proposition: Lemma normrX n x : `|x ^+ n| = `|x| ^+ n.
proof: Proof. by rewrite -(card_ord n) -!prodr_const normr_prod. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)