WORST_CASE(?,O(n^2))

Solution:
---------

  :: :: [A(6, 0) x A(6, 0)] -(6)-> A(6, 0)
  :: :: [A(12, 7) x A(12, 7)] -(5)-> A(5, 7)
  :: :: [A(15, 8) x A(15, 8)] -(7)-> A(7, 8)
  :: :: [A(15, 9) x A(15, 9)] -(6)-> A(6, 9)
  :: :: [A(4, 0) x A(4, 0)] -(4)-> A(4, 0)
  append :: [A(6, 0) x A(4, 0)] -(2)-> A(4, 0)
  append#1 :: [A(6, 0) x A(4, 0)] -(1)-> A(4, 0)
  appendAll :: [A(9, 7)] -(2)-> A(6, 0)
  appendAll#1 :: [A(5, 7)] -(1)-> A(2, 0)
  appendAll2 :: [A(12, 8)] -(2)-> A(6, 0)
  appendAll2#1 :: [A(7, 8)] -(1)-> A(3, 0)
  appendAll3 :: [A(9, 9)] -(2)-> A(3, 0)
  appendAll3#1 :: [A(6, 9)] -(1)-> A(2, 0)
  nil :: [] -(0)-> A(6, 0)
  nil :: [] -(0)-> A(5, 7)
  nil :: [] -(0)-> A(7, 8)
  nil :: [] -(0)-> A(6, 9)


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

  :: :: [A_cf(0, 0) x A_cf(0, 0)] -(0)-> A_cf(0, 0)
  :: :: [A_cf(4, 0) x A_cf(4, 0)] -(4)-> A_cf(4, 0)
  :: :: [A_cf(3, 0) x A_cf(3, 0)] -(3)-> A_cf(3, 0)
  :: :: [A_cf(5, 0) x A_cf(5, 0)] -(5)-> A_cf(5, 0)
  :: :: [A_cf(1, 0) x A_cf(1, 0)] -(1)-> A_cf(1, 0)
  :: :: [A_cf(6, 0) x A_cf(6, 0)] -(6)-> A_cf(6, 0)
  append :: [A_cf(0, 0) x A_cf(0, 0)] -(0)-> A_cf(0, 0)
  append :: [A_cf(4, 0) x A_cf(4, 0)] -(0)-> A_cf(4, 0)
  append :: [A_cf(4, 0) x A_cf(3, 0)] -(4)-> A_cf(3, 0)
  append :: [A_cf(1, 0) x A_cf(1, 0)] -(0)-> A_cf(1, 0)
  append :: [A_cf(3, 0) x A_cf(1, 0)] -(5)-> A_cf(1, 0)
  append :: [A_cf(3, 0) x A_cf(3, 0)] -(0)-> A_cf(3, 0)
  append#1 :: [A_cf(0, 0) x A_cf(0, 0)] -(0)-> A_cf(0, 0)
  append#1 :: [A_cf(4, 0) x A_cf(4, 0)] -(0)-> A_cf(4, 0)
  append#1 :: [A_cf(4, 0) x A_cf(3, 0)] -(4)-> A_cf(3, 0)
  append#1 :: [A_cf(1, 0) x A_cf(1, 0)] -(0)-> A_cf(1, 0)
  append#1 :: [A_cf(3, 0) x A_cf(1, 0)] -(5)-> A_cf(1, 0)
  append#1 :: [A_cf(3, 0) x A_cf(3, 0)] -(0)-> A_cf(3, 0)
  appendAll :: [A_cf(4, 0)] -(1)-> A_cf(4, 0)
  appendAll :: [A_cf(3, 0)] -(0)-> A_cf(0, 0)
  appendAll :: [A_cf(4, 0)] -(0)-> A_cf(4, 0)
  appendAll :: [A_cf(1, 0)] -(0)-> A_cf(0, 0)
  appendAll :: [A_cf(1, 0)] -(0)-> A_cf(1, 0)
  appendAll :: [A_cf(3, 0)] -(0)-> A_cf(3, 0)
  appendAll#1 :: [A_cf(4, 0)] -(0)-> A_cf(4, 0)
  appendAll#1 :: [A_cf(3, 0)] -(0)-> A_cf(0, 0)
  appendAll#1 :: [A_cf(1, 0)] -(0)-> A_cf(0, 0)
  appendAll#1 :: [A_cf(1, 0)] -(0)-> A_cf(1, 0)
  appendAll#1 :: [A_cf(3, 0)] -(0)-> A_cf(3, 0)
  appendAll2 :: [A_cf(5, 0)] -(0)-> A_cf(3, 0)
  appendAll2 :: [A_cf(3, 0)] -(0)-> A_cf(0, 0)
  appendAll2 :: [A_cf(1, 0)] -(3)-> A_cf(1, 0)
  appendAll2 :: [A_cf(4, 0)] -(0)-> A_cf(3, 0)
  appendAll2#1 :: [A_cf(5, 0)] -(0)-> A_cf(3, 0)
  appendAll2#1 :: [A_cf(3, 0)] -(0)-> A_cf(0, 0)
  appendAll2#1 :: [A_cf(1, 0)] -(3)-> A_cf(1, 0)
  appendAll2#1 :: [A_cf(4, 0)] -(0)-> A_cf(3, 0)
  appendAll3 :: [A_cf(3, 0)] -(0)-> A_cf(1, 0)
  appendAll3 :: [A_cf(6, 0)] -(0)-> A_cf(1, 0)
  appendAll3#1 :: [A_cf(3, 0)] -(0)-> A_cf(1, 0)
  appendAll3#1 :: [A_cf(6, 0)] -(0)-> A_cf(1, 0)
  nil :: [] -(0)-> A_cf(0, 0)
  nil :: [] -(0)-> A_cf(4, 0)
  nil :: [] -(0)-> A_cf(7, 2)
  nil :: [] -(0)-> A_cf(3, 0)
  nil :: [] -(0)-> A_cf(3, 2)
  nil :: [] -(0)-> A_cf(5, 0)
  nil :: [] -(0)-> A_cf(1, 0)
  nil :: [] -(0)-> A_cf(1, 2)
  nil :: [] -(0)-> A_cf(6, 0)


Base Constructors:
------------------
  ::_A :: [A(0) x A(0)] -(0)-> A(0)
  nil_A :: [] -(0)-> A(1, 0)
  nil_A :: [] -(0)-> A(0, 1)