YES
Time: 0.001158
TRS:
 {f(f(x, a()), a()) -> f(f(f(a(), a()), f(x, a())), a())}
 DP:
  DP:
   {f#(f(x, a()), a()) -> f#(f(f(a(), a()), f(x, a())), a()),
    f#(f(x, a()), a()) -> f#(f(a(), a()), f(x, a())),
    f#(f(x, a()), a()) -> f#(a(), a())}
  TRS:
  {f(f(x, a()), a()) -> f(f(f(a(), a()), f(x, a())), a())}
  EDG:
   {}
   STATUS:
    arrows: 1.000000
    SCCS (0):