/****************************************************************************** * Top contributors (to current version): * Andrew Reynolds, Dejan Jovanovic, Morgan Deters * * This file is part of the cvc5 project. * * Copyright (c) 2009-2021 by the authors listed in the file AUTHORS * in the top-level source directory and their institutional affiliations. * All rights reserved. See the file COPYING in the top-level source * directory for licensing information. * **************************************************************************** * * The theory engine. */ #include "theory/theory_engine.h" #include #include "base/map_util.h" #include "decision/decision_engine.h" #include "expr/attribute.h" #include "expr/node_builder.h" #include "expr/node_visitor.h" #include "options/quantifiers_options.h" #include "options/smt_options.h" #include "options/theory_options.h" #include "printer/printer.h" #include "proof/lazy_proof.h" #include "proof/proof_checker.h" #include "proof/proof_ensure_closed.h" #include "prop/prop_engine.h" #include "smt/dump.h" #include "smt/env.h" #include "smt/logic_exception.h" #include "smt/output_manager.h" #include "theory/combination_care_graph.h" #include "theory/decision_manager.h" #include "theory/quantifiers/first_order_model.h" #include "theory/quantifiers_engine.h" #include "theory/relevance_manager.h" #include "theory/rewriter.h" #include "theory/shared_solver.h" #include "theory/theory.h" #include "theory/theory_engine_proof_generator.h" #include "theory/theory_id.h" #include "theory/theory_model.h" #include "theory/theory_traits.h" #include "theory/uf/equality_engine.h" #include "util/resource_manager.h" using namespace std; using namespace cvc5::theory; namespace cvc5 { /* -------------------------------------------------------------------------- */ namespace theory { /** * IMPORTANT: The order of the theories is important. For example, strings * depends on arith, quantifiers needs to come as the very last. * Do not change this order. */ #define CVC5_FOR_EACH_THEORY \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_BUILTIN) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_BOOL) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_UF) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_ARITH) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_BV) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_FP) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_ARRAYS) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_DATATYPES) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_SEP) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_SETS) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_BAGS) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_STRINGS) \ CVC5_FOR_EACH_THEORY_STATEMENT(cvc5::theory::THEORY_QUANTIFIERS) } // namespace theory /* -------------------------------------------------------------------------- */ inline void flattenAnd(Node n, std::vector& out){ Assert(n.getKind() == kind::AND); for(Node::iterator i=n.begin(), i_end=n.end(); i != i_end; ++i){ Node curr = *i; if(curr.getKind() == kind::AND){ flattenAnd(curr, out); }else{ out.push_back(curr); } } } inline Node flattenAnd(Node n){ std::vector out; flattenAnd(n, out); return NodeManager::currentNM()->mkNode(kind::AND, out); } /** * Compute the string for a given theory id. In this module, we use * THEORY_SAT_SOLVER as an id, which is not a normal id but maps to * THEORY_LAST. Thus, we need our own string conversion here. * * @param id The theory id * @return The string corresponding to the theory id */ std::string getTheoryString(theory::TheoryId id) { if (id == theory::THEORY_SAT_SOLVER) { return "THEORY_SAT_SOLVER"; } else { std::stringstream ss; ss << id; return ss.str(); } } void TheoryEngine::finishInit() { Trace("theory") << "Begin TheoryEngine::finishInit" << std::endl; // NOTE: This seems to be required since // theory::TheoryTraits::isParametric cannot be accessed without // using the CVC5_FOR_EACH_THEORY_STATEMENT macro. -AJR std::vector paraTheories; #ifdef CVC5_FOR_EACH_THEORY_STATEMENT #undef CVC5_FOR_EACH_THEORY_STATEMENT #endif #define CVC5_FOR_EACH_THEORY_STATEMENT(THEORY) \ if (theory::TheoryTraits::isParametric \ && d_logicInfo.isTheoryEnabled(THEORY)) \ { \ paraTheories.push_back(theoryOf(THEORY)); \ } // Collect the parametric theories, which are given to the theory combination // manager below CVC5_FOR_EACH_THEORY; // Initialize the theory combination architecture if (options::tcMode() == options::TcMode::CARE_GRAPH) { d_tc.reset(new CombinationCareGraph(*this, d_env, paraTheories, d_pnm)); } else { Unimplemented() << "TheoryEngine::finishInit: theory combination mode " << options::tcMode() << " not supported"; } // create the relevance filter if any option requires it if (options::relevanceFilter()) { d_relManager.reset( new RelevanceManager(d_env.getUserContext(), theory::Valuation(this))); } // initialize the quantifiers engine if (d_logicInfo.isQuantified()) { // get the quantifiers engine, which is initialized by the quantifiers // theory d_quantEngine = d_theoryTable[THEORY_QUANTIFIERS]->getQuantifiersEngine(); Assert(d_quantEngine != nullptr); } // finish initializing the quantifiers engine, which must come before // initializing theory combination, since quantifiers engine may have a // special model builder object if (d_logicInfo.isQuantified()) { d_quantEngine->finishInit(this); } // initialize the theory combination manager, which decides and allocates the // equality engines to use for all theories. d_tc->finishInit(); // get pointer to the shared solver d_sharedSolver = d_tc->getSharedSolver(); // finish initializing the theories by linking them with the appropriate // utilities and then calling their finishInit method. for(TheoryId theoryId = theory::THEORY_FIRST; theoryId != theory::THEORY_LAST; ++ theoryId) { Theory* t = d_theoryTable[theoryId]; if (t == nullptr) { continue; } // setup the pointers to the utilities const EeTheoryInfo* eeti = d_tc->getEeTheoryInfo(theoryId); Assert(eeti != nullptr); // the theory's official equality engine is the one specified by the // equality engine manager t->setEqualityEngine(eeti->d_usedEe); // set the quantifiers engine t->setQuantifiersEngine(d_quantEngine); // set the decision manager for the theory t->setDecisionManager(d_decManager.get()); // finish initializing the theory t->finishInit(); } Trace("theory") << "End TheoryEngine::finishInit" << std::endl; } ProofNodeManager* TheoryEngine::getProofNodeManager() const { return d_pnm; } context::Context* TheoryEngine::getSatContext() const { return d_env.getContext(); } context::UserContext* TheoryEngine::getUserContext() const { return d_env.getUserContext(); } TheoryEngine::TheoryEngine(Env& env) : d_propEngine(nullptr), d_env(env), d_logicInfo(env.getLogicInfo()), d_pnm(d_env.isTheoryProofProducing() ? d_env.getProofNodeManager() : nullptr), d_lazyProof(d_pnm != nullptr ? new LazyCDProof(d_pnm, nullptr, d_env.getUserContext(), "TheoryEngine::LazyCDProof") : nullptr), d_tepg(new TheoryEngineProofGenerator(d_pnm, d_env.getUserContext())), d_tc(nullptr), d_sharedSolver(nullptr), d_quantEngine(nullptr), d_decManager(new