sum x y = x + y

sum :: Num a => a -> a -> a

##</code><code>##

sum :: Num a => a -> (a -> a)

##</code><code>##

increment = sum 1

##</code><code>##

sum 1 2
## really means
(sum 1) 2
## which is
(\y -> 1 + y) 2
##
1 + 2