bool mk_subsumption_checker::transform_rule(rule * r,
rule_subsumption_index& subs_index, rule_ref & res)
{
unsigned u_len = r->get_uninterpreted_tail_size();
unsigned len = r->get_tail_size();
if(u_len==0) {
res = r;
return true;
}
app_ref head(r->get_head(), m);
app_ref_vector tail(m);
svector<bool> tail_neg;
for(unsigned i=0; i<u_len; i++) {
app * tail_atom = r->get_tail(i);
bool neg = r->is_neg_tail(i);
if(m_total_relations.contains(tail_atom->get_decl())
|| subs_index.is_subsumed(tail_atom)) {
if(neg) {
//rule contains negated total relation, this means that it is unsatisfiable
//and can be removed
return false;
}
else {
//we remove total relations from the tail
continue;
}
}
if(!neg && head.get()==tail_atom) {
//rule contains its head positively in the tail, therefore
//it will never add any new facts to the relation, so it
//can be removed
return false;
}
tail.push_back(tail_atom);
tail_neg.push_back(neg);
}
if(tail.size()==u_len) {
res = r;
return true;
}
//we just copy the interpreted part of the tail
for(unsigned i=u_len; i<len; i++) {
tail.push_back(r->get_tail(i));
tail_neg.push_back(r->is_neg_tail(i));
}
SASSERT(tail.size()==tail_neg.size());
res = m_context.get_rule_manager().mk(head, tail.size(), tail.c_ptr(), tail_neg.c_ptr());
res->set_accounting_parent_object(m_context, r);
m_context.get_rule_manager().fix_unbound_vars(res, true);
m_context.get_rule_manager().mk_rule_rewrite_proof(*r, *res.get());
return true;
}
void mk_interp_tail_simplifier::rule_substitution::get_result(rule_ref & res) {
SASSERT(m_rule);
apply(m_rule->get_head(), m_head);
m_tail.reset();
m_neg.reset();
unsigned tail_len = m_rule->get_tail_size();
for (unsigned i=0; i<tail_len; i++) {
app_ref new_tail_el(m);
apply(m_rule->get_tail(i), new_tail_el);
m_tail.push_back(new_tail_el);
m_neg.push_back(m_rule->is_neg_tail(i));
}
mk_rule_inliner::remove_duplicate_tails(m_tail, m_neg);
SASSERT(m_tail.size() == m_neg.size());
res = m_context.get_rule_manager().mk(m_head, m_tail.size(), m_tail.c_ptr(), m_neg.c_ptr(),m_rule->name());
res->set_accounting_parent_object(m_context, m_rule);
res->norm_vars(res.get_manager());
}