantConflictFind;
  94   friend class inst::InstMatch;
  95   typedef context::CDHashMap< Node, bool, NodeHashFunction > BoolMap;
  96   typedef context::CDChunkList<Node> NodeList;
  97   typedef context::CDChunkList<bool> BoolList;
  98   typedef context::CDHashSet<Node, NodeHashFunction> NodeSet;
  99 private:
 100   /** reference to theory engine object */
 101   TheoryEngine* d_te;
 102   /** vector of utilities for quantifiers */
 103   std::vector< QuantifiersUtil* > d_util;
 104   /** vector of modules for quantifiers */
 105   std::vector< QuantifiersModule* > d_modules;
 106   /** instantiation notify */
 107   std::vector< InstantiationNotify* > d_inst_notify;
 108   /** equality query class */
 109   EqualityQueryQuantifiersEngine* d_eq_query;
 110   /** for computing relevance of quantifiers */
 111   QuantRelevance * d_quant_rel;
 112   /** relevant domain */
 113   quantifiers::RelevantDomain* d_rel_dom;
 114   /** alpha equivalence */
 115   quantifiers::AlphaEquivalence * d_alpha_equiv;
 116   /** model builder */
 117   quantifiers::QModelBuilder* d_builder;
 118   /** utility for effectively propositional logic */
 119   QuantEPR * d_qepr;
 120 private:
 121   /** instantiation engine */
 122   quantifiers::InstantiationEngine* d_inst_engine;
 123   /** model engine */
 124   quantifiers::ModelEngine* d_model_engine;
 125   /** bounded integers utility */
 126   quantifiers::BoundedIntegers * d_bint;
 127   /** Conflict find mechanism for quantifiers */
 128   quantifiers::QuantConflictFind* d_qcf;
 129   /** rewrite rules utility */
 130   quantifiers::RewriteEngine * d_rr_engine;
 131   /** subgoal generator */
 132   quantifiers::ConjectureGenerator * d_sg_gen;
 133   /** ceg instantiation */
 134   quantifiers::CegInstantiation * d_ceg_inst;
 135   /** lte partial instantiation */
 136   quantifiers::LtePartialInst * d_lte_part_inst;
 137   /** function definitions engine */
 138   quantifiers::FunDefEngine * d_fun_def_engine;
 139   /** quantifiers equality engine */
 140   quantifiers::QuantEqualityEngine * d_uee;
 141   /** full saturation */
 142   quantifiers::FullSaturation * d_fs;
 143   /** counterexample-based quantifier instantiation */
 144   quantifiers::InstStrategyCbqi * d_i_cbqi;
 145   /** quantifiers splitting */
 146   quantifiers::QuantDSplit * d_qsplit;
 147   /** quantifiers anti-skolemization */
 148   quantifiers::QuantAntiSkolem * d_anti_skolem;
 149   /** quantifiers instantiation propagtor */
 150   quantifiers::InstPropagator * d_inst_prop;
 151 public: //effort levels
 152   enum {
 153     QEFFORT_CONFLICT,
 154     QEFFORT_STANDARD,
 155     QEFFORT_MODEL,
 156     QEFFORT_LAST_CALL,
 157     //none
 158     QEFFORT_NONE,
 159   };
 160 private:  //this information is reset during check
 161   /** current effort level */
 162   unsigned d_curr_effort_level;
 163   /** are we in conflict */
 164   bool d_conflict;
 165   context::CDO< bool > d_conflict_c;
 166   /** has added lemma this round */
 167   bool d_hasAddedLemma;
 168 private:
 169   /** list of all quantifiers seen */
 170   std::map< Node, bool > d_quants;
 171   /** quantifiers reduced */
 172   BoolMap d_quants_red;
 173   std::map< Node, Node > d_quants_red_lem;
 174   /** list of all lemmas produced */
 175   //std::map< Node, bool > d_lemmas_produced;
 176   BoolMap d_lemmas_produced_c;
 177   /** lemmas waiting */
 178   std::vector< Node > d_lemmas_waiting;
 179   /** phase requirements waiting */
 180   std::map< Node, bool > d_phase_req_waiting;
 181   /** list of all instantiations produced for each quantifier */
