[Haskell-cafe] Re: [Haskell] specification of sum

(Moving this to the cafe.) G'day all. Quoting Cale Gibbard :

We already do rely on them in most cases. Of course, not every property can be proved by the compiler, but many pieces of code are going to assume quite a lot.

Agreed.

I think that the assumption that (+) and (*) in Num define something like a ring on the given type is a sensible one.

I'm not so certain. Octonian multiplication, to pick one example, is not associative, but I'd like to be able to use (*) nonetheless. Cheers, Andrew Bromage