1 /********************* */
4 ** Top contributors (to current version):
5 ** Andrew Reynolds, Morgan Deters, Dejan Jovanovic
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
12 ** \brief Base of the theory interface.
14 ** Base of the theory interface.
17 #include "cvc4_private.h"
19 #ifndef CVC4__THEORY__THEORY_H
20 #define CVC4__THEORY__THEORY_H
26 #include <unordered_set>
28 #include "context/cdhashset.h"
29 #include "context/cdlist.h"
30 #include "context/cdo.h"
31 #include "context/context.h"
32 #include "expr/node.h"
33 #include "options/options.h"
34 #include "options/theory_options.h"
35 #include "smt/logic_request.h"
36 #include "theory/assertion.h"
37 #include "theory/care_graph.h"
38 #include "theory/decision_manager.h"
39 #include "theory/ee_setup_info.h"
40 #include "theory/logic_info.h"
41 #include "theory/output_channel.h"
42 #include "theory/theory_id.h"
43 #include "theory/theory_inference_manager.h"
44 #include "theory/theory_rewriter.h"
45 #include "theory/theory_state.h"
46 #include "theory/trust_node.h"
47 #include "theory/trust_substitutions.h"
48 #include "theory/valuation.h"
49 #include "util/statistics_registry.h"
54 class ProofNodeManager
;
58 class QuantifiersEngine
;
60 class SubstitutionMap
;
64 class CandidateGenerator
;
65 }/* CVC4::theory::rrinst namespace */
69 }/* CVC4::theory::eq namespace */
72 * Base class for T-solvers. Abstract DPLL(T).
74 * This is essentially an interface class. The TheoryEngine has
75 * pointers to Theory. Note that only one specific Theory type (e.g.,
76 * TheoryUF) can exist per NodeManager, because of how the
77 * RegisteredAttr works. (If you need multiple instances of the same
78 * theory, you'll have to write a multiplexed theory that dispatches
81 * NOTE: A Theory has a special way of being initialized. The owner of a Theory
84 * (A) Using Theory as a standalone object, not associated with a TheoryEngine.
85 * In this case, simply call the public initialization method
86 * (Theory::finishInitStandalone).
88 * (B) TheoryEngine, which determines how the Theory acts in accordance with
89 * its theory combination policy. We require the following steps in order:
90 * (B.1) Get information about whether the theory wishes to use an equality
91 * eninge, and more specifically which equality engine notifications the Theory
92 * would like to be notified of (Theory::needsEqualityEngine).
93 * (B.2) Set the equality engine of the theory (Theory::setEqualityEngine),
94 * which we refer to as the "official equality engine" of this Theory. The
95 * equality engine passed to the theory must respect the contract(s) specified
96 * by the equality engine setup information (EeSetupInfo) returned in the
98 * (B.3) Set the other required utilities including setQuantifiersEngine and
100 * (B.4) Call the private initialization method (Theory::finishInit).
102 * Initialization of the second form happens during TheoryEngine::finishInit,
103 * after the quantifiers engine and model objects have been set up.
106 friend class ::CVC4::TheoryEngine
;
109 // Disallow default construction, copy, assignment.
111 Theory(const Theory
&) = delete;
112 Theory
& operator=(const Theory
&) = delete;
114 /** An integer identifying the type of the theory. */
117 /** The SAT search context for the Theory. */
118 context::Context
* d_satContext
;
120 /** The user level assertion context for the Theory. */
121 context::UserContext
* d_userContext
;
123 /** Information about the logic we're operating within. */
124 const LogicInfo
& d_logicInfo
;
127 * The assertFact() queue.
129 * These can not be TNodes as some atoms (such as equalities) are sent
130 * across theories without being stored in a global map.
132 context::CDList
<Assertion
> d_facts
;
134 /** Index into the head of the facts list */
135 context::CDO
<unsigned> d_factsHead
;
137 /** Indices for splitting on the shared terms. */
138 context::CDO
<unsigned> d_sharedTermsIndex
;
140 /** The care graph the theory will use during combination. */
141 CareGraph
* d_careGraph
;
144 * Pointer to the quantifiers engine (or NULL, if quantifiers are not
145 * supported or not enabled). Not owned by the theory.
147 QuantifiersEngine
* d_quantEngine
;
149 /** Pointer to the decision manager. */
150 DecisionManager
* d_decManager
;
153 /** Name of this theory instance. Along with the TheoryId this should provide
154 * an unique string identifier for each instance of a Theory class. We need
155 * this to ensure unique statistics names over multiple theory instances. */
156 std::string d_instanceName
;
158 // === STATISTICS ===
159 /** time spent in check calls */
160 TimerStat d_checkTime
;
161 /** time spent in theory combination */
162 TimerStat d_computeCareGraphTime
;
165 * The only method to add suff to the care graph.
167 void addCarePair(TNode t1
, TNode t2
);
170 * The function should compute the care graph over the shared terms.
171 * The default function returns all the pairs among the shared variables.
173 virtual void computeCareGraph();
176 * A list of shared terms that the theory has.
178 context::CDList
<TNode
> d_sharedTerms
;
181 * Construct a Theory.
183 * The pair <id, instance> is assumed to uniquely identify this Theory
184 * w.r.t. the SmtEngine.
187 context::Context
* satContext
,
188 context::UserContext
* userContext
,
191 const LogicInfo
& logicInfo
,
192 ProofNodeManager
* pnm
,
193 std::string instance
= ""); // taking : No default.
196 * This is called at shutdown time by the TheoryEngine, just before
197 * destruction. It is important because there are destruction
198 * ordering issues between PropEngine and Theory (based on what
199 * hard-links to Nodes are outstanding). As the fact queue might be
200 * nonempty, we ensure here that it's clear. If you overload this,
201 * you must make an explicit call here to this->Theory::shutdown()
204 virtual void shutdown() { }
207 * The output channel for the Theory.
209 OutputChannel
* d_out
;
212 * The valuation proxy for the Theory to communicate back with the
213 * theory engine (and other theories).
215 Valuation d_valuation
;
217 * Pointer to the official equality engine of this theory, which is owned by
218 * the equality engine manager of TheoryEngine.
220 eq::EqualityEngine
* d_equalityEngine
;
222 * The official equality engine, if we allocated it.
224 std::unique_ptr
<eq::EqualityEngine
> d_allocEqualityEngine
;
226 * The theory state, which contains contexts, valuation, and equality engine.
227 * Notice the theory is responsible for memory management of this class.
229 TheoryState
* d_theoryState
;
231 * The theory inference manager. This is a wrapper around the equality
232 * engine and the output channel. It ensures that the output channel and
233 * the equality engine are used properly.
235 TheoryInferenceManager
* d_inferManager
;
237 /** Pointer to proof node manager */
238 ProofNodeManager
* d_pnm
;
241 * Returns the next assertion in the assertFact() queue.
243 * @return the next assertion in the assertFact() queue
245 inline Assertion
get();
247 const LogicInfo
& getLogicInfo() const {
252 * Set separation logic heap. This is called when the location and data
253 * types for separation logic are determined. This should be called at
254 * most once, before solving.
256 * This currently should be overridden by the separation logic theory only.
258 virtual void declareSepHeap(TypeNode locT
, TypeNode dataT
) {}
261 * The theory that owns the uninterpreted sort.
263 static TheoryId s_uninterpretedSortOwner
;
265 void printFacts(std::ostream
& os
) const;
266 void debugPrintFacts() const;
268 /** is legal elimination
270 * Returns true if x -> val is a legal elimination of variable x. This is
271 * useful for ppAssert, when x = val is an entailed equality. This function
272 * determines whether indeed x can be eliminated from the problem via the
273 * substituion x -> val.
275 * The following criteria imply that x -> val is *not* a legal elimination:
276 * (1) If x is contained in val,
277 * (2) If the type of val is not a subtype of the type of x,
278 * (3) If val contains an operator that cannot be evaluated, and produceModels
279 * is true. For example, x -> sqrt(2) is not a legal elimination if we
280 * are producing models. This is because we care about the value of x, and
281 * its value must be computed (approximated) by the non-linear solver.
