Re: [Haskell-cafe] Inheritance and Wrappers

On Tue, Feb 1, 2011 at 11:47 AM, Ozgur Akgun wrote:

On 1 February 2011 11:41, John Lato wrote:

...

The important point is that this declares an AbGroup instance for every type, not just types with Num instances.

So, is there a way to declare an AbGroup instance for the types with num instances only?

Not to my knowledge. John