WORST_CASE(?,O(n^1))

Solution:
---------

  "cons" :: ["a"(0) x "b"(2)] -(2)-> "b"(2)
  "cons" :: ["a"(0) x "b"(1)] -(1)-> "b"(1)
  "cons" :: ["a"(0) x "b"(0)] -(0)-> "b"(0)
  "empty" :: [] -(0)-> "b"(2)
  "empty" :: [] -(0)-> "b"(1)
  "empty" :: [] -(0)-> "b"(0)
  "f" :: ["b"(1) x "b"(2)] -(2)-> "b"(0)
  "g" :: ["b"(1) x "b"(0)] -(1)-> "b"(0)


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