level update_max(level const & l, level const & new_lhs, level const & new_rhs) {
if (is_eqp(to_max_core(l).m_lhs, new_lhs) && is_eqp(to_max_core(l).m_rhs, new_rhs))
return l;
else if (is_max(l))
return mk_max(new_lhs, new_rhs);
else
return mk_imax(new_lhs, new_rhs);
}
vm_obj level_imax(vm_obj const & o1, vm_obj const & o2) {
return to_obj(mk_imax(to_level(o1), to_level(o2)));
}
level normalize(level const & l) {
auto p = to_offset(l);
level const & r = p.first;
switch (kind(r)) {
case level_kind::Succ:
lean_unreachable(); // LCOV_EXCL_LINE
case level_kind::Zero: case level_kind::Param:
case level_kind::Global: case level_kind::Meta:
return l;
case level_kind::IMax: {
auto l1 = normalize(imax_lhs(r));
auto l2 = normalize(imax_rhs(r));
if (!is_eqp(l1, imax_lhs(r)) || !is_eqp(l2, imax_rhs(r)))
return mk_succ(mk_imax(l1, l2), p.second);
else
return l;
}
case level_kind::Max: {
buffer<level> todo;
buffer<level> args;
push_max_args(r, todo);
for (level const & a : todo)
push_max_args(normalize(a), args);
std::sort(args.begin(), args.end(), is_norm_lt);
buffer<level> & rargs = todo;
rargs.clear();
unsigned i = 0;
if (is_explicit(args[i])) {
// find max explicit univierse
while (i+1 < args.size() && is_explicit(args[i+1]))
i++;
lean_assert(is_explicit(args[i]));
unsigned k = to_offset(args[i]).second;
// an explicit universe k is subsumed by succ^k(l)
unsigned j = i+1;
for (; j < args.size(); j++) {
if (to_offset(args[j]).second >= k)
break;
}
if (j < args.size()) {
// explicit universe was subsumed by succ^k'(l) where k' >= k
i++;
}
}
rargs.push_back(args[i]);
auto p_prev = to_offset(args[i]);
i++;
for (; i < args.size(); i++) {
auto p_curr = to_offset(args[i]);
if (p_prev.first == p_curr.first) {
if (p_prev.second < p_curr.second) {
p_prev = p_curr;
rargs.pop_back();
rargs.push_back(args[i]);
}
} else {
p_prev = p_curr;
rargs.push_back(args[i]);
}
}
for (level & a : rargs)
a = mk_succ(a, p.second);
return mk_max(rargs);
}}
lean_unreachable(); // LCOV_EXCL_LINE
}
