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Polysat: use constraint_literal and begin move to core-based conflict representation (#5489)

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* Rename solver_scope for fixplex tests

(otherwise the wrong constructor is called for polysat's solver_scope)

* Update conflict_core

* simplify

* Be clearer about constraint_literal lifetime

* remove old comment

* Remove status (positive/negative) from constraint

* Use constraint_literal in the solver

* Fix build (constraint -> get_constraint)
This commit is contained in:
Jakob Rath 2021-08-18 20:02:46 +02:00 • committed by GitHub
parent 30e9f24fa3
commit ebaea2159e
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GPG key ID: 4AEE18F83AFDEB23
19 changed files with 933 additions and 1004 deletions
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59
src/math/polysat/ule_constraint.cpp
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@ -18,12 +18,16 @@ Author:
namespace polysat {
std::ostream& ule_constraint::display(std::ostream& out) const {
out << m_lhs << " <= " << m_rhs;
return display_extra(out);
std::ostream& ule_constraint::display(std::ostream& out, lbool status) const {
out << m_lhs;
if (status == l_true) out << " <= ";
else if (status == l_false) out << " > ";
else out << " <=/> ";
out << m_rhs;
return display_extra(out, status);
}
void ule_constraint::narrow(solver& s) {
void ule_constraint::narrow(solver& s, bool is_positive) {
LOG_H3("Narrowing " << *this);
LOG("Assignment: " << assignments_pp(s));
auto p = lhs().subst_val(s.assignment());
@ -31,15 +35,13 @@ namespace polysat {
auto q = rhs().subst_val(s.assignment());
LOG("Substituted RHS: " << rhs() << " := " << q);
SASSERT(!is_undef());
if (is_always_false(p, q)) {
s.set_conflict(*this);
if (is_always_false(is_positive, p, q)) {
s.set_conflict({this, is_positive});
return;
}
if (p.is_val() && q.is_val()) {
SASSERT(!is_positive() || p.val() <= q.val());
SASSERT(!is_negative() || p.val() > q.val());
SASSERT(!is_positive || p.val() <= q.val());
SASSERT(is_positive || p.val() > q.val());
return;
}
@ -70,13 +72,13 @@ namespace polysat {
d = q.lo().val();
}
if (v != null_var) {
s.push_cjust(v, this);
s.push_cjust(v, {this, is_positive});
s.m_viable.intersect_ule(v, a, b, c, d, is_positive());
s.m_viable.intersect_ule(v, a, b, c, d, is_positive);
rational val;
if (s.m_viable.find_viable(v, val) == dd::find_t::singleton)
s.propagate(v, val, *this);
s.propagate(v, val, {this, is_positive});
return;
}
@ -84,39 +86,35 @@ namespace polysat {
// TODO: other cheap constraints possible?
}
bool ule_constraint::is_always_false(pdd const& lhs, pdd const& rhs) {
bool ule_constraint::is_always_false(bool is_positive, pdd const& lhs, pdd const& rhs) {
// TODO: other conditions (e.g. when forbidden interval would be full)
VERIFY(!is_undef());
if (is_positive())
if (is_positive)
return lhs.is_val() && rhs.is_val() && lhs.val() > rhs.val();
else
return (lhs.is_val() && rhs.is_val() && lhs.val() <= rhs.val()) || (lhs == rhs);
}
bool ule_constraint::is_always_false() {
return is_always_false(lhs(), rhs());
bool ule_constraint::is_always_false(bool is_positive) {
return is_always_false(is_positive, lhs(), rhs());
}
bool ule_constraint::is_currently_false(solver& s) {
bool ule_constraint::is_currently_false(solver& s, bool is_positive) {
auto p = lhs().subst_val(s.assignment());
auto q = rhs().subst_val(s.assignment());
return is_always_false(p, q);
return is_always_false(is_positive, p, q);
}
bool ule_constraint::is_currently_true(solver& s) {
bool ule_constraint::is_currently_true(solver& s, bool is_positive) {
auto p = lhs().subst_val(s.assignment());
auto q = rhs().subst_val(s.assignment());
VERIFY(!is_undef());
if (is_positive())
if (is_positive)
return p.is_val() && q.is_val() && p.val() <= q.val();
else
return p.is_val() && q.is_val() && p.val() > q.val();
}
bool ule_constraint::forbidden_interval(solver& s, pvar v, eval_interval& out_interval, constraint_literal& out_neg_cond)
bool ule_constraint::forbidden_interval(solver& s, bool is_positive, pvar v, eval_interval& out_interval, constraint_literal_ref& out_neg_cond)
{
SASSERT(!is_undef());
// Current only works when degree(v) is at most one on both sides
unsigned const deg1 = lhs().degree(v);
unsigned const deg2 = rhs().degree(v);
@ -249,7 +247,7 @@ namespace polysat {
out_neg_cond = s.m_constraints.eq(level(), condition_body);
if (is_trivial) {
if (is_positive())
if (is_positive)
// TODO: we cannot use empty intervals for interpolation. So we
// can remove the empty case (make it represent 'full' instead),
// and return 'false' here. Then we do not need the proper/full
@ -276,7 +274,7 @@ namespace polysat {
else
SASSERT(y_coeff.is_one());
if (is_negative()) {
if (!is_positive) {
swap(lo, hi);
lo_val.swap(hi_val);
}
@ -286,9 +284,8 @@ namespace polysat {
return true;
}
inequality ule_constraint::as_inequality() const {
SASSERT(!is_undef());
if (is_positive())
inequality ule_constraint::as_inequality(bool is_positive) const {
if (is_positive)
return inequality(lhs(), rhs(), false, this);
else
return inequality(rhs(), lhs(), true, this);