src/theory/theory_engine.h

   1 /*********************                                                        */
   2 /*! \file theory_engine.h
   3  ** \verbatim
   4  ** Top contributors (to current version):
   5  **   Dejan Jovanovic, Andrew Reynolds, Morgan Deters
   6  ** This file is part of the CVC4 project.
   7  ** Copyright (c) 2009-2020 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 The theory engine
  13  **
  14  ** The theory engine.
  15  **/
  16
  17 #include "cvc4_private.h"
  18
  19 #ifndef CVC4__THEORY_ENGINE_H
  20 #define CVC4__THEORY_ENGINE_H
  21
  22 #include <deque>
  23 #include <memory>
  24 #include <set>
  25 #include <unordered_map>
  26 #include <utility>
  27 #include <vector>
  28
  29 #include "base/check.h"
  30 #include "context/cdhashset.h"
  31 #include "expr/node.h"
  32 #include "options/options.h"
  33 #include "options/smt_options.h"
  34 #include "options/theory_options.h"
  35 #include "prop/prop_engine.h"
  36 #include "smt/command.h"
  37 #include "theory/atom_requests.h"
  38 #include "theory/engine_output_channel.h"
  39 #include "theory/interrupted.h"
  40 #include "theory/rewriter.h"
  41 #include "theory/shared_terms_database.h"
  42 #include "theory/sort_inference.h"
  43 #include "theory/substitutions.h"
  44 #include "theory/term_registration_visitor.h"
  45 #include "theory/theory.h"
  46 #include "theory/theory_preprocessor.h"
  47 #include "theory/uf/equality_engine.h"
  48 #include "theory/valuation.h"
  49 #include "util/hash.h"
  50 #include "util/resource_manager.h"
  51 #include "util/statistics_registry.h"
  52 #include "util/unsafe_interrupt_exception.h"
  53
  54 namespace CVC4 {
  55
  56 class ResourceManager;
  57 class LemmaProofRecipe;
  58
  59 /**
  60  * A pair of a theory and a node. This is used to mark the flow of
  61  * propagations between theories.
  62  */
  63 struct NodeTheoryPair {
  64   Node d_node;
  65   theory::TheoryId d_theory;
  66   size_t d_timestamp;
  67   NodeTheoryPair(TNode n, theory::TheoryId t, size_t ts = 0)
  68       : d_node(n), d_theory(t), d_timestamp(ts)
  69   {
  70   }
  71   NodeTheoryPair() : d_theory(theory::THEORY_LAST), d_timestamp() {}
  72   // Comparison doesn't take into account the timestamp
  73   bool operator == (const NodeTheoryPair& pair) const {
  74     return d_node == pair.d_node && d_theory == pair.d_theory;
  75   }
  76 };/* struct NodeTheoryPair */
  77
  78 struct NodeTheoryPairHashFunction {
  79   NodeHashFunction hashFunction;
  80   // Hash doesn't take into account the timestamp
  81   size_t operator()(const NodeTheoryPair& pair) const {
  82     uint64_t hash = fnv1a::fnv1a_64(NodeHashFunction()(pair.d_node));
  83     return static_cast<size_t>(fnv1a::fnv1a_64(pair.d_theory, hash));
  84   }
  85 };/* struct NodeTheoryPairHashFunction */
  86
  87
  88 /* Forward declarations */
  89 namespace theory {
  90 class CombinationEngine;
  91 class TheoryModel;
  92 class TheoryEngineModelBuilder;
  93 class EqEngineManagerDistributed;
  94
  95 class DecisionManager;
  96 class RelevanceManager;
  97
  98 namespace eq {
  99 class EqualityEngine;
 100 }  // namespace eq
 101
 102 namespace quantifiers {
 103 class TermDb;
 104 }
 105
 106 class EntailmentCheckParameters;
 107 class EntailmentCheckSideEffects;
 108 }/* CVC4::theory namespace */
 109
 110 class RemoveTermFormulas;
 111
 112 /**
 113  * This is essentially an abstraction for a collection of theories.  A
 114  * TheoryEngine provides services to a PropEngine, making various
 115  * T-solvers look like a single unit to the propositional part of
 116  * CVC4.