 182   std::map< Node, inst::InstMatchTrie > d_inst_match_trie;
 183   std::map< Node, inst::CDInstMatchTrie* > d_c_inst_match_trie;
 184   /** recorded instantiations */
 185   std::vector< std::pair< Node, std::vector< Node > > > d_recorded_inst;
 186   /** quantifiers that have been skolemized */
 187   BoolMap d_skolemized;
 188   /** term database */
 189   quantifiers::TermDb* d_term_db;
 190   /** all triggers will be stored in this trie */
 191   inst::TriggerTrie* d_tr_trie;
 192   /** extended model object */
 193   quantifiers::FirstOrderModel* d_model;
 194   /** statistics for debugging */
 195   std::map< Node, int > d_total_inst_debug;
 196   std::map< Node, int > d_temp_inst_debug;
 197   int d_total_inst_count_debug;
 198   /** inst round counters TODO: make context-dependent? */
 199   context::CDO< int > d_ierCounter_c;
 200   int d_ierCounter;
 201   int d_ierCounter_lc;
 202   int d_ierCounterLastLc;
 203   int d_inst_when_phase;
 204   /** has presolve been called */
 205   context::CDO< bool > d_presolve;
 206   /** presolve cache */
 207   NodeSet d_presolve_in;
 208   NodeList d_presolve_cache;
 209   BoolList d_presolve_cache_wq;
 210   BoolList d_presolve_cache_wic;
 211
 212 public:
 213   QuantifiersEngine(context::Context* c, context::UserContext* u, TheoryEngine* te);
 214   ~QuantifiersEngine();
 215   /** get theory engine */
 216   TheoryEngine* getTheoryEngine() { return d_te; }
 217   /** get equality query */
 218   EqualityQueryQuantifiersEngine* getEqualityQuery();
 219   /** get default sat context for quantifiers engine */
 220   context::Context* getSatContext();
 221   /** get default sat context for quantifiers engine */
 222   context::UserContext* getUserContext();
 223   /** get default output channel for the quantifiers engine */
 224   OutputChannel& getOutputChannel();
 225   /** get default valuation for the quantifiers engine */
 226   Valuation& getValuation();
 227   /** get relevant domain */
 228   quantifiers::RelevantDomain* getRelevantDomain() { return d_rel_dom; }
 229   /** get quantifier relevance */
 230   QuantRelevance* getQuantifierRelevance() { return d_quant_rel; }
 231   /** get the model builder */
 232   quantifiers::QModelBuilder* getModelBuilder() { return d_builder; }
 233   /** get utility for EPR */
 234   QuantEPR* getQuantEPR() { return d_qepr; }
 235 public:  //modules
 236   /** get instantiation engine */
 237   quantifiers::InstantiationEngine* getInstantiationEngine() { return d_inst_engine; }
 238   /** get model engine */
 239   quantifiers::ModelEngine* getModelEngine() { return d_model_engine; }
 240   /** get bounded integers utility */
 241   quantifiers::BoundedIntegers * getBoundedIntegers() { return d_bint; }
 242   /** Conflict find mechanism for quantifiers */
 243   quantifiers::QuantConflictFind* getConflictFind() { return d_qcf; }
 244   /** rewrite rules utility */
 245   quantifiers::RewriteEngine * getRewriteEngine() { return d_rr_engine; }
 246   /** subgoal generator */
 247   quantifiers::ConjectureGenerator * getConjectureGenerator() { return d_sg_gen; }
 248   /** ceg instantiation */
 249   quantifiers::CegInstantiation * getCegInstantiation() { return d_ceg_inst; }
 250   /** local theory ext partial inst */
 251   quantifiers::LtePartialInst * getLtePartialInst() { return d_lte_part_inst; }
 252   /** function definition engine */
 253   quantifiers::FunDefEngine * getFunDefEngine() { return d_fun_def_engine; }
 254   /** quantifiers equality engine */
