proposition: Lemma ord_Arr L A: ord (Arr L A) = max (1 + ord' L) (ord A).
proof: Proof. induction L; cbn -[max]. symmetry; eapply Nat.max_r. eapply ord_1. rewrite IHL, Nat.max_assoc. cbn [plus]. reflexivity. Qed.
imports: List Arith Lia Morphisms FinFun Undecidability.HOU(std.std) Undecidability.HOU.calculus(prelim terms syntax semantics equivalence typing order confluence)