Re: [Haskell-cafe] Contexts for type family instances

On 12 December 2010 13:03, Max Bolingbroke wrote:

type instance DUnit (a,b) = GuardEq (DUnit a) (DUnit b)

type family GuardEq a b :: * type instance GuardEq a a = a

Thanks Max, that seems to be what I need. Best wishes Stephen