Instance find_elt_compat A dom (m : t A dom) : Proper (X.eq ==> Logic.eq) (fun x => find x m).

Lemma fold_spec : forall A B (f : key -> A -> B -> B) dom (m : t A dom) (i : B), fold f m i = List.fold_left (fun acc xv => f (fst xv) (snd xv) acc) (elements m) i.