[Haskell-cafe] in-equality type constraint?

[Christopher Lane Hinson]

On Fri, 16 Jul 2010, Paul L wrote:

> Does anybody know why the type families only supports equality test
> like a ~ b, but not its negation?

I would suggest that type equality is actually used for type inference,
whereas proof of type inequality would have no consequence (that I can think of)
for the compiler.

Friendly,
--Lane