283 bool isLegalElimination(TNode x
, TNode val
);
284 //--------------------------------- private initialization
286 * Called to set the official equality engine. This should be done by
289 void setEqualityEngine(eq::EqualityEngine
* ee
);
290 /** Called to set the quantifiers engine. */
291 void setQuantifiersEngine(QuantifiersEngine
* qe
);
292 /** Called to set the decision manager. */
293 void setDecisionManager(DecisionManager
* dm
);
295 * Finish theory initialization. At this point, options and the logic
296 * setting are final, the master equality engine and quantifiers
297 * engine (if any) are initialized, and the official equality engine of this
298 * theory has been assigned. This base class implementation
299 * does nothing. This should be called by TheoryEngine only.
301 virtual void finishInit() {}
302 //--------------------------------- end private initialization
305 * This method is called to notify a theory that the node n should
306 * be considered a "shared term" by this theory. This does anything
307 * theory-specific concerning the fact that n is now marked as a shared
308 * term, which is done in addition to explicitly storing n as a shared
309 * term and adding it as a trigger term in the equality engine of this
310 * class (see addSharedTerm).
312 virtual void notifySharedTerm(TNode n
);
315 //--------------------------------- initialization
317 * @return The theory rewriter associated with this theory.
319 virtual TheoryRewriter
* getTheoryRewriter() = 0;
321 * Returns true if this theory needs an equality engine for checking
324 * If this method returns true, then the equality engine manager will
325 * initialize its equality engine field via setEqualityEngine above during
326 * TheoryEngine::finishInit, prior to calling finishInit for this theory.
328 * Additionally, if this method returns true, then this method is required to
329 * update the argument esi with instructions for initializing and setting up
330 * notifications from its equality engine, which is commonly done with
331 * a notifications class (eq::EqualityEngineNotify).
333 virtual bool needsEqualityEngine(EeSetupInfo
& esi
);
335 * Finish theory initialization, standalone version. This is used to
336 * initialize this class if it is not associated with a theory engine.
337 * This allocates the official equality engine of this Theory and then
338 * calls the finishInit method above.
340 void finishInitStandalone();
341 //--------------------------------- end initialization
344 * Return the ID of the theory responsible for the given type.
346 static inline TheoryId
theoryOf(TypeNode typeNode
) {
347 Trace("theory::internal") << "theoryOf(" << typeNode
<< ")" << std::endl
;
349 if (typeNode
.getKind() == kind::TYPE_CONSTANT
) {
350 id
= typeConstantToTheoryId(typeNode
.getConst
<TypeConstant
>());
352 id
= kindToTheoryId(typeNode
.getKind());
354 if (id
== THEORY_BUILTIN
) {
355 Trace("theory::internal") << "theoryOf(" << typeNode
<< ") == " << s_uninterpretedSortOwner
<< std::endl
;
356 return s_uninterpretedSortOwner
;
362 * Returns the ID of the theory responsible for the given node.
364 static TheoryId
theoryOf(options::TheoryOfMode mode
, TNode node
);
367 * Returns the ID of the theory responsible for the given node.
369 static inline TheoryId
theoryOf(TNode node
) {
370 return theoryOf(options::theoryOfMode(), node
);
374 * Set the owner of the uninterpreted sort.
376 static void setUninterpretedSortOwner(TheoryId theory
) {
377 s_uninterpretedSortOwner
= theory
;
381 * Get the owner of the uninterpreted sort.
383 static TheoryId
getUninterpretedSortOwner() {
384 return s_uninterpretedSortOwner
;
388 * Checks if the node is a leaf node of this theory
390 inline bool isLeaf(TNode node
) const {
391 return node
.getNumChildren() == 0 || theoryOf(node
) != d_id
;
395 * Checks if the node is a leaf node of a theory.
397 inline static bool isLeafOf(TNode node
, TheoryId theoryId
) {
398 return node
.getNumChildren() == 0 || theoryOf(node
) != theoryId
;
401 /** Returns true if the assertFact queue is empty*/
402 bool done() const { return d_factsHead
== d_facts
.size(); }
404 * Destructs a Theory.
409 * Subclasses of Theory may add additional efforts. DO NOT CHECK
410 * equality with one of these values (e.g. if STANDARD xxx) but
411 * rather use range checks (or use the helper functions below).
412 * Normally we call QUICK_CHECK or STANDARD; at the leaves we call
418 * Standard effort where theory need not do anything
420 EFFORT_STANDARD
= 50,
422 * Full effort requires the theory make sure its assertions are satisfiable
427 * Last call effort, called after theory combination has completed with
428 * no lemmas and a model is available.
