z3-z3-4.12.6.src.muz.spacer.spacer_proof_utils.h Maven / Gradle / Ivy
/*++
Copyright (c) 2017 Arie Gurfinkel
Module Name:
spacer_proof_utils.cpp
Abstract:
Utilities to traverse and manipulate proofs
Author:
Bernhard Gleiss
Arie Gurfinkel
Revision History:
--*/
#pragma once
#include "ast/ast.h"
namespace spacer {
bool is_arith_lemma(ast_manager& m, proof* pr);
bool is_farkas_lemma(ast_manager& m, proof* pr);
/// rewrites theory axioms into theory lemmas
class theory_axiom_reducer {
public:
theory_axiom_reducer(ast_manager& m) : m(m), m_pinned(m) {}
// reduce theory axioms and return transformed proof
proof_ref reduce(proof* pr);
private:
ast_manager &m;
// tracking all created expressions
expr_ref_vector m_pinned;
// maps each proof of a clause to the transformed subproof of
// that clause
obj_map m_cache;
void reset();
};
/// reduces the number of hypotheses in a proof
class hypothesis_reducer
{
public:
hypothesis_reducer(ast_manager &m) : m(m), m_pinned(m) {}
~hypothesis_reducer() {reset();}
// reduce hypothesis and return transformed proof
proof_ref reduce(proof* pf);
private:
typedef ptr_vector proof_ptr_vector;
ast_manager &m;
proof_ptr_vector m_empty_vector;
// created expressions
expr_ref_vector m_pinned;
// created sets of active hypothesis
ptr_vector m_pinned_active_hyps;
// maps a proof to the transformed proof
obj_map m_cache;
// maps a unit literal to its derivation
obj_map m_units;
// maps a proof node to the set of its active (i.e., in scope) hypotheses
obj_map m_active_hyps;
/// marks if an expression is ever used as a hypothesis in a proof
expr_mark m_hyp_mark;
/// marks a proof as open, i.e., has a non-discharged hypothesis as ancestor
expr_mark m_open_mark;
expr_mark m_visited;
void reset();
/// true if p is an ancestor of q
bool is_ancestor(proof *p, proof *q);
// compute active_hyps and parent_hyps for a given proof node and
// all its ancestors
void compute_hypsets(proof* pr);
// compute m_units
void collect_units(proof* pr);
// -- rewrite proof to reduce number of hypotheses used
proof* reduce_core(proof* pf);
proof* mk_lemma_core(proof *pf, expr *fact);
proof* mk_unit_resolution_core(proof* ures, ptr_buffer& args);
proof* mk_proof_core(proof* old, ptr_buffer& args);
};
}