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update

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This commit is contained in:
Jakob Rath 2021-09-07 14:06:32 +02:00
parent 7d58296ad2
commit 733c21bb20
6 changed files with 92 additions and 60 deletions
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67
src/math/polysat/explain.cpp
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@ -19,31 +19,44 @@ namespace polysat {
constraint_manager& explainer::cm() { return s().m_constraints; }
bool ex_polynomial_superposition::try_explain(pvar v, vector<signed_constraint> const& cjust_v, conflict_core& core) {
// TODO: check superposition into disequality again (see notes)
// TODO: use indexing/marking for this instead of allocating a temporary vector
// TODO(later): check superposition into disequality again (see notes)
bool ex_polynomial_superposition::try_explain(pvar v, /* vector<signed_constraint> const& cjust_v, */ conflict_core& core) {
// TODO: core saturation premises are from \Gamma (i.e., has_bvar)... but here we further restrict to the core; might need to revise
// -- especially: should take into account results from previous saturations (they will be in \Gamma, but only if we use the constraint or one of its descendants for the lemma)
// actually: we want to take one from the current cjust (currently true) and one from the conflict (currently false)
vector<signed_constraint> candidates;
for (auto c : core)
if (c->has_bvar() && c.is_positive() && c->is_eq() && c->contains_var(v))
candidates.push_back(c);
// TODO: c1 should a currently true constraint, while c2 should take a currently false constraint.
// remove candidates vector (premature optimization)
// we may want to apply this multiple times (a single resolve might not eliminate the variable).
// TODO: resolve multiple times... a single time might not be enough to eliminate the variable.
LOG_H3("Trying polynomial superposition...");
for (auto it1 = candidates.begin(); it1 != candidates.end(); ++it1) {
for (auto it2 = it1 + 1; it2 != candidates.end(); ++it2) {
signed_constraint c1 = *it1;
for (auto it1 = core.begin(); it1 != core.end(); ++it1) {
signed_constraint c1 = *it1;
if (!c1->has_bvar())
continue;
if (!c1.is_positive())
continue;
if (!c1->is_eq())
continue;
if (!c1->contains_var(v))
continue;
if (!c1.is_currently_true(s()))
continue;
for (auto it2 = core.begin(); it2 != core.end(); ++it2) {
signed_constraint c2 = *it2;
SASSERT(c1 != c2);
if (!c2->has_bvar())
continue;
if (!c2.is_positive())
continue;
if (!c2->is_eq())
continue;
if (!c2->contains_var(v))
continue;
if (!c2.is_currently_false(s()))
continue;
// c1 is true, c2 is false
LOG("c1: " << c1);
LOG("c2: " << c2);
pdd a = c1->to_eq().p();
pdd b = c2->to_eq().p();
pdd r = a;
@ -57,20 +70,26 @@ namespace polysat {
vector<signed_constraint> premises;
premises.push_back(c1);
premises.push_back(c2);
core.insert(c, std::move(premises));
return true;
// clause_builder clause(m_solver);
// clause.push_literal(~c1->blit());
// clause.push_literal(~c2->blit());
// clause.push_new_constraint(m_solver.m_constraints.eq(lvl, r));
// return clause.build();
if (!c->contains_var(v)) {
core.reset();
core.insert(c, std::move(premises));
return true;
} else {
core.insert(c, std::move(premises));
}
}
}
return false;
}
// LOG_H3("Attempting to explain conflict for v" << v);
// m_var = v;
// m_cjust_v = cjust;