proposition: Lemma cnvar_syme i : (i <= m) || (n <= m) -> cnvarsym 'e_i = 'e_i.
proof: Proof. move=> /orP[] H; first exact: cnvar_leq_symeE. case: (leqP i m) => [] H1; first exact: cnvar_leq_symeE. by rewrite !syme_geqnE ?raddf0 // (leq_ltn_trans H H1). 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