YES
O(n)
TRS:
 {
          a(x, g()) -> a(f(), a(g(), a(f(), x))),
  a(f(), a(f(), x)) -> a(x, g())
 }
 DUP: We consider a non-duplicating system.
  Trs:
   {
            a(x, g()) -> a(f(), a(g(), a(f(), x))),
    a(f(), a(f(), x)) -> a(x, g())
   }
  BOUND:
   Automaton:
    {
           f_4() -> 25,
           f_3() -> 20,
           f_2() -> 12,
           f_1() -> 6 | 3,
           f_0() -> 3,
           g_4() -> 26,
           g_3() -> 16,
           g_2() -> 11,
           g_1() -> 4,
           g_0() -> 3,
     a_4(26, 27) -> 28,
     a_4(25, 28) -> 13,
     a_4(25, 14) -> 27,
     a_3(20, 22) -> 13 | 7,
     a_3(20, 14) -> 21,
      a_3(20, 4) -> 21,
     a_3(16, 21) -> 22,
     a_3(14, 16) -> 13,
     a_2(14, 11) -> 7,
     a_2(12, 24) -> 21,
     a_2(12, 20) -> 23,
     a_2(12, 14) -> 13 | 7 | 3,
     a_2(12, 12) -> 13,
      a_2(12, 4) -> 13,
      a_2(12, 3) -> 13,
     a_2(11, 23) -> 24,
     a_2(11, 13) -> 14,
      a_2(4, 11) -> 13 | 7,
      a_1(14, 4) -> 3,
       a_1(6, 3) -> 7,
       a_1(4, 7) -> 4,
       a_1(4, 4) -> 13 | 7 | 3,
      a_1(3, 12) -> 7,
       a_1(3, 6) -> 7,
       a_1(3, 4) -> 13 | 7 | 3,
       a_0(3, 3) -> 3
    }
   Strict:
    {}
   Qed