Re: [Haskell-cafe] Applicative banana brackets

On Mon, Dec 14, 2015 at 9:38 PM, martin wrote: 2) Every arrow a b c is an applicative (a b) c, because comma = (&&&).

Conversely, every applicative that is polymorphic over some "internal" variable is automatically an arrow, through (&&&) = comma.

Where is the proof that (a b) is a Functor? Recall that the class method arr -- the closest kin to fmap -- has the type: (b -> c) -> a b c. -- Kim-Ee