Hi Haskell Cafe, I tried using type families over functions, but when I try it complains that the two lines marked conflict with each other. class Broadcast a where type Return a broadcast :: a -> Return a instance Broadcast [a -> r] where type Return [a -> r] = a -> [r] -- Conflict! broadcast fs a = [] instance Broadcast [a -> b -> r] where type Return [a -> b -> r] = a -> b -> [r] -- Conflict! broadcast fs a b = [] Given that in Haskell, every function of n+1 arguments is also a function of n arguments, this is likely the cause of the conflict. In this case, currying is not my friend. Unfortunately this means I'm stuck with numbered function names: bc0 :: [r] -> [r] bc0 rs = rs bc1 :: [a -> r] -> a -> [r] bc1 [] a = [] bc1 (r:rs) a = (r a):bc1 rs a bc2 rs a b = rs `bc1` a `bc1` b bc3 rs a b c = rs `bc1` a `bc1` b `bc1` c -- etc Cheers, -John