Definition substopt {A} (ret: option ident) (v: val) (P: environ -> A)  : environ -> A :=
match ret with
| Some id => subst id v P
| None => P
end.

Lemma pass_params_ni :
forall  l2
(te' : temp_env) (id : positive) te l,
bind_parameter_temps l2 l (te) = Some te' ->
(In id (map fst l2) -> False) ->
Map.get (make_tenv te') id = te ! id.