+
+ // (2*x + 6*y)^(-4) -> 1/16*(x + 3*y)^(-4)
+ if (num_exponent->is_integer() && is_exactly_a<add>(ebasis)) {
+ numeric icont = ebasis.integer_content();
+ const numeric lead_coeff =
+ ex_to<numeric>(ex_to<add>(ebasis).seq.begin()->coeff).div(icont);
+
+ const bool canonicalizable = lead_coeff.is_integer();
+ const bool unit_normal = lead_coeff.is_pos_integer();
+ if (canonicalizable && (! unit_normal))
+ icont = icont.mul(*_num_1_p);
+
+ if (canonicalizable && (icont != *_num1_p)) {
+ const add& addref = ex_to<add>(ebasis);
+ add* addp = new add(addref);
+ addp->setflag(status_flags::dynallocated);
+ addp->clearflag(status_flags::hash_calculated);
+ addp->overall_coeff = ex_to<numeric>(addp->overall_coeff).div_dyn(icont);
+ for (epvector::iterator i = addp->seq.begin(); i != addp->seq.end(); ++i)
+ i->coeff = ex_to<numeric>(i->coeff).div_dyn(icont);
+
+ const numeric c = icont.power(*num_exponent);
+ if (likely(c != *_num1_p))
+ return (new mul(power(*addp, *num_exponent), c))->setflag(status_flags::dynallocated);
+ else
+ return power(*addp, *num_exponent);
+ }
+ }
+