src/theory/theory_engine.h

   1 /*********************                                                        */
   2 /*! \file theory_engine.h
   3  ** \verbatim
   4  ** Top contributors (to current version):
   5  **   Dejan Jovanovic, Morgan Deters, Andrew Reynolds
   6  ** This file is part of the CVC4 project.
   7  ** Copyright (c) 2009-2018 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 <vector>
  27 #include <utility>
  28
  29 #include "base/cvc4_assert.h"
  30 #include "context/cdhashset.h"
  31 #include "expr/node.h"
  32 #include "options/options.h"
  33 #include "options/smt_options.h"
  34 #include "prop/prop_engine.h"
  35 #include "smt/command.h"
  36 #include "smt_util/lemma_channels.h"
  37 #include "theory/atom_requests.h"
  38 #include "theory/interrupted.h"
  39 #include "theory/rewriter.h"
  40 #include "theory/shared_terms_database.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/uf/equality_engine.h"
  46 #include "theory/valuation.h"
  47 #include "util/hash.h"
  48 #include "util/statistics_registry.h"
  49 #include "util/unsafe_interrupt_exception.h"
  50
  51 namespace CVC4 {
  52
  53 class ResourceManager;
  54 class LemmaProofRecipe;
  55
  56 /**
  57  * A pair of a theory and a node. This is used to mark the flow of
  58  * propagations between theories.
  59  */
  60 struct NodeTheoryPair {
  61   Node node;
  62   theory::TheoryId theory;
  63   size_t timestamp;
  64   NodeTheoryPair(TNode node, theory::TheoryId theory, size_t timestamp = 0)
  65   : node(node), theory(theory), timestamp(timestamp) {}
  66   NodeTheoryPair() : theory(theory::THEORY_LAST), timestamp() {}
  67   // Comparison doesn't take into account the timestamp
  68   bool operator == (const NodeTheoryPair& pair) const {
  69     return node == pair.node && theory == pair.theory;
  70   }
  71 };/* struct NodeTheoryPair */
  72
  73 struct NodeTheoryPairHashFunction {
  74   NodeHashFunction hashFunction;
  75   // Hash doesn't take into account the timestamp
  76   size_t operator()(const NodeTheoryPair& pair) const {
  77     uint64_t hash = fnv1a::fnv1a_64(NodeHashFunction()(pair.node));
  78     return static_cast<size_t>(fnv1a::fnv1a_64(pair.theory, hash));
  79   }
  80 };/* struct NodeTheoryPairHashFunction */
  81
  82
  83 /* Forward declarations */
  84 namespace theory {
  85   class TheoryModel;
  86   class TheoryEngineModelBuilder;
  87   class ITEUtilities;
  88
  89   namespace eq {
  90     class EqualityEngine;
  91   }/* CVC4::theory::eq namespace */
  92
  93   namespace quantifiers {
  94     class TermDb;
  95   }
  96
  97   class EntailmentCheckParameters;
  98   class EntailmentCheckSideEffects;
  99 }/* CVC4::theory namespace */
 100
 101 class DecisionEngine;
 102 class RemoveTermFormulas;
 103 class UnconstrainedSimplifier;
 104
 105 /**
 106  * This is essentially an abstraction for a collection of theories.  A
 107  * TheoryEngine provides services to a PropEngine, making various
 108  * T-solvers look like a single unit to the propositional part of
 109  * CVC4.
 110  */
 111 class TheoryEngine {
 112
 113   /** Shared terms database can use the internals notify the theories */
 114   friend class SharedTermsDatabase;
 115   friend class theory::quantifiers::TermDb;
 116
 117   /** Associated PropEngine engine */
 118   prop::PropEngine* d_propEngine;
 119
 120   /** Access to decision engine */
 121   DecisionEngine* d_decisionEngine;
 122
 123   /** Our context */
 124   context::Context* d_context;
 125
 126   /** Our user context */
 127   context::UserContext* d_userContext;
 128
 129   /**
 130    * A table of from theory IDs to theory pointers. Never use this table
 131    * directly, use theoryOf() instead.
