map<Enode *, bool> CoreSMTSolver::getBoolModel() {
map<Enode *, bool> ret;
for (int i = 0; i < trail.size(); i++) {
Lit const & l = trail[i];
Var const v = var(l);
if (v >= 2) {
Enode * e = theory_handler->varToEnode(v);
bool p = value(l) == l_True;
if (e->isNot()) {
e = e->get1st();
p = !p;
}
if (e->isVar()) {
if (sign(l)) {
p = !p;
}
ret.emplace(e, p);
}
}
}
return ret;
}
box refine_CE_with_nlopt_core(box counterexample, vector<Enode*> const & opt_ctrs, vector<Enode*> const & side_ctrs) {
// Plug-in `a` into the constraint and optimize `b` in the counterexample `M` by solving:
//
// ∃ y_opt ∈ I_y. ∀ y ∈ I_y. f(a, y_opt) >= f(a, y) — (2)
//
// using local optimizer (i.e. nlopt).
// Let `M’ = (a, b_opt)` be a model for (2).
DREAL_LOG_DEBUG << "================================" << endl;
DREAL_LOG_DEBUG << " Before Refinement " << endl;
DREAL_LOG_DEBUG << "================================" << endl;
DREAL_LOG_DEBUG << counterexample << endl;
DREAL_LOG_DEBUG << "================================" << endl;
static bool initialized = false;
static vector<double> lb, ub, init;
init.clear();
for (Enode * e : counterexample.get_vars()) {
if (e->isForallVar()) {
if (!initialized) {
lb.push_back(e->getDomainLowerBound());
ub.push_back(e->getDomainUpperBound());
}
init.push_back(counterexample[e].mid());
DREAL_LOG_DEBUG << lb.back() << " <= " << init.back() << " <= " << ub.back() << endl;
}
}
auto const n = init.size();
static nlopt::opt opt(nlopt::LD_SLSQP, n);
if (!initialized) {
opt.set_lower_bounds(lb);
opt.set_upper_bounds(ub);
// set tollerance
// TODO(soonhok): set precision
// opt.set_xtol_rel(0.0001);
opt.set_xtol_abs(0.001);
opt.set_maxtime(0.01);
initialized = true;
}
opt.remove_equality_constraints();
opt.remove_inequality_constraints();
// set objective function
vector<tuple<Enode *, box const &, bool> *> extra_vec;
Enode * e = opt_ctrs[0];
bool polarity = false;
while (e->isNot()) {
e = e->get1st();
polarity = !polarity;
}
auto extra = new tuple<Enode *, box const &, bool>(e, counterexample, polarity);
extra_vec.push_back(extra);
opt.set_min_objective(nlopt_obj, extra);
opt.add_inequality_constraint(nlopt_side_condition, extra);
DREAL_LOG_DEBUG << "objective function is added: " << e << endl;
// set side conditions
for (Enode * e : side_ctrs) {
bool polarity = false;
while (e->isNot()) {
e = e->get1st();
polarity = !polarity;
}
auto extra = new tuple<Enode *, box const &, bool>(e, counterexample, polarity);
extra_vec.push_back(extra);
DREAL_LOG_DEBUG << "refine_counterexample_with_nlopt: Side condition is added: " << e << endl;
if (e->isEq()) {
opt.add_equality_constraint(nlopt_side_condition, extra);
} else if (e->isLt() || e->isLeq() || e->isGt() || e->isGeq()) {
opt.add_inequality_constraint(nlopt_side_condition, extra);
}
}
try {
vector<double> output = opt.optimize(init);
unsigned i = 0;
for (Enode * e : counterexample.get_vars()) {
if (e->isForallVar()) {
counterexample[e] = output[i];
i++;
}
}
} catch (nlopt::roundoff_limited & e) {
} catch (std::runtime_error & e) {
DREAL_LOG_DEBUG << e.what() << endl;
}
for (auto extra : extra_vec) {
delete extra;
}
DREAL_LOG_DEBUG << "================================" << endl;
DREAL_LOG_DEBUG << " After Refinement " << endl;
DREAL_LOG_DEBUG << "================================" << endl;
DREAL_LOG_DEBUG << counterexample << endl;
DREAL_LOG_DEBUG << "================================" << endl;
return counterexample;
}
//
// Performs the actual cnfization
//
bool Tseitin::cnfize( Enode * formula, map< enodeid_t, Enode * > & cnf_cache )
{
(void)cnf_cache;
assert( formula );
assert( !formula->isAnd( ) );
