proposition: Lemma cnvarsym_id n : @cnvarsym R n n =1 id.
proof: Proof. by move=> f; apply val_inj; rewrite /= sympolyfP. 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