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 }/* 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::ModelEngine;
  89   friend class quantifiers::RewriteEngine;
  90   friend class quantifiers::QuantConflictFind;
  91   friend class inst::InstMatch;
  92 private:
  93   typedef context::CDHashMap< Node, bool, NodeHashFunction > BoolMap;
  94   /** reference to theory engine object */
  95   TheoryEngine* d_te;
  96   /** vector of modules for quantifiers */
  97   std::vector< QuantifiersModule* > d_modules;
  98   /** equality query class */
  99   EqualityQueryQuantifiersEngine* d_eq_query;
 100   /** for computing relevance of quantifiers */
 101   QuantRelevance * d_quant_rel;
 102   /** relevant domain */
 103   quantifiers::RelevantDomain* d_rel_dom;
 104   /** phase requirements for each quantifier for each instantiation literal */
 105   std::map< Node, QuantPhaseReq* > d_phase_reqs;
 106   /** instantiation engine */
 107   quantifiers::InstantiationEngine* d_inst_engine;
 108   /** model engine */
 109   quantifiers::ModelEngine* d_model_engine;
 110   /** bounded integers utility */
 111   quantifiers::BoundedIntegers * d_bint;
 112   /** Conflict find mechanism for quantifiers */
 113   quantifiers::QuantConflictFind* d_qcf;
 114   /** rewrite rules utility */
 115   quantifiers::RewriteEngine * d_rr_engine;
 116   /** subgoal generator */
 117   quantifiers::ConjectureGenerator * d_sg_gen;
 118 public: //effort levels
 119   enum {
 120     QEFFORT_CONFLICT,
 121     QEFFORT_STANDARD,
 122     QEFFORT_MODEL,
 123   };
 124 private:
 125   /** list of all quantifiers seen */
 126   std::vector< Node > d_quants;
 127   /** list of all lemmas produced */
 128   //std::map< Node, bool > d_lemmas_produced;
 129   BoolMap d_lemmas_produced_c;
 130   /** lemmas waiting */
 131   std::vector< Node > d_lemmas_waiting;
 132   /** phase requirements waiting */
 133   std::map< Node, bool > d_phase_req_waiting;
 134   /** has added lemma this round */
 135   bool d_hasAddedLemma;
 136   /** has a conflict been found */
 137   bool d_conflict;
 138   /** list of all instantiations produced for each quantifier */
 139   std::map< Node, inst::InstMatchTrie > d_inst_match_trie;
 140   std::map< Node, inst::CDInstMatchTrie* > d_c_inst_match_trie;
 141   /** quantifiers that have been skolemized */
 142   std::map< Node, bool > d_skolemized;
 143   /** term database */
 144   quantifiers::TermDb* d_term_db;
 145   /** all triggers will be stored in this trie */
 146   inst::TriggerTrie* d_tr_trie;
 147   /** extended model object */
 148   quantifiers::FirstOrderModel* d_model;
 149   /** statistics for debugging */
 150   std::map< Node, int > d_total_inst_debug;
 151   std::map< Node, int > d_temp_inst_debug;
 152   int d_total_inst_count_debug;
 153 private:
 154   KEEP_STATISTIC(TimerStat, d_time, "theory::QuantifiersEngine::time");
 155 public:
 156   QuantifiersEngine(context::Context* c, context::UserContext* u, TheoryEngine* te);
 157   ~QuantifiersEngine();
 158   /** get theory engine */
 159   TheoryEngine* getTheoryEngine() { return d_te; }
 160   /** get equality query object for the given type. The default is the
 161       generic one */
 162   EqualityQueryQuantifiersEngine* getEqualityQuery();
 163   /** get instantiation engine */
 164   quantifiers::InstantiationEngine* getInstantiationEngine() { return d_inst_engine; }
 165   /** get model engine */
 166   quantifiers::ModelEngine* getModelEngine() { return d_model_engine; }
 167   /** get default sat context for quantifiers engine */
 168   context::Context* getSatContext();