 255   quantifiers::QuantEqualityEngine * getQuantEqualityEngine() { return d_uee; }
 256   /** get full saturation */
 257   quantifiers::FullSaturation * getFullSaturation() { return d_fs; }
 258   /** get inst strategy cbqi */
 259   quantifiers::InstStrategyCbqi * getInstStrategyCbqi() { return d_i_cbqi; }
 260   /** get quantifiers splitting */
 261   quantifiers::QuantDSplit * getQuantDSplit() { return d_qsplit; }
 262   /** get quantifiers anti-skolemization */
 263   quantifiers::QuantAntiSkolem * getQuantAntiSkolem() { return d_anti_skolem; }
 264 private:
 265   /** owner of quantified formulas */
 266   std::map< Node, QuantifiersModule * > d_owner;
 267   std::map< Node, int > d_owner_priority;
 268 public:
 269   /** get owner */
 270   QuantifiersModule * getOwner( Node q );
 271   /** set owner */
 272   void setOwner( Node q, QuantifiersModule * m, int priority = 0 );
 273   /** considers */
 274   bool hasOwnership( Node q, QuantifiersModule * m = NULL );
 275   /** is finite bound */
 276   bool isFiniteBound( Node q, Node v );
 277 public:
 278   /** initialize */
 279   void finishInit();
 280   /** presolve */
 281   void presolve();
 282   /** notify preprocessed assertion */
 283   void ppNotifyAssertions( std::vector< Node >& assertions );
 284   /** check at level */
 285   void check( Theory::Effort e );
 286   /** notify that theories were combined */
 287   void notifyCombineTheories();
 288   /** register quantifier */
 289   bool registerQuantifier( Node f );
 290   /** register quantifier */
 291   void registerPattern( std::vector<Node> & pattern);
 292   /** assert universal quantifier */
 293   void assertQuantifier( Node q, bool pol );
 294   /** propagate */
 295   void propagate( Theory::Effort level );
 296   /** get next decision request */
 297   Node getNextDecisionRequest( unsigned& priority );
 298 private:
 299   /** reduceQuantifier, return true if reduced */
 300   bool reduceQuantifier( Node q );
 301   /** compute term vector */
 302   void computeTermVector( Node f, InstMatch& m, std::vector< Node >& vars, std::vector< Node >& terms );
 303   /** record instantiation, return true if it was non-duplicate */
 304   bool recordInstantiationInternal( Node q, std::vector< Node >& terms, bool modEq = false, bool addedLem = true );
 305   /** remove instantiation */
 306   bool removeInstantiationInternal( Node q, std::vector< Node >& terms );
 307   /** set instantiation level attr */
 308   static void setInstantiationLevelAttr( Node n, Node qn, uint64_t level );
 309 public:
 310   /** flush lemmas */
 311   void flushLemmas();
 312   /** get instantiation */
 313   Node getInstantiation( Node q, std::vector< Node >& vars, std::vector< Node >& terms, bool doVts = false );
 314   /** get instantiation */
 315   Node getInstantiation( Node q, InstMatch& m, bool doVts = false );
 316   /** get instantiation */
 317   Node getInstantiation( Node q, std::vector< Node >& terms, bool doVts = false );
 318   /** do substitution */
 319   Node getSubstitute( Node n, std::vector< Node >& terms );
 320   /** add lemma lem */
 321   bool addLemma( Node lem, bool doCache = true, bool doRewrite = true );
 322   /** remove pending lemma */
 323   bool removeLemma( Node lem );
 324   /** add require phase */
 325   void addRequirePhase( Node lit, bool req );
 326   /** do instantiation specified by m */
 327   bool addInstantiation( Node q, InstMatch& m, bool mkRep = false, bool modEq = false, bool doVts = false );
 328   /** add instantiation */
