proposition: Theorem is_tableau_std (d : unit) (T : inhOrderType d) (t : seq (seq T)) : is_tableau t = is_tableau (skew_reshape [::] (shape t) (std (to_word t))).
proof: Proof. rewrite -{1}(to_wordK t); apply is_tableau_reshape_std. by rewrite size_to_word. Qed.
imports: HB(structures) mathcomp(all_ssreflect) tools partition skewpart Yamanouchi ordtype tableau std stdtab