(* The following two lemmas is not now used. but after deep embedded hoare logic (SL_as_Logic) is ported, the frame does not need to be quantified in the semantic definition of semax. Then, these two lemmas can replace the other two afterwards. *)

Lemma rguard_tc_environ: forall {Espec: OracleKind} ge Delta' Delta (F: environ -> pred rmap) P k,
tycontext_sub Delta Delta' ->
rguard Espec ge Delta' (frame_ret_assert P F) k = rguard Espec ge Delta' (frame_ret_assert (conj_ret_assert P (fun rho => !! typecheck_environ Delta rho)) F) k.