 329   bool addInstantiation( Node q, std::vector< Node >& terms, bool mkRep = false, bool modEq = false, bool doVts = false );
 330   /** remove pending instantiation */
 331   bool removeInstantiation( Node q, Node lem, std::vector< Node >& terms );
 332   /** split on node n */
 333   bool addSplit( Node n, bool reqPhase = false, bool reqPhasePol = true );
 334   /** add split equality */
 335   bool addSplitEquality( Node n1, Node n2, bool reqPhase = false, bool reqPhasePol = true );
 336   /** add EPR axiom */
 337   bool addEPRAxiom( TypeNode tn );
 338   /** mark relevant quantified formula, this will indicate it should be checked before the others */
 339   void markRelevant( Node q );
 340   /** has added lemma */
 341   bool hasAddedLemma() { return !d_lemmas_waiting.empty() || d_hasAddedLemma; }
 342   /** is in conflict */
 343   bool inConflict() { return d_conflict; }
 344   /** get number of waiting lemmas */
 345   unsigned getNumLemmasWaiting() { return d_lemmas_waiting.size(); }
 346   /** get needs check */
 347   bool getInstWhenNeedsCheck( Theory::Effort e );
 348   /** get user pat mode */
 349   quantifiers::UserPatMode getInstUserPatMode();
 350   /** set instantiation level attr */
 351   static void setInstantiationLevelAttr( Node n, uint64_t level );
 352 public:
 353   /** get model */
 354   quantifiers::FirstOrderModel* getModel() { return d_model; }
 355   /** get term database */
 356   quantifiers::TermDb* getTermDatabase() { return d_term_db; }
 357   /** get term database sygus */
 358   quantifiers::TermDbSygus* getTermDatabaseSygus();
 359   /** get trigger database */
 360   inst::TriggerTrie* getTriggerDatabase() { return d_tr_trie; }
 361   /** add term to database */
 362   void addTermToDatabase( Node n, bool withinQuant = false, bool withinInstClosure = false );
 363   /** notification when master equality engine is updated */
 364   void eqNotifyNewClass(TNode t);
 365   void eqNotifyPreMerge(TNode t1, TNode t2);
 366   void eqNotifyPostMerge(TNode t1, TNode t2);
 367   void eqNotifyDisequal(TNode t1, TNode t2, TNode reason);
 368   /** get the master equality engine */
 369   eq::EqualityEngine* getMasterEqualityEngine() ;
 370   /** debug print equality engine */
 371   void debugPrintEqualityEngine( const char * c );
 372 public:
 373   /** print instantiations */
 374   void printInstantiations( std::ostream& out );
 375   /** print solution for synthesis conjectures */
 376   void printSynthSolution( std::ostream& out );
 377   /** get list of quantified formulas that were instantiated */
 378   void getInstantiatedQuantifiedFormulas( std::vector< Node >& qs );
 379   /** get instantiations */
 380   void getInstantiations( Node q, std::vector< Node >& insts );
 381   void getInstantiations( std::map< Node, std::vector< Node > >& insts );
 382   /** get instantiation term vectors */
 383   void getInstantiationTermVectors( Node q, std::vector< std::vector< Node > >& tvecs );
 384   void getInstantiationTermVectors( std::map< Node, std::vector< std::vector< Node > > >& insts );
 385   /** get instantiated conjunction */
 386   Node getInstantiatedConjunction( Node q );
 387   /** get unsat core lemmas */
 388   bool getUnsatCoreLemmas( std::vector< Node >& active_lemmas );
 389   bool getUnsatCoreLemmas( std::vector< Node >& active_lemmas, std::map< Node, Node >& weak_imp );
 390   /** get inst for lemmas */
 391   void getExplanationForInstLemmas( std::vector< Node >& lems, std::map< Node, Node >& quant, std::map< Node, std::vector< Node > >& tvec );
 392   /** statistics class */
 393   class Statistics {
 394   public:
