(* standard VST prelude *)
Instance CompSpecs : compspecs.Definition Vprog : varspecs.(* import funspecs from concurrency library *)
Definition acquire_spec := DECLARE _acquire acquire_spec.Definition release_spec := DECLARE _release release_spec.(* These histories should be usable for any atomically accessed location. *)
Inductive AE_hist_el := AE (r : val) (w : val).(* These histories should be usable for any atomically accessed location. *)
Inductive AE_hist_el := AE (r : val) (w : val).

(* Specifications: *)
Lemma apply_hist_app : forall h1 i h2, apply_hist i (h1 ++ h2) = match apply_hist i h1 with Some v => apply_hist v h2 | None => None end.