proposition: Lemma map_syme d : map_sympoly 'e_d = 'e_d.
proof: Proof. apply val_inj; rewrite /= /mesym rmorph_sum /=. apply eq_bigr => X _; rewrite rmorph_prod /=. by apply eq_bigr => i _; rewrite map_mpolyX. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssralg ssrint fingroup perm) mathcomp(ssrcomplements freeg mpoly) sorted tools ordtype permuted partition skewpart composition Yamanouchi std tableau stdtab skewtab permcent antisym Schur_mpoly therule Schur_altdef unitriginv