Hint Extern 60 (RStep _ ((_ @@ (_, _))%rel _ _)) =>
eapply rel_pull_rintro : typeclass_instances.
(** We can reuse an instance of [RElim] for the underlying relation to provide corresponding instances for the pulled relation. *)

Lemma rel_pull_relim {A B A' B'} (f: A -> A') (g: B -> B') R x y P Q:
RElim R (f x) (g y) P Q ->
RElim (R @@ (f, g)) x y P Q.