Set Implicit Arguments.
From Undecidability.HOU.calculus Require Export semantics typing.
From Undecidability.HOU Require Import calculus.order.
(* * Terms Extension *)
Notation "sigma •₊ A" := (map (subst_exp sigma) A) (at level 69).
Notation renL delta A := (map (ren delta) A).
Notation Vars := (flat_map vars).

Lemma tab_subst {X} sigma (f: nat -> exp X) n:
sigma •₊ tab f n = tab (f >> subst_exp sigma) n.