[Haskell-cafe] SystemF, universal quantification, and rigid type variables

[David Rush]

So I posted:

> In short, I'm trying to decide if there is a real difference between the 
> types:
> 
>     (forall a.a) -> b
>     a -> b
> 
> and frankly, I'm not seeing a difference... I'd actually love to be wrong. 
> Is there an actual difference between the types?

And Ruud Koot and Nikolay Kudasov both told me:

> YES.


Thanks, y'all. That actually means I was doing it right :)

- d