proposition: Lemma monsY_bij : bijective monsY.
proof: Proof. by exists Ymon; [exact: monsYK | exact: YmonK]. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssrint rat ssralg ssrnum algC matrix vector) mathcomp(mpoly) tools partition ordtype antisym Schur_mpoly Schur_altdef sympoly homogsym permcent