 169   /** get default sat context for quantifiers engine */
 170   context::Context* getUserContext();
 171   /** get default output channel for the quantifiers engine */
 172   OutputChannel& getOutputChannel();
 173   /** get default valuation for the quantifiers engine */
 174   Valuation& getValuation();
 175   /** get relevant domain */
 176   quantifiers::RelevantDomain* getRelevantDomain() { return d_rel_dom; }
 177   /** get quantifier relevance */
 178   QuantRelevance* getQuantifierRelevance() { return d_quant_rel; }
 179   /** get phase requirement information */
 180   QuantPhaseReq* getPhaseRequirements( Node f ) { return d_phase_reqs.find( f )==d_phase_reqs.end() ? NULL : d_phase_reqs[f]; }
 181   /** get phase requirement terms */
 182   void getPhaseReqTerms( Node f, std::vector< Node >& nodes );
 183   /** get bounded integers utility */
 184   quantifiers::BoundedIntegers * getBoundedIntegers() { return d_bint; }
 185   /** Conflict find mechanism for quantifiers */
 186   quantifiers::QuantConflictFind* getConflictFind() { return d_qcf; }
 187 public:
 188   /** initialize */
 189   void finishInit();
 190   /** check at level */
 191   void check( Theory::Effort e );
 192   /** register quantifier */
 193   void registerQuantifier( Node f );
 194   /** register quantifier */
 195   void registerPattern( std::vector<Node> & pattern);
 196   /** assert universal quantifier */
 197   void assertQuantifier( Node q, bool pol );
 198   /** propagate */
 199   void propagate( Theory::Effort level );
 200   /** get next decision request */
 201   Node getNextDecisionRequest();
 202 private:
 203   /** compute term vector */
 204   void computeTermVector( Node f, InstMatch& m, std::vector< Node >& vars, std::vector< Node >& terms );
 205   /** instantiate f with arguments terms */
 206   bool addInstantiation( Node f, std::vector< Node >& vars, std::vector< Node >& terms );
 207   /** set instantiation level attr */
 208   static void setInstantiationLevelAttr( Node n, Node qn, uint64_t level );
 209   /** flush lemmas */
 210   void flushLemmas();
 211 public:
 212   /** get instantiation */
 213   Node getInstantiation( Node f, std::vector< Node >& vars, std::vector< Node >& terms );
 214   /** get instantiation */
 215   Node getInstantiation( Node f, InstMatch& m );
 216   /** get instantiation */
 217   Node getInstantiation( Node f, std::vector< Node >& terms );
 218   /** do substitution */
 219   Node getSubstitute( Node n, std::vector< Node >& terms );
 220   /** exist instantiation ? */
 221   bool existsInstantiation( Node f, InstMatch& m, bool modEq = true, bool modInst = false );
 222   /** add lemma lem */
 223   bool addLemma( Node lem, bool doCache = true );
 224   /** add require phase */
 225   void addRequirePhase( Node lit, bool req );
 226   /** do instantiation specified by m */
 227   bool addInstantiation( Node f, InstMatch& m, bool mkRep = true, bool modEq = false, bool modInst = false );
 228   /** add instantiation */
 229   bool addInstantiation( Node f, std::vector< Node >& terms, bool mkRep = true, bool modEq = false, bool modInst = false );
 230   /** split on node n */
 231   bool addSplit( Node n, bool reqPhase = false, bool reqPhasePol = true );
 232   /** add split equality */
 233   bool addSplitEquality( Node n1, Node n2, bool reqPhase = false, bool reqPhasePol = true );
 234   /** has added lemma */
 235   bool hasAddedLemma() { return !d_lemmas_waiting.empty() || d_hasAddedLemma; }
 236   /** get number of waiting lemmas */
 237   int getNumLemmasWaiting() { return (int)d_lemmas_waiting.size(); }
