[Haskell-cafe] Re: Impredicativity confusion

[Gleb Alexeyev]

Dimitrios Vytiniotis wrote:

> I hope this helps more than confuses,
It really does, thank you. To understand your explanation completely I 
have to study 'Boxy types' paper thoroughly, but from the user's point 
of view everything is clear - GHC currently cannot correctly instantiate 
type variables in polymorphic function's type when some of arguments 
have polymorphic types and only types of arguments are given.