PolyKinds04.hs:5:16:
    Expecting one more argument to ‛Maybe’
    The first argument of ‛A’ should have kind ‛*’,
      but ‛Maybe’ has kind ‛* -> *’
    In the type ‛A Maybe’
    In the definition of data constructor ‛B1’
    In the data declaration for ‛B’