DecisionManager(d_env.getUserContext())), d_relManager(nullptr), d_inConflict(d_env.getContext(), false), d_inSatMode(false), d_hasShutDown(false), d_incomplete(d_env.getContext(), false), d_incompleteTheory(d_env.getContext(), THEORY_BUILTIN), d_incompleteId(d_env.getContext(), IncompleteId::UNKNOWN), d_propagationMap(d_env.getContext()), d_propagationMapTimestamp(d_env.getContext(), 0), d_propagatedLiterals(d_env.getContext()), d_propagatedLiteralsIndex(d_env.getContext(), 0), d_atomRequests(d_env.getContext()), d_combineTheoriesTime(smtStatisticsRegistry().registerTimer( "TheoryEngine::combineTheoriesTime")), d_true(), d_false(), d_interrupted(false), d_inPreregister(false), d_factsAsserted(d_env.getContext(), false) { for(TheoryId theoryId = theory::THEORY_FIRST; theoryId != theory::THEORY_LAST; ++ theoryId) { d_theoryTable[theoryId] = NULL; d_theoryOut[theoryId] = NULL; } if (options::sortInference()) { d_sortInfer.reset(new SortInference); } d_true = NodeManager::currentNM()->mkConst(true); d_false = NodeManager::currentNM()->mkConst(false); } TheoryEngine::~TheoryEngine() { Assert(d_hasShutDown); for(TheoryId theoryId = theory::THEORY_FIRST; theoryId != theory::THEORY_LAST; ++ theoryId) { if(d_theoryTable[theoryId] != NULL) { delete d_theoryTable[theoryId]; delete d_theoryOut[theoryId]; } } } void TheoryEngine::interrupt() { d_interrupted = true; } void TheoryEngine::preRegister(TNode preprocessed) { Debug("theory") << "TheoryEngine::preRegister( " << preprocessed << ")" << std::endl; d_preregisterQueue.push(preprocessed); if (!d_inPreregister) { // We're in pre-register d_inPreregister = true; // Process the pre-registration queue while (!d_preregisterQueue.empty()) { // Get the next atom to pre-register preprocessed = d_preregisterQueue.front(); d_preregisterQueue.pop(); // the atom should not have free variables Debug("theory") << "TheoryEngine::preRegister: " << preprocessed << std::endl; if (Configuration::isAssertionBuild()) { std::unordered_set fvs; expr::getFreeVariables(preprocessed, fvs); if (!fvs.empty()) { Unhandled() << "Preregistered term with free variable: " << preprocessed << ", fv=" << *fvs.begin(); } } // should not have witness Assert(!expr::hasSubtermKind(kind::WITNESS, preprocessed)); // pre-register with the shared solver, which handles // calling prepregister on individual theories, adding shared terms, // and setting up equalities to propagate in the shared term database. Assert(d_sharedSolver != nullptr); d_sharedSolver->preRegister(preprocessed); } // Leaving pre-register d_inPreregister = false; } } void TheoryEngine::printAssertions(const char* tag) { if (Trace.isOn(tag)) { for (TheoryId theoryId = THEORY_FIRST; theoryId < THEORY_LAST; ++theoryId) { Theory* theory = d_theoryTable[theoryId]; if (theory && d_logicInfo.isTheoryEnabled(theoryId)) { Trace(tag) << "--------------------------------------------" << endl; Trace(tag) << "Assertions of " << theory->getId() << ": " << endl; { context::CDList::const_iterator it = theory->facts_begin(), it_end = theory->facts_end(); for (unsigned i = 0; it != it_end; ++it, ++i) { if ((*it).d_isPreregistered) { Trace(tag) << "[" << i << "]: "; } else { Trace(tag) << "(" << i << "): "; } Trace(tag) << (*it).d_assertion << endl; } } if (d_logicInfo.isSharingEnabled()) { Trace(tag) << "Shared terms of " << theory->getId() << ": " << endl; context::CDList::const_iterator it = theory->shared_terms_begin(), it_end = theory->shared_terms_end(); for (unsigned i = 0; it != it_end; ++ it, ++i) { Trace(tag) << "[" << i << "]: " << (*it) << endl; } } } } } } void TheoryEngine::dumpAssertions(const char* tag) { if (Dump.isOn(tag)) { const Printer& printer = d_env.getPrinter(); std::ostream& out = d_env.getDumpOut(); printer.toStreamCmdComment(out, "Starting completeness check"); for (TheoryId theoryId = THEORY_FIRST; theoryId < THEORY_LAST; ++theoryId) { Theory* theory = d_theoryTable[theoryId]; if (theory && d_logicInfo.isTheoryEnabled(theoryId)) { printer.toStreamCmdComment(out, "Completeness check"); printer.toStreamCmdPush(out); // Dump the shared terms if (d_logicInfo.isSharingEnabled()) { printer.toStreamCmdComment(out, "Shared terms"); context::CDList::const_iterator it = theory->shared_terms_begin(), it_end = theory->shared_terms_end(); for (unsigned i = 0; it != it_end; ++ it, ++i) { stringstream ss; ss << (*it); printer.toStreamCmdComment(out, ss.str()); } } // Dump the assertions printer.toStreamCmdComment(out, "Assertions"); context::CDList::const_iterator it = theory->facts_begin(), it_end = theory->facts_end(); for (; it != it_end; ++ it) { // Get the assertion Node assertionNode = (*it).d_assertion; // Purify all the terms if ((*it).d_isPreregistered) { printer.toStreamCmdComment(out, "Preregistered"); } else { printer.toStreamCmdComment(out, "Shared assertion"); } printer.toStreamCmdAssert(out, assertionNode); } printer.toStreamCmdCheckSat(out); printer.toStreamCmdPop(out); } } } } /** * Check all (currently-active) theories for conflicts. * @param effort the effort level to use */ void TheoryEngine::check(Theory::Effort effort) { // spendResource(); // Reset the interrupt flag d_interrupted = false; #ifdef CVC5_FOR_EACH_THEORY_STATEMENT #undef CVC5_FOR_EACH_THEORY_STATEMENT #endif #define CVC5_FOR_EACH_THEORY_STATEMENT(THEORY) \ if (theory::TheoryTraits::hasCheck \ && d_logicInfo.isTheoryEnabled(THEORY)) \ { \ theoryOf(THEORY)->check(effort); \ if (d_inConflict) \ { \ Debug("conflict") << THEORY << " in conflict. " << std::endl; \ break; \ } \ } // Do the checking try { // Mark the output channel unused (if this is FULL_EFFORT, and nothing // is done by the theories, no additional check will be needed) d_outputChannelUsed = false; // Mark the lemmas flag (no lemmas added) d_lemmasAdded = false; Debug("theory") << "TheoryEngine::check(" << effort << "): d_factsAsserted = " << (d_factsAsserted ? "true" : "false") << endl; // If in full effort, we have a fake new assertion just to jumpstart the checking if (Theory::fullEffort(effort)) { d_factsAsserted = true; // Reset round for the relevance manager, which notice only sets a flag // to indicate that its information must be recomputed. if (d_relManager != nullptr) { d_relManager->resetRound(); } d_tc->resetRound(); } // Check until done while (d_factsAsserted && !d_inConflict && !d_lemmasAdded) { Debug("theory") << "TheoryEngine::check(" << effort << "): running check" << endl; Trace("theory::assertions") << endl; if (Trace.isOn("theory::assertions")) { printAssertions("theory::assertions"); } if(Theory::fullEffort(effort)) { Trace("theory::assertions::fulleffort") << endl; if (Trace.isOn("theory::assertions::fulleffort")) { printAssertions("theory::assertions::fulleffort"); } } // Note that we've discharged all the facts d_factsAsserted = false; // Do the checking CVC5_FOR_EACH_THEORY; Debug("theory") << "TheoryEngine::check(" << effort << "): running propagation after the initial check" << endl; // We are still satisfiable, propagate as much as possible propagate(effort); // We do combination if all has been processed and we are in fullcheck if (Theory::fullEffort(effort) && d_logicInfo.isSharingEnabled() && !d_factsAsserted && !needCheck() && !d_inConflict) { // Do the combination Debug("theory") << "TheoryEngine::check(" << effort << "): running combination" << endl; { TimerStat::CodeTimer combineTheoriesTimer(d_combineTheoriesTime); d_tc->combineTheories(); } if(d_logicInfo.isQuantified()){ d_quantEngine->notifyCombineTheories(); } } } // Must consult quantifiers theory for last call to ensure sat, or otherwise add a lemma if( Theory::fullEffort(effort) && ! d_inConflict && ! needCheck() ) { Trace("theory::assertions-model") << endl; if (Trace.isOn("theory::assertions-model")) { printAssertions("theory::assertions-model"); } // reset the model in the combination engine d_tc->resetModel(); //checks for theories requiring the model go at last call for (TheoryId theoryId = THEORY_FIRST; theoryId < THEORY_LAST; ++theoryId) { if( theoryId!