Hmmm... If you think of all parameter lists as tuples with some anonymous type, [un]packed transparently like Python parameter lists, then a multimethod defines a type class with one method (itself), the set of parameter lists to which it can be applied. So it would seem that multimethods can be a special case of type classes. That's the best I can do right now, assuming I've understood all the terms. Maybe you can do more with it.

Figuring out what type classes have to do with implicit parameters will take more than one afternoon of reading. It seems I can't read the other paper because I'm not an ACM member. But I guess Deca is going to be delayed again? :)