proposition: Lemma sympe1E : 'p_1 = 'e_1.
proof: Proof. Proof using. apply val_inj; rewrite syme1 /=. by apply eq_bigr => i _; rewrite expr1. 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