On Mon, 2010-11-22 at 14:48 +0800, Magicloud Magiclouds wrote: > (+) :: A -> A -> A > (+) a b = > A (elem1 a + elem1 b) (elem2 a + elem2 b) -- I got errors here, for > the (+) is ambiguous. That's because (+) is implicitly imported from the Prelude. If you import Prelude hiding ((+)) the error disappears. Sebastian