=THEORY_QUANTIFIERS ){ Theory* theory = d_theoryTable[theoryId]; if (theory && d_logicInfo.isTheoryEnabled(theoryId)) { if( theory->needsCheckLastEffort() ){ if (!d_tc->buildModel()) { break; } theory->check(Theory::EFFORT_LAST_CALL); } } } } if (!d_inConflict) { if(d_logicInfo.isQuantified()) { // quantifiers engine must check at last call effort d_quantEngine->check(Theory::EFFORT_LAST_CALL); } } if (!d_inConflict && !needCheck()) { // We only mark that we are in "SAT mode". We build the model later only // if the user asks for it via getBuiltModel. d_inSatMode = true; } } Debug("theory") << "TheoryEngine::check(" << effort << "): done, we are " << (d_inConflict ? "unsat" : "sat") << (d_lemmasAdded ? " with new lemmas" : " with no new lemmas"); Debug("theory") << ", need check = " << (needCheck() ? "YES" : "NO") << endl; if( Theory::fullEffort(effort) && !d_inConflict && !needCheck()) { // Do post-processing of model from the theories (e.g. used for THEORY_SEP // to construct heap model) d_tc->postProcessModel(d_incomplete.get()); } } catch(const theory::Interrupted&) { Trace("theory") << "TheoryEngine::check() => interrupted" << endl; } // If fulleffort, check all theories if(Dump.isOn("theory::fullcheck") && Theory::fullEffort(effort)) { if (!d_inConflict && !needCheck()) { dumpAssertions("theory::fullcheck"); } } } void TheoryEngine::propagate(Theory::Effort effort) { // Reset the interrupt flag d_interrupted = false; // Definition of the statement that is to be run by every theory #ifdef CVC5_FOR_EACH_THEORY_STATEMENT #undef CVC5_FOR_EACH_THEORY_STATEMENT #endif #define CVC5_FOR_EACH_THEORY_STATEMENT(THEORY) \ if (theory::TheoryTraits::hasPropagate \ && d_logicInfo.isTheoryEnabled(THEORY)) \ { \ theoryOf(THEORY)->propagate(effort); \ } // Reset the interrupt flag d_interrupted = false; // Propagate for each theory using the statement above CVC5_FOR_EACH_THEORY; } Node TheoryEngine::getNextDecisionRequest() { return d_decManager->getNextDecisionRequest(); } bool TheoryEngine::properConflict(TNode conflict) const { bool value; if (conflict.getKind() == kind::AND) { for (unsigned i = 0; i < conflict.getNumChildren(); ++ i) { if (! getPropEngine()->hasValue(conflict[i], value)) { Debug("properConflict") << "Bad conflict is due to unassigned atom: " << conflict[i] << endl; return false; } if (! value) { Debug("properConflict") << "Bad conflict is due to false atom: " << conflict[i] << endl; return false; } if (conflict[i] != Rewriter::rewrite(conflict[i])) { Debug("properConflict") << "Bad conflict is due to atom not in normal form: " << conflict[i] << " vs " << Rewriter::rewrite(conflict[i]) << endl; return false; } } } else { if (! getPropEngine()->hasValue(conflict, value)) { Debug("properConflict") << "Bad conflict is due to unassigned atom: " << conflict << endl; return false; } if(! value) { Debug("properConflict") << "Bad conflict is due to false atom: " << conflict << endl; return false; } if (conflict != Rewriter::rewrite(conflict)) { Debug("properConflict") << "Bad conflict is due to atom not in normal form: " << conflict << " vs " << Rewriter::rewrite(conflict) << endl; return false; } } return true; } TheoryModel* TheoryEngine::getModel() { Assert(d_tc != nullptr); TheoryModel* m = d_tc->getModel(); Assert(m != nullptr); return m; } TheoryModel* TheoryEngine::getBuiltModel() { Assert(d_tc != nullptr); // If this method was called, we should be in SAT mode, and produceModels // should be true. AlwaysAssert(options::produceModels()); if (!d_inSatMode) { // not available, perhaps due to interuption. return nullptr; } // must build model at this point if (!d_tc->buildModel()) { return nullptr; } return d_tc->getModel(); } bool TheoryEngine::buildModel() { Assert(d_tc != nullptr); return d_tc->buildModel(); } bool TheoryEngine::presolve() { // Reset the interrupt flag d_interrupted = false; // Reset the decision manager. This clears its decision strategies that are // no longer valid in this user context. d_decManager->presolve(); try { // Definition of the statement that is to be run by every theory #ifdef CVC5_FOR_EACH_THEORY_STATEMENT #undef CVC5_FOR_EACH_THEORY_STATEMENT #endif #define CVC5_FOR_EACH_THEORY_STATEMENT(THEORY) \ if (theory::TheoryTraits::hasPresolve) \ { \ theoryOf(THEORY)->presolve(); \ if (d_inConflict) \ { \ return true; \ } \ } // Presolve for each theory using the statement above CVC5_FOR_EACH_THEORY; } catch(const theory::Interrupted&) { Trace("theory") << "TheoryEngine::presolve() => interrupted" << endl; } // return whether we have a conflict return false; }/* TheoryEngine::presolve() */ void TheoryEngine::postsolve() { // no longer in SAT mode d_inSatMode = false; // Reset the interrupt flag d_interrupted = false; bool CVC5_UNUSED wasInConflict = d_inConflict; try { // Definition of the statement that is to be run by every theory #ifdef CVC5_FOR_EACH_THEORY_STATEMENT #undef CVC5_FOR_EACH_THEORY_STATEMENT #endif #define CVC5_FOR_EACH_THEORY_STATEMENT(THEORY) \ if (theory::TheoryTraits::hasPostsolve) \ { \ theoryOf(THEORY)->postsolve(); \ Assert(!d_inConflict || wasInConflict) \ << "conflict raised during postsolve()"; \ } // Postsolve for each theory using the statement above CVC5_FOR_EACH_THEORY; } catch(const theory::Interrupted&) { Trace("theory") << "TheoryEngine::postsolve() => interrupted" << endl; } }/* TheoryEngine::postsolve() */ void TheoryEngine::notifyRestart() { // Reset the interrupt flag d_interrupted = false; // Definition of the statement that is to be run by every theory #ifdef CVC5_FOR_EACH_THEORY_STATEMENT #undef CVC5_FOR_EACH_THEORY_STATEMENT #endif #define CVC5_FOR_EACH_THEORY_STATEMENT(THEORY) \ if (theory::TheoryTraits::hasNotifyRestart \ && d_logicInfo.isTheoryEnabled(THEORY)) \ { \ theoryOf(THEORY)->notifyRestart(); \ } // notify each theory using the statement above CVC5_FOR_EACH_THEORY; } void TheoryEngine::ppStaticLearn(TNode in, NodeBuilder& learned) { // Reset the interrupt flag d_interrupted = false; // Definition of the statement that is to be run by every theory #ifdef CVC5_FOR_EACH_THEORY_STATEMENT #undef CVC5_FOR_EACH_THEORY_STATEMENT #endif #define CVC5_FOR_EACH_THEORY_STATEMENT(THEORY) \ if (theory::TheoryTraits::hasPpStaticLearn) \ { \ theoryOf(THEORY)->ppStaticLearn(in, learned); \ } // static learning for each theory using the statement above CVC5_FOR_EACH_THEORY; } bool TheoryEngine::isRelevant(Node lit) const { if (d_relManager != nullptr) { return d_relManager->isRelevant(lit); } // otherwise