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compute polysat unsat core

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This commit is contained in:
Jakob Rath 2023-02-03 17:37:09 +01:00
parent 579275a17d
commit 1a733a3a50
3 changed files with 105 additions and 13 deletions
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84
src/math/polysat/conflict.cpp
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@ -412,7 +412,7 @@ namespace polysat {
s.inc_activity(v);
m_vars.remove(v);
for (auto const& c : s.m_viable.get_constraints(v))
for (signed_constraint const c : s.m_viable.get_constraints(v))
insert(c);
for (auto const& i : s.m_viable.units(v)) {
insert(s.eq(i.lo(), i.lo_val()));
@ -500,18 +500,82 @@ namespace polysat {
#endif
void conflict::find_deps(dependency_vector& out_deps) const {
sat::literal_vector todo;
sat::literal_set done;
sat::literal_vector todo_lits;
sat::literal_set done_lits;
unsigned_vector todo_vars;
uint_set done_vars;
indexed_uint_set deps;
LOG("conflict: " << *this);
LOG("Conflict: " << *this);
// TODO: starting at literals/variables in the conflict, chase propagations backwards and accumulate dependencies.
verbose_stream() << "WARNING: unsat_core requested but dependency tracking in polysat is TODO\n";
for (signed_constraint c : *this) {
dependency d = s.m_bvars.dep(c.blit());
if (!d.is_null())
deps.insert(d.val());
auto const enqueue_lit = [&](sat::literal lit) {
if (done_lits.contains(lit))
return;
// verbose_stream() << "enqueue " << lit_pp(s, lit) << "\n";
todo_lits.push_back(lit);
done_lits.insert(lit);
};
auto const enqueue_var = [&](pvar v) {
if (done_vars.contains(v))
return;
// verbose_stream() << "enqueue v" << v << "\n";
todo_vars.push_back(v);
done_vars.insert(v);
};
// Starting at literals/variables in the conflict, chase propagations backwards and accumulate dependencies.
for (signed_constraint c : *this)
enqueue_lit(c.blit());
for (pvar v : m_vars)
enqueue_var(v);
while (!todo_vars.empty() || !todo_lits.empty()) {
while (!todo_vars.empty()) {
pvar const v = todo_vars.back();
todo_vars.pop_back();
if (s.m_justification[v].is_decision())
continue;
SASSERT(s.m_justification[v].is_propagation());
for (signed_constraint c : s.m_viable.get_constraints(v))
enqueue_lit(c.blit());
for (auto const& i : s.m_viable.units(v)) {
enqueue_lit(s.try_eval(s.eq(i.lo(), i.lo_val())));
enqueue_lit(s.try_eval(s.eq(i.hi(), i.hi_val())));
}
}
while (!todo_lits.empty()) {
sat::literal const lit = todo_lits.back();
todo_lits.pop_back();
dependency const d = s.m_bvars.dep(lit);
if (!d.is_null())
deps.insert(d.val());
if (s.m_bvars.is_decision(lit))
continue;
else if (s.m_bvars.is_assumption(lit))
continue;
else if (s.m_bvars.is_bool_propagation(lit)) {
for (sat::literal other : *s.m_bvars.reason(lit))
enqueue_lit(other);
}
else if (s.m_bvars.is_evaluation(lit)) {
unsigned const lvl = s.m_bvars.level(lit);
for (pvar v : s.lit2cnstr(lit).vars()) {
if (!s.is_assigned(v))
continue;
if (s.get_level(v) > lvl)
continue;
enqueue_var(v);
}
}
else {
UNREACHABLE();
}
}
}
for (unsigned d : deps)