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 bool notifyInstantiation( unsigned quant_e, Node q, Node lem, std::vector< Node >& terms, Node body ) = 0;
  51   virtual void filterInstantiations() = 0;
  52 };
  53
  54 namespace quantifiers {
  55   class FirstOrderModel;
  56   //modules
  57   class InstantiationEngine;
  58   class ModelEngine;
  59   class BoundedIntegers;
  60   class QuantConflictFind;
  61   class RewriteEngine;
  62   class RelevantDomain;
  63   class QModelBuilder;
  64   class ConjectureGenerator;
  65   class CegInstantiation;
  66   class LtePartialInst;
  67   class AlphaEquivalence;
  68   class FunDefEngine;
  69   class QuantEqualityEngine;
  70   class FullSaturation;
  71   class InstStrategyCbqi;
  72   class InstStrategyCegqi;
  73   class QuantDSplit;
  74   class QuantAntiSkolem;
  75   class EqualityInference;
  76   class InstPropagator;
  77 }/* CVC4::theory::quantifiers */
  78
  79 namespace inst {
  80   class TriggerTrie;
  81 }/* CVC4::theory::inst */
  82
  83 //class EfficientEMatcher;
  84 class EqualityQueryQuantifiersEngine;
  85
  86 class QuantifiersEngine {
  87   friend class quantifiers::InstantiationEngine;
  88   friend class quantifiers::InstStrategyCegqi;
  89   friend class quantifiers::ModelEngine;
  90   friend class quantifiers::RewriteEngine;
  91   friend class quantifiers::QuantConflictFind;
  92   friend class inst::InstMatch;
  93   typedef context::CDHashMap< Node, bool, NodeHashFunction > BoolMap;
  94   typedef context::CDChunkList<Node> NodeList;
  95   typedef context::CDChunkList<bool> BoolList;
  96   typedef context::CDHashSet<Node, NodeHashFunction> NodeSet;
  97 private:
  98   /** reference to theory engine object */
  99   TheoryEngine* d_te;
 100   /** vector of utilities for quantifiers */
 101   std::vector< QuantifiersUtil* > d_util;
 102   /** vector of modules for quantifiers */
 103   std::vector< QuantifiersModule* > d_modules;
 104   /** instantiation notify */
 105   std::vector< InstantiationNotify* > d_inst_notify;
 106   /** equality query class */
 107   EqualityQueryQuantifiersEngine* d_eq_query;
 108   /** for computing relevance of quantifiers */
 109   QuantRelevance * d_quant_rel;
 110   /** relevant domain */
 111   quantifiers::RelevantDomain* d_rel_dom;
 112   /** alpha equivalence */
 113   quantifiers::AlphaEquivalence * d_alpha_equiv;
 114   /** model builder */
 115   quantifiers::QModelBuilder* d_builder;
 116   /** utility for effectively propositional logic */
 117   QuantEPR * d_qepr;
 118 private:
 119   /** instantiation engine */
 120   quantifiers::InstantiationEngine* d_inst_engine;
 121   /** model engine */
 122   quantifiers::ModelEngine* d_model_engine;
 123   /** bounded integers utility */
 124   quantifiers::BoundedIntegers * d_bint;
 125   /** Conflict find mechanism for quantifiers */
 126   quantifiers::QuantConflictFind* d_qcf;
 127   /** rewrite rules utility */
 128   quantifiers::RewriteEngine * d_rr_engine;
 129   /** subgoal generator */
 130   quantifiers::ConjectureGenerator * d_sg_gen;
 131   /** ceg instantiation */
 132   quantifiers::CegInstantiation * d_ceg_inst;
 133   /** lte partial instantiation */
 134   quantifiers::LtePartialInst * d_lte_part_inst;
 135   /** function definitions engine */
 136   quantifiers::FunDefEngine * d_fun_def_engine;
 137   /** quantifiers equality engine */
 138   quantifiers::QuantEqualityEngine * d_uee;
 139   /** full saturation */
 140   quantifiers::FullSaturation * d_fs;
 141   /** counterexample-based quantifier instantiation */
 142   quantifiers::InstStrategyCbqi * d_i_cbqi;
 143   /** quantifiers splitting */