 238   /** set instantiation level attr */
 239   static void setInstantiationLevelAttr( Node n, uint64_t level );
 240   /** is term eligble for instantiation? */
 241   bool isTermEligibleForInstantiation( Node n, Node f, bool print = false );
 242 public:
 243   /** get number of quantifiers */
 244   int getNumQuantifiers() { return (int)d_quants.size(); }
 245   /** get quantifier */
 246   Node getQuantifier( int i ) { return d_quants[i]; }
 247 public:
 248   /** get model */
 249   quantifiers::FirstOrderModel* getModel() { return d_model; }
 250   /** get term database */
 251   quantifiers::TermDb* getTermDatabase() { return d_term_db; }
 252   /** get trigger database */
 253   inst::TriggerTrie* getTriggerDatabase() { return d_tr_trie; }
 254   /** add term to database */
 255   void addTermToDatabase( Node n, bool withinQuant = false );
 256   /** get the master equality engine */
 257   eq::EqualityEngine* getMasterEqualityEngine() ;
 258 public:
 259   /** print instantiations */
 260   void printInstantiations( std::ostream& out );
 261   /** statistics class */
 262   class Statistics {
 263   public:
 264     IntStat d_num_quant;
 265     IntStat d_instantiation_rounds;
 266     IntStat d_instantiation_rounds_lc;
 267     IntStat d_instantiations;
 268     IntStat d_inst_duplicate;
 269     IntStat d_inst_duplicate_eq;
 270     IntStat d_lit_phase_req;
 271     IntStat d_lit_phase_nreq;
 272     IntStat d_triggers;
 273     IntStat d_simple_triggers;
 274     IntStat d_multi_triggers;
 275     IntStat d_multi_trigger_instantiations;
 276     Statistics();
 277     ~Statistics();
 278   };/* class QuantifiersEngine::Statistics */
 279   Statistics d_statistics;
 280 };/* class QuantifiersEngine */
 281
 282
 283
 284 /** equality query object using theory engine */
 285 class EqualityQueryQuantifiersEngine : public EqualityQuery
 286 {
 287 private:
 288   /** pointer to theory engine */
 289   QuantifiersEngine* d_qe;
 290   /** internal representatives */
 291   std::map< Node, Node > d_int_rep;
 292   /** rep score */
 293   std::map< Node, int > d_rep_score;
 294   /** reset count */
 295   int d_reset_count;
 296
 297   bool d_liberal;
 298 private:
 299   /** node contains */
 300   Node getInstance( Node n, std::vector< Node >& eqc );
 301   /** get score */
 302   int getRepScore( Node n, Node f, int index );
 303 public:
 304   EqualityQueryQuantifiersEngine( QuantifiersEngine* qe ) : d_qe( qe ), d_reset_count( 0 ), d_liberal( false ){}
 305   ~EqualityQueryQuantifiersEngine(){}
 306   /** reset */
 307   void reset();
 308   /** general queries about equality */
 309   bool hasTerm( Node a );
 310   Node getRepresentative( Node a );
 311   bool areEqual( Node a, Node b );
 312   bool areDisequal( Node a, Node b );
 313   eq::EqualityEngine* getEngine();
 314   void getEquivalenceClass( Node a, std::vector< Node >& eqc );
 315   /** getInternalRepresentative gets the current best representative in the equivalence class of a, based on some criteria.
 316       If cbqi is active, this will return a term in the equivalence class of "a" that does
 317       not contain instantiation constants, if such a term exists.
 318    */
 319   Node getInternalRepresentative( Node a, Node f, int index );
 320   /** flatten representatives */
 321   void flattenRepresentatives( std::map< TypeNode, std::vector< Node > >& reps );
 322
 323   void setLiberal( bool l ) { d_liberal = l; }
 324 }; /* EqualityQueryQuantifiersEngine */
 325
 326 }/* CVC4::theory namespace */
 327 }/* CVC4 namespace */
 328
 329 #endif /* __CVC4__THEORY__QUANTIFIERS_ENGINE_H */