}
const ex& sym = r.lhs();
// find existing minimal degree
- int real_ldegree = basis.expand().ldegree(sym-r.rhs());
+ ex eb = basis.expand();
+ int real_ldegree = 0;
+ if (eb.info(info_flags::rational_function))
+ real_ldegree = eb.ldegree(sym-r.rhs());
if (real_ldegree == 0) {
int orderloop = 0;
do {