must assume its relevant return true; } void TheoryEngine::shutdown() { // Set this first; if a Theory shutdown() throws an exception, // at least the destruction of the TheoryEngine won't confound // matters. d_hasShutDown = true; // Shutdown all the theories for(TheoryId theoryId = theory::THEORY_FIRST; theoryId < theory::THEORY_LAST; ++theoryId) { if(d_theoryTable[theoryId]) { theoryOf(theoryId)->shutdown(); } } } theory::Theory::PPAssertStatus TheoryEngine::solve( TrustNode tliteral, TrustSubstitutionMap& substitutionOut) { // Reset the interrupt flag d_interrupted = false; TNode literal = tliteral.getNode(); TNode atom = literal.getKind() == kind::NOT ? literal[0] : literal; Trace("theory::solve") << "TheoryEngine::solve(" << literal << "): solving with " << theoryOf(atom)->getId() << endl; if(! d_logicInfo.isTheoryEnabled(Theory::theoryOf(atom)) && Theory::theoryOf(atom) != THEORY_SAT_SOLVER) { stringstream ss; ss << "The logic was specified as " << d_logicInfo.getLogicString() << ", which doesn't include " << Theory::theoryOf(atom) << ", but got a preprocessing-time fact for that theory." << endl << "The fact:" << endl << literal; throw LogicException(ss.str()); } Theory::PPAssertStatus solveStatus = theoryOf(atom)->ppAssert(tliteral, substitutionOut); Trace("theory::solve") << "TheoryEngine::solve(" << literal << ") => " << solveStatus << endl; return solveStatus; } TrustNode TheoryEngine::ppRewriteEquality(TNode eq) { Assert(eq.getKind() == kind::EQUAL); std::vector lems; TrustNode trn = theoryOf(eq)->ppRewrite(eq, lems); // should never introduce a skolem to eliminate an equality Assert(lems.empty()); return trn; } void TheoryEngine::notifyPreprocessedAssertions( const std::vector& assertions) { // call all the theories for (TheoryId theoryId = theory::THEORY_FIRST; theoryId < theory::THEORY_LAST; ++theoryId) { if (d_theoryTable[theoryId]) { theoryOf(theoryId)->ppNotifyAssertions(assertions); } } if (d_relManager != nullptr) { d_relManager->notifyPreprocessedAssertions(assertions); } } bool TheoryEngine::markPropagation(TNode assertion, TNode originalAssertion, theory::TheoryId toTheoryId, theory::TheoryId fromTheoryId) { // What and where we are asserting NodeTheoryPair toAssert(assertion, toTheoryId, d_propagationMapTimestamp); // What and where it came from NodeTheoryPair toExplain(originalAssertion, fromTheoryId, d_propagationMapTimestamp); // See if the theory already got this literal PropagationMap::const_iterator find = d_propagationMap.find(toAssert); if (find != d_propagationMap.end()) { // The theory already knows this Trace("theory::assertToTheory") << "TheoryEngine::markPropagation(): already there" << endl; return false; } Trace("theory::assertToTheory") << "TheoryEngine::markPropagation(): marking [" << d_propagationMapTimestamp << "] " << assertion << ", " << toTheoryId << " from " << originalAssertion << ", " << fromTheoryId << endl; // Mark the propagation d_propagationMap[toAssert] = toExplain; d_propagationMapTimestamp = d_propagationMapTimestamp + 1; return true; } void TheoryEngine::assertToTheory(TNode assertion, TNode originalAssertion, theory::TheoryId toTheoryId, theory::TheoryId fromTheoryId) { Trace("theory::assertToTheory") << "TheoryEngine::assertToTheory(" << assertion << ", " << originalAssertion << "," << toTheoryId << ", " << fromTheoryId << ")" << endl; Assert(toTheoryId != fromTheoryId); if(toTheoryId != THEORY_SAT_SOLVER && ! d_logicInfo.isTheoryEnabled(toTheoryId)) { stringstream ss; ss << "The logic was specified as " << d_logicInfo.getLogicString() << ", which doesn't include " << toTheoryId << ", but got an asserted fact to that theory." << endl << "The fact:" << endl << assertion; throw LogicException(ss.str()); } if (d_inConflict) { return; } // If sharing is disabled, things are easy if (!d_logicInfo.isSharingEnabled()) { Assert(assertion == originalAssertion); if (fromTheoryId == THEORY_SAT_SOLVER) { // Send to the apropriate theory theory::Theory* toTheory = theoryOf(toTheoryId); // We assert it, and we know it's preregistereed toTheory->assertFact(assertion, true); // Mark that we have more information d_factsAsserted = true; } else { Assert(toTheoryId == THEORY_SAT_SOLVER); // Check for propositional conflict bool value; if (d_propEngine->hasValue(assertion, value)) { if (!value) { Trace("theory::propagate") << "TheoryEngine::assertToTheory(" << assertion << ", " << toTheoryId << ", " << fromTheoryId << "): conflict (no sharing)" << endl; Trace("dtview::conflict") << ":THEORY-CONFLICT: " << assertion << std::endl; markInConflict(); } else { return; } } d_propagatedLiterals.push_back(assertion); } return; } // determine the actual theory that will process/explain the fact, which is // THEORY_BUILTIN if the theory uses the central equality engine TheoryId toTheoryIdProp = (Theory::expUsingCentralEqualityEngine(toTheoryId)) ? THEORY_BUILTIN : toTheoryId; // If sending to the shared solver, it's also simple if (toTheoryId == THEORY_BUILTIN) { if (markPropagation( assertion, originalAssertion, toTheoryIdProp, fromTheoryId)) { // assert to the shared solver bool polarity = assertion.getKind() != kind::NOT; TNode atom = polarity ? assertion : assertion[0]; d_sharedSolver->assertShared(atom, polarity, assertion); } return; } // Things from the SAT solver are already normalized, so they go // directly to the apropriate theory if (fromTheoryId == THEORY_SAT_SOLVER) { // We know that this is normalized, so just send it off to the theory if (markPropagation( assertion, originalAssertion, toTheoryIdProp, fromTheoryId)) { // Is it preregistered bool preregistered = d_propEngine->isSatLiteral(assertion) && Theory::theoryOf(assertion) == toTheoryId; // We assert it theoryOf(toTheoryId)->assertFact(assertion, preregistered); // Mark that we have more information d_factsAsserted = true; } return; } // Propagations to the SAT solver are just enqueued for pickup by // the SAT solver later if (toTheoryId == THEORY_SAT_SOLVER) { Assert(toTheoryIdProp == toTheoryId); if (markPropagation(assertion, originalAssertion, toTheoryId, fromTheoryId)) { // Enqueue for propagation to the SAT solver d_propagatedLiterals.push_back(assertion); // Check for propositional conflicts bool value; if (d_propEngine->hasValue(assertion, value) && !value) { Trace("theory::propagate") << "TheoryEngine::assertToTheory(" << assertion << ", " << toTheoryId << ", " << fromTheoryId << "): conflict (sharing)" << endl; Trace("dtview::conflict") << ":THEORY-CONFLICT: " << assertion << std::endl; markInConflict(); } } return; } Assert(assertion.getKind() == kind::EQUAL || (assertion.getKind() == kind::NOT && assertion[0].getKind() == kind::EQUAL)); // Normalize Node normalizedLiteral = Rewriter::rewrite(assertion); // See if it rewrites false directly -> conflict if (normalizedLiteral.isConst()) { if (!normalizedLiteral.getConst()) { // Mark the propagation for explanations if (markPropagation(normalizedLiteral, originalAssertion, toTheoryIdProp, fromTheoryId)) { // special case, trust node has no proof generator TrustNode trnn = TrustNode::mkTrustConflict(normalizedLiteral); // Get the explanation (conflict will figure out where it came from) conflict(trnn, toTheoryId); } else { Unreachable(); } return; } } // Try and assert (note that we assert the non-normalized one) if (markPropagation( assertion, originalAssertion, toTheoryIdProp, fromTheoryId)) { // Check if has been pre-registered with the theory bool preregistered = d_propEngine->isSatLiteral(assertion) && Theory::theoryOf(assertion) == toTheoryId; // Assert away theoryOf(toTheoryId)->assertFact(assertion, preregistered); d_factsAsserted = true; } return; } void TheoryEngine::assertFact(TNode literal) { Trace("theory") << "TheoryEngine::assertFact(" << literal << ")" << endl; // spendResource(); // If we're in conflict, nothing to do if (d_inConflict) { return; } // Get the atom bool polarity = literal.getKind() != kind::NOT; TNode atom = polarity ? literal : literal[0]; if (d_logicInfo.isSharingEnabled()) { // If any shared terms, it's time to do sharing work d_sharedSolver->preNotifySharedFact(atom); // If it's an equality, assert it to the shared term manager, even though the terms are not // yet shared. As the terms become shared later, the shared terms manager will then add them // to the assert the equality to the interested theories if (atom.getKind() == kind::EQUAL) { // Assert it to the the owning theory assertToTheory(literal, literal, /* to */ Theory::theoryOf(atom), /* from */ THEORY_SAT_SOLVER); // Shared terms manager will assert to interested theories directly, as // the terms become shared assertToTheory(literal, literal, /* to */ THEORY_BUILTIN, /* from */ THEORY_SAT_SOLVER); // Now, let's check for any atom triggers from lemmas AtomRequests::atom_iterator it = d_atomRequests.getAtomIterator(atom); while (!it.done()) { const AtomRequests::Request& request = it.get(); Node toAssert = polarity ? (Node)request.d_atom : request.d_atom.notNode(); Debug("theory::atoms") << "TheoryEngine::assertFact(" << literal << "): sending requested " << toAssert << endl; assertToTheory( toAssert, literal, request.d_toTheory, THEORY_SAT_SOLVER); it.next(); } } else { // Not an equality, just assert to the appropriate theory assertToTheory(literal, literal, /* to */ Theory::theoryOf(atom), /* from */ THEORY_SAT_SOLVER); } } else { // Assert the fact to the appropriate theory directly assertToTheory(literal, literal, /* to */ Theory::theoryOf(atom), /* from */ THEORY_SAT_SOLVER); } } bool TheoryEngine::propagate(TNode literal, theory::TheoryId theory) { Debug("theory::propagate") << "TheoryEngine::propagate(" << literal << ", " << theory << ")" << endl; Trace("dtview::prop") << std::string(d_env.getContext()->getLevel(), ' ') << ":THEORY-PROP: " << literal << endl; // spendResource(); // Get the atom bool polarity = literal.getKind() != kind::NOT; TNode atom = polarity ? literal : literal[0]; if (d_logicInfo.isSharingEnabled() && atom.getKind() == kind::EQUAL) { if (d_propEngine->isSatLiteral(literal)) { // We propagate SAT literals to SAT assertToTheory(literal, literal, /* to */ THEORY_SAT_SOLVER, /* from */ theory); } if (theory != THEORY_BUILTIN) { // Assert to the shared terms database assertToTheory(literal, literal, /* to */ THEORY_BUILTIN, /* from */ theory); } } else { // Just send off to the SAT solver Assert(d_propEngine->isSatLiteral(literal)); assertToTheory(literal, literal, /* to */ THEORY_SAT_SOLVER, /* from */ theory); } return !d_inConflict; } const LogicInfo& TheoryEngine::getLogicInfo() const { return d_logicInfo; } bool TheoryEngine::getSepHeapTypes(TypeNode& locType, TypeNode& dataType) const { if (d_sepLocType.isNull()) { return false; } locType = d_sepLocType; dataType = d_sepDataType; return true; } void TheoryEngine::declareSepHeap(TypeNode locT, TypeNode dataT) { Theory* tsep = theoryOf(THEORY_SEP); if (tsep == nullptr) { Assert(false) << "TheoryEngine::declareSepHeap called without the " "separation logic theory enabled"; return; } // Definition of the statement that is to be run by every theory #ifdef CVC5_FOR_EACH_THEORY_STATEMENT #undef CVC5_FOR_EACH_THEORY_STATEMENT #endif #define CVC5_FOR_EACH_THEORY_STATEMENT(THEORY) \ theoryOf(THEORY)->declareSepHeap(locT, dataT); // notify each theory using the statement above CVC5_FOR_EACH_THEORY; // remember the types we have set d_sepLocType = locT; d_sepDataType = dataT; } theory::EqualityStatus TheoryEngine::getEqualityStatus(TNode a, TNode b) { Assert(a.getType().isComparableTo(b.getType())); return d_sharedSolver->getEqualityStatus(a, b); } const std::unordered_set& TheoryEngine::getRelevantAssertions( bool& success) { // if we are not in SAT mode, or there is no relevance manager, we fail if (!d_inSatMode || d_relManager == nullptr) { success = false; return d_emptyRelevantSet; } return d_relManager->getRelevantAssertions(success); } Node TheoryEngine::getModelValue(TNode var) { if (var.isConst()) { // the model value of a constant must be itself return var; } Assert(d_sharedSolver->isShared(var)); return theoryOf(Theory::theoryOf(var.getType()))->getModelValue(var); } TrustNode TheoryEngine::getExplanation(TNode node) { Debug("theory::explain") << "TheoryEngine::getExplanation(" << node << "): current propagation index = " << d_propagationMapTimestamp << endl; bool polarity = node.getKind() != kind::NOT; TNode atom = polarity ? node : node[0]; // If we're not in shared mode, explanations are simple if (!d_logicInfo.isSharingEnabled()) { Debug("theory::explain") << "TheoryEngine::getExplanation: sharing is NOT enabled. " << " Responsible theory is: " << theoryOf(atom)->getId() << std::endl; TrustNode texplanation = theoryOf(atom)->explain(node); Node explanation = texplanation.getNode(); Debug("theory::explain") << "TheoryEngine::getExplanation(" << node << ") => " << explanation << endl; if (isProofEnabled()) { texplanation.debugCheckClosed( "te-proof-exp", "texplanation no share", false); // check if no generator, if so, add THEORY_LEMMA if (texplanation.getGenerator() == nullptr) { Node proven = texplanation.getProven(); TheoryId tid = theoryOf(atom)->getId(); Node tidn = builtin::BuiltinProofRuleChecker::mkTheoryIdNode(tid); d_lazyProof->addStep(proven, PfRule::THEORY_LEMMA, {}, {proven, tidn}); texplanation = TrustNode::mkTrustPropExp(node, explanation, d_lazyProof.get()); } } return texplanation; } Debug("theory::explain") << "TheoryEngine::getExplanation: sharing IS enabled" << std::endl; // Initial thing to explain NodeTheoryPair toExplain(node, THEORY_SAT_SOLVER, d_propagationMapTimestamp); Assert(d_propagationMap.find(toExplain) != d_propagationMap.end()); NodeTheoryPair nodeExplainerPair = d_propagationMap[toExplain]; Debug("theory::explain") << "TheoryEngine::getExplanation: explainer for node " << nodeExplainerPair.d_node << " is theory: " << nodeExplainerPair.d_theory << std::endl; // Create the workplace for explanations std::vector vec{d_propagationMap[toExplain]}; // Process the explanation TrustNode texplanation = getExplanation(vec); Debug("theory::explain") << "TheoryEngine::getExplanation(" << node << ") => " << texplanation.getNode() << endl; return texplanation; } struct AtomsCollect { std::vector d_atoms; std::unordered_set d_visited; public: typedef void return_type; bool alreadyVisited(TNode current, TNode parent) { // Check if already visited if (d_visited.find(current) != d_visited.end()) return true; // Don't visit non-boolean