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