proposition: Lemma monsYK : cancel monsY Ymon.
proof: Proof. move=> mz; apply mnmP => i. by rewrite mnmE tnth_mktuple mnmE /= vecmx_indexK. 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