if (!current.getType().isBoolean()) return true; // New node return false; } void visit(TNode current, TNode parent) { if (Theory::theoryOf(current) != theory::THEORY_BOOL) { d_atoms.push_back(current); } d_visited.insert(current); } void start(TNode node) {} void done(TNode node) {} std::vector getAtoms() const { return d_atoms; } }; void TheoryEngine::ensureLemmaAtoms(TNode n, theory::TheoryId atomsTo) { Assert(atomsTo != THEORY_LAST); Debug("theory::atoms") << "TheoryEngine::ensureLemmaAtoms(" << n << ", " << atomsTo << ")" << endl; AtomsCollect collectAtoms; NodeVisitor::run(collectAtoms, n); ensureLemmaAtoms(collectAtoms.getAtoms(), atomsTo); } void TheoryEngine::ensureLemmaAtoms(const std::vector& atoms, theory::TheoryId atomsTo) { for (unsigned i = 0; i < atoms.size(); ++ i) { // Non-equality atoms are either owned by theory or they don't make sense if (atoms[i].getKind() != kind::EQUAL) { continue; } // The equality Node eq = atoms[i]; // Simple normalization to not repeat stuff if (eq[0] > eq[1]) { eq = eq[1].eqNode(eq[0]); } // Rewrite the equality Node eqNormalized = Rewriter::rewrite(atoms[i]); Debug("theory::atoms") << "TheoryEngine::ensureLemmaAtoms(): " << eq << " with nf " << eqNormalized << endl; // If the equality is a boolean constant, we send immediately if (eqNormalized.isConst()) { if (eqNormalized.getConst()) { assertToTheory(eq, eqNormalized, /** to */ atomsTo, /** Sat solver */ theory::THEORY_SAT_SOLVER); } else { assertToTheory(eq.notNode(), eqNormalized.notNode(), /** to */ atomsTo, /** Sat solver */ theory::THEORY_SAT_SOLVER); } continue; }else if( eqNormalized.getKind() != kind::EQUAL){ Assert(eqNormalized.getKind() == kind::BOOLEAN_TERM_VARIABLE || (eqNormalized.getKind() == kind::NOT && eqNormalized[0].getKind() == kind::BOOLEAN_TERM_VARIABLE)); // this happens for Boolean term equalities V = true that are rewritten to V, we should skip // TODO : revisit this continue; } // If the normalization did the just flips, keep the flip if (eqNormalized[0] == eq[1] && eqNormalized[1] == eq[0]) { eq = eqNormalized; } // Check if the equality is already known by the sat solver if (d_propEngine->isSatLiteral(eqNormalized)) { bool value; if (d_propEngine->hasValue(eqNormalized, value)) { if (value) { assertToTheory(eq, eqNormalized, atomsTo, theory::THEORY_SAT_SOLVER); continue; } else { assertToTheory(eq.notNode(), eqNormalized.notNode(), atomsTo, theory::THEORY_SAT_SOLVER); continue; } } } // If the theory is asking about a different form, or the form is ok but if will go to a different theory // then we must figure it out if (eqNormalized != eq || Theory::theoryOf(eq) != atomsTo) { // If you get eqNormalized, send atoms[i] to atomsTo d_atomRequests.add(eqNormalized, eq, atomsTo); } } } void TheoryEngine::lemma(TrustNode tlemma, theory::LemmaProperty p, theory::TheoryId from) { // For resource-limiting (also does a time check). // spendResource(); Assert(tlemma.getKind() == TrustNodeKind::LEMMA || tlemma.getKind() == TrustNodeKind::CONFLICT); // get the node Node node = tlemma.getNode(); Node lemma = tlemma.getProven(); Assert(!expr::hasFreeVar(lemma)); // when proofs are enabled, we ensure the trust node has a generator by // adding a trust step to the lazy proof maintained by this class if (isProofEnabled()) { // ensure proof: set THEORY_LEMMA if no generator is provided if (tlemma.getGenerator() == nullptr) { // internal lemmas should have generators Assert(from != THEORY_LAST); // add theory lemma step to proof Node tidn = builtin::BuiltinProofRuleChecker::mkTheoryIdNode(from); d_lazyProof->addStep(lemma, PfRule::THEORY_LEMMA, {}, {lemma, tidn}); // update the trust node tlemma = TrustNode::mkTrustLemma(lemma, d_lazyProof.get()); } // ensure closed tlemma.debugCheckClosed("te-proof-debug", "TheoryEngine::lemma_initial"); } if(Dump.isOn("t-lemmas")) { // we dump the negation of the lemma, to show validity of the lemma Node n = lemma.negate(); const Printer& printer = d_env.getPrinter(); std::ostream& out = d_env.getDumpOut(); printer.toStreamCmdComment(out, "theory lemma: expect valid"); printer.toStreamCmdCheckSat(out, n); } // assert the lemma d_propEngine->assertLemma(tlemma, p); // If specified, we must add this lemma to the set of those that need to be // justified, where note we pass all auxiliary lemmas in skAsserts as well, // since these by extension must be justified as well. if (d_relManager != nullptr && isLemmaPropertyNeedsJustify(p)) { std::vector skAsserts; std::vector sks; Node retLemma = d_propEngine->getPreprocessedTerm(tlemma.getProven(), skAsserts, sks); d_relManager->notifyPreprocessedAssertion(retLemma); d_relManager->notifyPreprocessedAssertions(skAsserts); } // Mark that we added some lemmas d_lemmasAdded = true; } void TheoryEngine::markInConflict() { #ifdef CVC5_FOR_EACH_THEORY_STATEMENT #undef CVC5_FOR_EACH_THEORY_STATEMENT #endif #define CVC5_FOR_EACH_THEORY_STATEMENT(THEORY) \ theoryOf(THEORY)->notifyInConflict(); CVC5_FOR_EACH_THEORY; d_inConflict = true; } void TheoryEngine::conflict(TrustNode tconflict, TheoryId theoryId) { Assert(tconflict.getKind() == TrustNodeKind::CONFLICT); TNode conflict = tconflict.getNode(); Debug("theory::conflict") << "TheoryEngine::conflict(" << conflict << ", " << theoryId << ")" << endl; Trace("te-proof-debug") << "Check closed conflict" << std::endl; // doesn't require proof generator, yet, since THEORY_LEMMA is added below tconflict.debugCheckClosed( "te-proof-debug", "TheoryEngine::conflict_initial", false); Trace("dtview::conflict") << ":THEORY-CONFLICT: " << conflict << std::endl; // Mark that we are in conflict markInConflict(); if(Dump.isOn("t-conflicts")) { const Printer& printer = d_env.getPrinter(); std::ostream& out = d_env.getDumpOut(); printer.toStreamCmdComment(out, "theory conflict: expect unsat"); printer.toStreamCmdCheckSat(out, conflict); } // In the multiple-theories case, we need to reconstruct the conflict if (d_logicInfo.isSharingEnabled()) { // Create the workplace for explanations std::vector vec; vec.push_back( NodeTheoryPair(conflict, theoryId, d_propagationMapTimestamp)); // Process the explanation TrustNode tncExp = getExplanation(vec); Trace("te-proof-debug") << "Check closed conflict explained with sharing" << std::endl; tncExp.debugCheckClosed("te-proof-debug", "TheoryEngine::conflict_explained_sharing"); Node fullConflict = tncExp.getNode(); if (isProofEnabled()) { Trace("te-proof-debug") << "Process conflict: " << conflict << std::endl; Trace("te-proof-debug") << "Conflict " << tconflict << " from " << tconflict.identifyGenerator() << std::endl; Trace("te-proof-debug") << "Explanation " << tncExp << " from " << tncExp.identifyGenerator() << std::endl; Assert(d_lazyProof != nullptr); if (tconflict.getGenerator() != nullptr) { d_lazyProof->addLazyStep(tconflict.getProven(), tconflict.getGenerator()); } else { // add theory lemma step Node tidn = builtin::BuiltinProofRuleChecker::mkTheoryIdNode(theoryId); Node conf = tconflict.getProven(); d_lazyProof->addStep(conf, PfRule::THEORY_LEMMA, {}, {conf, tidn}); } // store the explicit step, which should come from a different // generator, e.g. d_tepg. Node proven = tncExp.getProven(); Assert(tncExp.getGenerator() != d_lazyProof.get()); Trace("te-proof-debug") << "add