(* Copied from canon.v end. *)

Lemma semax_pre_post'': forall P' R' Espec {cs: compspecs} Delta R P c,
local (tc_environ Delta) && P |-- P' ->
local (tc_environ Delta) && R' |-- RA_normal R ->
@semax cs Espec Delta P' c (normal_ret_assert R') ->
@semax cs Espec Delta P c R.