430 EFFORT_LAST_CALL
= 200
433 static inline bool standardEffortOrMore(Effort e
) CVC4_CONST_FUNCTION
434 { return e
>= EFFORT_STANDARD
; }
435 static inline bool standardEffortOnly(Effort e
) CVC4_CONST_FUNCTION
436 { return e
>= EFFORT_STANDARD
&& e
< EFFORT_FULL
; }
437 static inline bool fullEffort(Effort e
) CVC4_CONST_FUNCTION
438 { return e
== EFFORT_FULL
; }
441 * Get the id for this Theory.
443 TheoryId
getId() const {
448 * Get the SAT context associated to this Theory.
450 context::Context
* getSatContext() const {
455 * Get the context associated to this Theory.
457 context::UserContext
* getUserContext() const {
458 return d_userContext
;
462 * Set the output channel associated to this theory.
464 void setOutputChannel(OutputChannel
& out
) {
469 * Get the output channel associated to this theory.
471 OutputChannel
& getOutputChannel() {
476 * Get the valuation associated to this theory.
478 Valuation
& getValuation() {
482 /** Get the equality engine being used by this theory. */
483 eq::EqualityEngine
* getEqualityEngine();
486 * Get the quantifiers engine associated to this theory.
488 QuantifiersEngine
* getQuantifiersEngine() {
489 return d_quantEngine
;
492 /** Get the decision manager associated to this theory. */
493 DecisionManager
* getDecisionManager() { return d_decManager
; }
496 * @return The theory state associated with this theory.
498 TheoryState
* getTheoryState() { return d_theoryState
; }
501 * @return The theory inference manager associated with this theory.
503 TheoryInferenceManager
* getInferenceManager() { return d_inferManager
; }
506 * Expand definitions in the term node. This returns a term that is
507 * equivalent to node. It wraps this term in a TrustNode of kind
508 * TrustNodeKind::REWRITE. If node is unchanged by this method, the
509 * null TrustNode may be returned. This is an optimization to avoid
510 * constructing the trivial equality (= node node) internally within
513 * The purpose of this method is typically to eliminate the operators in node
514 * that are syntax sugar that cannot otherwise be eliminated during rewriting.
515 * For example, division relies on the introduction of an uninterpreted
516 * function for the divide-by-zero case, which we do not introduce with
517 * the rewriter, since this function may be cached in a non-global fashion.
519 * Some theories have kinds that are effectively definitions and should be
520 * expanded before they are handled. Definitions allow a much wider range of
521 * actions than the normal forms given by the rewriter. However no
522 * assumptions can be made about subterms having been expanded or rewritten.
523 * Where possible rewrite rules should be used, definitions should only be
524 * used when rewrites are not possible, for example in handling
525 * under-specified operations using partially defined functions.
527 * Some theories like sets use expandDefinition as a "context
528 * independent preRegisterTerm". This is required for cases where
529 * a theory wants to be notified about a term before preprocessing
530 * and simplification but doesn't necessarily want to rewrite it.
532 virtual TrustNode
expandDefinition(Node node
)
534 // by default, do nothing
535 return TrustNode::null();
539 * Pre-register a term. Done one time for a Node per SAT context level.
541 virtual void preRegisterTerm(TNode
);
544 * Assert a fact in the current context.
546 void assertFact(TNode assertion
, bool isPreregistered
) {
547 Trace("theory") << "Theory<" << getId() << ">::assertFact["
548 << d_satContext
->getLevel() << "](" << assertion
<< ", "
549 << (isPreregistered
? "true" : "false") << ")" << std::endl
;
550 d_facts
.push_back(Assertion(assertion
, isPreregistered
));
553 /** Add shared term to the theory. */
554 void addSharedTerm(TNode node
);
557 * Return the current theory care graph. Theories should overload
558 * computeCareGraph to do the actual computation, and use addCarePair to add
559 * pairs to the care graph.
561 void getCareGraph(CareGraph
* careGraph
);
564 * Return the status of two terms in the current context. Should be
565 * implemented in sub-theories to enable more efficient theory-combination.
567 virtual EqualityStatus
getEqualityStatus(TNode a
, TNode b
);
570 * Return the model value of the give shared term (or null if not available).
