(* Condition variables *)
(*Definition _cond_t := 4%positive.*)
Definition tcond := tint.
(* Does this need to be anything special? *)
Definition cond_var {cs} sh v := @data_at_ cs sh tcond v.
(*+ Specification of each concurrent primitive *)

Lemma fash_equiv_approx: forall n (R: pred rmap),
(|> (R <=> approx n R))%pred n.