[Haskell-cafe] function terms

[Henning Thielemann]

On Wed, 6 Jul 2011, Ian Childs wrote:

> Yes they are Haskell expressions - I called them terms because actually they 
> are GADTs of type Term a and Term b. I can't use type 'b -> c' as they are 
> part of a larger pattern.
>
> I have a function that returns a witness to 's :: Term a' and 't :: Term b' 
> having the same type, if they do, but I am wondering how to extend this to 
> the first argument of an arrow type.

Can you give us a bit more (but not too much) code in order to show the 
problem?