 117  */
 118 class TheoryEngine {
 119
 120   /** Shared terms database can use the internals notify the theories */
 121   friend class SharedTermsDatabase;
 122   friend class theory::CombinationEngine;
 123   friend class theory::quantifiers::TermDb;
 124   friend class theory::EngineOutputChannel;
 125
 126   /** Associated PropEngine engine */
 127   prop::PropEngine* d_propEngine;
 128
 129   /** Our context */
 130   context::Context* d_context;
 131
 132   /** Our user context */
 133   context::UserContext* d_userContext;
 134
 135   /**
 136    * A table of from theory IDs to theory pointers. Never use this table
 137    * directly, use theoryOf() instead.
 138    */
 139   theory::Theory* d_theoryTable[theory::THEORY_LAST];
 140
 141   /**
 142    * A collection of theories that are "active" for the current run.
 143    * This set is provided by the user (as a logic string, say, in SMT-LIBv2
 144    * format input), or else by default it's all-inclusive.  This is important
 145    * because we can optimize for single-theory runs (no sharing), can reduce
 146    * the cost of walking the DAG on registration, etc.
 147    */
 148   const LogicInfo& d_logicInfo;
 149
 150   /**
 151    * The database of shared terms.
 152    */
 153   SharedTermsDatabase d_sharedTerms;
 154
 155   /**
 156    * The distributed equality manager. This class is responsible for
 157    * configuring the theories of this class for handling equalties
 158    * in a "distributed" fashion, i.e. each theory maintains a unique
 159    * instance of an equality engine. These equality engines are memory
 160    * managed by this class.
 161    */
 162   std::unique_ptr<theory::EqEngineManagerDistributed> d_eeDistributed;
 163
 164   /**
 165    * The quantifiers engine
 166    */
 167   theory::QuantifiersEngine* d_quantEngine;
 168   /**
 169    * The decision manager
 170    */
 171   std::unique_ptr<theory::DecisionManager> d_decManager;
 172   /** The relevance manager */
 173   std::unique_ptr<theory::RelevanceManager> d_relManager;
 174
 175   /**
 176    * Default model object
 177    */
 178   theory::TheoryModel* d_curr_model;
 179   bool d_aloc_curr_model;
 180   /**
 181    * Model builder object
 182    */
 183   theory::TheoryEngineModelBuilder* d_curr_model_builder;
 184   bool d_aloc_curr_model_builder;
 185   /** are we in eager model building mode? (see setEagerModelBuilding). */
 186   bool d_eager_model_building;
 187
 188   typedef std::unordered_map<Node, Node, NodeHashFunction> NodeMap;
 189   typedef std::unordered_map<TNode, Node, TNodeHashFunction> TNodeMap;
 190
 191   /**
 192    * Used for "missed-t-propagations" dumping mode only.  A set of all
 193    * theory-propagable literals.
 194    */
 195   context::CDList<TNode> d_possiblePropagations;
 196
 197   /**
 198    * Used for "missed-t-propagations" dumping mode only.  A
 199    * context-dependent set of those theory-propagable literals that
 200    * have been propagated.
 201    */
 202   context::CDHashSet<Node, NodeHashFunction> d_hasPropagated;
 203
 204   /**
 205    * Output channels for individual theories.
 206    */
 207   theory::EngineOutputChannel* d_theoryOut[theory::THEORY_LAST];
 208
 209   /**
 210    * Are we in conflict.
 211    */
 212   context::CDO<bool> d_inConflict;
 213
 214   /**
 215    * Are we in "SAT mode"? In this state, the user can query for the model.
 216    * This corresponds to the state in Figure 4.1, page 52 of the SMT-LIB
 217    * standard, version 2.6.
 218    */
 219   bool d_inSatMode;
 220
 221   /**
 222    * Called by the theories to notify of a conflict.
 223    */
 224   void conflict(TNode conflict, theory::TheoryId theoryId);
 225
 226   /**
 227    * Debugging flag to ensure that shutdown() is called before the
 228    * destructor.
 229    */
 230   bool d_hasShutDown;
 231
 232   /**
 233    * True if a theory has notified us of incompleteness (at this
 234    * context level or below).
