Program Instance resultUnsized (r : Result) : UnsizedChecker (checker r).
Next Obligation.
rewrite !semFmapSize !semReturnSize. apply imset_eq. reflexivity.
Qed.

(* Specifications: *)
Lemma semCheckableUnitSize (t : unit) size : semCheckableSize t size <-> True.
Lemma semCheckableUnit (t : unit) : semCheckable t <-> True.
Program Instance unitUnsized : UnsizedChecker (checker tt).