proposition: Lemma tak_fun_rho: tak_fun par rho.
proof: Proof. intros s t H; induction H; cbn; trivial. - auto. - subst u; eapply subst_compatible_par; auto. intros []; cbn; auto. - destruct s; auto. inv H; inv IHpar1. econstructor; eauto. Qed.
imports: Morphisms Setoid Undecidability.HOU(std.std) Undecidability.HOU.calculus(prelim terms semantics)