 235    */
 236   context::CDO<bool> d_incomplete;
 237
 238   /**
 239    * Called by the theories to notify that the current branch is incomplete.
 240    */
 241   void setIncomplete(theory::TheoryId theory) {
 242     d_incomplete = true;
 243   }
 244
 245
 246   /**
 247    * Mapping of propagations from recievers to senders.
 248    */
 249   typedef context::CDHashMap<NodeTheoryPair, NodeTheoryPair, NodeTheoryPairHashFunction> PropagationMap;
 250   PropagationMap d_propagationMap;
 251
 252   /**
 253    * Timestamp of propagations
 254    */
 255   context::CDO<size_t> d_propagationMapTimestamp;
 256
 257   /**
 258    * Literals that are propagated by the theory. Note that these are TNodes.
 259    * The theory can only propagate nodes that have an assigned literal in the
 260    * SAT solver and are hence referenced in the SAT solver.
 261    */
 262   context::CDList<TNode> d_propagatedLiterals;
 263
 264   /**
 265    * The index of the next literal to be propagated by a theory.
 266    */
 267   context::CDO<unsigned> d_propagatedLiteralsIndex;
 268
 269   /**
 270    * Called by the output channel to propagate literals and facts
 271    * @return false if immediate conflict
 272    */
 273   bool propagate(TNode literal, theory::TheoryId theory);
 274
 275   /**
 276    * Internal method to call the propagation routines and collect the
 277    * propagated literals.
 278    */
 279   void propagate(theory::Theory::Effort effort);
 280
 281   /**
 282    * A variable to mark if we added any lemmas.
 283    */
 284   bool d_lemmasAdded;
 285
 286   /**
 287    * A variable to mark if the OutputChannel was "used" by any theory
 288    * since the start of the last check.  If it has been, we require
 289    * a FULL_EFFORT check before exiting and reporting SAT.
 290    *
 291    * See the documentation for the needCheck() function, below.
 292    */
 293   bool d_outputChannelUsed;
 294
 295   /** Atom requests from lemmas */
 296   AtomRequests d_atomRequests;
 297
 298   /**
 299    * Adds a new lemma, returning its status.
 300    * @param node the lemma
 301    * @param negated should the lemma be asserted negated
 302    * @param p the properties of the lemma.
 303    */
 304   theory::LemmaStatus lemma(TNode node,
 305                             ProofRule rule,
 306                             bool negated,
 307                             theory::LemmaProperty p,
 308                             theory::TheoryId atomsTo);
 309
 310   /** Enusre that the given atoms are send to the given theory */
 311   void ensureLemmaAtoms(const std::vector<TNode>& atoms, theory::TheoryId theory);
 312
 313   /** sort inference module */
 314   SortInference d_sortInfer;
 315
 316   /** The theory preprocessor */
 317   theory::TheoryPreprocessor d_tpp;
 318
 319   /** Time spent in theory combination */
 320   TimerStat d_combineTheoriesTime;
 321
 322   Node d_true;
 323   Node d_false;
 324
 325   /** Whether we were just interrupted (or not) */
 326   bool d_interrupted;
 327   ResourceManager* d_resourceManager;
 328
 329  public:
 330   /** Constructs a theory engine */
 331   TheoryEngine(context::Context* context,
 332                context::UserContext* userContext,
 333                ResourceManager* rm,
 334                RemoveTermFormulas& iteRemover,
 335                const LogicInfo& logic);
 336
 337   /** Destroys a theory engine */
 338   ~TheoryEngine();
 339
 340   void interrupt();
 341
 342   /** "Spend" a resource during a search or preprocessing.*/
 343   void spendResource(ResourceManager::Resource r);
 344
 345   /**
 346    * Adds a theory. Only one theory per TheoryId can be present, so if
 347    * there is another theory it will be deleted.
