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/****************************************************************************** |
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* Top contributors (to current version): |
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* Gereon Kremer |
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* |
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* This file is part of the cvc5 project. |
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* |
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* Copyright (c) 2009-2021 by the authors listed in the file AUTHORS |
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* in the top-level source directory and their institutional affiliations. |
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* All rights reserved. See the file COPYING in the top-level source |
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* directory for licensing information. |
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* **************************************************************************** |
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* |
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* Implements the proof generator for CAD. |
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*/ |
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#include "cvc5_private.h" |
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#ifndef CVC5__THEORY__ARITH__NL__CAD__PROOF_GENERATOR_H |
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#define CVC5__THEORY__ARITH__NL__CAD__PROOF_GENERATOR_H |
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#ifdef CVC5_POLY_IMP |
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#include <poly/polyxx.h> |
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#include <vector> |
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#include "expr/node.h" |
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#include "proof/lazy_tree_proof_generator.h" |
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#include "proof/proof_set.h" |
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#include "theory/arith/nl/cad/cdcac_utils.h" |
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namespace cvc5 { |
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class ProofGenerator; |
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namespace theory { |
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namespace arith { |
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namespace nl { |
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struct VariableMapper; |
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namespace cad { |
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/** |
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* This class manages the proof creation during a run of the CAD solver. |
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* |
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* Though it implements the ProofGenerator interface getProofFor(Node), it only |
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* gives a proof for a single node. |
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* |
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* It uses a LazyTreeProofGenerator internally to manage the tree-based proof |
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* construction. |
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*/ |
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class CADProofGenerator |
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{ |
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public: |
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friend std::ostream& operator<<(std::ostream& os, |
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const CADProofGenerator& proof); |
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CADProofGenerator(context::Context* ctx, ProofNodeManager* pnm); |
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/** Start a new proof in this proof generator */ |
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void startNewProof(); |
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/** Start a new recursive call */ |
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void startRecursive(); |
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/** Finish the current recursive call */ |
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void endRecursive(size_t intervalId); |
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/** Start a new scope, corresponding to a guess in CDCAC */ |
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void startScope(); |
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/** Finish a scope and add the (generalized) sample that was refuted */ |
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void endScope(const std::vector<Node>& args); |
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/** Return the current proof generator */ |
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ProofGenerator* getProofGenerator() const; |
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/** |
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* Calls LazyTreeProofGenerator::pruneChildren(f), but decorates the |
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* predicate such that f only accepts the index. |
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* @param f A Callable bool(std::size_t) |
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*/ |
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template <typename F> |
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void pruneChildren(F&& f) |
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{ |
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d_current->pruneChildren( |
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[&f](const detail::TreeProofNode& tpn) { return f(tpn.d_objectId); }); |
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} |
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/** |
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* Add a direct interval conflict as generated in getUnsatIntervals(). |
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* Its meaning is: |
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* over the partial assignment a, var is not in interval because p~sc~0 |
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* and the origin of this is constraint. |
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* |
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* @param var The variable for which the interval is excluded |
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* @param vm A variable mapper between cvc5 and libpoly variables |
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* @param p The polynomial of the constraint |
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* @param a The current partial assignment |
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* @param sc The sign condition of the constraint |
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* @param interval The concrete interval that is excluded |
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* @param constraint The assumption that yields p and sc |
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*/ |
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void addDirect(Node var, |
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VariableMapper& vm, |
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const poly::Polynomial& p, |
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const poly::Assignment& a, |
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poly::SignCondition& sc, |
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const poly::Interval& interval, |
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Node constraint, |
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size_t intervalId); |
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/** |
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* Constructs the (generalized) interval that is to be excluded from a |
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* CACInterval. It should be called after the recursive call to construct the |
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* generalized sample necessary for endScope(). |
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* |
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* @param var The variable for which the interval is excluded |
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* @param i The concrete interval that is excluded |
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* @param a The current partial assignment |
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* @param s The sample point that is refuted for var |
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* @param vm A variable mapper between cvc5 and libpoly variables |
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*/ |
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std::vector<Node> constructCell(Node var, |
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const CACInterval& i, |
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const poly::Assignment& a, |
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const poly::Value& s, |
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VariableMapper& vm); |
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private: |
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/** The proof node manager used for the proofs */ |
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ProofNodeManager* d_pnm; |
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/** The list of generated proofs */ |
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CDProofSet<LazyTreeProofGenerator> d_proofs; |
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/** The current proof */ |
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LazyTreeProofGenerator* d_current; |
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/** Constant false */ |
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Node d_false; |
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/** Constant zero */ |
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Node d_zero; |
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}; |
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/** |
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* Prints the underlying LazyTreeProofGenerator. Please check the documentation |
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* of std::ostream& operator<<(std::ostream&, const LazyTreeProofGenerator&) |
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*/ |
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std::ostream& operator<<(std::ostream& os, const CADProofGenerator& proof); |
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} // namespace cad |
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} // namespace nl |
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} // namespace arith |
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} // namespace theory |
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} // namespace cvc5 |
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#endif |
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#endif |