(* * Copyright (c) 2009 Robert Dockins and Aquinas Hobor. * *)
(* Coq development: using indirection theory to model types in l-calculus *)
(* lam_ref_mach_lemmas.v: various boring lemmas about the machine *)
(* COERCIONS *)
(* DECIDABILTY *)
(* SUBSTITUTION *)

Lemma subst_subst_env_lt : forall env n m v e,
n < m ->
subst n v (subst_env' m env e) =
subst_env' m env (subst n v e).