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       1                 :            : /******************************************************************************
       2                 :            :  * This file is part of the cvc5 project.
       3                 :            :  *
       4                 :            :  * Copyright (c) 2009-2026 by the authors listed in the file AUTHORS
       5                 :            :  * in the top-level source directory and their institutional affiliations.
       6                 :            :  * All rights reserved.  See the file COPYING in the top-level source
       7                 :            :  * directory for licensing information.
       8                 :            :  * ****************************************************************************
       9                 :            :  *
      10                 :            :  * The theory engine output channel.
      11                 :            :  */
      12                 :            : 
      13                 :            : #include "cvc5_private.h"
      14                 :            : 
      15                 :            : #ifndef CVC5__THEORY__OUTPUT_CHANNEL_H
      16                 :            : #define CVC5__THEORY__OUTPUT_CHANNEL_H
      17                 :            : 
      18                 :            : #include "expr/node.h"
      19                 :            : #include "proof/trust_node.h"
      20                 :            : #include "theory/incomplete_id.h"
      21                 :            : #include "theory/inference_id.h"
      22                 :            : #include "theory/lemma_property.h"
      23                 :            : #include "theory/theory_id.h"
      24                 :            : #include "util/resource_manager.h"
      25                 :            : #include "util/statistics_stats.h"
      26                 :            : 
      27                 :            : namespace cvc5::internal {
      28                 :            : 
      29                 :            : class TheoryEngine;
      30                 :            : 
      31                 :            : namespace theory {
      32                 :            : 
      33                 :            : class Theory;
      34                 :            : 
      35                 :            : /**
      36                 :            :  * An output channel for Theory that passes messages back to a TheoryEngine
      37                 :            :  * for a given Theory.
      38                 :            :  *
      39                 :            :  * Notice that it has interfaces trustedConflict and trustedLemma which are
      40                 :            :  * used for ensuring that proof generators are associated with the lemmas
      41                 :            :  * and conflicts sent on this output channel.
      42                 :            :  */
      43                 :            : class OutputChannel
      44                 :            : {
      45                 :            :   friend class internal::TheoryEngine;
      46                 :            : 
      47                 :            :  public:
      48                 :            :   /** Default constructor */
      49                 :            :   OutputChannel();
      50                 :            :   /** Constructor for use by theory */
      51                 :            :   OutputChannel(StatisticsRegistry& sr,
      52                 :            :                 TheoryEngine* engine,
      53                 :            :                 theory::TheoryId theory);
      54                 :            :   /** Constructor for use by non-theory */
      55                 :            :   OutputChannel(StatisticsRegistry& sr,
      56                 :            :                 TheoryEngine* engine,
      57                 :            :                 const std::string& name,
      58                 :            :                 size_t id = 0);
      59                 :     802324 :   virtual ~OutputChannel() {}
      60                 :            : 
      61                 :            :   /**
      62                 :            :    * With safePoint(), the theory signals that it is at a safe point
      63                 :            :    * and can be interrupted.
      64                 :            :    *
      65                 :            :    * @throws Interrupted if the theory can be safely interrupted.
      66                 :            :    */
      67                 :            :   virtual void safePoint(Resource r);
      68                 :            :   /**
      69                 :            :    * Indicate a theory conflict has arisen.
      70                 :            :    *
      71                 :            :    * @param n - a conflict at the current decision level.  This should
      72                 :            :    * be an AND-kinded node of literals that are TRUE in the current
      73                 :            :    * assignment and are in conflict (i.e., at least one must be
      74                 :            :    * assigned false), or else a literal by itself (in the case of a
      75                 :            :    * unit conflict) which is assigned TRUE (and T-conflicting) in the
      76                 :            :    * current assignment.
      77                 :            :    */
      78                 :            :   virtual void conflict(TNode conflictNode, InferenceId id);
      79                 :            :   /**
      80                 :            :    * Propagate a theory literal.
      81                 :            :    *
      82                 :            :    * @param n - a theory consequence at the current decision level
      83                 :            :    * @return false if an immediate conflict was encountered
      84                 :            :    */
      85                 :            :   virtual bool propagate(TNode literal);
      86                 :            : 
      87                 :            :   /**
      88                 :            :    * Tell the core that a valid theory lemma at decision level 0 has
      89                 :            :    * been detected.  (This requests a split.)
      90                 :            :    *
      91                 :            :    * @param n - a theory lemma valid at decision level 0
      92                 :            :    * @param p The properties of the lemma
      93                 :            :    */
      94                 :            :   virtual void lemma(TNode lemma,
      95                 :            :                      InferenceId id,
      96                 :            :                      LemmaProperty p = LemmaProperty::NONE);
      97                 :            :   /**
      98                 :            :    * If a decision is made on n that is not requested from a theory, it must be
      99                 :            :    * in the phase specified. Note that this is enforced *globally*, i.e., it is
     100                 :            :    * completely context-INdependent.  If you ever preferPhase() on a literal,
     101                 :            :    * it is phase-locked forever and ever.  If it is to ever have the
     102                 :            :    * other phase as its assignment, it will be because it has been
     103                 :            :    * propagated that way (or it's a unit, at decision level 0).
