class Misty m where

  banana:: (f -> m b) -> m f -> m b

  furry':: (a -> b) -> m a -> m b

apple::Misty m =>

    m a -> m (a -> b) -> m b

apple ma mf = banana (\f -> furry' f ma) mf

in a word: 'a' in banana may be a function 

f = a -> b