At 2002-05-04 12:45, Samuel E. Moelius III wrote:

type Thing m = m ()

type Const a b = a

f :: Thing m -> Thing m f x = x

test :: Thing (Const Int) -> Thing (Const Int)

This is wrong. Type synonyms must be fully applied, whereas you have Const applied only to one argument, not two. 'Const' isn't really a type-constructor, it's more like a macro. Is it something in the air? Spring is here, and everyone wants type-lambda... -- Ashley Yakeley, Seattle WA