 348    */
 349   template <class TheoryClass>
 350   inline void addTheory(theory::TheoryId theoryId)
 351   {
 352     Assert(d_theoryTable[theoryId] == NULL && d_theoryOut[theoryId] == NULL);
 353     d_theoryOut[theoryId] = new theory::EngineOutputChannel(this, theoryId);
 354     d_theoryTable[theoryId] = new TheoryClass(d_context,
 355                                               d_userContext,
 356                                               *d_theoryOut[theoryId],
 357                                               theory::Valuation(this),
 358                                               d_logicInfo,
 359                                               nullptr);
 360     theory::Rewriter::registerTheoryRewriter(
 361         theoryId, d_theoryTable[theoryId]->getTheoryRewriter());
 362   }
 363
 364   void setPropEngine(prop::PropEngine* propEngine)
 365   {
 366     d_propEngine = propEngine;
 367   }
 368
 369   /**
 370    * Called when all initialization of options/logic is done, after theory
 371    * objects have been created.
 372    *
 373    * This initializes the quantifiers engine, the "official" equality engines
 374    * of each theory as required, and the model and model builder utilities.
 375    */
 376   void finishInit();
 377
 378   /**
 379    * Get a pointer to the underlying propositional engine.
 380    */
 381   inline prop::PropEngine* getPropEngine() const {
 382     return d_propEngine;
 383   }
 384
 385   /**
 386    * Get a pointer to the underlying sat context.
 387    */
 388   inline context::Context* getSatContext() const {
 389     return d_context;
 390   }
 391
 392   /**
 393    * Get a pointer to the underlying user context.
 394    */
 395   inline context::Context* getUserContext() const {
 396     return d_userContext;
 397   }
 398
 399   /**
 400    * Get a pointer to the underlying quantifiers engine.
 401    */
 402   theory::QuantifiersEngine* getQuantifiersEngine() const {
 403     return d_quantEngine;
 404   }
 405   /**
 406    * Get a pointer to the underlying decision manager.
 407    */
 408   theory::DecisionManager* getDecisionManager() const
 409   {
 410     return d_decManager.get();
 411   }
 412
 413  private:
 414   /**
 415    * Queue of nodes for pre-registration.
 416    */
 417   std::queue<TNode> d_preregisterQueue;
 418
 419   /**
 420    * Boolean flag denoting we are in pre-registration.
 421    */
 422   bool d_inPreregister;
 423
 424   /**
 425    * Did the theories get any new facts since the last time we called
 426    * check()
 427    */
 428   context::CDO<bool> d_factsAsserted;
 429
 430   /**
 431    * Map from equality atoms to theories that would like to be notified about them.
 432    */
 433
 434
 435   /**
 436    * Assert the formula to the given theory.
 437    * @param assertion the assertion to send (not necesserily normalized)
 438    * @param original the assertion as it was sent in from the propagating theory
 439    * @param toTheoryId the theory to assert to
 440    * @param fromTheoryId the theory that sent it
 441    */
 442   void assertToTheory(TNode assertion, TNode originalAssertion, theory::TheoryId toTheoryId, theory::TheoryId fromTheoryId);
 443
 444   /**
 445    * Marks a theory propagation from a theory to a theory where a
 446    * theory could be the THEORY_SAT_SOLVER for literals coming from
 447    * or being propagated to the SAT solver. If the receiving theory
 448    * already recieved the literal, the method returns false, otherwise
 449    * it returns true.
 450    *
 451    * @param assertion the normalized assertion being sent
 452    * @param originalAssertion the actual assertion that was sent
 453    * @param toTheoryId the theory that is on the receiving end
 454    * @param fromTheoryId the theory that sent the assertion
 455    * @return true if a new assertion, false if theory already got it
 456    */
 457   bool markPropagation(TNode assertion, TNode originalAssertions, theory::TheoryId toTheoryId, theory::TheoryId fromTheoryId);
 458
 459   /**
 460    * Computes the explanation by travarsing the propagation graph and
 461    * asking relevant theories to explain the propagations. Initially
 462    * the explanation vector should contain only the element (node, theory)
 463    * where the node is the one to be explained, and the theory is the
 464    * theory that sent the literal. The lemmaProofRecipe will contain a list
 465    * of the explanation steps required to produce the original node.