572 * TODO (project #39): this method is likely to become deprecated.
574 virtual Node
getModelValue(TNode var
) { return Node::null(); }
576 /** T-propagate new literal assignments in the current context. */
577 virtual void propagate(Effort level
= EFFORT_FULL
) {}
580 * Return an explanation for the literal represented by parameter n
581 * (which was previously propagated by this theory).
583 virtual TrustNode
explain(TNode n
)
585 Unimplemented() << "Theory " << identify()
586 << " propagated a node but doesn't implement the "
587 "Theory::explain() interface!";
588 return TrustNode::null();
591 //--------------------------------- check
593 * Does this theory wish to be called to check at last call effort? This is
594 * the case for any theory that wishes to run when a model is available.
596 virtual bool needsCheckLastEffort() { return false; }
598 * Check the current assignment's consistency.
600 * An implementation of check() is required to either:
601 * - return a conflict on the output channel,
603 * - throw an exception
604 * - or call get() until done() is true.
606 * The standard method for check consists of a loop that processes the entire
607 * fact queue when preCheck returns false. It makes four theory-specific
608 * callbacks, (preCheck, postCheck, preNotifyFact, notifyFact) as described
609 * below. It asserts each fact to the official equality engine when
610 * preNotifyFact returns false.
612 * Theories that use this check method must use an official theory
613 * state object (d_theoryState).
615 void check(Effort level
= EFFORT_FULL
);
617 * Pre-check, called before the fact queue of the theory is processed.
618 * If this method returns false, then the theory will process its fact
619 * queue. If this method returns true, then the theory has indicated
620 * its check method should finish immediately.
622 virtual bool preCheck(Effort level
= EFFORT_FULL
);
624 * Post-check, called after the fact queue of the theory is processed.
626 virtual void postCheck(Effort level
= EFFORT_FULL
);
628 * Pre-notify fact, return true if the theory processed it. If this
629 * method returns false, then the atom will be added to the equality engine
630 * of the theory and notifyFact will be called with isInternal=false.
632 * Theories that implement check but do not use official equality
633 * engines should always return true for this method.
635 * @param atom The atom
636 * @param polarity Its polarity
637 * @param fact The original literal that was asserted
638 * @param isPrereg Whether the assertion is preregistered
639 * @param isInternal Whether the origin of the fact was internal. If this
640 * is false, the fact was asserted via the fact queue of the theory.
641 * @return true if the theory completely processed this fact, i.e. it does
642 * not need to assert the fact to its equality engine.
644 virtual bool preNotifyFact(
645 TNode atom
, bool pol
, TNode fact
, bool isPrereg
, bool isInternal
);
647 * Notify fact, called immediately after the fact was pushed into the
650 * @param atom The atom
651 * @param polarity Its polarity
652 * @param fact The original literal that was asserted.
653 * @param isInternal Whether the origin of the fact was internal. If this
654 * is false, the fact was asserted via the fact queue of the theory.
656 virtual void notifyFact(TNode atom
, bool pol
, TNode fact
, bool isInternal
);
657 //--------------------------------- end check
659 //--------------------------------- collect model info
661 * Get all relevant information in this theory regarding the current
662 * model. This should be called after a call to check( FULL_EFFORT )
663 * for all theories with no conflicts and no lemmas added.
665 * This method returns true if and only if the equality engine of m is
666 * consistent as a result of this call.
668 * The standard method for collectModelInfo computes the relevant terms,
669 * asserts the theory's equality engine to the model (if necessary) and
670 * then calls computeModelValues.
672 * TODO (project #39): this method should be non-virtual, once all theories
673 * conform to the new standard, delete, move to model manager distributed.
675 virtual bool collectModelInfo(TheoryModel
* m
, const std::set
<Node
>& termSet
);
677 * Compute terms that are not necessarily part of the assertions or
678 * shared terms that should be considered relevant, add them to termSet.
680 virtual void computeRelevantTerms(std::set
<Node
>& termSet
);
682 * Collect model values, after equality information is added to the model.
683 * The argument termSet is the set of relevant terms returned by
684 * computeRelevantTerms.
