YES

Problem:
 f(f(a(),f(a(),a())),x) -> f(x,f(f(a(),a()),a()))

Proof:
 DP Processor:
  DPs:
   f#(f(a(),f(a(),a())),x) -> f#(f(a(),a()),a())
   f#(f(a(),f(a(),a())),x) -> f#(x,f(f(a(),a()),a()))
  TRS:
   f(f(a(),f(a(),a())),x) -> f(x,f(f(a(),a()),a()))
  EDG Processor:
   DPs:
    f#(f(a(),f(a(),a())),x) -> f#(f(a(),a()),a())
    f#(f(a(),f(a(),a())),x) -> f#(x,f(f(a(),a()),a()))
   TRS:
    f(f(a(),f(a(),a())),x) -> f(x,f(f(a(),a()),a()))
   graph:
    f#(f(a(),f(a(),a())),x) -> f#(x,f(f(a(),a()),a())) ->
    f#(f(a(),f(a(),a())),x) -> f#(f(a(),a()),a())
    f#(f(a(),f(a(),a())),x) -> f#(x,f(f(a(),a()),a())) ->
    f#(f(a(),f(a(),a())),x) -> f#(x,f(f(a(),a()),a()))
   CDG Processor:
    DPs:
     f#(f(a(),f(a(),a())),x) -> f#(f(a(),a()),a())
     f#(f(a(),f(a(),a())),x) -> f#(x,f(f(a(),a()),a()))
    TRS:
     f(f(a(),f(a(),a())),x) -> f(x,f(f(a(),a()),a()))
    graph:
     
    Qed