WORST_CASE(?,O(n^1))

Solution:
---------

  + :: [A(15) x A(6)] -(8)-> A(0)
  0 :: [] -(0)-> A(15)
  s :: [A(15)] -(15)-> A(15)
  s :: [A(0)] -(0)-> A(0)
  s :: [A(6)] -(6)-> A(6)


Cost Free Signatures:
---------------------

  + :: [A_cf(0) x A_cf(0)] -(0)-> A_cf(0)
  0 :: [] -(0)-> A_cf(0)
  s :: [A_cf(0)] -(0)-> A_cf(0)


Base Constructors:
------------------
  0_A :: [] -(0)-> A(1)
  s_A :: [A(1)] -(1)-> A(1)