 144   quantifiers::QuantDSplit * d_qsplit;
 145   /** quantifiers anti-skolemization */
 146   quantifiers::QuantAntiSkolem * d_anti_skolem;
 147   /** quantifiers instantiation propagtor */
 148   quantifiers::InstPropagator * d_inst_prop;
 149 private:
 150   /** whether we are tracking instantiation lemmas */
 151   bool d_trackInstLemmas;
 152 public: //effort levels
 153   enum {
 154     QEFFORT_CONFLICT,
 155     QEFFORT_STANDARD,
 156     QEFFORT_MODEL,
 157     QEFFORT_LAST_CALL,
 158     //none
 159     QEFFORT_NONE,
 160   };
 161 private:  //this information is reset during check
 162   /** current effort level */
 163   unsigned d_curr_effort_level;
 164   /** are we in conflict */
 165   bool d_conflict;
 166   context::CDO< bool > d_conflict_c;
 167   /** has added lemma this round */
 168   bool d_hasAddedLemma;
 169 private:
 170   /** list of all quantifiers seen */
 171   std::map< Node, bool > d_quants;
 172   /** quantifiers reduced */
 173   BoolMap d_quants_red;
 174   std::map< Node, Node > d_quants_red_lem;
 175   /** list of all lemmas produced */
 176   //std::map< Node, bool > d_lemmas_produced;
 177   BoolMap d_lemmas_produced_c;
 178   /** lemmas waiting */
 179   std::vector< Node > d_lemmas_waiting;
 180   /** phase requirements waiting */
 181   std::map< Node, bool > d_phase_req_waiting;
 182   /** list of all instantiations produced for each quantifier */
 183   std::map< Node, inst::InstMatchTrie > d_inst_match_trie;
 184   std::map< Node, inst::CDInstMatchTrie* > d_c_inst_match_trie;
 185   /** recorded instantiations */
 186   std::vector< std::pair< Node, std::vector< Node > > > d_recorded_inst;
 187   /** quantifiers that have been skolemized */
 188   BoolMap d_skolemized;
 189   /** term database */
 190   quantifiers::TermDb* d_term_db;
 191   /** all triggers will be stored in this trie */
 192   inst::TriggerTrie* d_tr_trie;
 193   /** extended model object */
 194   quantifiers::FirstOrderModel* d_model;
 195   /** statistics for debugging */
 196   std::map< Node, int > d_total_inst_debug;
 197   std::map< Node, int > d_temp_inst_debug;
 198   int d_total_inst_count_debug;
 199   /** inst round counters TODO: make context-dependent? */
 200   context::CDO< int > d_ierCounter_c;
 201   int d_ierCounter;
 202   int d_ierCounter_lc;
 203   int d_ierCounterLastLc;
 204   int d_inst_when_phase;
 205   /** has presolve been called */
 206   context::CDO< bool > d_presolve;
 207   /** presolve cache */
 208   NodeSet d_presolve_in;
 209   NodeList d_presolve_cache;
 210   BoolList d_presolve_cache_wq;
 211   BoolList d_presolve_cache_wic;
 212
 213 public:
 214   QuantifiersEngine(context::Context* c, context::UserContext* u, TheoryEngine* te);
 215   ~QuantifiersEngine();
 216   /** get theory engine */
 217   TheoryEngine* getTheoryEngine() { return d_te; }
 218   /** get equality query */
 219   EqualityQueryQuantifiersEngine* getEqualityQuery();
 220   /** get default sat context for quantifiers engine */
 221   context::Context* getSatContext();
 222   /** get default sat context for quantifiers engine */
 223   context::UserContext* getUserContext();
 224   /** get default output channel for the quantifiers engine */
 225   OutputChannel& getOutputChannel();
 226   /** get default valuation for the quantifiers engine */
 227   Valuation& getValuation();
 228   /** get relevant domain */
 229   quantifiers::RelevantDomain* getRelevantDomain() { return d_rel_dom; }
 230   /** get quantifier relevance */
 231   QuantRelevance* getQuantifierRelevance() { return d_quant_rel; }
 232   /** get the model builder */
 233   quantifiers::QModelBuilder* getModelBuilder() { return d_builder; }
