/**
\brief Return \c true if a cycle is detected.
*/
bool main_loop(func_decl * f) {
if (get_color(f) == CLOSED)
return false;
m_todo.push_back(f);
while (!m_todo.empty()) {
func_decl * f = m_todo.back();
switch (get_color(f)) {
case CLOSED:
m_todo.pop_back();
break;
case OPEN:
set_color(f, IN_PROGRESS);
if (visit_children(f)) {
SASSERT(m_todo.back() == f);
m_todo.pop_back();
set_color(f, CLOSED);
}
break;
case IN_PROGRESS:
if (all_children_closed(f)) {
SASSERT(m_todo.back() == f);
set_color(f, CLOSED);
} else {
m_todo.reset();
return true;
}
break;
default:
UNREACHABLE();
}
}
return false;
}
void process(expr * f) {
if (fvisited.is_marked(f))
return;
fvisited.mark(f);
todo.push_back(f);
while (!todo.empty()) {
expr * t = todo.back();
todo.pop_back();
if (is_uninterp_const(t))
continue;
if (is_app(t) && to_app(t)->get_family_id() == m.get_basic_family_id() && to_app(t)->get_num_args() > 0) {
decl_kind k = to_app(t)->get_decl_kind();
if (k == OP_OR || k == OP_NOT || k == OP_IFF || ((k == OP_EQ || k == OP_ITE) && m.is_bool(to_app(t)->get_arg(1)))) {
unsigned num = to_app(t)->get_num_args();
for (unsigned i = 0; i < num; i++) {
expr * arg = to_app(t)->get_arg(i);
if (fvisited.is_marked(arg))
continue;
fvisited.mark(arg);
todo.push_back(arg);
}
}
}
else {
quick_for_each_expr(proc, tvisited, t);
}
}
}
void reduce(proof* pf, proof_ref &out)
{
proof *res = nullptr;
m_todo.reset();
m_todo.push_back(pf);
ptr_buffer<proof> args;
bool dirty = false;
while (!m_todo.empty()) {
proof *p, *tmp, *pp;
unsigned todo_sz;
p = m_todo.back();
if (m_cache.find(p, tmp)) {
res = tmp;
m_todo.pop_back();
continue;
}
dirty = false;
args.reset();
todo_sz = m_todo.size();
for (unsigned i = 0, sz = m.get_num_parents(p); i < sz; ++i) {
pp = m.get_parent(p, i);
if (m_cache.find(pp, tmp)) {
args.push_back(tmp);
dirty = dirty || pp != tmp;
} else {
m_todo.push_back(pp);
}
}
if (todo_sz < m_todo.size()) { continue; }
else { m_todo.pop_back(); }
if (m.is_hypothesis(p)) {
// hyp: replace by a corresponding unit
if (m_units.find(m.get_fact(p), tmp)) {
res = tmp;
} else { res = p; }
}
else if (!dirty) { res = p; }
else if (m.is_lemma(p)) {
//lemma: reduce the premise; remove reduced consequences from conclusion
SASSERT(args.size() == 1);
res = mk_lemma_core(args.get(0), m.get_fact(p));
compute_mark1(res);
} else if (m.is_unit_resolution(p)) {
// unit: reduce units; reduce the first premise; rebuild unit resolution
res = mk_unit_resolution_core(args.size(), args.c_ptr());
compute_mark1(res);
} else {
// other: reduce all premises; reapply
if (m.has_fact(p)) { args.push_back(to_app(m.get_fact(p))); }
SASSERT(p->get_decl()->get_arity() == args.size());
res = m.mk_app(p->get_decl(), args.size(), (expr * const*)args.c_ptr());
m_pinned.push_back(res);
compute_mark1(res);
}
SASSERT(res);
m_cache.insert(p, res);
if (m.has_fact(res) && m.is_false(m.get_fact(res))) { break; }
}
out = res;
}
