proposition: Lemma commword_morph (u v : seq 'I_n) : commword (u ++ v) = (commword u) * (commword v).
proof: Proof. Proof using . by rewrite /commword big_cat. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssralg) mathcomp(ssrcomplements freeg mpoly) tools ordtype partition Yamanouchi std tableau stdtab Schensted congr plactic stdplact Yam_plact Greene_inv shuffle Schur_mpoly