Program Instance unsizedMonotonicChecker (c : Checker) `{UnsizedChecker c} : 
  SizeMonotonicChecker c.

Lemma semBindGenSize {A} (gen : G A) (f : A -> Checker) (s: nat): semCheckerSize (bindGen gen f) s <-> forall a, semGenSize gen s a -> semCheckerSize (f a) s.