 132    */
 133   theory::Theory* d_theoryTable[theory::THEORY_LAST];
 134
 135   /**
 136    * A collection of theories that are "active" for the current run.
 137    * This set is provided by the user (as a logic string, say, in SMT-LIBv2
 138    * format input), or else by default it's all-inclusive.  This is important
 139    * because we can optimize for single-theory runs (no sharing), can reduce
 140    * the cost of walking the DAG on registration, etc.
 141    */
 142   const LogicInfo& d_logicInfo;
 143
 144   /**
 145    * The database of shared terms.
 146    */
 147   SharedTermsDatabase d_sharedTerms;
 148
 149   /**
 150    * Master equality engine, to share with theories.
 151    */
 152   theory::eq::EqualityEngine* d_masterEqualityEngine;
 153
 154   /** notify class for master equality engine */
 155   class NotifyClass : public theory::eq::EqualityEngineNotify {
 156     TheoryEngine& d_te;
 157   public:
 158     NotifyClass(TheoryEngine& te): d_te(te) {}
 159     bool eqNotifyTriggerEquality(TNode equality, bool value) override
 160     {
 161       return true;
 162     }
 163     bool eqNotifyTriggerPredicate(TNode predicate, bool value) override
 164     {
 165       return true;
 166     }
 167     bool eqNotifyTriggerTermEquality(theory::TheoryId tag,
 168                                      TNode t1,
 169                                      TNode t2,
 170                                      bool value) override
 171     {
 172       return true;
 173     }
 174     void eqNotifyConstantTermMerge(TNode t1, TNode t2) override {}
 175     void eqNotifyNewClass(TNode t) override { d_te.eqNotifyNewClass(t); }
 176     void eqNotifyPreMerge(TNode t1, TNode t2) override
 177     {
 178       d_te.eqNotifyPreMerge(t1, t2);
 179     }
 180     void eqNotifyPostMerge(TNode t1, TNode t2) override
 181     {
 182       d_te.eqNotifyPostMerge(t1, t2);
 183     }
 184     void eqNotifyDisequal(TNode t1, TNode t2, TNode reason) override
 185     {
 186       d_te.eqNotifyDisequal(t1, t2, reason);
 187     }
 188   };/* class TheoryEngine::NotifyClass */
 189   NotifyClass d_masterEENotify;
 190
 191   /**
 192    * notification methods
 193    */
 194   void eqNotifyNewClass(TNode t);
 195   void eqNotifyPreMerge(TNode t1, TNode t2);
 196   void eqNotifyPostMerge(TNode t1, TNode t2);
 197   void eqNotifyDisequal(TNode t1, TNode t2, TNode reason);
 198
 199   /**
 200    * The quantifiers engine
 201    */
 202   theory::QuantifiersEngine* d_quantEngine;
 203
 204   /**
 205    * Default model object
 206    */
 207   theory::TheoryModel* d_curr_model;
 208   bool d_aloc_curr_model;
 209   /**
 210    * Model builder object
 211    */
 212   theory::TheoryEngineModelBuilder* d_curr_model_builder;
 213   bool d_aloc_curr_model_builder;
 214
 215   typedef std::unordered_map<Node, Node, NodeHashFunction> NodeMap;
 216   typedef std::unordered_map<TNode, Node, TNodeHashFunction> TNodeMap;
 217
 218   /**
 219   * Cache for theory-preprocessing of assertions
 220    */
 221   NodeMap d_ppCache;
 222
 223   /**
 224    * Used for "missed-t-propagations" dumping mode only.  A set of all
 225    * theory-propagable literals.
 226    */
 227   context::CDList<TNode> d_possiblePropagations;
 228
 229   /**
 230    * Used for "missed-t-propagations" dumping mode only.  A
 231    * context-dependent set of those theory-propagable literals that
 232    * have been propagated.
 233    */
 234   context::CDHashSet<Node, NodeHashFunction> d_hasPropagated;
 235
 236
 237   /**
 238    * Statistics for a particular theory.
