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