|| is_ex_exactly_of_type(*it1, mul) || is_ex_exactly_of_type(*it2, mul)
|| is_ex_exactly_of_type(*it1, ncmul) || is_ex_exactly_of_type(*it2, ncmul)) {
// One of the factors became a sum or product:
// re-expand expression and run again
|| is_ex_exactly_of_type(*it1, mul) || is_ex_exactly_of_type(*it2, mul)
|| is_ex_exactly_of_type(*it1, ncmul) || is_ex_exactly_of_type(*it2, ncmul)) {
// One of the factors became a sum or product:
// re-expand expression and run again