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z3/src/math/polysat/explain.h
Nikolaj Bjorner 83efb1413a na
2021-12-11 08:41:04 -08:00

88 lines
2.5 KiB
C++

/*++
Copyright (c) 2021 Microsoft Corporation
Module Name:
Conflict explanation
Author:
Nikolaj Bjorner (nbjorner) 2021-03-19
Jakob Rath 2021-04-6
--*/
#pragma once
#include "math/polysat/conflict.h"
#include "math/polysat/constraint.h"
#include "math/polysat/clause_builder.h"
#include "math/polysat/interval.h"
namespace polysat {
class solver;
class explainer {
friend class conflict;
protected:
solver& s;
public:
explainer(solver& s) :s(s) {}
virtual ~explainer() {}
virtual bool try_explain(pvar v, /* vector<signed_constraint> const& cjust_v, */ conflict& core) = 0;
};
class ex_polynomial_superposition : public explainer {
private:
signed_constraint resolve1(pvar v, signed_constraint c1, signed_constraint c2);
lbool find_replacement(signed_constraint c2, pvar v, conflict& core);
void reduce_by(pvar v, conflict& core);
bool reduce_by(pvar, signed_constraint c, conflict& core);
lbool try_explain1(pvar v, conflict& core);
public:
ex_polynomial_superposition(solver& s) : explainer(s) {}
bool try_explain(pvar v, conflict& core) override;
};
#if 0
class conflict_explainer {
solver& m_solver;
// conflict m_conflict;
vector<constraint> m_new_assertions; // to be inserted into Gamma (conclusions from saturation)
scoped_ptr_vector<inference_engine> inference_engines;
bool push_omega_mul(clause_builder& clause, unsigned level, unsigned p, pdd const& x, pdd const& y);
// Gamma
// search_state& search() { return m_solver.m_search; }
// Core
// conflict& conflict() { return m_solver.m_conflict; }
public:
/** Create empty conflict */
conflict_explainer(solver& s);
/** Perform one step of core saturation, if possible.
* Core saturation derives new constraints according applicable inference rules.
*/
bool saturate();
/** resolve conflict state against assignment to v */
void resolve(pvar v, ptr_vector<constraint> const& cjust_v);
void resolve(sat::literal lit);
// TODO: move conflict resolution from solver into this class.
// we have a single public method as entry point to conflict resolution.
// what do we need to return?
/** conflict resolution until first (relevant) decision */
void resolve();
};
#endif
}