Enode * arg_def = egraph.valDupMap1( formula );
if ( arg_def != NULL )
{
vector< Enode * > clause;
clause.push_back( arg_def );
#ifdef PRODUCE_PROOF
if ( config.produce_inter > 0 )
return solver.addSMTClause( clause, egraph.getIPartitions( formula ) );
#endif
return solver.addSMTClause( clause );
}
vector< Enode * > unprocessed_enodes; // Stack for unprocessed enodes
unprocessed_enodes.push_back( formula ); // formula needs to be processed
//
// Visit the DAG of the formula from the leaves to the root
//
while( !unprocessed_enodes.empty( ) )
{
Enode * enode = unprocessed_enodes.back( );
//
// Skip if the node has already been processed before
//
if ( egraph.valDupMap1( enode ) != NULL )
{
unprocessed_enodes.pop_back( );
continue;
}
bool unprocessed_children = false;
Enode * arg_list;
for ( arg_list = enode->getCdr( ) ;
arg_list != egraph.enil ;
arg_list = arg_list->getCdr( ) )
{
Enode * arg = arg_list->getCar( );
assert( arg->isTerm( ) );
//
// Push only if it is an unprocessed boolean operator
//
if ( enode->isBooleanOperator( )
&& egraph.valDupMap1( arg ) == NULL )
{
unprocessed_enodes.push_back( arg );
unprocessed_children = true;
}
//
// If it is an atom (either boolean or theory) just
// store it in the cache
//
else if ( arg->isAtom( ) )
{
egraph.storeDupMap1( arg, arg );
}
}
//
// SKip if unprocessed_children
//
if ( unprocessed_children )
continue;
unprocessed_enodes.pop_back( );
Enode * result = NULL;
//
// At this point, every child has been processed
//
//
// Do the actual cnfization, according to the node type
//
char def_name[ 32 ];
if ( enode->isLit( ) )
{
result = enode;
}
else if ( enode->isNot( ) )
{
Enode * arg_def = egraph.valDupMap1( enode->get1st( ) );
assert( arg_def );
result = egraph.mkNot( egraph.cons( arg_def ) ); // Toggle the literal
}
else
{
Enode * arg_def = NULL;
Enode * new_arg_list = egraph.copyEnodeEtypeListWithCache( enode->getCdr( ) );
//
// If the enode is not top-level it needs a definition
//
if ( formula != enode )
{
sprintf( def_name, CNF_STR, formula->getId( ), enode->getId( ) );
egraph.newSymbol( def_name, sstore.mkBool( ) );
arg_def = egraph.mkVar( def_name );
#ifdef PRODUCE_PROOF
if ( config.produce_inter > 0 )
{
// Tag Positive and negative literals
egraph.tagIFormula( arg_def
, egraph.getIPartitions( enode ) );
egraph.tagIFormula( egraph.mkNot( egraph.cons( arg_def ) )
, egraph.getIPartitions( enode ) );
}
#endif
}
#ifdef PRODUCE_PROOF
uint64_t partitions = 0;
if ( config.produce_inter > 0 )
{
partitions = egraph.getIPartitions( enode );
assert( partitions != 0 );
}
#endif
//
// Handle boolean operators
//
if ( enode->isAnd( ) )
cnfizeAnd( new_arg_list, arg_def
#ifdef PRODUCE_PROOF
, partitions
#endif
);
else if ( enode->isOr( ) )
cnfizeOr( new_arg_list, arg_def
#ifdef PRODUCE_PROOF
, partitions
#endif
);
else if ( enode->isIff( ) )
cnfizeIff( new_arg_list, arg_def
#ifdef PRODUCE_PROOF
, partitions
#endif
);
else if ( enode->isXor( ) )
cnfizeXor( new_arg_list, arg_def
#ifdef PRODUCE_PROOF
, partitions
#endif
);
else
{
opensmt_error2( "operator not handled ", enode->getCar( ) );
}
if ( arg_def != NULL )
result = arg_def;
}
assert( egraph.valDupMap1( enode ) == NULL );
egraph.storeDupMap1( enode, result );
}
if ( formula->isNot( ) )
{
// Retrieve definition of argument
Enode * arg_def = egraph.valDupMap1( formula->get1st( ) );
assert( arg_def );
vector< Enode * > clause;
clause.push_back( toggleLit( arg_def ) );
#ifdef PRODUCE_PROOF
if ( config.produce_inter > 0 )
return solver.addSMTClause( clause, egraph.getIPartitions( formula ) );
#endif
return solver.addSMTClause( clause );
}
return true;
}