Fixpoint iota_formals (i: ident) (tl: typelist) :=
match tl with
| Tcons t tl' => (i,t) :: iota_formals (i+1)%positive tl'
| Tnil => nil
end.
Ltac make_sequential :=
match goal with
| |- @semax _ _ _ _ _ (normal_ret_assert _) => idtac
| |- _ => apply sequential
end.

Lemma typed_true_of_bool':
forall x (P: Prop),
((x=true) -> P) ->
(typed_true tint (Val.of_bool x) -> P).