WORST_CASE(?,O(n^1))

Solution:
---------

  cons :: [a(0) x a(12)] -(12)-> a(12)
  cons :: [a(0) x a(0)] -(0)-> a(0)
  empty :: [] -(0)-> a(12)
  f :: [a(12) x a(0)] -(12)-> a(0)
  g :: [a(12) x a(0) x a(0)] -(15)-> a(0)


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

  cons :: [a_cf(0) x a_cf(0)] -(0)-> a_cf(0)
  empty :: [] -(0)-> a_cf(0)
  f :: [a_cf(0) x a_cf(0)] -(0)-> a_cf(0)
  g :: [a_cf(0) x a_cf(0) x a_cf(0)] -(0)-> a_cf(0)


Base Constructors:
------------------
  cons_a :: [a(0) x a(1)] -(1)-> a(1)
  empty_a :: [] -(0)-> a(1)