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Simplify handling of side lemmas in conflict

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This commit is contained in:
Jakob Rath 2022-10-07 16:19:41 +02:00
parent 8b4a36e3bd
commit 8333664433
6 changed files with 90 additions and 58 deletions
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48
src/math/polysat/explain.cpp
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@ -15,24 +15,9 @@ Author:
#include "math/polysat/log.h"
#include "math/polysat/solver.h"
namespace polysat {
// TODO: rename file
/*
struct post_propagate2 : public inference {
const char* name;
signed_constraint conclusion;
signed_constraint premise1;
signed_constraint premise2;
post_propagate2(const char* name, signed_constraint conclusion, signed_constraint premise1, signed_constraint premise2)
: name(name), conclusion(conclusion), premise1(premise1), premise2(premise2) {}
std::ostream& display(std::ostream& out) const override {
return out << "Post-propagate (by " << name << "), "
<< "conclusion " << conclusion.blit() << ": " << conclusion
<< " from " << premise1.blit() << ": " << premise1
<< " and " << premise2.blit() << ": " << premise2;
}
};
*/
namespace polysat {
struct inference_sup : public inference {
const char* name;
@ -76,33 +61,22 @@ namespace polysat {
// c2 ... constraint that is currently false
// Try to replace it with a new false constraint (derived from superposition with a true constraint)
lbool ex_polynomial_superposition::find_replacement(signed_constraint c2, pvar v, conflict& core) {
vector<signed_constraint> premises;
#if 0
for (auto si : s.m_search) {
if (!si.is_boolean())
continue;
if (si.is_resolved())
continue;
auto c1 = s.lit2cnstr(si.lit());
if (!c1->contains_var(v))
continue;
if (!c1.is_eq())
continue;
if (!c1.is_currently_true(s))
continue;
#else
for (auto c1 : s.m_viable.get_constraints(v)) {
if (!c1->contains_var(v)) // side conditions do not contain v; skip them here
continue;
if (!c1.is_eq())
continue;
SASSERT(c1.is_currently_true(s));
#endif
SASSERT(c2.is_currently_false(s));
SASSERT_EQ(c1.bvalue(s), l_true);
SASSERT_EQ(c2.bvalue(s), l_true);
signed_constraint c = resolve1(v, c1, c2);
if (!c)
continue;
SASSERT(c.is_currently_false(s));
// TODO: move this case distinction into conflict::add_lemma?
char const* inf_name = "?";
switch (c.bvalue(s)) {
case l_false:
@ -117,12 +91,12 @@ namespace polysat {
inf_name = "l_undef";
// c evaluates to false,
// c should be unit-propagated to l_true by c1 /\ c2 ==> c
core.bool_propagate(c, {c1, c2});
// TODO: log inference?
core.add_lemma({c, ~c1, ~c2});
core.log_inference(inference_sup("l_undef lemma", v, c2, c1));
SASSERT_EQ(l_true, c.bvalue(s));
SASSERT(c.is_currently_false(s));
break;
case l_true:
// c is just another constraint on the search stack; could be equivalent or better
inf_name = "l_true";
break;
default: