WORST_CASE(?,O(n^1))

Solution:
---------

  * :: [A(0) x A(0)] -(0)-> A(9)
  + :: [A(1) x A(0)] -(0)-> A(1)
  + :: [A(3) x A(0)] -(0)-> A(3)
  0 :: [] -(0)-> A(9)
  0 :: [] -(0)-> A(7)
  s :: [A(9)] -(9)-> A(9)
  s :: [A(0)] -(0)-> A(0)
  sqr :: [A(0)] -(2)-> A(5)
  sum :: [A(9)] -(7)-> A(0)


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

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


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