T7368a.hs:8:6: error:
    • Couldn't match kind ‘* -> *’ with ‘*’
      When matching types
        f :: * -> *
        Bad :: (* -> *) -> *
      Expected: f (Bad f)
        Actual: Bad w0
    • In the pattern: Bad x
      In an equation for ‘fun’: fun (Bad x) = True
    • Relevant bindings include
        fun :: f (Bad f) -> Bool (bound at T7368a.hs:8:1)