Hint Extern 0 (RExists _ (rel_incr _ _ _) _ _) =>
eapply rel_incr_rintro : typeclass_instances.

Lemma rel_incr_rdestruct {W A B} acc R w T:
(forall w, exists Tw, RDestruct (R w) Tw /\ Convertible (T w) Tw) ->
RDestruct
(@rel_incr W A B acc R w)
(fun P => forall w', acc w w' -> Delay.unpack (T w' P)).