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/********************* */
/*! \file theory_preprocessor.h
** \verbatim
** Top contributors (to current version):
** Andrew Reynolds, Morgan Deters, Dejan Jovanovic
** 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 The theory preprocessor.
**/
#include "cvc4_private.h"
#ifndef CVC4__THEORY__THEORY_PREPROCESSOR_H
#define CVC4__THEORY__THEORY_PREPROCESSOR_H
#include <unordered_map>
#include "context/cdhashmap.h"
#include "context/context.h"
#include "expr/lazy_proof.h"
#include "expr/node.h"
#include "expr/tconv_seq_proof_generator.h"
#include "expr/term_conversion_proof_generator.h"
#include "smt/term_formula_removal.h"
#include "theory/trust_node.h"
namespace CVC4 {
class LogicInfo;
class TheoryEngine;
class RemoveTermFormulas;
namespace theory {
/**
* The preprocessor used in TheoryEngine.
*/
class TheoryPreprocessor
{
typedef context::CDHashMap<Node, Node, NodeHashFunction> NodeMap;
public:
/** Constructs a theory preprocessor */
TheoryPreprocessor(TheoryEngine& engine,
context::UserContext* userContext,
ProofNodeManager* pnm = nullptr);
/** Destroys a theory preprocessor */
~TheoryPreprocessor();
/**
* Preprocesses the given assertion node. It returns a TrustNode of kind
* TrustNodeKind::REWRITE indicating the preprocessed form of node. It stores
* additional lemmas in newLemmas, which are trust nodes of kind
* TrustNodeKind::LEMMA. These correspond to e.g. lemmas corresponding to ITE
* removal. For each lemma in newLemmas, we add the corresponding skolem that
* the lemma defines.
*
* @param node The assertion to preprocess,
* @param newLemmas The lemmas to add to the set of assertions,
* @param newSkolems The skolems that newLemmas correspond to,
* @return The (REWRITE) trust node corresponding to rewritten node via
* preprocessing.
*/
TrustNode preprocess(TNode node,
std::vector<TrustNode>& newLemmas,
std::vector<Node>& newSkolems);
/**
* Same as above, but transforms the proof of node into a proof of the
* preprocessed node and returns the LEMMA trust node.
*
* @param node The assertion to preprocess,
* @param newLemmas The lemmas to add to the set of assertions,
* @param newSkolems The skolems that newLemmas correspond to,
* @return The (LEMMA) trust node corresponding to the proof of the rewritten
* form of the proven field of node.
*/
TrustNode preprocessLemma(TrustNode node,
std::vector<TrustNode>& newLemmas,
std::vector<Node>& newSkolems);
/** Get the term formula removal utility */
RemoveTermFormulas& getRemoveTermFormulas();
private:
/**
* Runs theory specific preprocessing (Theory::ppRewrite) on the non-Boolean
* parts of the node.
*/
TrustNode theoryPreprocess(TNode node);
/**
* Internal helper for preprocess, which also optionally preprocesses the
* new lemmas generated until a fixed point is reached based on argument
* procLemmas.
*/
TrustNode preprocessInternal(TNode node,
std::vector<TrustNode>& newLemmas,
std::vector<Node>& newSkolems,
bool procLemmas);
/**
* Internal helper for preprocessLemma, which also optionally preprocesses the
* new lemmas generated until a fixed point is reached based on argument
* procLemmas.
*/
TrustNode preprocessLemmaInternal(TrustNode node,
std::vector<TrustNode>& newLemmas,
std::vector<Node>& newSkolems,
bool procLemmas);
/** Reference to owning theory engine */
TheoryEngine& d_engine;
/** Logic info of theory engine */
const LogicInfo& d_logicInfo;
/** Cache for theory-preprocessing of assertions */
NodeMap d_ppCache;
/** The term formula remover */
RemoveTermFormulas d_tfr;
/** The term context, which computes hash values for term contexts. */
InQuantTermContext d_iqtc;
/**
* A term conversion proof generator storing preprocessing and rewriting
* steps.
*/
std::unique_ptr<TConvProofGenerator> d_tpg;
/**
* A term conversion sequence generator, which applies theory preprocessing,
* term formula removal, and rewriting in sequence.
*/
std::unique_ptr<TConvSeqProofGenerator> d_tspg;
/**
* A term conversion proof generator storing rewriting steps, which is used
* for calls to preprocess when doTheoryPreprocess is false. We store
* (top-level) rewrite steps only. Notice this is intentionally separate
* from d_tpg, which interleaves both preprocessing and rewriting.
*/
std::unique_ptr<TConvProofGenerator> d_tpgRew;
/** A lazy proof, for additional lemmas. */
std::unique_ptr<LazyCDProof> d_lp;
/** Helper for theoryPreprocess */
Node ppTheoryRewrite(TNode term);
/**
* Rewrite with proof, which stores a REWRITE step in d_tpg if necessary
* and returns the rewritten form of term.
*/
Node rewriteWithProof(Node term);
/**
* Preprocess with proof, which calls the appropriate ppRewrite method,
* stores the corresponding rewrite step in d_tpg if necessary and returns
* the preprocessed and rewritten form of term. It should be the case that
* term is already in rewritten form.
*/
Node preprocessWithProof(Node term);
/** Proofs enabled */
bool isProofEnabled() const;
};
} // namespace theory
} // namespace CVC4
#endif /* CVC4__THEORY__THEORY_PREPROCESSOR_H */
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