== Signature ==
  0 :: Int
  1 :: Int
(+) :: Int -> Int -> Int
(*) :: Int -> Int -> Int

== Laws ==
  1. x * 0 = 0
  2. x * 1 = x
  3. 0 * x = 0
  4. 1 * x = x
  5. x + 0 = x
  6. 0 + x = x
  7. x * y = y * x
  8. x + y = y + x
  9. (x * y) * z = x * (y * z)
 10. (x + y) + z = x + (y + z)
 11. x * (y + 1) = x + (x * y)
 12. (x * y) + (x * z) = x * (y + z)
 13. x * (y + (y + y)) = y * (x + (x + x))