proposition: Lemma normCKC x : `|x| ^+ 2 = x^* * x.
proof: Proof. by rewrite normCK mulrC. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)