tcfail122.hs:9:9: error:
    • Couldn't match kind ‘*’ with ‘* -> *’
      When matching types
        c0 :: (* -> *) -> *
        a :: * -> *
      Expected: a b
        Actual: c0 d0
    • In the expression:
          undefined :: forall (c :: (* -> *) -> *) (d :: * -> *). c d
      In the expression:
        [undefined :: forall a b. a b,
         undefined :: forall (c :: (* -> *) -> *) (d :: * -> *). c d]
      In an equation for ‘foo’:
          foo
            = [undefined :: forall a b. a b,
               undefined :: forall (c :: (* -> *) -> *) (d :: * -> *). c d]
    • Relevant bindings include
        foo :: [a b] (bound at tcfail122.hs:8:1)