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