src/theory/inference_manager_buffered.h

   1 /*********************                                                        */
   2 /*! \file inference_manager_buffered.h
   3  ** \verbatim
   4  ** Top contributors (to current version):
   5  **   Andrew Reynolds
   6  ** This file is part of the CVC4 project.
   7  ** Copyright (c) 2009-2020 by the authors listed in the file AUTHORS
   8  ** in the top-level source directory) and their institutional affiliations.
   9  ** All rights reserved.  See the file COPYING in the top-level source
  10  ** directory for licensing information.\endverbatim
  11  **
  12  ** \brief A buffered inference manager
  13  **/
  14
  15 #include "cvc4_private.h"
  16
  17 #ifndef CVC4__THEORY__INFERENCE_MANAGER_BUFFERED_H
  18 #define CVC4__THEORY__INFERENCE_MANAGER_BUFFERED_H
  19
  20 #include "context/cdhashmap.h"
  21 #include "expr/node.h"
  22 #include "theory/theory_inference.h"
  23 #include "theory/theory_inference_manager.h"
  24
  25 namespace CVC4 {
  26 namespace theory {
  27
  28 /**
  29  * The buffered inference manager.  This class implements standard methods
  30  * for buffering facts, lemmas and phase requirements.
  31  */
  32 class InferenceManagerBuffered : public TheoryInferenceManager
  33 {
  34  public:
  35   InferenceManagerBuffered(Theory& t,
  36                            TheoryState& state,
  37                            ProofNodeManager* pnm);
  38   virtual ~InferenceManagerBuffered() {}
  39   /**
  40    * Have we processed an inference during this call to check? In particular,
  41    * this returns true if we have a pending fact or lemma, or have encountered
  42    * a conflict.
  43    */
  44   bool hasProcessed() const;
  45   /**
  46    * Do we have a pending fact to add as an internal fact to the equality
  47    * engine?
  48    */
  49   bool hasPendingFact() const;
  50   /** Do we have a pending lemma to send on the output channel? */
  51   bool hasPendingLemma() const;
  52   /**
  53    * Add pending lemma lem with property p, with proof generator pg. If
  54    * non-null, pg must be able to provide a proof for lem for the remainder
  55    * of the user context. Pending lemmas are sent to the output channel using
  56    * doPendingLemmas.
  57    */
  58   void addPendingLemma(Node lem,
  59                        LemmaProperty p = LemmaProperty::NONE,
  60                        ProofGenerator* pg = nullptr);
  61   /**
  62    * Add pending lemma, where lemma can be a (derived) class of the
  63    * theory inference base class.
  64    */
  65   void addPendingLemma(std::unique_ptr<TheoryInference> lemma);
  66   /**
  67    * Add pending fact, which adds a fact on the pending fact queue. It must
  68    * be the case that:
  69    * (1) exp => conc is valid,
  70    * (2) exp is a literal (or conjunction of literals) that holds in the
  71    * equality engine of the theory.
  72    *
  73    * Pending facts are sent to the equality engine of this class using
  74    * doPendingFacts.
  75    */
  76   void addPendingFact(Node conc, Node exp, ProofGenerator* pg = nullptr);
  77   /**
  78    * Add pending fact, where fact can be a (derived) class of the
  79    * theory inference base class.
  80    */
  81   void addPendingFact(std::unique_ptr<TheoryInference> fact);
  82   /** Add pending phase requirement
  83    *
  84    * This method is called to indicate this class should send a phase
  85    * requirement request to the output channel for literal lit to be
  86    * decided with polarity pol. The literal lit should be a SAT literal
  87    * by the time that doPendingPhaseRequirements is called. Typically,
  88    * lit is a literal that is a subformula of a pending lemma that is processed
  89    * prior to sending the phase requirement.
  90    */
  91   void addPendingPhaseRequirement(Node lit, bool pol);
  92   /** Do pending facts
  93    *
  94    * This method asserts pending facts (d_pendingFact) with explanations
  95    * to the equality engine of the theory via calls
  96    * to assertInternalFact.
  97    *
  98    * It terminates early if a conflict is encountered, for instance, by
  99    * equality reasoning within the equality engine.
 100    *
 101    * Regardless of whether a conflict is encountered, the vector d_pendingFact
 102    * is cleared after this call.
 103    */
 104   void doPendingFacts();
 105   /** Do pending lemmas
 106    *
 107    * This method send all pending lemmas (d_pendingLem) on the output
 108    * channel of the theory.
 109    *
 110    * Unlike doPendingFacts, this function will not terminate early if a conflict
 111    * has already been encountered by the theory. The vector d_pendingLem is
 112    * cleared after this call.
 113    */
 114   void doPendingLemmas();
 115   /**
 116    * Do pending phase requirements. Calls the output channel for all pending
 117    * phase requirements and clears d_pendingReqPhase.
 118    */
 119   void doPendingPhaseRequirements();
 120   /** Clear pending facts, without processing */
 121   void clearPendingFacts();
 122   /** Clear pending lemmas, without processing */
 123   void clearPendingLemmas();
 124   /** Clear pending phase requirements, without processing */
 125   void clearPendingPhaseRequirements();
 126
 127   /** Returns the number of pending lemmas. */
 128   std::size_t numPendingLemmas() const;
 129   /** Returns the number of pending facts. */
 130   std::size_t numPendingFacts() const;
 131
 132  protected:
 133   /** A set of pending inferences to be processed as lemmas */
 134   std::vector<std::unique_ptr<TheoryInference>> d_pendingLem;
 135   /** A set of pending inferences to be processed as facts */
 136   std::vector<std::unique_ptr<TheoryInference>> d_pendingFact;
 137   /** A map from literals to their pending phase requirement */
 138   std::map<Node, bool> d_pendingReqPhase;
 139 };
 140
 141 }  // namespace theory
 142 }  // namespace CVC4
 143
 144 #endif