[Haskell-beginners] Question on terminology

[Rein Henrichs]

Ben, I just assumed that g was a typo for f.

On Thu, Mar 3, 2016 at 10:10 AM Ben Rogalski <bwrogalski at gmail.com> wrote:

> I'm having trouble understanding this:
>
> > IIUC, one would describe fmap as "lifting" a function g into a functor f,
> > in the sense of
> >
> > Functor f => (g a b) -> g a -> g b
> >
> >
> > Is there an inverse concept (? co-lift ?) that describes
> >
> > Functor f => (g a -> g b) -> a -> b
> >
>
> It seems like these are type declarations for functions, with class
> constraints that say f must be a Functor, but then f doesn't appear
> anywhere else in the declaration. Why is this?
>
> Thanks,
> -Ben
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