proposition: Lemma normr0 : `|0 : V| = 0.
proof: Proof. by rewrite -(mulr0n 0) normrMn mulr0n. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)