lazy step " << tncExp.identifyGenerator() << " for " << proven << std::endl; d_lazyProof->addLazyStep(proven, tncExp.getGenerator()); pfgEnsureClosed(proven, d_lazyProof.get(), "te-proof-debug", "TheoryEngine::conflict_during"); Node fullConflictNeg = fullConflict.notNode(); std::vector children; children.push_back(proven); std::vector args; args.push_back(fullConflictNeg); if (conflict == d_false) { AlwaysAssert(proven == fullConflictNeg); } else { if (fullConflict != conflict) { // ------------------------- explained ---------- from theory // fullConflict => conflict ~conflict // ------------------------------------------ MACRO_SR_PRED_TRANSFORM // ~fullConflict children.push_back(conflict.notNode()); args.push_back(mkMethodId(MethodId::SB_LITERAL)); d_lazyProof->addStep( fullConflictNeg, PfRule::MACRO_SR_PRED_TRANSFORM, children, args); } } } // pass the processed trust node TrustNode tconf = TrustNode::mkTrustConflict(fullConflict, d_lazyProof.get()); Debug("theory::conflict") << "TheoryEngine::conflict(" << conflict << ", " << theoryId << "): full = " << fullConflict << endl; Assert(properConflict(fullConflict)); Trace("te-proof-debug") << "Check closed conflict with sharing" << std::endl; tconf.debugCheckClosed("te-proof-debug", "TheoryEngine::conflict:sharing"); lemma(tconf, LemmaProperty::REMOVABLE); } else { // When only one theory, the conflict should need no processing Assert(properConflict(conflict)); // pass the trust node that was sent from the theory lemma(tconflict, LemmaProperty::REMOVABLE, theoryId); } } void TheoryEngine::setIncomplete(theory::TheoryId theory, theory::IncompleteId id) { d_incomplete = true; d_incompleteTheory = theory; d_incompleteId = id; } TrustNode TheoryEngine::getExplanation( std::vector& explanationVector) { Assert(explanationVector.size() == 1); Node conclusion = explanationVector[0].d_node; // if the theory explains using the central equality engine, we always start // with THEORY_BUILTIN. if (Theory::expUsingCentralEqualityEngine(explanationVector[0].d_theory)) { explanationVector[0].d_theory = THEORY_BUILTIN; } std::shared_ptr lcp; if (isProofEnabled()) { Trace("te-proof-exp") << "=== TheoryEngine::getExplanation " << conclusion << std::endl; lcp.reset(new LazyCDProof( d_pnm, nullptr, nullptr, "TheoryEngine::LazyCDProof::getExplanation")); } unsigned i = 0; // Index of the current literal we are processing std::unique_ptr> inputAssertions = nullptr; // the overall explanation std::set exp; // vector of trust nodes to explain at the end std::vector> texplains; // cache of nodes we have already explained by some theory std::unordered_map cache; while (i < explanationVector.size()) { // Get the current literal to explain NodeTheoryPair toExplain = explanationVector[i]; Debug("theory::explain") << "[i=" << i << "] TheoryEngine::explain(): processing [" << toExplain.d_timestamp << "] " << toExplain.d_node << " sent from " << toExplain.d_theory << endl; if (cache.find(toExplain.d_node) != cache.end() && cache[toExplain.d_node] < toExplain.d_timestamp) { ++i; continue; } cache[toExplain.d_node] = toExplain.d_timestamp; // If a true constant or a negation of a false constant we can ignore it if ((toExplain.d_node.isConst() && toExplain.d_node.getConst()) || (toExplain.d_node.getKind() == kind::NOT && toExplain.d_node[0].isConst() && !toExplain.d_node[0].getConst())) { ++ i; // if we are building a proof if (lcp != nullptr) { Trace("te-proof-exp") << "- explain " << toExplain.d_node << " trivially..." << std::endl; // ------------------MACRO_SR_PRED_INTRO // toExplain.d_node std::vector children; std::vector args; args.push_back(toExplain.d_node); lcp->addStep( toExplain.d_node, PfRule::MACRO_SR_PRED_INTRO, children, args); } continue; } // If from the SAT solver, keep it if (toExplain.d_theory == THEORY_SAT_SOLVER) { Debug("theory::explain") << "\tLiteral came from THEORY_SAT_SOLVER. Keeping it." << endl; exp.insert(explanationVector[i++].d_node); // it will be a free assumption in the proof Trace("te-proof-exp") << "- keep " << toExplain.d_node << std::endl; continue; } // If an and, expand it if (toExplain.d_node.getKind() == kind::AND) { Debug("theory::explain") << "TheoryEngine::explain(): expanding " << toExplain.d_node << " got from " << toExplain.d_theory << endl; size_t nchild = toExplain.d_node.getNumChildren(); for (size_t k = 0; k < nchild; ++k) { NodeTheoryPair newExplain( toExplain.d_node[k], toExplain.d_theory, toExplain.d_timestamp); explanationVector.push_back(newExplain); } if (lcp != nullptr) { Trace("te-proof-exp") << "- AND expand " << toExplain.d_node << std::endl; // delay explanation, use a dummy trust node TrustNode tnAndExp = TrustNode::mkTrustPropExp( toExplain.d_node, toExplain.d_node, nullptr); texplains.push_back( std::pair(THEORY_LAST, tnAndExp)); } ++ i; continue; } // See if it was sent to the theory by another theory PropagationMap::const_iterator find = d_propagationMap.find(toExplain); if (find != d_propagationMap.end()) { Debug("theory::explain") << "\tTerm was propagated by another theory (theory = " << getTheoryString((*find).second.d_theory) << ")" << std::endl; // There is some propagation, check if its a timely one if ((*find).second.d_timestamp < toExplain.d_timestamp) { Debug("theory::explain") << "\tRelevant timetsamp, pushing " << (*find).second.d_node << "to index = " << explanationVector.size() << std::endl; explanationVector.push_back((*find).second); ++i; if (lcp != nullptr) { if (!CDProof::isSame(toExplain.d_node, (*find).second.d_node)) { Trace("te-proof-exp") << "- t-explained cached: " << toExplain.d_node << " by " << (*find).second.d_node << std::endl; // delay explanation, use a dummy trust node that says that // (*find).second.d_node explains toExplain.d_node. TrustNode tnRewExp = TrustNode::mkTrustPropExp( toExplain.d_node, (*find).second.d_node, nullptr); texplains.push_back( std::pair(THEORY_LAST, tnRewExp)); } } continue; } } // It was produced by the theory, so ask for an explanation TrustNode texplanation = d_sharedSolver->explain(toExplain.d_node, toExplain.d_theory); if (lcp != nullptr) { texplanation.debugCheckClosed("te-proof-exp", "texplanation", false); Trace("te-proof-exp") << "- t-explained[" << toExplain.d_theory << "]: " << toExplain.d_node << " by " << texplanation.getNode() << std::endl; // should prove the propagation we asked for Assert(texplanation.getKind() == TrustNodeKind::PROP_EXP && texplanation.getProven()[1] == toExplain.d_node); // if not a trivial explanation if (!CDProof::isSame(texplanation.getNode(), toExplain.d_node)) { // We add it to the list of theory explanations, to be processed at // the end of this method. We wait to explain here because it may // be that a later explanation may preempt the need for proving this // step. For instance, if the conclusion lit is later added as an // assumption in the final explanation. This avoids cyclic proofs. texplains.push_back( std::pair(toExplain.d_theory, texplanation)); } } Node explanation = texplanation.getNode(); Debug("theory::explain") << "TheoryEngine::explain(): got explanation " << explanation << " got from " << toExplain.d_theory << endl; Assert(explanation != toExplain.d_node) << "wasn't