 234   /** get utility for EPR */
 235   QuantEPR* getQuantEPR() { return d_qepr; }
 236 public:  //modules
 237   /** get instantiation engine */
 238   quantifiers::InstantiationEngine* getInstantiationEngine() { return d_inst_engine; }
 239   /** get model engine */
 240   quantifiers::ModelEngine* getModelEngine() { return d_model_engine; }
 241   /** get bounded integers utility */
 242   quantifiers::BoundedIntegers * getBoundedIntegers() { return d_bint; }
 243   /** Conflict find mechanism for quantifiers */
 244   quantifiers::QuantConflictFind* getConflictFind() { return d_qcf; }
 245   /** rewrite rules utility */
 246   quantifiers::RewriteEngine * getRewriteEngine() { return d_rr_engine; }
 247   /** subgoal generator */
 248   quantifiers::ConjectureGenerator * getConjectureGenerator() { return d_sg_gen; }
 249   /** ceg instantiation */
 250   quantifiers::CegInstantiation * getCegInstantiation() { return d_ceg_inst; }
 251   /** local theory ext partial inst */
 252   quantifiers::LtePartialInst * getLtePartialInst() { return d_lte_part_inst; }
 253   /** function definition engine */
 254   quantifiers::FunDefEngine * getFunDefEngine() { return d_fun_def_engine; }
 255   /** quantifiers equality engine */
 256   quantifiers::QuantEqualityEngine * getQuantEqualityEngine() { return d_uee; }
 257   /** get full saturation */
 258   quantifiers::FullSaturation * getFullSaturation() { return d_fs; }
 259   /** get inst strategy cbqi */
 260   quantifiers::InstStrategyCbqi * getInstStrategyCbqi() { return d_i_cbqi; }
 261   /** get quantifiers splitting */
 262   quantifiers::QuantDSplit * getQuantDSplit() { return d_qsplit; }
 263   /** get quantifiers anti-skolemization */
 264   quantifiers::QuantAntiSkolem * getQuantAntiSkolem() { return d_anti_skolem; }
 265 private:
 266   /** owner of quantified formulas */
 267   std::map< Node, QuantifiersModule * > d_owner;
 268   std::map< Node, int > d_owner_priority;
 269 public:
 270   /** get owner */
 271   QuantifiersModule * getOwner( Node q );
 272   /** set owner */
 273   void setOwner( Node q, QuantifiersModule * m, int priority = 0 );
 274   /** considers */
 275   bool hasOwnership( Node q, QuantifiersModule * m = NULL );
 276 public:
 277   /** initialize */
 278   void finishInit();
 279   /** presolve */
 280   void presolve();
 281   /** notify preprocessed assertion */
 282   void ppNotifyAssertions( std::vector< Node >& assertions );
 283   /** check at level */
 284   void check( Theory::Effort e );
 285   /** notify that theories were combined */
 286   void notifyCombineTheories();
 287   /** register quantifier */
 288   bool registerQuantifier( Node f );
 289   /** register quantifier */
 290   void registerPattern( std::vector<Node> & pattern);
 291   /** assert universal quantifier */
 292   void assertQuantifier( Node q, bool pol );
 293   /** propagate */
 294   void propagate( Theory::Effort level );
 295   /** get next decision request */
 296   Node getNextDecisionRequest();
 297 private:
 298   /** reduceQuantifier, return true if reduced */
 299   bool reduceQuantifier( Node q );
 300   /** compute term vector */
 301   void computeTermVector( Node f, InstMatch& m, std::vector< Node >& vars, std::vector< Node >& terms );
 302   /** record instantiation, return true if it was non-duplicate */
 303   bool recordInstantiationInternal( Node q, std::vector< Node >& terms, bool modEq = false, bool addedLem = true );
 304   /** remove instantiation */
 305   bool removeInstantiationInternal( Node q, std::vector< Node >& terms );
 306   /** set instantiation level attr */
 307   static void setInstantiationLevelAttr( Node n, Node qn, uint64_t level );
