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Polysat disjunctive lemmas (WIP) (#5275)

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* Extend search state by boolean literals

* Only resolve against positive equality

* mk_dep_ref

* Make clause non-owning

* scoped_clause

* Use scoped_clause

* minor

* scoped_ptr move assignment

* WIP: internal handling of disjunctive constraints

* leaf_value

* disjunctive constraints continued

* Fix bool_lit

* Actually add constraints to storage

* Some fixes

* more fixes

* constraint should have a bool_lit instead of a bool_var

* propagate(bool_lit)

* updates

* interface changes

* small fixes

* Make sat::dimacs_lit's constructor explicit

(otherwise, calling operator<< with sat::literal is ambiguous)

* Use sat::literal

* Print test name at the beginning

* Convention: constraint corresponds to the positive boolean literal

* Make constraint ownership more explicit

* clause stores literals
This commit is contained in:
Jakob Rath 2021-05-21 22:50:25 +02:00 • committed by GitHub
parent 49e9782238
commit 28996429df
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GPG key ID: 4AEE18F83AFDEB23
24 changed files with 1196 additions and 360 deletions
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32
src/math/polysat/eq_constraint.cpp
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@ -19,10 +19,13 @@ Author:
namespace polysat {
std::ostream& eq_constraint::display(std::ostream& out) const {
return out << p() << (sign() == pos_t ? " == 0" : " != 0") << " [" << m_status << "]";
out << p() << (sign() == pos_t ? " == 0" : " != 0") << " @" << level();
if (is_undef())
out << " [inactive]";
return out;
}
constraint* eq_constraint::resolve(solver& s, pvar v) {
scoped_ptr<constraint> eq_constraint::resolve(solver& s, pvar v) {
if (is_positive())
return eq_resolve(s, v);
if (is_negative())
@ -33,8 +36,8 @@ namespace polysat {
void eq_constraint::narrow(solver& s) {
SASSERT(!is_undef());
LOG("Assignment: " << s.m_search);
auto q = p().subst_val(s.m_search);
LOG("Assignment: " << s.assignment());
auto q = p().subst_val(s.assignment());
LOG("Substituted: " << p() << " := " << q);
if (q.is_zero()) {
if (is_positive())
@ -88,7 +91,7 @@ namespace polysat {
}
bool eq_constraint::is_currently_false(solver& s) {
pdd r = p().subst_val(s.m_search);
pdd r = p().subst_val(s.assignment());
if (is_positive())
return r.is_never_zero();
if (is_negative())
@ -98,7 +101,7 @@ namespace polysat {
}
bool eq_constraint::is_currently_true(solver& s) {
pdd r = p().subst_val(s.m_search);
pdd r = p().subst_val(s.assignment());
if (is_positive())
return r.is_zero();
if (is_negative())
@ -112,11 +115,13 @@ namespace polysat {
* Equality constraints
*/
constraint* eq_constraint::eq_resolve(solver& s, pvar v) {
scoped_ptr<constraint> eq_constraint::eq_resolve(solver& s, pvar v) {
LOG("Resolve " << *this << " upon v" << v);
if (s.m_conflict.size() != 1)
return nullptr;
constraint* c = s.m_conflict[0];
if (!s.m_conflict.clauses().empty())
return nullptr;
constraint* c = s.m_conflict.units()[0];
SASSERT(c->is_currently_false(s));
// 'c == this' can happen if propagation was from decide() with only one value left
// (e.g., if there's an unsatisfiable clause and we try all values).
@ -124,7 +129,7 @@ namespace polysat {
if (c == this)
return nullptr;
SASSERT(is_currently_true(s)); // TODO: might not always hold (due to similar case as in comment above?)
if (c->is_eq()) {
if (c->is_eq() && c->is_positive()) {
pdd a = c->to_eq().p();
pdd b = p();
pdd r = a;
@ -132,9 +137,7 @@ namespace polysat {
return nullptr;
p_dependency_ref d(s.m_dm.mk_join(c->dep(), dep()), s.m_dm);
unsigned lvl = std::max(c->level(), level());
constraint* lemma = constraint::eq(lvl, s.m_next_bvar++, pos_t, r, d);
lemma->assign_eh(true);
return lemma;
return s.m_constraints.eq(lvl, pos_t, r, d);
}
return nullptr;
}
@ -144,7 +147,7 @@ namespace polysat {
* Disequality constraints
*/
constraint* eq_constraint::diseq_resolve(solver& s, pvar v) {
scoped_ptr<constraint> eq_constraint::diseq_resolve(solver& s, pvar v) {
NOT_IMPLEMENTED_YET();
return nullptr;
}
@ -162,6 +165,7 @@ namespace polysat {
return false;
if (deg == 0) {
return false;
UNREACHABLE(); // this case is not useful for conflict resolution (but it could be handled in principle)
// i is empty or full, condition would be this constraint itself?
return true;
@ -191,7 +195,7 @@ namespace polysat {
*/
// Concrete values of evaluable terms
auto e1s = e1.subst_val(s.m_search);
auto e1s = e1.subst_val(s.assignment());
auto e2s = m.zero();
SASSERT(e1s.is_val());
SASSERT(e2s.is_val());