 239    */
 240   class Statistics {
 241
 242     static std::string mkName(std::string prefix,
 243                               theory::TheoryId theory,
 244                               std::string suffix) {
 245       std::stringstream ss;
 246       ss << prefix << theory << suffix;
 247       return ss.str();
 248     }
 249
 250    public:
 251     IntStat conflicts, propagations, lemmas, requirePhase, restartDemands;
 252
 253     Statistics(theory::TheoryId theory);
 254     ~Statistics();
 255   };/* class TheoryEngine::Statistics */
 256
 257   /**
 258    * An output channel for Theory that passes messages
 259    * back to a TheoryEngine.
 260    */
 261   class EngineOutputChannel : public theory::OutputChannel {
 262     friend class TheoryEngine;
 263
 264     /**
 265      * The theory engine we're communicating with.
 266      */
 267     TheoryEngine* d_engine;
 268
 269     /**
 270      * The statistics of the theory interractions.
 271      */
 272     Statistics d_statistics;
 273
 274     /** The theory owning this channel. */
 275     theory::TheoryId d_theory;
 276
 277    public:
 278     EngineOutputChannel(TheoryEngine* engine, theory::TheoryId theory)
 279         : d_engine(engine), d_statistics(theory), d_theory(theory) {}
 280
 281     void safePoint(uint64_t amount) override {
 282       spendResource(amount);
 283       if (d_engine->d_interrupted) {
 284         throw theory::Interrupted();
 285       }
 286     }
 287
 288     void conflict(TNode conflictNode,
 289                   std::unique_ptr<Proof> pf = nullptr) override;
 290     bool propagate(TNode literal) override;
 291
 292     theory::LemmaStatus lemma(TNode lemma, ProofRule rule,
 293                               bool removable = false, bool preprocess = false,
 294                               bool sendAtoms = false) override;
 295
 296     theory::LemmaStatus splitLemma(TNode lemma,
 297                                    bool removable = false) override;
 298
 299     void demandRestart() override {
 300       NodeManager* curr = NodeManager::currentNM();
 301       Node restartVar = curr->mkSkolem(
 302           "restartVar", curr->booleanType(),
 303           "A boolean variable asserted to be true to force a restart");
 304       Trace("theory::restart")
 305           << "EngineOutputChannel<" << d_theory << ">::restart(" << restartVar
 306           << ")" << std::endl;
 307       ++d_statistics.restartDemands;
 308       lemma(restartVar, RULE_INVALID, true);
 309     }
 310
 311     void requirePhase(TNode n, bool phase) override {
 312       Debug("theory") << "EngineOutputChannel::requirePhase(" << n << ", "
 313                       << phase << ")" << std::endl;
 314       ++d_statistics.requirePhase;
 315       d_engine->d_propEngine->requirePhase(n, phase);
 316     }
 317
 318     void setIncomplete() override {
 319       Trace("theory") << "TheoryEngine::setIncomplete()" << std::endl;
 320       d_engine->setIncomplete(d_theory);
 321     }
 322
 323     void spendResource(unsigned amount) override {
 324       d_engine->spendResource(amount);
 325     }
 326
 327     void handleUserAttribute(const char* attr, theory::Theory* t) override {
 328       d_engine->handleUserAttribute(attr, t);
 329     }
 330
 331    private:
 332     /**
 333      * A helper function for registering lemma recipes with the proof engine
 334      */
 335     void registerLemmaRecipe(Node lemma, Node originalLemma, bool preprocess,
 336                              theory::TheoryId theoryId);
 337   }; /* class TheoryEngine::EngineOutputChannel */
 338
 339   /**
 340    * Output channels for individual theories.
 341    */
 342   EngineOutputChannel* d_theoryOut[theory::THEORY_LAST];
 343
 344   /**
 345    * Are we in conflict.
 346    */
 347   context::CDO<bool> d_inConflict;
 348
 349   /**
 350    * Called by the theories to notify of a conflict.
 351    */
 352   void conflict(TNode conflict, theory::TheoryId theoryId);
 353
 354   /**
 355    * Debugging flag to ensure that shutdown() is called before the
 356    * destructor.