686 virtual bool collectModelValues(TheoryModel
* m
,
687 const std::set
<Node
>& termSet
);
688 /** if theories want to do something with model after building, do it here */
689 virtual void postProcessModel( TheoryModel
* m
){ }
690 //--------------------------------- end collect model info
692 //--------------------------------- preprocessing
694 * Statically learn from assertion "in," which has been asserted
695 * true at the top level. The theory should only add (via
696 * ::operator<< or ::append()) to the "learned" builder---it should
697 * *never* clear it. It is a conjunction to add to the formula at
698 * the top-level and may contain other theories' contributions.
700 virtual void ppStaticLearn(TNode in
, NodeBuilder
<>& learned
) { }
702 enum PPAssertStatus
{
703 /** Atom has been solved */
704 PP_ASSERT_STATUS_SOLVED
,
705 /** Atom has not been solved */
706 PP_ASSERT_STATUS_UNSOLVED
,
707 /** Atom is inconsistent */
708 PP_ASSERT_STATUS_CONFLICT
712 * Given a literal and its proof generator (encapsulated by trust node tin),
713 * add the solved substitutions to the map, if any. The method should return
714 * true if the literal can be safely removed from the input problem.
716 * Note that tin has trude node kind LEMMA. Its proof generator should be
717 * take into account when adding a substitution to outSubstitutions when
718 * proofs are enabled.
720 virtual PPAssertStatus
ppAssert(TrustNode tin
,
721 TrustSubstitutionMap
& outSubstitutions
);
724 * Given an atom of the theory coming from the input formula, this
725 * method can be overridden in a theory implementation to rewrite
726 * the atom into an equivalent form. This is only called just
727 * before an input atom to the engine. This method returns a TrustNode of
728 * kind TrustNodeKind::REWRITE, which carries information about the proof
729 * generator for the rewrite. Similarly to expandDefinition, this method may
730 * return the null TrustNode if atom is unchanged.
732 virtual TrustNode
ppRewrite(TNode atom
) { return TrustNode::null(); }
735 * Notify preprocessed assertions. Called on new assertions after
736 * preprocessing before they are asserted to theory engine.
738 virtual void ppNotifyAssertions(const std::vector
<Node
>& assertions
) {}
739 //--------------------------------- end preprocessing
742 * A Theory is called with presolve exactly one time per user
743 * check-sat. presolve() is called after preregistration,
744 * rewriting, and Boolean propagation, (other theories'
745 * propagation?), but the notified Theory has not yet had its
746 * check() or propagate() method called. A Theory may empty its
747 * assertFact() queue using get(). A Theory can raise conflicts,
748 * add lemmas, and propagate literals during presolve().
750 * NOTE: The presolve property must be added to the kinds file for
753 virtual void presolve() { }
756 * A Theory is called with postsolve exactly one time per user
757 * check-sat. postsolve() is called after the query has completed
758 * (regardless of whether sat, unsat, or unknown), and after any
759 * model-querying related to the query has been performed.
760 * After this call, the theory will not get another check() or
761 * propagate() call until presolve() is called again. A Theory
762 * cannot raise conflicts, add lemmas, or propagate literals during
765 virtual void postsolve() { }
768 * Notification sent to the theory wheneven the search restarts.
769 * Serves as a good time to do some clean-up work, and you can
770 * assume you're at DL 0 for the purposes of Contexts. This function
771 * should not use the output channel.
773 virtual void notifyRestart() { }
776 * Identify this theory (for debugging, dynamic configuration,
779 virtual std::string
identify() const = 0;
781 /** Set user attribute
782 * This function is called when an attribute is set by a user. In SMT-LIBv2 this is done
783 * via the syntax (! n :attr)
785 virtual void setUserAttribute(const std::string
& attr
, Node n
, std::vector
<Node
> node_values
, std::string str_value
) {
786 Unimplemented() << "Theory " << identify()
787 << " doesn't support Theory::setUserAttribute interface";
790 typedef context::CDList
<Assertion
>::const_iterator assertions_iterator
;
793 * Provides access to the facts queue, primarily intended for theory
794 * debugging purposes.
796 * @return the iterator to the beginning of the fact queue
798 assertions_iterator
facts_begin() const {
799 return d_facts
.begin();
803 * Provides access to the facts queue, primarily intended for theory
804 * debugging purposes.
