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Begin reorganizing resolve_value

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This commit is contained in:
Jakob Rath 2021-09-07 11:40:50 +02:00
parent b4e14c31d0
commit 7d58296ad2
6 changed files with 113 additions and 25 deletions
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54
src/math/polysat/explain.cpp
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@ -17,6 +17,60 @@ Author:
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: 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).
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;
signed_constraint c2 = *it2;
SASSERT(c1 != c2);
LOG("c1: " << c1);
LOG("c2: " << c2);
pdd a = c1->to_eq().p();
pdd b = c2->to_eq().p();
pdd r = a;
if (!a.resolve(v, b, r) && !b.resolve(v, a, r))
continue;
unsigned const lvl = std::max(c1->level(), c2->level());
signed_constraint c = cm().eq(lvl, r);
LOG("resolved: " << c << " currently false? " << c.is_currently_false(s()));
if (!c.is_currently_false(s()))
continue;
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();
}
}
return false;
}
// LOG_H3("Attempting to explain conflict for v" << v);
// m_var = v;
// m_cjust_v = cjust;