     104                 :            :    *
     105                 :            :    * @param n - a theory atom with a SAT literal assigned; must have
     106                 :            :    * been pre-registered
     107                 :            :    * @param phase - the phase to decide on n
     108                 :            :    */
     109                 :            :   virtual void preferPhase(TNode n, bool phase);
     110                 :            :   /**
     111                 :            :    * Notification from a theory that it realizes it is model unsound at
     112                 :            :    * this SAT context level.  If SAT is later determined by the
     113                 :            :    * TheoryEngine, it should actually return an UNKNOWN result.
     114                 :            :    */
     115                 :            :   virtual void setModelUnsound(IncompleteId id);
     116                 :            :   /**
     117                 :            :    * Notification from a theory that it realizes it is refutation unsound at
     118                 :            :    * this user context level.  If UNSAT is later determined by the
     119                 :            :    * TheoryEngine, it should actually return an UNKNOWN result.
     120                 :            :    */
     121                 :            :   virtual void setRefutationUnsound(IncompleteId id);
     122                 :            :   /**
     123                 :            :    * "Spend" a "resource."  The meaning is specific to the context in
     124                 :            :    * which the theory is operating, and may even be ignored.  The
     125                 :            :    * intended meaning is that if the user has set a limit on the "units
     126                 :            :    * of resource" that can be expended in a search, and that limit is
     127                 :            :    * exceeded, then the search is terminated.  Note that the check for
     128                 :            :    * termination occurs in the main search loop, so while theories
     129                 :            :    * should call OutputChannel::spendResource() during particularly
     130                 :            :    * long-running operations, they cannot rely on resource() to break
     131                 :            :    * out of infinite or intractable computations.
     132                 :            :    */
     133                 :            :   virtual void spendResource(Resource r);
     134                 :            : 
     135                 :            :   /**
     136                 :            :    * Let pconf be the pair (Node conf, ProofGenerator * pfg). This method
     137                 :            :    * sends conf on the output channel of this class whose proof can be generated
     138                 :            :    * by the generator pfg. Apart from pfg, the interface for this method is
     139                 :            :    * the same as calling OutputChannel::lemma on conf.
     140                 :            :    */
     141                 :            :   virtual void trustedConflict(TrustNode pconf, InferenceId id);
     142                 :            :   /**
     143                 :            :    * Let plem be the pair (Node lem, ProofGenerator * pfg).
     144                 :            :    * Send lem on the output channel of this class whose proof can be generated
     145                 :            :    * by the generator pfg. Apart from pfg, the interface for this method is
     146                 :            :    * the same as calling OutputChannel::lemma on lem.
     147                 :            :    */
     148                 :            :   virtual void trustedLemma(TrustNode plem,
     149                 :            :                             InferenceId id,
     150                 :            :                             LemmaProperty p = LemmaProperty::NONE);
     151                 :            :   /**
     152                 :            :    * Mark used. Called when we wish to mark that the output channel is used,
     153                 :            :    * for example, if we wish to manually call check again, even if no lemmas
     154                 :            :    * are sent. Note that theory engine determines whether to recheck
     155                 :            :    * (TheoryEngine::needsCheck) if lemmas were sent or if the output channel
     156                 :            :    * is marked as used.
     157                 :            :    */
     158                 :            :   virtual void markUsed();
     159                 :            :   /**
     160                 :            :    * Get the theory identifier
     161                 :            :    */
     162                 :            :   TheoryId getId() const;
     163                 :            : 
     164                 :            :  protected:
     165                 :            :   /**
     166                 :            :    * Statistics for a particular theory.
     167                 :            :    */
     168                 :            :   class Statistics
     169                 :            :   {
     170                 :            :    public:
     171                 :            :     Statistics();
     172                 :            :     Statistics(StatisticsRegistry& sr, const std::string& statPrefix);
     173                 :            :     /** Number of calls to conflict, propagate, lemma, preferPhase */
     174                 :            :     IntStat conflicts, propagations, lemmas, preferPhase, trustedConflicts,
     175                 :            :         trustedLemmas;
     176                 :            :   };
     177                 :            :   /** The theory engine we're communicating with. */
     178                 :            :   TheoryEngine* d_engine;
     179                 :            :   /** The name of the owner of this channel. */
     180                 :            :   std::string d_name;
     181                 :            :   /** The statistics of the theory interractions. */
     182                 :            :   Statistics d_statistics;
     183                 :            :   /** The theory owning this channel. */
     184                 :            :   theory::TheoryId d_theory;
     185                 :            : };
     186                 :            : 
     187                 :            : }  // namespace theory
     188                 :            : }  // namespace cvc5::internal
     189                 :            : 
     190                 :            : #endif /* CVC5__THEORY__OUTPUT_CHANNEL_H */