proposition: Lemma map_syms d (la : 'P_d) : map_sympoly 's[la] = 's[la].
proof: Proof. apply val_inj; rewrite /= rmorph_sum /=. apply eq_bigr => X _; rewrite rmorph_prod; apply eq_bigr => /= i _. by 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