proposition: Lemma LRcoeff_computeP : LRyam_compute P1 P2 P = LRyam_coeff.
proof: Proof. Proof using . rewrite /LRyam_coeff /LRyam_set /LRyam_compute /LRyam_enum. rewrite cardE (eq_enum (in_set _)) /enum_mem -enumT. rewrite (eq_filter (a2 := (fun x => is_skew_reshape_tableau P P1 (val x)))). - by rewrite -(size_map val) map_filter_comp enum_yamevalE map_id. - by move=> i /=; rewrite unfold_in. 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