WORST_CASE(?,O(n^1))

Solution:
---------

  0 :: [] -(0)-> A(5)
  0 :: [] -(0)-> A(1)
  0 :: [] -(0)-> A(9)
  0 :: [] -(0)-> A(0)
  cons :: [A(0) x A(0)] -(0)-> A(0)
  conv :: [A(9)] -(1)-> A(0)
  half :: [A(5)] -(1)-> A(9)
  lastbit :: [A(1)] -(1)-> A(0)
  nil :: [] -(0)-> A(0)
  s :: [A(5)] -(5)-> A(5)
  s :: [A(1)] -(1)-> A(1)
  s :: [A(9)] -(9)-> A(9)
  s :: [A(0)] -(0)-> A(0)


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

  0 :: [] -(0)-> A_cf(0)
  cons :: [A_cf(0) x A_cf(0)] -(0)-> A_cf(0)
  conv :: [A_cf(0)] -(0)-> A_cf(0)
  half :: [A_cf(0)] -(0)-> A_cf(0)
  lastbit :: [A_cf(0)] -(0)-> A_cf(0)
  nil :: [] -(0)-> A_cf(0)
  s :: [A_cf(0)] -(0)-> A_cf(0)