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);
}
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));
}
}
static void display_core(sat::solver const& s, vector<sat::literal_vector> const& tracking_clauses) {
std::cout << "core\n";
sat::literal_vector const& c = s.get_core();
for (unsigned i = 0; i < c.size(); ++i) {
sat::literal_vector const& cls = tracking_clauses[c[i].var()];
for (unsigned j = 0; j < cls.size(); ++j) {
std::cout << cls[j] << " ";
}
std::cout << "\n";
}
}
static void display_model(sat::solver const & s) {
sat::model const & m = s.get_model();
for (unsigned i = 1; i < m.size(); i++) {
switch (m[i]) {
case l_false: std::cout << "-" << i << " "; break;
case l_undef: break;
case l_true: std::cout << i << " "; break;
}
}
std::cout << "\n";
}
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 track_clauses(sat::solver const& src,
sat::solver& dst,
sat::literal_vector& assumptions,
vector<sat::literal_vector>& tracking_clauses) {
for (sat::bool_var v = 0; v < src.num_vars(); ++v) {
dst.mk_var(false, true);
}
sat::literal_vector lits;
sat::literal lit;
sat::clause * const * it = src.begin_clauses();
sat::clause * const * end = src.end_clauses();
svector<sat::solver::bin_clause> bin_clauses;
src.collect_bin_clauses(bin_clauses, false);
tracking_clauses.reserve(2*src.num_vars() + static_cast<unsigned>(end - it) + bin_clauses.size());
for (sat::bool_var v = 1; v < src.num_vars(); ++v) {
if (src.value(v) != l_undef) {
bool sign = src.value(v) == l_false;
lits.reset();
lits.push_back(sat::literal(v, sign));
track_clause(dst, lits, assumptions, tracking_clauses);
}
}
for (; it != end; ++it) {
lits.reset();
sat::clause& cls = *(*it);
lits.append(static_cast<unsigned>(cls.end()-cls.begin()), cls.begin());
track_clause(dst, lits, assumptions, tracking_clauses);
}
for (unsigned i = 0; i < bin_clauses.size(); ++i) {
lits.reset();
lits.push_back(bin_clauses[i].first);
lits.push_back(bin_clauses[i].second);
track_clause(dst, lits, assumptions, tracking_clauses);
}
}
bool parse_dimacs_core(Buffer & in, std::ostream& err, sat::solver & solver) {
sat::literal_vector lits;
try {
while (true) {
skip_whitespace(in);
if (*in == EOF) {
break;
}
else if (*in == 'c' || *in == 'p') {
skip_line(in);
}
else {
read_clause(in, err, solver, lits);
solver.mk_clause(lits.size(), lits.c_ptr());
}
}
}
catch (lex_error) {
return false;
}
return true;
}