proposition: Lemma normr_le0 v : `|v| <= 0 = (v == 0).
proof: Proof. by rewrite -normr_eq0 eq_le normr_ge0 andbT. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)