mc22.hs:9:9: error:
    No instance for (Functor t) arising from a use of ‘fmap’
    Possible fix:
      add (Functor t) to the context of
        a type expected by the context:
          (a -> b) -> t a -> t b
        or the inferred type of foo :: [t [Char]]
    In the expression: fmap
    In a stmt of a monad comprehension: then group using take 5
    In the expression:
      [x + 1 | x <- ["Hello", "World"], then group using take 5]

mc22.hs:10:26: error:
    Couldn't match type ‘a’ with ‘t a’
    ‘a’ is a rigid type variable bound by
    a type expected by the context:
      forall a. [a] -> [t a]
    at mc22.hs:9:9
    Expected type: [a] -> [t a]
      Actual type: [t a] -> [t a]
    In the expression: take 5
    In a stmt of a monad comprehension: then group using take 5
    Relevant bindings include foo :: [t [Char]] (bound at mc22.hs:8:1)