 357    */
 358   bool d_hasShutDown;
 359
 360   /**
 361    * True if a theory has notified us of incompleteness (at this
 362    * context level or below).
 363    */
 364   context::CDO<bool> d_incomplete;
 365
 366   /**
 367    * Called by the theories to notify that the current branch is incomplete.
 368    */
 369   void setIncomplete(theory::TheoryId theory) {
 370     d_incomplete = true;
 371   }
 372
 373
 374   /**
 375    * Mapping of propagations from recievers to senders.
 376    */
 377   typedef context::CDHashMap<NodeTheoryPair, NodeTheoryPair, NodeTheoryPairHashFunction> PropagationMap;
 378   PropagationMap d_propagationMap;
 379
 380   /**
 381    * Timestamp of propagations
 382    */
 383   context::CDO<size_t> d_propagationMapTimestamp;
 384
 385   /**
 386    * Literals that are propagated by the theory. Note that these are TNodes.
 387    * The theory can only propagate nodes that have an assigned literal in the
 388    * SAT solver and are hence referenced in the SAT solver.
 389    */
 390   context::CDList<TNode> d_propagatedLiterals;
 391
 392   /**
 393    * The index of the next literal to be propagated by a theory.
 394    */
 395   context::CDO<unsigned> d_propagatedLiteralsIndex;
 396
 397   /**
 398    * Called by the output channel to propagate literals and facts
 399    * @return false if immediate conflict
 400    */
 401   bool propagate(TNode literal, theory::TheoryId theory);
 402
 403   /**
 404    * Internal method to call the propagation routines and collect the
 405    * propagated literals.
 406    */
 407   void propagate(theory::Theory::Effort effort);
 408
 409   /**
 410    * A variable to mark if we added any lemmas.
 411    */
 412   bool d_lemmasAdded;
 413
 414   /**
 415    * A variable to mark if the OutputChannel was "used" by any theory
 416    * since the start of the last check.  If it has been, we require
 417    * a FULL_EFFORT check before exiting and reporting SAT.
 418    *
 419    * See the documentation for the needCheck() function, below.
 420    */
 421   bool d_outputChannelUsed;
 422
 423   /** Atom requests from lemmas */
 424   AtomRequests d_atomRequests;
 425
 426   /**
 427    * Adds a new lemma, returning its status.
 428    * @param node the lemma
 429    * @param negated should the lemma be asserted negated
 430    * @param removable can the lemma be remove (restrictions apply)
 431    * @param needAtoms if not THEORY_LAST, then
 432    */
 433   theory::LemmaStatus lemma(TNode node,
 434                             ProofRule rule,
 435                             bool negated,
 436                             bool removable,
 437                             bool preprocess,
 438                             theory::TheoryId atomsTo);
 439
 440   /** Enusre that the given atoms are send to the given theory */
 441   void ensureLemmaAtoms(const std::vector<TNode>& atoms, theory::TheoryId theory);
 442
 443   RemoveTermFormulas& d_tform_remover;
 444
 445   /** sort inference module */
 446   SortInference d_sortInfer;
 447
 448   /** Time spent in theory combination */
 449   TimerStat d_combineTheoriesTime;
 450
 451   Node d_true;
 452   Node d_false;
 453
 454   /** Whether we were just interrupted (or not) */
 455   bool d_interrupted;
 456   ResourceManager* d_resourceManager;
 457
 458   /** Container for lemma input and output channels. */
 459   LemmaChannels* d_channels;
 460
 461 public:
 462
 463   /** Constructs a theory engine */
 464   TheoryEngine(context::Context* context, context::UserContext* userContext,
 465                RemoveTermFormulas& iteRemover, const LogicInfo& logic,
 466                LemmaChannels* channels);
 467
 468   /** Destroys a theory engine */
 469   ~TheoryEngine();
 470
 471   void interrupt();
 472
 473   /** "Spend" a resource during a search or preprocessing.*/
 474   void spendResource(unsigned amount);
 475
 476   /**
 477    * Adds a theory. Only one theory per TheoryId can be present, so if
 478    * there is another theory it will be deleted.
