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