(** Correctness of this comparison *)
Definition Cmp c x y := CompSpec L.eq L.lt x y c.
Local Hint Unfold Cmp flip : core.

Lemma compare_more_Cmp : forall x1 cont x2 r2 e2 l,
Cmp (cont (cons r2 e2)) l (elements r2 ++ flatten_e e2) ->
Cmp (compare_more x1 cont (More x2 r2 e2)) (x1::l)
(flatten_e (More x2 r2 e2)).