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#fix #5328

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in-processing for "pure" PB constraints isn't model preserving and therefore removed.
This commit is contained in:
Nikolaj Bjorner 2021-06-05 12:02:33 -07:00
parent 85b672ee85
commit 1fd6b66ecc
2 changed files with 13 additions and 39 deletions
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39
src/sat/smt/pb_solver.cpp
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@ -132,7 +132,6 @@ namespace pb {
remove_constraint(p, "is tight"); remove_constraint(p, "is tight");
} }
else { else {
unsigned sz = p.size(); unsigned sz = p.size();
clear_watch(p); clear_watch(p);
unsigned j = 0; unsigned j = 0;
@ -1470,7 +1469,6 @@ namespace pb {
return true; return true;
} }
else if (c.lit() != sat::null_literal && value(c.lit()) != l_true) { else if (c.lit() != sat::null_literal && value(c.lit()) != l_true) {
// else if (c.lit() != sat::null_literal && value(c.lit()) == l_false) {
return true; return true;
} }
else { else {
@ -2025,7 +2023,7 @@ namespace pb {
unit_strengthen(); unit_strengthen();
cleanup_clauses(); cleanup_clauses();
cleanup_constraints(); cleanup_constraints();
update_pure();
count++; count++;
} }
while (count < 10 && (m_simplify_change || trail_sz < s().init_trail_size())); while (count < 10 && (m_simplify_change || trail_sz < s().init_trail_size()));
@ -2047,41 +2045,6 @@ namespace pb {
// if (s().m_clauses.size() < 80000) lp_lookahead_reduction(); // if (s().m_clauses.size() < 80000) lp_lookahead_reduction();
} }
/*
* ~lit does not occur in clauses
* ~lit is only in one constraint use list
* lit == C
* -> ignore assignments to ~lit for C
*
* ~lit does not occur in clauses
* lit is only in one constraint use list
* lit == C
* -> negate: ~lit == ~C
*/
void solver::update_pure() {
//return;
for (constraint* cp : m_constraints) {
literal lit = cp->lit();
if (lit != sat::null_literal &&
!cp->is_pure() &&
value(lit) == l_undef &&
get_wlist(~lit).size() == 1 &&
m_clause_use_list.get(lit).empty()) {
clear_watch(*cp);
cp->negate();
lit.neg();
}
if (lit != sat::null_literal &&
!cp->is_pure() &&
m_cnstr_use_list[(~lit).index()].size() == 1 &&
get_wlist(lit).size() == 1 &&
m_clause_use_list.get(~lit).empty()) {
cp->set_pure();
get_wlist(~lit).erase(sat::watched(cp->cindex())); // just ignore assignments to false
}
}
}
void solver::mutex_reduction() { void solver::mutex_reduction() {
literal_vector lits; literal_vector lits;
for (unsigned v = 0; v < s().num_vars(); ++v) { for (unsigned v = 0; v < s().num_vars(); ++v) {

13
src/sat/tactic/sat_tactic.cpp
View file

@ -56,6 +56,12 @@ class sat_tactic : public tactic {
for (func_decl* f : funs) for (func_decl* f : funs)
tout << mk_ismt2_pp(f, m) << "\n"; tout << mk_ismt2_pp(f, m) << "\n";
); );
expr_ref_vector fmls_to_validate(m);
if (gparams::get_ref().get_bool("model_validate", false))
for (unsigned i = 0; i < g->size(); ++i)
fmls_to_validate.push_back(g->form(i));
g->reset(); g->reset();
g->m().compact_memory(); g->m().compact_memory();
@ -65,7 +71,8 @@ class sat_tactic : public tactic {
dep2assumptions(dep2asm, assumptions); dep2assumptions(dep2asm, assumptions);
lbool r = m_solver->check(assumptions.size(), assumptions.data()); lbool r = m_solver->check(assumptions.size(), assumptions.data());
TRACE("sat", tout << "result of checking: " << r << " "; TRACE("sat", tout << "result of checking: " << r << " ";
if (r == l_undef) tout << m_solver->get_reason_unknown(); tout << "\n";); if (r == l_undef) tout << m_solver->get_reason_unknown(); tout << "\n";
if (m_goal2sat.has_interpreted_funs()) tout << "has interpreted\n";);
if (r == l_false) { if (r == l_false) {
expr_dependency * lcore = nullptr; expr_dependency * lcore = nullptr;
if (produce_core) { if (produce_core) {
@ -106,6 +113,10 @@ class sat_tactic : public tactic {
break; break;
} }
} }
for (auto* f : fmls_to_validate)
if (md->is_false(f))
IF_VERBOSE(0, verbose_stream() << "failed to validate: " << mk_pp(f, m) << "\n";);
m_goal2sat.update_model(md); m_goal2sat.update_model(md);
TRACE("sat_tactic", model_v2_pp(tout, *md);); TRACE("sat_tactic", model_v2_pp(tout, *md););
g->add(model2model_converter(md.get())); g->add(model2model_converter(md.get()));