sent to you, so why are you explaining it trivially, for " "fact " << explanation; // Mark the explanation NodeTheoryPair newExplain( explanation, toExplain.d_theory, toExplain.d_timestamp); explanationVector.push_back(newExplain); ++ i; } // make the explanation node Node expNode; if (exp.size() == 0) { // Normalize to true expNode = NodeManager::currentNM()->mkConst(true); } else if (exp.size() == 1) { // All the same, or just one expNode = *exp.begin(); } else { NodeBuilder conjunction(kind::AND); std::set::const_iterator it = exp.begin(); std::set::const_iterator it_end = exp.end(); while (it != it_end) { conjunction << *it; ++it; } expNode = conjunction; } // if we are building a proof, go back through the explanations and // build the proof if (lcp != nullptr) { if (Trace.isOn("te-proof-exp")) { Trace("te-proof-exp") << "Explanation is:" << std::endl; for (TNode e : exp) { Trace("te-proof-exp") << " " << e << std::endl; } Trace("te-proof-exp") << "=== Replay explanations..." << std::endl; } // Now, go back and add the necessary steps of theory explanations, i.e. // add those that prove things that aren't in the final explanation. We // iterate in reverse order so that most recent steps take priority. This // avoids cyclic proofs in the lazy proof we are building (lcp). for (std::vector>::reverse_iterator it = texplains.rbegin(), itEnd = texplains.rend(); it != itEnd; ++it) { TrustNode trn = it->second; Assert(trn.getKind() == TrustNodeKind::PROP_EXP); Node proven = trn.getProven(); Assert(proven.getKind() == kind::IMPLIES); Node tConc = proven[1]; Trace("te-proof-exp") << "- Process " << trn << std::endl; if (exp.find(tConc) != exp.end()) { // already added to proof Trace("te-proof-exp") << "...already added" << std::endl; continue; } Node symTConc = CDProof::getSymmFact(tConc); if (!symTConc.isNull()) { if (exp.find(symTConc) != exp.end()) { // symmetric direction Trace("te-proof-exp") << "...already added (SYMM)" << std::endl; continue; } } // remember that we've explained this formula, to avoid cycles in lcp exp.insert(tConc); TheoryId ttid = it->first; Node tExp = proven[0]; if (ttid == THEORY_LAST) { if (tConc == tExp) { // dummy trust node, do AND expansion Assert(tConc.getKind() == kind::AND); // tConc[0] ... tConc[n] // ---------------------- AND_INTRO // tConc std::vector pfChildren; pfChildren.insert(pfChildren.end(), tConc.begin(), tConc.end()); lcp->addStep(tConc, PfRule::AND_INTRO, pfChildren, {}); Trace("te-proof-exp") << "...via AND_INTRO" << std::endl; continue; } // otherwise should hold by rewriting Assert(Rewriter::rewrite(tConc) == Rewriter::rewrite(tExp)); // tExp // ---- MACRO_SR_PRED_TRANSFORM // tConc lcp->addStep(tConc, PfRule::MACRO_SR_PRED_TRANSFORM, {tExp}, {tConc}); Trace("te-proof-exp") << "...via MACRO_SR_PRED_TRANSFORM" << std::endl; continue; } if (tExp == tConc) { // trivial Trace("te-proof-exp") << "...trivial" << std::endl; continue; } // ------------- Via theory // tExp tExp => tConc // ---------------------------------MODUS_PONENS // tConc if (trn.getGenerator() != nullptr) { Trace("te-proof-exp") << "...via theory generator" << std::endl; lcp->addLazyStep(proven, trn.getGenerator()); } else { Trace("te-proof-exp") << "...via trust THEORY_LEMMA" << std::endl; // otherwise, trusted theory lemma Node tidn = builtin::BuiltinProofRuleChecker::mkTheoryIdNode(it->first); lcp->addStep(proven, PfRule::THEORY_LEMMA, {}, {proven, tidn}); } std::vector pfChildren; pfChildren.push_back(trn.getNode()); pfChildren.push_back(proven); lcp->addStep(tConc, PfRule::MODUS_PONENS, pfChildren, {}); } // store in the proof generator TrustNode trn = d_tepg->mkTrustExplain(conclusion, expNode, lcp); // return the trust node return trn; } return TrustNode::mkTrustPropExp(conclusion, expNode, nullptr); } bool TheoryEngine::isProofEnabled() const { return d_pnm != nullptr; } void TheoryEngine::checkTheoryAssertionsWithModel(bool hardFailure) { for(TheoryId theoryId = THEORY_FIRST; theoryId < THEORY_LAST; ++theoryId) { Theory* theory = d_theoryTable[theoryId]; if(theory && d_logicInfo.isTheoryEnabled(theoryId)) { for(context::CDList::const_iterator it = theory->facts_begin(), it_end = theory->facts_end(); it != it_end; ++it) { Node assertion = (*it).d_assertion; if (!isRelevant(assertion)) { // not relevant, skip continue; } Node val = d_tc->getModel()->getValue(assertion); if (val != d_true) { std::stringstream ss; ss << " " << theoryId << " has an asserted fact that the model doesn't satisfy." << endl << "The fact: " << assertion << endl << "Model value: " << val << endl; if (hardFailure) { if (val == d_false) { // Always an error if it is false InternalError() << ss.str(); } else { // Otherwise just a warning. Notice this case may happen for // assertions with unevaluable operators, e.g. transcendental // functions. It also may happen for separation logic, where // check-model support is limited. Warning() << ss.str(); } } } } } } } std::pair TheoryEngine::entailmentCheck(options::TheoryOfMode mode, TNode lit) { TNode atom = (lit.getKind() == kind::NOT) ? lit[0] : lit; if( atom.getKind()==kind::AND || atom.getKind()==kind::OR || atom.getKind()==kind::IMPLIES ){ //Boolean connective, recurse std::vector< Node > children; bool pol = (lit.getKind()!=kind::NOT); bool is_conjunction = pol==(lit.getKind()==kind::AND); for( unsigned i=0; i chres = entailmentCheck(mode, ch); if( chres.first ){ if( !is_conjunction ){ return chres; }else{ children.push_back( chres.second ); } }else if( !chres.first && is_conjunction ){ return std::pair(false, Node::null()); } } if( is_conjunction ){ return std::pair(true, NodeManager::currentNM()->mkNode(kind::AND, children)); }else{ return std::pair(false, Node::null()); } }else if( atom.getKind()==kind::ITE || ( atom.getKind()==kind::EQUAL && atom[0].getType().isBoolean() ) ){ bool pol = (lit.getKind()!=kind::NOT); for( unsigned r=0; r<2; r++ ){ Node ch = atom[0]; if( r==1 ){ ch = ch.negate(); } std::pair chres = entailmentCheck(mode, ch); if( chres.first ){ Node ch2 = atom[ atom.getKind()==kind::ITE ? r+1 : 1 ]; if( pol==( atom.getKind()==kind::ITE ? true : r==1 ) ){ ch2 = ch2.negate(); } std::pair chres2 = entailmentCheck(mode, ch2); if( chres2.first ){ return std::pair(true, NodeManager::currentNM()->mkNode(kind::AND, chres.second, chres2.second)); }else{ break; } } } return std::pair(false, Node::null()); }else{ //it is a theory atom theory::TheoryId tid = theory::Theory::theoryOf(mode, atom); theory::Theory* th = theoryOf(tid); Assert(th != NULL); Trace("theory-engine-entc") << "Entailment check : " << lit << std::endl; std::pair chres = th->entailmentCheck(lit); return chres; } } bool TheoryEngine::isFiniteType(TypeNode tn) const { return isCardinalityClassFinite(tn.getCardinalityClass(), options::finiteModelFind()); } void TheoryEngine::spendResource(Resource r) { d_env.getResourceManager()->spendResource(r); } void TheoryEngine::initializeProofChecker(ProofChecker* pc) { for (theory::TheoryId id = theory::THEORY_FIRST; id < theory::THEORY_LAST; ++id) { ProofRuleChecker* prc = d_theoryTable[id]->getProofChecker(); if (prc) { prc->registerTo(pc); } } } theory::Rewriter* TheoryEngine::getRewriter() { return d_env.getRewriter(); } } // namespace cvc5