(*Clight-specific: Require Import VST.veric.extend_tc. Require Import VST.veric.Clight_seplog. Require Import VST.veric.Clight_assert_lemmas. Require Import VST.veric.tycontext. Require Import VST.veric.expr2. Require Import VST.veric.expr_lemmas. *)
Local Open Scope pred.
Obligation Tactic := idtac.
Ltac destruct_cjoin phi HH :=
match goal with
|   |- context [@proj1_sig rmap _ ?X] => destruct X as [phi HH]; simpl
|  H: context [@proj1_sig rmap _ ?X] |- _ => destruct X as [phi HH]; simpl in H
end.

Lemma dec_pure: forall r, {exists k, exists pp, r = PURE k pp}+{core r = NO Share.bot bot_unreadable}.