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add checks for flipping externals / assumptions in model converter, fix scc converter bug

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-12-13 14:06:35 -08:00
parent caaad8825d
commit aeabdb4aae
5 changed files with 31 additions and 7 deletions
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26
src/sat/sat_model_converter.cpp
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@ -39,6 +39,22 @@ namespace sat {
return *this;
}
bool model_converter::legal_to_flip(bool_var v) const {
// std::cout << "check " << v << " " << m_solver << "\n";
if (m_solver && m_solver->is_assumption(v)) {
std::cout << "flipping assumption v" << v << "\n";
UNREACHABLE();
throw solver_exception("flipping assumption");
}
if (m_solver && m_solver->is_external(v)) {
std::cout << "flipping external v" << v << "\n";
UNREACHABLE();
throw solver_exception("flipping external");
}
return !m_solver || !m_solver->is_assumption(v);
}
void model_converter::process_stack(model & m, literal_vector const& c, elim_stackv const& stack) const {
SASSERT(!stack.empty());
unsigned sz = stack.size();
@ -50,6 +66,7 @@ namespace sat {
sat = value_at(c[j], m) == l_true;
}
if (!sat) {
VERIFY(legal_to_flip(lit.var()));
m[lit.var()] = lit.sign() ? l_false : l_true;
}
}
@ -59,7 +76,7 @@ namespace sat {
vector<entry>::const_iterator begin = m_entries.begin();
vector<entry>::const_iterator it = m_entries.end();
bool first = true;
//VERIFY(!m_solver || m_solver->check_clauses(m));
//SASSERT(!m_solver || m_solver->check_clauses(m));
while (it != begin) {
--it;
SASSERT(it->get_kind() != ELIM_VAR || m[it->var()] == l_undef);
@ -69,11 +86,13 @@ namespace sat {
bool var_sign = false;
unsigned index = 0;
literal_vector clause;
VERIFY(legal_to_flip(it->var()));
for (literal l : it->m_clauses) {
if (l == null_literal) {
// end of clause
elim_stack* st = it->m_elim_stack[index];
if (!sat) {
if (!sat) {
VERIFY(legal_to_flip(it->var()));
m[it->var()] = var_sign ? l_false : l_true;
}
if (st) {
@ -101,6 +120,7 @@ namespace sat {
if (value_at(l, m) == l_true)
sat = true;
else if (!sat && v != it->var() && m[v] == l_undef) {
VERIFY(legal_to_flip(v));
// clause can be satisfied by assigning v.
m[v] = sign ? l_false : l_true;
// if (first) std::cout << "set: " << l << "\n";
@ -170,6 +190,7 @@ namespace sat {
entry & e = m_entries.back();
SASSERT(e.var() == v);
SASSERT(e.get_kind() == k);
VERIFY(legal_to_flip(v));
return e;
}
@ -213,6 +234,7 @@ namespace sat {
for (literal l : c) e.m_clauses.push_back(l);
e.m_clauses.push_back(null_literal);
e.m_elim_stack.push_back(elims.empty() ? nullptr : alloc(elim_stack, elims));
for (auto const& s : elims) VERIFY(legal_to_flip(s.second.var()));
TRACE("sat_mc_bug", tout << "adding: " << c << "\n";);
}