 308 public:
 309   /** flush lemmas */
 310   void flushLemmas();
 311   /** get instantiation */
 312   Node getInstantiation( Node q, std::vector< Node >& vars, std::vector< Node >& terms, bool doVts = false );
 313   /** get instantiation */
 314   Node getInstantiation( Node q, InstMatch& m, bool doVts = false );
 315   /** get instantiation */
 316   Node getInstantiation( Node q, std::vector< Node >& terms, bool doVts = false );
 317   /** do substitution */
 318   Node getSubstitute( Node n, std::vector< Node >& terms );
 319   /** add lemma lem */
 320   bool addLemma( Node lem, bool doCache = true, bool doRewrite = true );
 321   /** remove pending lemma */
 322   bool removeLemma( Node lem );
 323   /** add require phase */
 324   void addRequirePhase( Node lit, bool req );
 325   /** do instantiation specified by m */
 326   bool addInstantiation( Node q, InstMatch& m, bool mkRep = false, bool modEq = false, bool doVts = false );
 327   /** add instantiation */
 328   bool addInstantiation( Node q, std::vector< Node >& terms, bool mkRep = false, bool modEq = false, bool doVts = false );
 329   /** remove pending instantiation */
 330   bool removeInstantiation( Node q, Node lem, std::vector< Node >& terms );
 331   /** split on node n */
 332   bool addSplit( Node n, bool reqPhase = false, bool reqPhasePol = true );
 333   /** add split equality */
 334   bool addSplitEquality( Node n1, Node n2, bool reqPhase = false, bool reqPhasePol = true );
 335   /** mark relevant quantified formula, this will indicate it should be checked before the others */
 336   void markRelevant( Node q );
 337   /** has added lemma */
 338   bool hasAddedLemma() { return !d_lemmas_waiting.empty() || d_hasAddedLemma; }
 339   /** is in conflict */
 340   bool inConflict() { return d_conflict; }
 341   /** get number of waiting lemmas */
 342   unsigned getNumLemmasWaiting() { return d_lemmas_waiting.size(); }
 343   /** get needs check */
 344   bool getInstWhenNeedsCheck( Theory::Effort e );
 345   /** get user pat mode */
 346   quantifiers::UserPatMode getInstUserPatMode();
 347   /** set instantiation level attr */
 348   static void setInstantiationLevelAttr( Node n, uint64_t level );
 349 public:
 350   /** get model */
 351   quantifiers::FirstOrderModel* getModel() { return d_model; }
 352   /** get term database */
 353   quantifiers::TermDb* getTermDatabase() { return d_term_db; }
 354   /** get term database sygus */
 355   quantifiers::TermDbSygus* getTermDatabaseSygus();
 356   /** get trigger database */
 357   inst::TriggerTrie* getTriggerDatabase() { return d_tr_trie; }
 358   /** add term to database */
 359   void addTermToDatabase( Node n, bool withinQuant = false, bool withinInstClosure = false );
 360   /** notification when master equality engine is updated */
 361   void eqNotifyNewClass(TNode t);
 362   void eqNotifyPreMerge(TNode t1, TNode t2);
 363   void eqNotifyPostMerge(TNode t1, TNode t2);
 364   void eqNotifyDisequal(TNode t1, TNode t2, TNode reason);
 365   /** get the master equality engine */
 366   eq::EqualityEngine* getMasterEqualityEngine() ;
 367   /** debug print equality engine */
 368   void debugPrintEqualityEngine( const char * c );
 369 public:
 370   /** print instantiations */
 371   void printInstantiations( std::ostream& out );
 372   /** print solution for synthesis conjectures */
 373   void printSynthSolution( std::ostream& out );
 374   /** get instantiations */
 375   void getInstantiations( std::map< Node, std::vector< Node > >& insts );
 376   /** get unsat core lemmas */
 377   bool getUnsatCoreLemmas( std::vector< Node >& active_lemmas );
