proposition: Lemma normal_inhab x A: normal (inhab x A).
proof: Proof. unfold inhab. generalize (arity A + x) as k. induction (arity A); cbn; eauto using normal_lam_intro. Qed.
imports: PeanoNat Lia List Undecidability.HOU(calculus.calculus concon.conservativity_constants unification.higher_order_unification unification.systemunification unification.nth_order_unification)