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 prune_unfixed(sat::literal_vector& lambda, sat::model const& m) {
for (unsigned i = 0; i < lambda.size(); ++i) {
if ((m[lambda[i].var()] == l_false) != lambda[i].sign()) {
lambda[i] = lambda.back();
lambda.pop_back();
--i;
}
}
}
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);
}
static void brute_force_consequences(sat::solver& s, sat::literal_vector const& asms, sat::literal_vector const& gamma, sat::literal_vector& backbones) {
for (unsigned i = 0; i < gamma.size(); ++i) {
sat::literal nlit = ~gamma[i];
sat::literal_vector asms1(asms);
asms1.push_back(nlit);
lbool r = s.check(asms1.size(), asms1.c_ptr());
if (r == l_false) {
backbones.push_back(gamma[i]);
}
}
}
static void back_remove(sat::literal_vector& lits, sat::literal l) {
for (unsigned i = lits.size(); i > 0; ) {
--i;
if (lits[i] == l) {
lits[i] = lits.back();
lits.pop_back();
return;
}
}
std::cout << "UNREACHABLE\n";
}
void read_clause(Buffer & in, std::ostream& err, sat::solver & solver, sat::literal_vector & lits) {
int parsed_lit;
int var;
lits.reset();
while (true) {
parsed_lit = parse_int(in, err);
if (parsed_lit == 0)
break;
var = abs(parsed_lit);
SASSERT(var > 0);
while (static_cast<unsigned>(var) >= solver.num_vars())
solver.mk_var();
lits.push_back(sat::literal(var, parsed_lit < 0));
}
}