Definition interp_lock := resourcemaps.interp_lock.Definition islock (l : nat) (R : map -> Prop) (m : map) :=
  exists lock, m l = Some (inr lock) /\ interp_lock lock = R.

(* Specifications: *)
Lemma islock_inj : forall v R1 R2 m, islock v R1 m -> islock v R2 m -> R1 = R2.