Section LIFT.
Context `{kf: KripkeFrame}.
Context {A1 B1 A2 B2 A B: Type}.
(** For elementary relations, the corresponding Kripke relation can just ignore the Kripke world. *)
Definition k (R: rel A B): klr W A B :=
fun w => R.
Global Instance k_rel var:
Monotonic k (var ++> - ==> var).

Lemma k_rintro R (w: W) (x: A) (y: B):
RIntro (R x y) (k R w) x y.