YES
Time: 0.002351
TRS:
 {f(x, f(a(), a())) -> f(f(a(), f(f(a(), a()), a())), x)}
 DP:
  DP:
   {f#(x, f(a(), a())) -> f#(f(a(), f(f(a(), a()), a())), x),
    f#(x, f(a(), a())) -> f#(f(a(), a()), a()),
    f#(x, f(a(), a())) -> f#(a(), f(f(a(), a()), a()))}
  TRS:
  {f(x, f(a(), a())) -> f(f(a(), f(f(a(), a()), a())), x)}
  EDG:
   {}
   STATUS:
    arrows: 1.000000
    SCCS (0):