YES(?,O(n^1))
TRS:
 {f(f(x, a()), a()) -> f(f(f(x, a()), f(a(), a())), a())}
 DUP: We consider a non-duplicating system.
  Trs:
   {f(f(x, a()), a()) -> f(f(f(x, a()), f(a(), a())), a())}
  BOUND:
   Bound: match(-raise)-bounded by 2
   Automaton:
    {
         a_2() -> 6*
         a_1() -> 2*
         a_0() -> 1*
     f_2(9, 6) -> 3*
     f_2(7, 8) -> 9*
     f_2(6, 6) -> 8*
     f_2(5, 6) -> 7*
     f_1(5, 2) -> 3 | 1
     f_1(3, 4) -> 5*
     f_1(2, 2) -> 4*
     f_1(1, 2) -> 3*
     f_0(1, 1) -> 1*
    }
   Strict:
    {}
   Qed