const exprt qbf_squolem_coret::f_get(literalt l)
{
if(squolem->isUniversal(l.var_no()))
{
assert(l.var_no()!=0);
variable_mapt::const_iterator it=variable_map.find(l.var_no());
if(it==variable_map.end())
throw "Variable map error";
const exprt &sym=it->second.first;
unsigned index=it->second.second;
exprt extract_expr(ID_extractbit, typet(ID_bool));
extract_expr.copy_to_operands(sym);
typet uint_type(ID_unsignedbv);
uint_type.set(ID_width, 32);
extract_expr.copy_to_operands(from_integer(index, uint_type));
if(l.sign()) extract_expr.negate();
return extract_expr;
}
function_cachet::const_iterator it=function_cache.find(l.var_no());
if(it!=function_cache.end())
{
#if 0
std::cout << "CACHE HIT for " << l.dimacs() << std::endl;
#endif
if(l.sign())
return not_exprt(it->second);
else
return it->second;
}
else
{
WitnessStack *wsp = squolem->getModelFunction(Literal(l.dimacs()));
exprt res;
if(wsp==NULL || wsp->empty())
{
// res=exprt(ID_nondet_bool, typet(ID_bool));
res=false_exprt(); // just set it to zero
}
else if(wsp->pSize<=wsp->nSize)
res=f_get_cnf(wsp);
else
res=f_get_dnf(wsp);
function_cache[l.var_no()] = res;
if(l.sign())
return not_exprt(res);
else
return res;
}
}
tvt satcheck_lingelingt::l_get(literalt a) const
{
if(a.is_constant())
return tvt(a.sign());
tvt result;
if(a.var_no()>lglmaxvar(solver))
return tvt(tvt::TV_UNKNOWN);
const int val=lglderef(solver, a.dimacs());
if(val>0)
result=tvt(true);
else if(val<0)
result=tvt(false);
else
return tvt(tvt::TV_UNKNOWN);
return result;
}
/// Returns true if an assumed literal is in conflict if the formula is UNSAT.
///
/// NOTE: if the literal is not in the assumption it causes an
/// assertion failure in lingeling.
bool satcheck_lingelingt::is_in_conflict(literalt a) const
{
assert(!a.is_constant());
return lglfailed(solver, a.dimacs())!=0;
}
void satcheck_lingelingt::set_frozen(literalt a)
{
if(!a.is_constant())
lglfreeze(solver, a.dimacs());
}