--    a b c
-- 1) (a b) c
-- 2) a (b c)
-- 3) (a b c)   <= Haskell

plus :: Int -> Int -> Int
plus a b = a + b

demo :: Int -> Int
demo x = plus x $ head lst
     where lst = [1..100]


plus2, double :: Int -> Int

double x = x + x

plus2 x = x + 2

plusNDouble = double . plus2