proposition: Lemma mpermM m (s1 s2 : 'S_n) : m#(s1 * s2)%g = m#s2#s1.
proof: Proof. by apply/mnmP=> i; rewrite !mnmE permM. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype tuple finfun bigop finset binomial) mathcomp(order fingroup perm ssralg zmodp poly ssrint) mathcomp(matrix vector) mathcomp(bigenough) ssrcomplements freeg