Module Import P := Properties M.
Hint Resolve elements_spec2 : core.
Hint Immediate
min_elt_spec1 min_elt_spec2 min_elt_spec3
max_elt_spec1 max_elt_spec2 max_elt_spec3 : set.
Definition gtb x y := match E.compare x y with Gt => true | _ => false end.
Definition leb x := fun y => negb (gtb x y).
Definition elements_lt x s := List.filter (gtb x) (elements s).
Definition elements_ge x s := List.filter (leb x) (elements s).
Instance gtb_compat x : Proper (E.eq==>Logic.eq) (gtb x).
Instance leb_compat x : Proper (E.eq==>Logic.eq) (leb x).
Hint Resolve gtb_compat leb_compat : core.

Lemma elements_Add : forall s s' x, ~In x s -> Add x s s' ->
eqlistA E.eq (elements s') (elements_lt x s ++ x :: elements_ge x s).