 466    */
 467   void getExplanation(std::vector<NodeTheoryPair>& explanationVector, LemmaProofRecipe* lemmaProofRecipe);
 468
 469 public:
 470
 471   /**
 472    * Signal the start of a new round of assertion preprocessing
 473    */
 474   void preprocessStart();
 475
 476   /**
 477    * Runs theory specific preprocessing on the non-Boolean parts of
 478    * the formula.  This is only called on input assertions, after ITEs
 479    * have been removed.
 480    */
 481   Node preprocess(TNode node);
 482
 483   /** Notify (preprocessed) assertions. */
 484   void notifyPreprocessedAssertions(const std::vector<Node>& assertions);
 485
 486   /** Return whether or not we are incomplete (in the current context). */
 487   inline bool isIncomplete() const { return d_incomplete; }
 488
 489   /**
 490    * Returns true if we need another round of checking.  If this
 491    * returns true, check(FULL_EFFORT) _must_ be called by the
 492    * propositional layer before reporting SAT.
 493    *
 494    * This is especially necessary for incomplete theories that lazily
 495    * output some lemmas on FULL_EFFORT check (e.g. quantifier reasoning
 496    * outputing quantifier instantiations).  In such a case, a lemma can
 497    * be asserted that is simplified away (perhaps it's already true).
 498    * However, we must maintain the invariant that, if a theory uses the
 499    * OutputChannel, it implicitly requests that another check(FULL_EFFORT)
 500    * be performed before exit, even if no new facts are on its fact queue,
 501    * as it might decide to further instantiate some lemmas, precluding
 502    * a SAT response.
 503    */
 504   inline bool needCheck() const {
 505     return d_outputChannelUsed || d_lemmasAdded;
 506   }
 507   /**
 508    * Is the literal lit (possibly) critical for satisfying the input formula in
 509    * the current context? This call is applicable only during collectModelInfo
 510    * or during LAST_CALL effort.
 511    */
 512   bool isRelevant(Node lit) const;
 513
 514   /**
 515    * This is called at shutdown time by the SmtEngine, just before
 516    * destruction.  It is important because there are destruction
 517    * ordering issues between PropEngine and Theory.
 518    */
 519   void shutdown();
 520
 521   /**
 522    * Solve the given literal with a theory that owns it.
 523    */
 524   theory::Theory::PPAssertStatus solve(TNode literal,
 525                                     theory::SubstitutionMap& substitutionOut);
 526
 527   /**
 528    * Preregister a Theory atom with the responsible theory (or
 529    * theories).
 530    */
 531   void preRegister(TNode preprocessed);
 532
 533   /**
 534    * Assert the formula to the appropriate theory.
 535    * @param node the assertion
 536    */
 537   void assertFact(TNode node);
 538
 539   /**
 540    * Check all (currently-active) theories for conflicts.
 541    * @param effort the effort level to use
 542    */
 543   void check(theory::Theory::Effort effort);
 544
 545   /**
 546    * Run the combination framework.
 547    */
 548   void combineTheories();
 549
 550   /**
 551    * Calls ppStaticLearn() on all theories, accumulating their
 552    * combined contributions in the "learned" builder.
 553    */
 554   void ppStaticLearn(TNode in, NodeBuilder<>& learned);
 555
 556   /**
 557    * Calls presolve() on all theories and returns true
 558    * if one of the theories discovers a conflict.
 559    */
 560   bool presolve();
 561
 562    /**
 563    * Calls postsolve() on all theories.
 564    */
 565   void postsolve();
 566
 567   /**
 568    * Calls notifyRestart() on all active theories.
 569    */
 570   void notifyRestart();
 571
 572   void getPropagatedLiterals(std::vector<TNode>& literals) {
 573     for (; d_propagatedLiteralsIndex < d_propagatedLiterals.size(); d_propagatedLiteralsIndex = d_propagatedLiteralsIndex + 1) {
 574       Debug("getPropagatedLiterals") << "TheoryEngine::getPropagatedLiterals: propagating: " << d_propagatedLiterals[d_propagatedLiteralsIndex] << std::endl;
 575       literals.push_back(d_propagatedLiterals[d_propagatedLiteralsIndex]);
 576     }
 577   }
 578
 579   /**
 580    * Returns the next decision request, or null if none exist. The next
 581    * decision request is a literal that this theory engine prefers the SAT
 582    * solver to make as its next decision. Decision requests are managed by
 583    * the decision manager d_decManager.
