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fix bug in unsat core extraction in sat solver

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2014-08-18 23:43:51 -07:00
parent 1c56d6ee95
commit a47f3df703
14 changed files with 70 additions and 53 deletions
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44
src/sat/sat_solver.cpp
View file

@ -727,11 +727,7 @@ namespace sat {
if (inconsistent()) return l_false;
init_assumptions(num_lits, lits);
propagate(false);
if (inconsistent()) {
if (tracking_assumptions())
resolve_conflict();
return l_false;
}
if (check_inconsistent()) return l_false;
cleanup();
if (m_config.m_max_conflicts > 0 && m_config.m_burst_search > 0) {
m_restart_threshold = m_config.m_burst_search;
@ -745,8 +741,8 @@ namespace sat {
// iff3_finder(*this)();
simplify_problem();
if (check_inconsistent()) return l_false;
if (inconsistent()) return l_false;
m_next_simplify = m_config.m_restart_initial * m_config.m_simplify_mult1;
if (m_config.m_max_conflicts == 0) {
@ -769,6 +765,7 @@ namespace sat {
restart();
if (m_conflicts >= m_next_simplify) {
simplify_problem();
if (check_inconsistent()) return l_false;
m_next_simplify = static_cast<unsigned>(m_conflicts * m_config.m_simplify_mult2);
if (m_next_simplify > m_conflicts + m_config.m_simplify_max)
m_next_simplify = m_conflicts + m_config.m_simplify_max;
@ -886,6 +883,17 @@ namespace sat {
}
}
bool solver::check_inconsistent() {
if (inconsistent()) {
if (tracking_assumptions())
resolve_conflict();
return true;
}
else {
return false;
}
}
void solver::init_assumptions(unsigned num_lits, literal const* lits) {
if (num_lits == 0 && m_user_scope_literals.empty()) {
return;
@ -1575,32 +1583,37 @@ namespace sat {
bool_var var = antecedent.var();
unsigned var_lvl = lvl(var);
SASSERT(var < num_vars());
TRACE("sat", tout << antecedent << " " << (is_marked(var)?"+":"-") << "\n";);
if (!is_marked(var)) {
mark(var);
m_unmark.push_back(var);
if (is_assumption(antecedent)) {
m_core.push_back(antecedent);
}
}
}
}
void solver::process_consequent_for_unsat_core(literal consequent, justification const& js) {
TRACE("sat", tout << "processing consequent: " << consequent << "\n";
TRACE("sat", tout << "processing consequent: ";
if (consequent == null_literal) tout << "null\n";
else tout << consequent << "\n";
display_justification(tout << "js kind: ", js);
tout << "\n";);
switch (js.get_kind()) {
case justification::NONE:
break;
case justification::BINARY:
SASSERT(consequent != null_literal);
process_antecedent_for_unsat_core(~(js.get_literal()));
break;
case justification::TERNARY:
SASSERT(consequent != null_literal);
process_antecedent_for_unsat_core(~(js.get_literal1()));
process_antecedent_for_unsat_core(~(js.get_literal2()));
break;
case justification::CLAUSE: {
clause & c = *(m_cls_allocator.get_clause(js.get_clause_offset()));
unsigned i = 0;
unsigned i = 0;
if (consequent != null_literal) {
SASSERT(c[0] == consequent || c[1] == consequent);
if (c[0] == consequent) {
@ -1611,7 +1624,7 @@ namespace sat {
i = 2;
}
}
unsigned sz = c.size();
unsigned sz = c.size();
for (; i < sz; i++)
process_antecedent_for_unsat_core(~c[i]);
break;
@ -1652,6 +1665,11 @@ namespace sat {
if (m_conflict_lvl == 0) {
return;
}
SASSERT(m_unmark.empty());
DEBUG_CODE({
for (unsigned i = 0; i < m_trail.size(); ++i) {
SASSERT(!is_marked(m_trail[i].var()));
}});
unsigned old_size = m_unmark.size();
int idx = skip_literals_above_conflict_level();
@ -1674,9 +1692,9 @@ namespace sat {
literal consequent = m_not_l;
justification js = m_conflict;
while (true) {
process_consequent_for_unsat_core(consequent, js);
idx--;
while (idx >= 0) {
literal l = m_trail[idx];
if (is_marked(l.var()))
@ -1695,6 +1713,7 @@ namespace sat {
bool_var c_var = consequent.var();
SASSERT(lvl(consequent) == m_conflict_lvl);
js = m_justification[c_var];
idx--;
}
reset_unmark(old_size);
if (m_config.m_minimize_core) {
@ -1983,7 +2002,8 @@ namespace sat {
assigned at level 0.
*/
void solver::minimize_lemma() {
m_unmark.reset();
SASSERT(m_unmark.empty());
//m_unmark.reset();
updt_lemma_lvl_set();
unsigned sz = m_lemma.size();

2
src/sat/sat_solver.h
View file

@ -247,6 +247,8 @@ namespace sat {
bool is_marked_lit(literal l) const { return m_lit_mark[l.index()] != 0; }
void mark_lit(literal l) { SASSERT(!is_marked_lit(l)); m_lit_mark[l.index()] = true; }
void unmark_lit(literal l) { SASSERT(is_marked_lit(l)); m_lit_mark[l.index()] = false; }
bool check_inconsistent();
// -----------------------
//