Hi Folks, The type signature of ($) is: ($) :: (a -> b) -> a -> b That tells me that ($) is a function that takes two arguments: 1. A function which maps values of type "a" to values of type "b" 2. A value of type "a" and it returns a value of type "b". Okay, I can understand that. So, I created some examples: ($) odd 3 -- returns True odd $ 3 -- returns True Good. But then I saw this in an article: ($ 3) odd What does ($ 3) mean? I thought the first argument to ($) is a function? I checked the type of ($ 3) and it is: ($ 3) :: Num a => (a -> b) -> b I don't understand that. How did that happen? Why can I take a second argument and wrap it in parentheses with ($) and then that second argument pops out and becomes the argument to a function? I decided to see if other functions behaved similarly. Here is the type signature for the "map" function: map :: (a -> b) -> [a] -> [b] That looks very similar to the type signature for ($). So, I reasoned, I should be able to do the same kind of thing: let list=[1,2,3] (map list) odd But that fails. Why? Why does that fail whereas a very similar looking form succeeds when ($) is used? /Roger