multiply x y = x * y
multiply 10 20 



twopi = 6.28

twopi () = 6.28 
twopi :: Num a => () -> a 
twopi () 


multiply_by_10 = (10 * )
map multiply_by_10 [1, 2, 3] 
multiply_all_by_10 = map multiply_by_10
multiply_all_by_10 [1, 2, 3]