// Convert the lists to a map
exmap m;
- for (lst::const_iterator its = ls.begin(), itr = lr.begin(); its != ls.end(); ++its, ++itr) {
+ for (auto its = ls.begin(), itr = lr.begin(); its != ls.end(); ++its, ++itr) {
m.insert(std::make_pair(*its, *itr));
// Search for products and powers in the expressions to be substituted