mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-05-01 12:55:52 +00:00
Code Activity

build_lemma returns clause_builder; adjust reason in revert_bool_decision

Browse source
This commit is contained in:
Jakob Rath 2021-09-07 15:02:29 +02:00
parent 733c21bb20
commit 24f96acf4f
8 changed files with 83 additions and 75 deletions
Download patch file Download diff file Expand all files Collapse all files

52
src/math/polysat/conflict_core.cpp
View file

@ -130,11 +130,35 @@ namespace polysat {
m_solver->activate_constraint(c);
}
clause_ref conflict_core::build_lemma(unsigned model_level) {
/** Create fallback lemma that excludes the current search state */
clause_builder conflict_core::build_fallback_lemma(unsigned lvl) {
LOG_H3("Creating fallback lemma for level " << lvl);
LOG_V("m_search: " << m_solver->m_search);
clause_builder lemma(*m_solver);
unsigned todo = lvl;
unsigned i = 0;
while (todo > 0) {
auto const& item = m_solver->m_search[i++];
if (!m_solver->is_decision(item))
continue;
LOG_V("Adding: " << item);
if (item.is_assignment()) {
pvar v = item.var();
auto c = ~cm().eq(0, m_solver->var(v) - m_solver->m_value[v]);
cm().ensure_bvar(c.get());
lemma.push_literal(c.blit());
} else {
sat::literal lit = item.lit();
lemma.push_literal(~lit);
}
--todo;
}
return lemma;
}
clause_builder conflict_core::build_core_lemma(unsigned model_level) {
LOG_H3("build lemma from core");
sat::literal_vector literals;
p_dependency_ref dep = m_solver->mk_dep_ref(null_dependency);
unsigned lvl = 0;
clause_builder lemma(*m_solver);
// TODO: try a final core reduction step?
@ -146,12 +170,7 @@ namespace polysat {
// Insert the temporary constraint from saturation into \Gamma.
handle_saturation_premises(c);
}
if (c->unit_clause()) {
dep = m_solver->m_dm.mk_join(dep, c->unit_dep());
continue;
}
lvl = std::max(lvl, c->level());
literals.push_back(~c.blit());
lemma.push(c);
}
if (m_needs_model) {
@ -166,13 +185,20 @@ namespace polysat {
// SASSERT(!m_solver->m_justification[v].is_unassigned()); // TODO: why does this trigger????
if (m_solver->m_justification[v].level() > model_level)
continue;
auto diseq = ~cm().eq(lvl, m_solver->var(v) - m_solver->m_value[v]);
auto diseq = ~cm().eq(lemma.level(), m_solver->var(v) - m_solver->m_value[v]);
cm().ensure_bvar(diseq.get());
literals.push_back(diseq.blit());
lemma.push(diseq);
}
}
return clause::from_literals(lvl, std::move(dep), std::move(literals));
return lemma;
}
clause_builder conflict_core::build_lemma(unsigned reverted_level) {
if (is_bailout())
return build_fallback_lemma(reverted_level);
else
return build_core_lemma(reverted_level - 1);
}
bool conflict_core::resolve_value(pvar v, vector<signed_constraint> const& cjust_v) {