806 * @return the iterator to the end of the fact queue
808 assertions_iterator
facts_end() const {
809 return d_facts
.end();
812 * Whether facts have been asserted to this theory.
814 * @return true iff facts have been asserted to this theory.
816 bool hasFacts() { return !d_facts
.empty(); }
818 /** Return total number of facts asserted to this theory */
819 size_t numAssertions() {
820 return d_facts
.size();
823 typedef context::CDList
<TNode
>::const_iterator shared_terms_iterator
;
826 * Provides access to the shared terms, primarily intended for theory
827 * debugging purposes.
829 * @return the iterator to the beginning of the shared terms list
831 shared_terms_iterator
shared_terms_begin() const {
832 return d_sharedTerms
.begin();
836 * Provides access to the facts queue, primarily intended for theory
837 * debugging purposes.
839 * @return the iterator to the end of the shared terms list
841 shared_terms_iterator
shared_terms_end() const {
842 return d_sharedTerms
.end();
847 * This is a utility function for constructing a copy of the currently shared terms
848 * in a queriable form. As this is
850 std::unordered_set
<TNode
, TNodeHashFunction
> currentlySharedTerms() const;
853 * This allows the theory to be queried for whether a literal, lit, is
854 * entailed by the theory. This returns a pair of a Boolean and a node E.
856 * If the Boolean is true, then E is a formula that entails lit and E is propositionally
857 * entailed by the assertions to the theory.
859 * If the Boolean is false, it is "unknown" if lit is entailed and E may be
862 * The literal lit is either an atom a or (not a), which must belong to the theory:
863 * There is some TheoryOfMode m s.t. Theory::theoryOf(m, a) == this->getId().
865 * There are NO assumptions that a or the subterms of a have been
866 * preprocessed in any form. This includes ppRewrite, rewriting,
867 * preregistering, registering, definition expansion or ITE removal!
869 * Theories are free to limit the amount of effort they use and so may
870 * always opt to return "unknown". Both "unknown" and "not entailed",
871 * may return for E a non-boolean Node (e.g. Node::null()). (There is no explicit output
872 * for the negation of lit is entailed.)
874 * If lit is theory valid, the return result may be the Boolean constant
877 * If lit is entailed by multiple assertions on the theory's getFact()
878 * queue, a_1, a_2, ... and a_k, this may return E=(and a_1 a_2 ... a_k) or
879 * another theory entailed explanation E=(and (and a_1 a_2) (and a3 a_4) ... a_k)
881 * If lit is entailed by a single assertion on the theory's getFact()
882 * queue, say a, this may return E=a.
884 * The theory may always return false!
886 * Theories may not touch their output stream during an entailment check.
888 * @param lit a literal belonging to the theory.
889 * @return a pair <b,E> s.t. if b is true, then a formula E such that
890 * E |= lit in the theory.
892 virtual std::pair
<bool, Node
> entailmentCheck(TNode lit
);
895 std::ostream
& operator<<(std::ostream
& os
, theory::Theory::Effort level
);
898 inline theory::Assertion
Theory::get() {
899 Assert(!done()) << "Theory::get() called with assertion queue empty!";
902 Assertion fact
= d_facts
[d_factsHead
];
903 d_factsHead
= d_factsHead
+ 1;
905 Trace("theory") << "Theory::get() => " << fact
<< " (" << d_facts
.size() - d_factsHead
<< " left)" << std::endl
;
910 inline std::ostream
& operator<<(std::ostream
& out
,
911 const CVC4::theory::Theory
& theory
) {
912 return out
<< theory
.identify();
915 inline std::ostream
& operator << (std::ostream
& out
, theory::Theory::PPAssertStatus status
) {
917 case theory::Theory::PP_ASSERT_STATUS_SOLVED
:
918 out
<< "SOLVE_STATUS_SOLVED"; break;
919 case theory::Theory::PP_ASSERT_STATUS_UNSOLVED
:
920 out
<< "SOLVE_STATUS_UNSOLVED"; break;
921 case theory::Theory::PP_ASSERT_STATUS_CONFLICT
:
922 out
<< "SOLVE_STATUS_CONFLICT"; break;
929 }/* CVC4::theory namespace */
930 }/* CVC4 namespace */
932 #endif /* CVC4__THEORY__THEORY_H */