 479    */
 480   template <class TheoryClass>
 481   inline void addTheory(theory::TheoryId theoryId) {
 482     Assert(d_theoryTable[theoryId] == NULL && d_theoryOut[theoryId] == NULL);
 483     d_theoryOut[theoryId] = new EngineOutputChannel(this, theoryId);
 484     d_theoryTable[theoryId] =
 485         new TheoryClass(d_context, d_userContext, *d_theoryOut[theoryId],
 486                         theory::Valuation(this), d_logicInfo);
 487   }
 488
 489   inline void setPropEngine(prop::PropEngine* propEngine) {
 490     Assert(d_propEngine == NULL);
 491     d_propEngine = propEngine;
 492   }
 493
 494   inline void setDecisionEngine(DecisionEngine* decisionEngine) {
 495     Assert(d_decisionEngine == NULL);
 496     d_decisionEngine = decisionEngine;
 497   }
 498
 499   /** Called when all initialization of options/logic is done */
 500   void finishInit();
 501
 502   /**
 503    * Get a pointer to the underlying propositional engine.
 504    */
 505   inline prop::PropEngine* getPropEngine() const {
 506     return d_propEngine;
 507   }
 508
 509   /**
 510    * Get a pointer to the underlying sat context.
 511    */
 512   inline context::Context* getSatContext() const {
 513     return d_context;
 514   }
 515
 516   /**
 517    * Get a pointer to the underlying user context.
 518    */
 519   inline context::Context* getUserContext() const {
 520     return d_userContext;
 521   }
 522
 523   /**
 524    * Get a pointer to the underlying quantifiers engine.
 525    */
 526   theory::QuantifiersEngine* getQuantifiersEngine() const {
 527     return d_quantEngine;
 528   }
 529
 530 private:
 531
 532   /**
 533    * Helper for preprocess
 534    */
 535   Node ppTheoryRewrite(TNode term);
 536
 537   /**
 538    * Queue of nodes for pre-registration.
 539    */
 540   std::queue<TNode> d_preregisterQueue;
 541
 542   /**
 543    * Boolean flag denoting we are in pre-registration.
 544    */
 545   bool d_inPreregister;
 546
 547   /**
 548    * Did the theories get any new facts since the last time we called
 549    * check()
 550    */
 551   context::CDO<bool> d_factsAsserted;
 552
 553   /**
 554    * Map from equality atoms to theories that would like to be notified about them.
 555    */
 556
 557
 558   /**
 559    * Assert the formula to the given theory.
 560    * @param assertion the assertion to send (not necesserily normalized)
 561    * @param original the assertion as it was sent in from the propagating theory
 562    * @param toTheoryId the theory to assert to
 563    * @param fromTheoryId the theory that sent it
 564    */
 565   void assertToTheory(TNode assertion, TNode originalAssertion, theory::TheoryId toTheoryId, theory::TheoryId fromTheoryId);
 566
 567   /**
 568    * Marks a theory propagation from a theory to a theory where a
 569    * theory could be the THEORY_SAT_SOLVER for literals coming from
 570    * or being propagated to the SAT solver. If the receiving theory
 571    * already recieved the literal, the method returns false, otherwise
 572    * it returns true.
 573    *
 574    * @param assertion the normalized assertion being sent
 575    * @param originalAssertion the actual assertion that was sent
 576    * @param toTheoryId the theory that is on the receiving end
 577    * @param fromTheoryId the theory that sent the assertino
 578    * @return true if a new assertion, false if theory already got it
 579    */
 580   bool markPropagation(TNode assertion, TNode originalAssertions, theory::TheoryId toTheoryId, theory::TheoryId fromTheoryId);
 581
 582   /**
 583    * Computes the explanation by travarsing the propagation graph and
 584    * asking relevant theories to explain the propagations. Initially
 585    * the explanation vector should contain only the element (node, theory)
 586    * where the node is the one to be explained, and the theory is the
 587    * theory that sent the literal. The lemmaProofRecipe will contain a list
 588    * of the explanation steps required to produce the original node.
