YES
TRS:
 {f(f(a(), x), a()) -> f(f(a(), f(a(), a())), x)}
 DP:
  Strict:
   {f#(f(a(), x), a()) -> f#(f(a(), f(a(), a())), x),
    f#(f(a(), x), a()) -> f#(a(), f(a(), a())),
    f#(f(a(), x), a()) -> f#(a(), a())}
  Weak:
  {f(f(a(), x), a()) -> f(f(a(), f(a(), a())), x)}
  EDG:
   {(f#(f(a(), x), a()) -> f#(f(a(), f(a(), a())), x), f#(f(a(), x), a()) -> f#(a(), a()))
    (f#(f(a(), x), a()) -> f#(f(a(), f(a(), a())), x), f#(f(a(), x), a()) -> f#(a(), f(a(), a())))
    (f#(f(a(), x), a()) -> f#(f(a(), f(a(), a())), x), f#(f(a(), x), a()) -> f#(f(a(), f(a(), a())), x))}
   SCCS:
    Scc:
     {f#(f(a(), x), a()) -> f#(f(a(), f(a(), a())), x)}
    SCC:
     Strict:
      {f#(f(a(), x), a()) -> f#(f(a(), f(a(), a())), x)}
     Weak:
     {f(f(a(), x), a()) -> f(f(a(), f(a(), a())), x)}
     BOUND:
      Bound: match(-raise)-DP-bounded by 0
      Automaton:
       {     b_0() -> 5*
             a_0() -> 2*
        f#_0(4, 5) -> 1*
        f#_0(4, 3) -> 1*
         f_0(2, 3) -> 4*
         f_0(2, 2) -> 3*}
      Strict:
       {}
      Qed