crosser

   $ cat /etc/apt/preferences.d/firefox-ppa-pin-400 
   Package: \*
   Pin: release o=LP-PPA-mozillateam
   Pin-Priority: 900

  send(makeUrl("http://..."))

  {-
   - Find numeric value of the first figure of the decimal representation
   - of a number:
   - 1. convert it to a string of decimal characters (show)
   - 2. take the first character of the string (head)
   - 3. convert the character to a string containing one charcter (:[])
   - 4. convert the string of one decimal character into an integer (read :: Int)
   -}
  
  main = do
    let
      firstfigure1 :: Int
      firstfigure1 = read . (:[]) . head . show $ 413
    print firstfigure1
  
    {-
     - Reverse the order of composition. Define "right-pointing" versions for
     - (.) and ($)
     -}
  
    let
      (.>) = flip (.)  -- it will become infixl 9 by default
      ($>) = flip ($)
      infixr 0 $>      -- We need value lower than the above. Use the same as $
  
      firstfigure2 :: Int
      firstfigure2 = 413 $> show .> head .> (:[]) .> read :: Int
    print firstfigure2