WORST_CASE(?,O(n^1))

Solution:
---------

  "append" :: ["A"(11) x "A"(14)] -(4)-> "A"(0)
  "cons" :: ["A"(0) x "A"(0)] -(0)-> "A"(0)
  "cons" :: ["A"(0) x "A"(3)] -(3)-> "A"(3)
  "cons" :: ["A"(0) x "A"(4)] -(4)-> "A"(4)
  "cons" :: ["A"(0) x "A"(11)] -(11)-> "A"(11)
  "false" :: [] -(0)-> "A"(12)
  "hd" :: ["A"(3)] -(1)-> "A"(0)
  "ifappend" :: ["A"(0) x "A"(14) x "A"(11)] -(3)-> "A"(0)
  "is_empty" :: ["A"(0)] -(4)-> "A"(0)
  "nil" :: [] -(0)-> "A"(0)
  "nil" :: [] -(0)-> "A"(11)
  "tl" :: ["A"(4)] -(3)-> "A"(0)
  "true" :: [] -(0)-> "A"(14)


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

  "append" :: ["A"_cf(0) x "A"_cf(0)] -(0)-> "A"_cf(0)
  "cons" :: ["A"_cf(0) x "A"_cf(0)] -(0)-> "A"_cf(0)
  "ifappend" :: ["A"_cf(0) x "A"_cf(0) x "A"_cf(0)] -(0)-> "A"_cf(0)
  "nil" :: [] -(0)-> "A"_cf(0)


Base Constructors:
------------------
  "\"cons\"_A" :: ["A"(0) x "A"(1)] -(1)-> "A"(1)
  "\"false\"_A" :: [] -(0)-> "A"(1)
  "\"nil\"_A" :: [] -(0)-> "A"(1)
  "\"true\"_A" :: [] -(0)-> "A"(1)