WORST_CASE(?,O(n^2))

Solution:
---------

  "::" :: ["A"(0, 0) x "A"(3, 0)] -(3)-> "A"(3, 0)
  "::" :: ["A"(0, 0) x "A"(0, 0)] -(0)-> "A"(0, 0)
  "append" :: ["A"(3, 0) x "A"(0, 0)] -(6)-> "A"(0, 0)
  "append#1" :: ["A"(3, 0) x "A"(0, 0)] -(5)-> "A"(0, 0)
  "leaf" :: [] -(0)-> "A"(0, 15)
  "nil" :: [] -(0)-> "A"(3, 0)
  "nil" :: [] -(0)-> "A"(4, 7)
  "node" :: ["A"(0, 0) x "A"(15, 15) x "A"(15, 15)] -(15)-> "A"(0, 15)
  "node" :: ["A"(0, 0) x "A"(0, 0) x "A"(0, 0)] -(0)-> "A"(0, 0)
  "subtrees" :: ["A"(0, 15)] -(2)-> "A"(0, 2)
  "subtrees#1" :: ["A"(0, 15)] -(1)-> "A"(0, 1)
  "subtrees#2" :: ["A"(12, 3) x "A"(0, 0) x "A"(15, 15) x "A"(0, 0)] -(13)-> "A"(0, 0)
  "subtrees#3" :: ["A"(0, 2) x "A"(10, 3) x "A"(0, 0) x "A"(0, 0) x "A"(0, 0)] -(10)-> "A"(0, 0)


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

  "::" :: ["A"_cf(0, 0) x "A"_cf(0, 0)] -(0)-> "A"_cf(0, 0)
  "::" :: ["A"_cf(0, 0) x "A"_cf(0, 0)] -(0)-> "A"_cf(0, 1)
  "::" :: ["A"_cf(0, 0) x "A"_cf(0, 0)] -(0)-> "A"_cf(0, 9)
  "::" :: ["A"_cf(0, 0) x "A"_cf(0, 0)] -(0)-> "A"_cf(0, 4)
  "::" :: ["A"_cf(0, 0) x "A"_cf(12, 0)] -(12)-> "A"_cf(12, 2)
  "::" :: ["A"_cf(0, 0) x "A"_cf(12, 0)] -(12)-> "A"_cf(12, 0)
  "append" :: ["A"_cf(0, 0) x "A"_cf(0, 0)] -(0)-> "A"_cf(0, 0)
  "append" :: ["A"_cf(0, 0) x "A"_cf(0, 1)] -(0)-> "A"_cf(0, 1)
  "append" :: ["A"_cf(0, 0) x "A"_cf(0, 1)] -(0)-> "A"_cf(0, 0)
  "append" :: ["A"_cf(12, 0) x "A"_cf(12, 2)] -(0)-> "A"_cf(12, 2)
  "append" :: ["A"_cf(0, 0) x "A"_cf(0, 0)] -(1)-> "A"_cf(0, 0)
  "append#1" :: ["A"_cf(0, 0) x "A"_cf(0, 0)] -(0)-> "A"_cf(0, 0)
  "append#1" :: ["A"_cf(0, 0) x "A"_cf(0, 1)] -(0)-> "A"_cf(0, 1)
  "append#1" :: ["A"_cf(0, 0) x "A"_cf(0, 1)] -(0)-> "A"_cf(0, 0)
  "append#1" :: ["A"_cf(12, 0) x "A"_cf(12, 2)] -(0)-> "A"_cf(12, 2)
  "append#1" :: ["A"_cf(0, 0) x "A"_cf(0, 0)] -(1)-> "A"_cf(0, 0)
  "leaf" :: [] -(0)-> "A"_cf(0, 0)
  "leaf" :: [] -(0)-> "A"_cf(15, 0)
  "nil" :: [] -(0)-> "A"_cf(0, 0)
  "nil" :: [] -(0)-> "A"_cf(15, 1)
  "nil" :: [] -(0)-> "A"_cf(1, 15)
  "nil" :: [] -(0)-> "A"_cf(14, 4)
  "nil" :: [] -(0)-> "A"_cf(12, 0)
  "nil" :: [] -(0)-> "A"_cf(0, 13)
  "node" :: ["A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(0, 0)] -(0)-> "A"_cf(0, 0)
  "node" :: ["A"_cf(15, 0) x "A"_cf(15, 0) x "A"_cf(15, 0)] -(15)-> "A"_cf(15, 0)
  "subtrees" :: ["A"_cf(0, 0)] -(0)-> "A"_cf(0, 1)
  "subtrees" :: ["A"_cf(0, 0)] -(0)-> "A"_cf(0, 0)
  "subtrees" :: ["A"_cf(15, 0)] -(0)-> "A"_cf(12, 2)
  "subtrees" :: ["A"_cf(15, 0)] -(0)-> "A"_cf(0, 0)
  "subtrees#1" :: ["A"_cf(0, 0)] -(0)-> "A"_cf(0, 1)
  "subtrees#1" :: ["A"_cf(15, 0)] -(0)-> "A"_cf(12, 2)
  "subtrees#1" :: ["A"_cf(15, 0)] -(0)-> "A"_cf(0, 0)
  "subtrees#2" :: ["A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(0, 0)] -(0)-> "A"_cf(0, 1)
  "subtrees#2" :: ["A"_cf(0, 1) x "A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(0, 0)] -(0)-> "A"_cf(0, 1)
  "subtrees#2" :: ["A"_cf(12, 0) x "A"_cf(0, 0) x "A"_cf(15, 0) x "A"_cf(0, 0)] -(15)-> "A"_cf(12, 2)
  "subtrees#2" :: ["A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(15, 0) x "A"_cf(0, 0)] -(15)-> "A"_cf(0, 0)
  "subtrees#3" :: ["A"_cf(0, 1) x "A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(0, 0)] -(0)-> "A"_cf(0, 1)
  "subtrees#3" :: ["A"_cf(0, 1) x "A"_cf(0, 1) x "A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(0, 0)] -(0)-> "A"_cf(0, 4)
  "subtrees#3" :: ["A"_cf(12, 2) x "A"_cf(12, 0) x "A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(0, 0)] -(14)-> "A"_cf(12, 2)
  "subtrees#3" :: ["A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(0, 0) x "A"_cf(0, 0)] -(14)-> "A"_cf(0, 0)


Base Constructors:
------------------
  "\"::\"_A" :: ["A"(0, 0) x "A"(1, 0)] -(1)-> "A"(1, 0)
  "\"::\"_A" :: ["A"(0, 0) x "A"(0, 0)] -(0)-> "A"(0, 1)
  "\"leaf\"_A" :: [] -(0)-> "A"(1, 0)
  "\"leaf\"_A" :: [] -(0)-> "A"(0, 1)
  "\"nil\"_A" :: [] -(0)-> "A"(1, 0)
  "\"nil\"_A" :: [] -(0)-> "A"(0, 1)
  "\"node\"_A" :: ["A"(1, 0) x "A"(1, 0) x "A"(1, 0)] -(1)-> "A"(1, 0)
  "\"node\"_A" :: ["A"(0, 0) x "A"(1, 1) x "A"(1, 1)] -(1)-> "A"(0, 1)