Overlap10.hs:10:7:
    Couldn't match expected type ‘F a Bool’ with actual type ‘Bool’
    In the expression: False
    In an equation for ‘g’: g x = False
    Relevant bindings include
      x :: a (bound at Overlap10.hs:10:3)
      g :: a -> F a Bool (bound at Overlap10.hs:10:1)