 584    */
 585   Node getNextDecisionRequest();
 586
 587   bool properConflict(TNode conflict) const;
 588   bool properPropagation(TNode lit) const;
 589   bool properExplanation(TNode node, TNode expl) const;
 590
 591   /**
 592    * Returns an explanation of the node propagated to the SAT solver.
 593    */
 594   Node getExplanation(TNode node);
 595
 596   /**
 597    * Returns an explanation of the node propagated to the SAT solver and the theory
 598    * that propagated it.
 599    */
 600   Node getExplanationAndRecipe(TNode node, LemmaProofRecipe* proofRecipe);
 601
 602   /**
 603    * collect model info
 604    */
 605   bool collectModelInfo(theory::TheoryModel* m);
 606   /** post process model */
 607   void postProcessModel( theory::TheoryModel* m );
 608
 609   /**
 610    * Get the pointer to the model object used by this theory engine.
 611    */
 612   theory::TheoryModel* getModel();
 613   /**
 614    * Get the current model for the current set of assertions. This method
 615    * should only be called immediately after a satisfiable or unknown
 616    * response to a check-sat call, and only if produceModels is true.
 617    *
 618    * If the model is not already built, this will cause this theory engine
 619    * to build the model.
 620    *
 621    * If the model is not available (for instance, if the last call to check-sat
 622    * was interrupted), then this returns the null pointer.
 623    */
 624   theory::TheoryModel* getBuiltModel();
 625   /** set eager model building
 626    *
 627    * If this method is called, then this TheoryEngine will henceforth build
 628    * its model immediately after every satisfiability check that results
 629    * in a satisfiable or unknown result. The motivation for this mode is to
 630    * accomodate API users that get the model object from the TheoryEngine,
 631    * where we want to ensure that this model is always valid.
 632    * TODO (#2648): revisit this.
 633    */
 634   void setEagerModelBuilding() { d_eager_model_building = true; }
 635
 636   /** get synth solutions
 637    *
 638    * This method returns true if there is a synthesis solution available. This
 639    * is the case if the last call to check satisfiability originated in a
 640    * check-synth call, and the synthesis solver successfully found a solution
 641    * for all active synthesis conjectures.
 642    *
 643    * This method adds entries to sol_map that map functions-to-synthesize with
 644    * their solutions, for all active conjectures. This should be called
 645    * immediately after the solver answers unsat for sygus input.
 646    *
 647    * For details on what is added to sol_map, see
 648    * SynthConjecture::getSynthSolutions.
 649    */
 650   bool getSynthSolutions(std::map<Node, std::map<Node, Node> >& sol_map);
 651
 652   /**
 653    * Get the model builder
 654    */
 655   theory::TheoryEngineModelBuilder* getModelBuilder() { return d_curr_model_builder; }
 656
 657   /**
 658    * Get the theory associated to a given Node.
 659    *
 660    * @returns the theory, or NULL if the TNode is
 661    * of built-in type.
 662    */
 663   inline theory::Theory* theoryOf(TNode node) const {
 664     return d_theoryTable[theory::Theory::theoryOf(node)];
 665   }
 666
 667   /**
 668    * Get the theory associated to a the given theory id.
 669    *
 670    * @returns the theory
 671    */
 672   inline theory::Theory* theoryOf(theory::TheoryId theoryId) const {
 673     Assert(theoryId < theory::THEORY_LAST);
 674     return d_theoryTable[theoryId];
 675   }
 676
 677   inline bool isTheoryEnabled(theory::TheoryId theoryId) const {
 678     return d_logicInfo.isTheoryEnabled(theoryId);
 679   }
 680   /** get the logic info used by this theory engine */
 681   const LogicInfo& getLogicInfo() const;
 682   /**
 683    * Returns the equality status of the two terms, from the theory
 684    * that owns the domain type.  The types of a and b must be the same.
