Chapter: Fib

Section: Math
  fib : Integer -> Integer
  fib (n) =
   if n <= 1 then n
   else fib (n - 1) + fib (n - 2)

  double : Integer -> Integer
  double (n) = n + n

Section: Main
  opening : [Console] Nothing = act
   print-line-uni (show (fib 20))
  end