 589    */
 590   void getExplanation(std::vector<NodeTheoryPair>& explanationVector, LemmaProofRecipe* lemmaProofRecipe);
 591
 592 public:
 593
 594   /**
 595    * Signal the start of a new round of assertion preprocessing
 596    */
 597   void preprocessStart();
 598
 599   /**
 600    * Runs theory specific preprocessing on the non-Boolean parts of
 601    * the formula.  This is only called on input assertions, after ITEs
 602    * have been removed.
 603    */
 604   Node preprocess(TNode node);
 605
 606   /** Notify (preprocessed) assertions. */
 607   void notifyPreprocessedAssertions(const std::vector<Node>& assertions);
 608
 609   /** Return whether or not we are incomplete (in the current context). */
 610   inline bool isIncomplete() const { return d_incomplete; }
 611
 612   /**
 613    * Returns true if we need another round of checking.  If this
 614    * returns true, check(FULL_EFFORT) _must_ be called by the
 615    * propositional layer before reporting SAT.
 616    *
 617    * This is especially necessary for incomplete theories that lazily
 618    * output some lemmas on FULL_EFFORT check (e.g. quantifier reasoning
 619    * outputing quantifier instantiations).  In such a case, a lemma can
 620    * be asserted that is simplified away (perhaps it's already true).
 621    * However, we must maintain the invariant that, if a theory uses the
 622    * OutputChannel, it implicitly requests that another check(FULL_EFFORT)
 623    * be performed before exit, even if no new facts are on its fact queue,
 624    * as it might decide to further instantiate some lemmas, precluding
 625    * a SAT response.
 626    */
 627   inline bool needCheck() const {
 628     return d_outputChannelUsed || d_lemmasAdded;
 629   }
 630
 631   /**
 632    * This is called at shutdown time by the SmtEngine, just before
 633    * destruction.  It is important because there are destruction
 634    * ordering issues between PropEngine and Theory.
 635    */
 636   void shutdown();
 637
 638   /**
 639    * Solve the given literal with a theory that owns it.
 640    */
 641   theory::Theory::PPAssertStatus solve(TNode literal,
 642                                     theory::SubstitutionMap& substitutionOut);
 643
 644   /**
 645    * Preregister a Theory atom with the responsible theory (or
 646    * theories).
 647    */
 648   void preRegister(TNode preprocessed);
 649
 650   /**
 651    * Assert the formula to the appropriate theory.
 652    * @param node the assertion
 653    */
 654   void assertFact(TNode node);
 655
 656   /**
 657    * Check all (currently-active) theories for conflicts.
 658    * @param effort the effort level to use
 659    */
 660   void check(theory::Theory::Effort effort);
 661
 662   /**
 663    * Run the combination framework.
 664    */
 665   void combineTheories();
 666
 667   /**
 668    * Calls ppStaticLearn() on all theories, accumulating their
 669    * combined contributions in the "learned" builder.
 670    */
 671   void ppStaticLearn(TNode in, NodeBuilder<>& learned);
 672
 673   /**
 674    * Calls presolve() on all theories and returns true
 675    * if one of the theories discovers a conflict.
 676    */
 677   bool presolve();
 678
 679    /**
 680    * Calls postsolve() on all theories.
 681    */
 682   void postsolve();
 683
 684   /**
 685    * Calls notifyRestart() on all active theories.
 686    */
 687   void notifyRestart();
 688
 689   void getPropagatedLiterals(std::vector<TNode>& literals) {
 690     for (; d_propagatedLiteralsIndex < d_propagatedLiterals.size(); d_propagatedLiteralsIndex = d_propagatedLiteralsIndex + 1) {
 691       Debug("getPropagatedLiterals") << "TheoryEngine::getPropagatedLiterals: propagating: " << d_propagatedLiterals[d_propagatedLiteralsIndex] << std::endl;
 692       literals.push_back(d_propagatedLiterals[d_propagatedLiteralsIndex]);
 693     }
 694   }
 695
 696   Node getNextDecisionRequest();
 697
 698   bool properConflict(TNode conflict) const;
 699   bool properPropagation(TNode lit) const;
 700   bool properExplanation(TNode node, TNode expl) const;
 701
 702   /**
 703    * Returns an explanation of the node propagated to the SAT solver.
