proposition: Lemma tabnat_of_ord_subproof (t : tabsh la) : is_stdtab_of_shape la (tabnat_of_ord_fun t).
proof: Proof. rewrite /tabnat_of_ord_fun. case: eqP => [Hev | _]; last by case: (hyper_stdtabsh la). rewrite /= /is_stdtab -incr_tab // tabshP /= /eval. rewrite shape_map_tab shape_tabsh eq_refl andbT. by rewrite to_word_map_tab tabsh_is_std. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssralg ssrint fingroup perm) mathcomp(mpoly) tools combclass ordtype sorted partition tableau skewpart skewtab antisym Schur_mpoly freeSchur therule std stdtab unitriginv presentSn