 395     TimerStat d_time;
 396     TimerStat d_qcf_time;
 397     TimerStat d_ematching_time;
 398     IntStat d_num_quant;
 399     IntStat d_instantiation_rounds;
 400     IntStat d_instantiation_rounds_lc;
 401     IntStat d_instantiations;
 402     IntStat d_inst_duplicate;
 403     IntStat d_inst_duplicate_eq;
 404     IntStat d_inst_duplicate_ent;
 405     IntStat d_triggers;
 406     IntStat d_simple_triggers;
 407     IntStat d_multi_triggers;
 408     IntStat d_multi_trigger_instantiations;
 409     IntStat d_red_alpha_equiv;
 410     IntStat d_instantiations_user_patterns;
 411     IntStat d_instantiations_auto_gen;
 412     IntStat d_instantiations_guess;
 413     IntStat d_instantiations_qcf;
 414     IntStat d_instantiations_qcf_prop;
 415     IntStat d_instantiations_fmf_exh;
 416     IntStat d_instantiations_fmf_mbqi;
 417     IntStat d_instantiations_cbqi;
 418     IntStat d_instantiations_rr;
 419     Statistics();
 420     ~Statistics();
 421   };/* class QuantifiersEngine::Statistics */
 422   Statistics d_statistics;
 423 };/* class QuantifiersEngine */
 424
 425
 426
 427 /** equality query object using theory engine */
 428 class EqualityQueryQuantifiersEngine : public EqualityQuery
 429 {
 430 private:
 431   /** pointer to theory engine */
 432   QuantifiersEngine* d_qe;
 433   /** quantifiers equality inference */
 434   quantifiers::EqualityInference * d_eq_inference;
 435   context::CDO< unsigned > d_eqi_counter;
 436   /** internal representatives */
 437   std::map< TypeNode, std::map< Node, Node > > d_int_rep;
 438   /** rep score */
 439   std::map< Node, int > d_rep_score;
 440   /** reset count */
 441   int d_reset_count;
 442
 443   /** processInferences : will merge equivalence classes in master equality engine, if possible */
 444   bool processInferences( Theory::Effort e );
 445   /** node contains */
 446   Node getInstance( Node n, const std::vector< Node >& eqc, std::hash_map<TNode, Node, TNodeHashFunction>& cache );
 447   /** get score */
 448   int getRepScore( Node n, Node f, int index, TypeNode v_tn );
 449   /** flatten representatives */
 450   void flattenRepresentatives( std::map< TypeNode, std::vector< Node > >& reps );
 451 public:
 452   EqualityQueryQuantifiersEngine( context::Context* c, QuantifiersEngine* qe );
 453   virtual ~EqualityQueryQuantifiersEngine();
 454   /** reset */
 455   bool reset( Theory::Effort e );
 456   /** identify */
 457   std::string identify() const { return "EqualityQueryQE"; }
 458   /** general queries about equality */
 459   bool hasTerm( Node a );
 460   Node getRepresentative( Node a );
 461   bool areEqual( Node a, Node b );
 462   bool areDisequal( Node a, Node b );
 463   eq::EqualityEngine* getEngine();
 464   void getEquivalenceClass( Node a, std::vector< Node >& eqc );
 465   TNode getCongruentTerm( Node f, std::vector< TNode >& args );
 466   /** getInternalRepresentative gets the current best representative in the equivalence class of a, based on some criteria.
 467       If cbqi is active, this will return a term in the equivalence class of "a" that does
 468       not contain instantiation constants, if such a term exists.
 469    */
 470   Node getInternalRepresentative( Node a, Node f, int index );
 471   /** get quantifiers equality inference */
 472   quantifiers::EqualityInference * getEqualityInference() { return d_eq_inference; }
 473 }; /* EqualityQueryQuantifiersEngine */
 474
 475 }/* CVC4::theory namespace */
 476 }/* CVC4 namespace */
 477
 478 #endif /* __CVC4__THEORY__QUANTIFIERS_ENGINE_H */