static lbool core_chunking(sat::solver& s, sat::bool_var_vector& vars, sat::literal_vector const& asms, vector<sat::literal_vector>& conseq, unsigned K) {
lbool r = s.check(asms.size(), asms.c_ptr());
if (r != l_true) {
return r;
}
sat::model const & m = s.get_model();
sat::literal_vector lambda, backbones;
for (unsigned i = 0; i < vars.size(); i++) {
lambda.push_back(sat::literal(vars[i], m[vars[i]] == l_false));
}
while (!lambda.empty()) {
IF_VERBOSE(1, verbose_stream() << "(sat-backbone-core " << lambda.size() << " " << backbones.size() << ")\n";);
unsigned k = std::min(K, lambda.size());
sat::literal_vector gamma, omegaN;
for (unsigned i = 0; i < k; ++i) {
sat::literal l = lambda[lambda.size() - i - 1];
gamma.push_back(l);
omegaN.push_back(~l);
}
while (true) {
sat::literal_vector asms1(asms);
asms1.append(omegaN);
r = s.check(asms1.size(), asms1.c_ptr());
if (r == l_true) {
IF_VERBOSE(1, verbose_stream() << "(sat) " << omegaN << "\n";);
prune_unfixed(lambda, s.get_model());
break;
}
static void track_clause(sat::solver& dst,
sat::literal_vector& lits,
sat::literal_vector& assumptions,
vector<sat::literal_vector>& tracking_clauses) {
sat::literal lit = sat::literal(dst.mk_var(true, false), false);
tracking_clauses.set(lit.var(), lits);
lits.push_back(~lit);
dst.mk_clause(lits.size(), lits.c_ptr());
assumptions.push_back(lit);
}