proposition: Lemma dominant_mpart d m : m \is dominant -> mdeg m = d -> { p : 'P_d | m = mpart p }.
proof: Proof. move=> mdom degm. have hpm : is_part_of_n d (partm m). by rewrite /= -degm sumn_partm eqxx /=. by exists (IntPartN hpm); rewrite partmK. 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