proposition: Lemma is_row_yamrow : is_row (ncons d2 0%N [::]).
proof: Proof. Proof using . by elim: d2 => [| [|d]]. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(ssralg) mathcomp(mpoly) tools ordcast combclass partition skewpart Yamanouchi ordtype std tableau stdtab Schensted congr plactic Greene_inv stdplact Yam_plact skewtab shuffle Schur_mpoly freeSchur