 685    */
 686   theory::EqualityStatus getEqualityStatus(TNode a, TNode b);
 687
 688   /**
 689    * Returns the value that a theory that owns the type of var currently
 690    * has (or null if none);
 691    */
 692   Node getModelValue(TNode var);
 693
 694   /**
 695    * Takes a literal and returns an equivalent literal that is guaranteed to be a SAT literal
 696    */
 697   Node ensureLiteral(TNode n);
 698
 699   /**
 700    * Print all instantiations made by the quantifiers module.
 701    */
 702   void printInstantiations( std::ostream& out );
 703
 704   /**
 705    * Print solution for synthesis conjectures found by ce_guided_instantiation module
 706    */
 707   void printSynthSolution( std::ostream& out );
 708
 709   /**
 710    * Get list of quantified formulas that were instantiated
 711    */
 712   void getInstantiatedQuantifiedFormulas( std::vector< Node >& qs );
 713
 714   /**
 715    * Get instantiation methods
 716    *   first inputs forall x.q[x] and returns ( q[a], ..., q[z] )
 717    *   second inputs forall x.q[x] and returns ( a, ..., z )
 718    *   third and fourth return mappings e.g. forall x.q1[x] -> ( q1[a]...q1[z] ) , ... , forall x.qn[x] -> ( qn[a]...qn[z] )
 719    */
 720   void getInstantiations( Node q, std::vector< Node >& insts );
 721   void getInstantiationTermVectors( Node q, std::vector< std::vector< Node > >& tvecs );
 722   void getInstantiations( std::map< Node, std::vector< Node > >& insts );
 723   void getInstantiationTermVectors( std::map< Node, std::vector< std::vector< Node > > >& insts );
 724
 725   /**
 726    * Get instantiated conjunction, returns q[t1] ^ ... ^ q[tn] where t1...tn are current set of instantiations for q.
 727    *   Can be used for quantifier elimination when satisfiable and q[t1] ^ ... ^ q[tn] |= q
 728    */
 729   Node getInstantiatedConjunction( Node q );
 730
 731   /**
 732    * Forwards an entailment check according to the given theoryOfMode.
 733    * See theory.h for documentation on entailmentCheck().
 734    */
 735   std::pair<bool, Node> entailmentCheck(options::TheoryOfMode mode, TNode lit);
 736
 737  private:
 738   /** Default visitor for pre-registration */
 739   PreRegisterVisitor d_preRegistrationVisitor;
 740
 741   /** Visitor for collecting shared terms */
 742   SharedTermsVisitor d_sharedTermsVisitor;
 743
 744   /** Dump the assertions to the dump */
 745   void dumpAssertions(const char* tag);
 746
 747   /** For preprocessing pass lifting bit-vectors of size 1 to booleans */
 748 public:
 749
 750   SharedTermsDatabase* getSharedTermsDatabase();
 751
 752   SortInference* getSortInference() { return &d_sortInfer; }
 753
 754   /** Prints the assertions to the debug stream */
 755   void printAssertions(const char* tag);
 756
 757 private:
 758
 759   std::map< std::string, std::vector< theory::Theory* > > d_attr_handle;
 760
 761  public:
 762   /** Set user attribute.
 763    *
 764    * This function is called when an attribute is set by a user.  In SMT-LIBv2
 765    * this is done via the syntax (! n :attr)
 766    */
 767   void setUserAttribute(const std::string& attr,
 768                         Node n,
 769                         const std::vector<Node>& node_values,
 770                         const std::string& str_value);
 771
 772   /** Handle user attribute.
 773    *
 774    * Associates theory t with the attribute attr.  Theory t will be
 775    * notified whenever an attribute of name attr is set.
 776    */
 777   void handleUserAttribute(const char* attr, theory::Theory* t);
 778
 779   /**
 780    * Check that the theory assertions are satisfied in the model.
 781    * This function is called from the smt engine's checkModel routine.
 782    */
 783   void checkTheoryAssertionsWithModel(bool hardFailure);
 784
 785  private:
 786   IntStat d_arithSubstitutionsAdded;
 787
 788 };/* class TheoryEngine */
 789
 790 }/* CVC4 namespace */
 791
 792 #endif /* CVC4__THEORY_ENGINE_H */