 704    */
 705   Node getExplanation(TNode node);
 706
 707   /**
 708    * Returns an explanation of the node propagated to the SAT solver and the theory
 709    * that propagated it.
 710    */
 711   Node getExplanationAndRecipe(TNode node, LemmaProofRecipe* proofRecipe);
 712
 713   /**
 714    * collect model info
 715    */
 716   bool collectModelInfo(theory::TheoryModel* m);
 717   /** post process model */
 718   void postProcessModel( theory::TheoryModel* m );
 719
 720   /**
 721    * Get the current model
 722    */
 723   theory::TheoryModel* getModel();
 724
 725   /** get synth solutions
 726    *
 727    * This function adds entries to sol_map that map functions-to-synthesize with
 728    * their solutions, for all active conjectures. This should be called
 729    * immediately after the solver answers unsat for sygus input.
 730    *
 731    * For details on what is added to sol_map, see
 732    * CegConjecture::getSynthSolutions.
 733    */
 734   void getSynthSolutions(std::map<Node, Node>& sol_map);
 735
 736   /**
 737    * Get the model builder
 738    */
 739   theory::TheoryEngineModelBuilder* getModelBuilder() { return d_curr_model_builder; }
 740
 741   /**
 742    * Get the theory associated to a given Node.
 743    *
 744    * @returns the theory, or NULL if the TNode is
 745    * of built-in type.
 746    */
 747   inline theory::Theory* theoryOf(TNode node) const {
 748     return d_theoryTable[theory::Theory::theoryOf(node)];
 749   }
 750
 751   /**
 752    * Get the theory associated to a the given theory id.
 753    *
 754    * @returns the theory
 755    */
 756   inline theory::Theory* theoryOf(theory::TheoryId theoryId) const {
 757     return d_theoryTable[theoryId];
 758   }
 759
 760   inline bool isTheoryEnabled(theory::TheoryId theoryId) const {
 761     return d_logicInfo.isTheoryEnabled(theoryId);
 762   }
 763   /** get the logic info used by this theory engine */
 764   const LogicInfo& getLogicInfo() const;
 765   /**
 766    * Returns the equality status of the two terms, from the theory
 767    * that owns the domain type.  The types of a and b must be the same.
 768    */
 769   theory::EqualityStatus getEqualityStatus(TNode a, TNode b);
 770
 771   /**
 772    * Returns the value that a theory that owns the type of var currently
 773    * has (or null if none);
 774    */
 775   Node getModelValue(TNode var);
 776
 777   /**
 778    * Takes a literal and returns an equivalent literal that is guaranteed to be a SAT literal
 779    */
 780   Node ensureLiteral(TNode n);
 781
 782   /**
 783    * Print all instantiations made by the quantifiers module.
 784    */
 785   void printInstantiations( std::ostream& out );
 786
 787   /**
 788    * Print solution for synthesis conjectures found by ce_guided_instantiation module
 789    */
 790   void printSynthSolution( std::ostream& out );
 791
 792   /**
 793    * Get list of quantified formulas that were instantiated
 794    */
 795   void getInstantiatedQuantifiedFormulas( std::vector< Node >& qs );
 796
 797   /**
 798    * Get instantiation methods
 799    *   first inputs forall x.q[x] and returns ( q[a], ..., q[z] )
 800    *   second inputs forall x.q[x] and returns ( a, ..., z )
 801    *   third and fourth return mappings e.g. forall x.q1[x] -> ( q1[a]...q1[z] ) , ... , forall x.qn[x] -> ( qn[a]...qn[z] )
 802    */
 803   void getInstantiations( Node q, std::vector< Node >& insts );
 804   void getInstantiationTermVectors( Node q, std::vector< std::vector< Node > >& tvecs );
 805   void getInstantiations( std::map< Node, std::vector< Node > >& insts );
 806   void getInstantiationTermVectors( std::map< Node, std::vector< std::vector< Node > > >& insts );
 807
 808   /**
 809    * Get instantiated conjunction, returns q[t1] ^ ... ^ q[tn] where t1...tn are current set of instantiations for q.
