Currently, Applicative is a superclass of Alternative. Unfortunately, the *only* laws for Alternative are the monoid laws. Sensible sets of laws have been proposed in the past, but unfortunately *none* of them cover all the current important instances. Thus we have a rather awkward situation where Alternative is a subclass of Applicative, but there's no real way to take advantage of that fact. There are essentially no useful functions that would end up with signatures that look like p :: (Applicative f, Alternative f) => ... I'm wondering, therefore, what people think of the idea of making Alternative entirely independent—just a version of Monoid with a different kind. class Alternative f where empty :: f a (<|>) :: f a -> f a -> f a A second option would be to go with a Functor superclass for Alternative; that might save some typing over the independent Alternative, and it comes with the free theorem fmap f empty = empty