Global Instance None_rel:
  Monotonic (@None) (forallr R, option_rel R).Global Instance option_subrel_params:
  Params (@option_rel) 3.

Lemma option_rel_some_inv A B (R: rel A B) (x: option A) (y: option B) (a: A): option_rel R x y -> x = Some a -> exists b, y = Some b /\ R a b.