proposition: Lemma length_maxpermMl s : length (maxperm * s) = 'C(n, 2) - length s.
proof: Proof. by rewrite -lengthV invMg maxpermV length_maxpermMr lengthV. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(fingroup perm morphism presentation) mathcomp(ssralg poly ssrint) permcomp tools permuted combclass congr