bool all_commutative = true;
exvector::const_iterator noncommutative_element; // point to first found nc element
- exvector::const_iterator i = seq.begin(), end = seq.end();
+ auto i = seq.begin(), end = seq.end();
while (i != end) {
unsigned rt = i->return_type();
if (rt == return_types::noncommutative_composite)