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diff --git a/src/theory/inference_manager_buffered.h b/src/theory/inference_manager_buffered.h new file mode 100644 index 000000000..bb46ef566 --- /dev/null +++ b/src/theory/inference_manager_buffered.h @@ -0,0 +1,161 @@ +/********************* */ +/*! \file inference_manager_buffered.h + ** \verbatim + ** Top contributors (to current version): + ** Andrew Reynolds + ** This file is part of the CVC4 project. + ** Copyright (c) 2009-2020 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.\endverbatim + ** + ** \brief A buffered inference manager + **/ + +#include "cvc4_private.h" + +#ifndef CVC4__THEORY__INFERENCE_MANAGER_BUFFERED_H +#define CVC4__THEORY__INFERENCE_MANAGER_BUFFERED_H + +#include "context/cdhashmap.h" +#include "expr/node.h" +#include "theory/theory_inference_manager.h" + +namespace CVC4 { +namespace theory { + +/** + * A lemma base class. This class is an abstract data structure for storing + * pending lemmas in the inference manager below. + */ +class Lemma +{ + public: + Lemma(Node n, LemmaProperty p, ProofGenerator* pg) + : d_node(n), d_property(p), d_pg(pg) + { + } + virtual ~Lemma() {} + /** + * Called just before this lemma is sent on the output channel. The purpose + * of this callback is to do any specific process of the lemma, e.g. take + * debug statistics, cache, etc. + * + * @return true if the lemma should be sent on the output channel. + */ + virtual bool notifySend() { return true; } + /** The lemma to send */ + Node d_node; + /** The lemma property (see OutputChannel::lemma) */ + LemmaProperty d_property; + /** + * The proof generator for this lemma, which if non-null, is wrapped in a + * TrustNode to be set on the output channel via trustedLemma at the time + * the lemma is sent. This proof generator must be able to provide a proof + * for d_node in the remainder of the user context. + */ + ProofGenerator* d_pg; +}; + +/** + * The buffered inference manager. This class implements standard methods + * for buffering facts, lemmas and phase requirements. + */ +class InferenceManagerBuffered : public TheoryInferenceManager +{ + public: + InferenceManagerBuffered(Theory& t, + TheoryState& state, + ProofNodeManager* pnm); + ~InferenceManagerBuffered() {} + /** + * Have we processed an inference during this call to check? In particular, + * this returns true if we have a pending fact or lemma, or have encountered + * a conflict. + */ + bool hasProcessed() const; + /** + * Do we have a pending fact to add as an internal fact to the equality + * engine? + */ + bool hasPendingFact() const; + /** Do we have a pending lemma to send on the output channel? */ + bool hasPendingLemma() const; + /** + * Add pending lemma lem with property p, with proof generator pg. If + * non-null, pg must be able to provide a proof for lem for the remainder + * of the user context. Pending lemmas are sent to the output channel using + * doPendingLemmas. + */ + void addPendingLemma(Node lem, + LemmaProperty p = LemmaProperty::NONE, + ProofGenerator* pg = nullptr); + /** + * Add pending lemma, where lemma can be a (derived) class of the + * above one. Pending lemmas are sent to the output channel using + * doPendingLemmas. + */ + void addPendingLemma(std::shared_ptr<Lemma> lemma); + /** + * Add pending fact, which adds a fact on the pending fact queue. It must + * be the case that: + * (1) exp => fact is valid, + * (2) exp is a literal (or conjunction of literals) that holds in the + * equality engine of the theory. + * + * Pending facts are sent to the equality engine of this class using + * doPendingFacts. + */ + void addPendingFact(Node fact, Node exp); + /** Add pending phase requirement + * + * This method is called to indicate this class should send a phase + * requirement request to the output channel for literal lit to be + * decided with polarity pol. The literal lit should be a SAT literal + * by the time that doPendingPhaseRequirements is called. Typically, + * lit is a literal that is a subformula of a pending lemma that is processed + * prior to sending the phase requirement. + */ + void addPendingPhaseRequirement(Node lit, bool pol); + /** Do pending facts + * + * This method asserts pending facts (d_pendingFact) with explanations + * to the equality engine of the theory via calls + * to assertInternalFact. + * + * It terminates early if a conflict is encountered, for instance, by + * equality reasoning within the equality engine. + * + * Regardless of whether a conflict is encountered, the vector d_pendingFact + * is cleared after this call. + */ + void doPendingFacts(); + /** Do pending lemmas + * + * This method send all pending lemmas (d_pendingLem) on the output + * channel of the theory. + * + * Unlike doPendingFacts, this function will not terminate early if a conflict + * has already been encountered by the theory. The vector d_pendingLem is + * cleared after this call. + */ + void doPendingLemmas(); + /** + * Do pending phase requirements. Calls the output channel for all pending + * phase requirements and clears d_pendingReqPhase. + */ + void doPendingPhaseRequirements(); + + protected: + /** A set of pending lemmas */ + std::vector<std::shared_ptr<Lemma>> d_pendingLem; + /** A set of pending facts, paired with their explanations */ + std::vector<std::pair<Node, Node>> d_pendingFact; + /** A map from literals to their pending phase requirement */ + std::map<Node, bool> d_pendingReqPhase; +}; + +} // namespace theory +} // namespace CVC4 + +#endif |