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