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working on propagation with undef main literal

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2018-02-20 01:46:35 -08:00
parent 4c1379e8c9
commit 75ba65a18a
1 changed files with 15 additions and 5 deletions
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20
src/sat/ba_solver.cpp
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@ -1647,6 +1647,7 @@ namespace sat {
return true; return true;
} }
else if (c.lit() != null_literal && value(c.lit()) != l_true) { else if (c.lit() != null_literal && value(c.lit()) != l_true) {
// else if (c.lit() != null_literal && value(c.lit()) == l_false) {
return true; return true;
} }
else { else {
@ -1954,6 +1955,13 @@ namespace sat {
} }
void ba_solver::get_antecedents(literal l, card const& c, literal_vector& r) { void ba_solver::get_antecedents(literal l, card const& c, literal_vector& r) {
if (l == ~c.lit()) {
for (unsigned i = c.k() - 1; i < c.size(); ++i) {
VERIFY(value(c[i]) == l_false);
r.push_back(~c[i]);
}
return;
}
DEBUG_CODE( DEBUG_CODE(
bool found = false; bool found = false;
for (unsigned i = 0; !found && i < c.k(); ++i) { for (unsigned i = 0; !found && i < c.k(); ++i) {
@ -1962,7 +1970,7 @@ namespace sat {
SASSERT(found);); SASSERT(found););
// IF_VERBOSE(0, if (_debug_conflict) verbose_stream() << "ante " << l << " " << c << "\n"); // IF_VERBOSE(0, if (_debug_conflict) verbose_stream() << "ante " << l << " " << c << "\n");
SASSERT(c.lit() == null_literal || value(c.lit()) != l_false); VERIFY(c.lit() == null_literal || value(c.lit()) != l_false);
if (c.lit() != null_literal) r.push_back(value(c.lit()) == l_true ? c.lit() : ~c.lit()); if (c.lit() != null_literal) r.push_back(value(c.lit()) == l_true ? c.lit() : ~c.lit());
for (unsigned i = c.k(); i < c.size(); ++i) { for (unsigned i = c.k(); i < c.size(); ++i) {
SASSERT(value(c[i]) == l_false); SASSERT(value(c[i]) == l_false);
@ -2349,7 +2357,7 @@ namespace sat {
return l_false; return l_false;
} }
SASSERT(value(alit) == l_false); SASSERT(value(alit) == l_false);
SASSERT(c.lit() == null_literal || value(c.lit()) == l_true); VERIFY(c.lit() == null_literal || value(c.lit()) != l_false);
unsigned index = 0; unsigned index = 0;
for (index = 0; index <= bound; ++index) { for (index = 0; index <= bound; ++index) {
if (c[index] == alit) { if (c[index] == alit) {
@ -2377,6 +2385,7 @@ namespace sat {
if (bound != index && value(c[bound]) == l_false) { if (bound != index && value(c[bound]) == l_false) {
TRACE("ba", tout << "conflict " << c[bound] << " " << alit << "\n";); TRACE("ba", tout << "conflict " << c[bound] << " " << alit << "\n";);
if (c.lit() != null_literal && value(c.lit()) == l_undef) { if (c.lit() != null_literal && value(c.lit()) == l_undef) {
if (index + 1 < bound) c.swap(index, bound - 1);
assign(c, ~c.lit()); assign(c, ~c.lit());
return inconsistent() ? l_false : l_true; return inconsistent() ? l_false : l_true;
} }
@ -2384,14 +2393,15 @@ namespace sat {
return l_false; return l_false;
} }
if (index != bound) {
c.swap(index, bound);
}
// TRACE("ba", tout << "no swap " << index << " " << alit << "\n";); // TRACE("ba", tout << "no swap " << index << " " << alit << "\n";);
// there are no literals to swap with, // there are no literals to swap with,
// prepare for unit propagation by swapping the false literal into // prepare for unit propagation by swapping the false literal into
// position bound. Then literals in positions 0..bound-1 have to be // position bound. Then literals in positions 0..bound-1 have to be
// assigned l_true. // assigned l_true.
if (index != bound) {
c.swap(index, bound);
}
if (c.lit() != null_literal && value(c.lit()) == l_undef) { if (c.lit() != null_literal && value(c.lit()) == l_undef) {
return l_true; return l_true;