proposition: Lemma msymMm p (s1 s2 : 'S_n) : msym (s1 * s2)%g p = msym s2 (msym s1 p).
proof: Proof. by apply/mpolyP=> m; rewrite !mcoeff_sym mpermM. 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