Definition env_initial_value (e: env) (m: mem) :=
forall id b ty chunk,
e!id = Some(b, ty) -> access_mode ty = By_value chunk -> Mem.load chunk m b 0 = Some Vundef.

Lemma create_undef_temps_exten:
forall id l1 l2,
(In id (var_names l1) <-> In id (var_names l2)) ->
(create_undef_temps l1)!id = (create_undef_temps l2)!id.