[Haskell-beginners] Trying to prove Applicative is superclass of Functor, etc

[Dániel Arató]

> Oh, and by the way, is it enough then to create an instance of Applicative
> or Monad to automatically get an instance of the respective superclasses?
> And the generalization for any superclass/subclass? Would be great... If
> not why so?

I think the latest GHC should be able to give you the superclass
instances like you said. Before GHC 7.10 the class hierarchy was a bit
disjointed: a Monad was not necessarily an Applicative (even though it
should be).
https://wiki.haskell.org/Functor-Applicative-Monad_Proposal

Daniel