intros.
destruct Q as [?Q ?Q ?Q ?Q].
eapply semax_post; eauto; intros; apply andp_left2; simpl; auto; normalize.
Qed.

Lemma sequential':
forall Q Espec {cs: compspecs} Delta P c R,
@semax cs Espec Delta P c (normal_ret_assert Q) ->
@semax cs Espec Delta P c (overridePost Q R).