WORST_CASE(?,O(n^1))

Solution:
---------

  - :: [A(0) x A(1)] -(1)-> A(0)
  0 :: [] -(0)-> A(3)
  0 :: [] -(0)-> A(1)
  0 :: [] -(0)-> A(0)
  double :: [A(3)] -(1)-> A(1)
  half :: [A(1)] -(1)-> A(0)
  if :: [A(0) x A(0) x A(0)] -(1)-> A(0)
  s :: [A(3)] -(3)-> A(3)
  s :: [A(1)] -(1)-> A(1)
  s :: [A(0)] -(0)-> A(0)


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

  - :: [A_cf(0) x A_cf(0)] -(0)-> A_cf(0)
  0 :: [] -(0)-> A_cf(0)
  double :: [A_cf(0)] -(0)-> A_cf(0)
  half :: [A_cf(0)] -(0)-> A_cf(0)
  s :: [A_cf(0)] -(0)-> A_cf(0)