Re: [Haskell-cafe] Re: Num instances for 2-dimensional types

On Wed, Oct 7, 2009 at 12:08 PM, Ben Franksen wrote:

More generally, any ring with multiplicative unit (let's call it 'one') will do.

Isn't that every ring? As I understand it, the multiplication in a ring is required to form a monoid. -- Dave Menendez http://www.eyrie.org/~zednenem/