proposition: Lemma changeUtakeP : is_RStabpair (RS (take d1 w), val U1).
proof: Proof. Proof using Htake. by rewrite /is_RStabpair is_tableau_RS Htake /= eq_refl andbT. 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