 810    *   Can be used for quantifier elimination when satisfiable and q[t1] ^ ... ^ q[tn] |= q
 811    */
 812   Node getInstantiatedConjunction( Node q );
 813
 814   /**
 815    * Forwards an entailment check according to the given theoryOfMode.
 816    * See theory.h for documentation on entailmentCheck().
 817    */
 818   std::pair<bool, Node> entailmentCheck(theory::TheoryOfMode mode, TNode lit, const theory::EntailmentCheckParameters* params = NULL, theory::EntailmentCheckSideEffects* out = NULL);
 819
 820 private:
 821
 822   /** Default visitor for pre-registration */
 823   PreRegisterVisitor d_preRegistrationVisitor;
 824
 825   /** Visitor for collecting shared terms */
 826   SharedTermsVisitor d_sharedTermsVisitor;
 827
 828   /** Dump the assertions to the dump */
 829   void dumpAssertions(const char* tag);
 830
 831   /**
 832    * A collection of ite preprocessing passes.
 833    */
 834   theory::ITEUtilities* d_iteUtilities;
 835
 836
 837   /** For preprocessing pass simplifying unconstrained expressions */
 838   UnconstrainedSimplifier* d_unconstrainedSimp;
 839
 840   /** For preprocessing pass lifting bit-vectors of size 1 to booleans */
 841 public:
 842   void staticInitializeBVOptions(const std::vector<Node>& assertions);
 843
 844   Node ppSimpITE(TNode assertion);
 845   /** Returns false if an assertion simplified to false. */
 846   bool donePPSimpITE(std::vector<Node>& assertions);
 847
 848   void ppUnconstrainedSimp(std::vector<Node>& assertions);
 849
 850   SharedTermsDatabase* getSharedTermsDatabase() { return &d_sharedTerms; }
 851
 852   theory::eq::EqualityEngine* getMasterEqualityEngine() { return d_masterEqualityEngine; }
 853
 854   RemoveTermFormulas* getTermFormulaRemover() { return &d_tform_remover; }
 855
 856   SortInference* getSortInference() { return &d_sortInfer; }
 857
 858   /** Prints the assertions to the debug stream */
 859   void printAssertions(const char* tag);
 860
 861   /** Theory alternative is in use. */
 862   bool useTheoryAlternative(const std::string& name);
 863
 864   /** Enables using a theory alternative by name. */
 865   void enableTheoryAlternative(const std::string& name);
 866
 867 private:
 868   std::set< std::string > d_theoryAlternatives;
 869
 870   std::map< std::string, std::vector< theory::Theory* > > d_attr_handle;
 871
 872  public:
 873   /** Set user attribute.
 874    *
 875    * This function is called when an attribute is set by a user.  In SMT-LIBv2
 876    * this is done via the syntax (! n :attr)
 877    */
 878   void setUserAttribute(const std::string& attr,
 879                         Node n,
 880                         const std::vector<Node>& node_values,
 881                         const std::string& str_value);
 882
 883   /** Handle user attribute.
 884    *
 885    * Associates theory t with the attribute attr.  Theory t will be
 886    * notified whenever an attribute of name attr is set.
 887    */
 888   void handleUserAttribute(const char* attr, theory::Theory* t);
 889
 890   /**
 891    * Check that the theory assertions are satisfied in the model.
 892    * This function is called from the smt engine's checkModel routine.
 893    */
 894   void checkTheoryAssertionsWithModel(bool hardFailure);
 895
 896  private:
 897   IntStat d_arithSubstitutionsAdded;
 898
 899 };/* class TheoryEngine */
 900
 901 }/* CVC4 namespace */
 902
 903 #endif /* __CVC4__THEORY_ENGINE_H */