proposition: Lemma mesym0E : 's_0 = 1.
proof: Proof. rewrite mesymE (bigD1 set0) ?cards0 //= mesym1_set0 mpolyX0. by rewrite big1 ?addr0 // => i /andP[/eqP/cards0_eq->]; rewrite eqxx. 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