 378   bool getUnsatCoreLemmas( std::vector< Node >& active_lemmas, std::map< Node, Node >& weak_imp );
 379   /** get inst for lemmas */
 380   void getExplanationForInstLemmas( std::vector< Node >& lems, std::map< Node, Node >& quant, std::map< Node, std::vector< Node > >& tvec );
 381   /** statistics class */
 382   class Statistics {
 383   public:
 384     TimerStat d_time;
 385     IntStat d_num_quant;
 386     IntStat d_instantiation_rounds;
 387     IntStat d_instantiation_rounds_lc;
 388     IntStat d_instantiations;
 389     IntStat d_inst_duplicate;
 390     IntStat d_inst_duplicate_eq;
 391     IntStat d_triggers;
 392     IntStat d_simple_triggers;
 393     IntStat d_multi_triggers;
 394     IntStat d_multi_trigger_instantiations;
 395     IntStat d_red_alpha_equiv;
 396     IntStat d_red_lte_partial_inst;
 397     IntStat d_instantiations_user_patterns;
 398     IntStat d_instantiations_auto_gen;
 399     IntStat d_instantiations_guess;
 400     IntStat d_instantiations_cbqi_arith;
 401     Statistics();
 402     ~Statistics();
 403   };/* class QuantifiersEngine::Statistics */
 404   Statistics d_statistics;
 405 };/* class QuantifiersEngine */
 406
 407
 408
 409 /** equality query object using theory engine */
 410 class EqualityQueryQuantifiersEngine : public EqualityQuery
 411 {
 412 private:
 413   /** pointer to theory engine */
 414   QuantifiersEngine* d_qe;
 415   /** quantifiers equality inference */
 416   quantifiers::EqualityInference * d_eq_inference;
 417   context::CDO< unsigned > d_eqi_counter;
 418   /** internal representatives */
 419   std::map< TypeNode, std::map< Node, Node > > d_int_rep;
 420   /** rep score */
 421   std::map< Node, int > d_rep_score;
 422   /** reset count */
 423   int d_reset_count;
 424
 425   /** processInferences : will merge equivalence classes in master equality engine, if possible */
 426   bool processInferences( Theory::Effort e );
 427   /** node contains */
 428   Node getInstance( Node n, const std::vector< Node >& eqc, std::hash_map<TNode, Node, TNodeHashFunction>& cache );
 429   /** get score */
 430   int getRepScore( Node n, Node f, int index, TypeNode v_tn );
 431   /** flatten representatives */
 432   void flattenRepresentatives( std::map< TypeNode, std::vector< Node > >& reps );
 433 public:
 434   EqualityQueryQuantifiersEngine( context::Context* c, QuantifiersEngine* qe );
 435   virtual ~EqualityQueryQuantifiersEngine();
 436   /** reset */
 437   bool reset( Theory::Effort e );
 438   /** identify */
 439   std::string identify() const { return "EqualityQueryQE"; }
 440   /** general queries about equality */
 441   bool hasTerm( Node a );
 442   Node getRepresentative( Node a );
 443   bool areEqual( Node a, Node b );
 444   bool areDisequal( Node a, Node b );
 445   eq::EqualityEngine* getEngine();
 446   void getEquivalenceClass( Node a, std::vector< Node >& eqc );
 447   TNode getCongruentTerm( Node f, std::vector< TNode >& args );
 448   /** getInternalRepresentative gets the current best representative in the equivalence class of a, based on some criteria.
 449       If cbqi is active, this will return a term in the equivalence class of "a" that does
 450       not contain instantiation constants, if such a term exists.
 451    */
 452   Node getInternalRepresentative( Node a, Node f, int index );
 453   /** get quantifiers equality inference */
 454   quantifiers::EqualityInference * getEqualityInference() { return d_eq_inference; }
 455 }; /* EqualityQueryQuantifiersEngine */
 456
 457 }/* CVC4::theory namespace */
 458 }/* CVC4 namespace */
 459
 460 #endif /* __CVC4__THEORY__QUANTIFIERS_ENGINE_H */