YES

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

Proof:
 DP Processor:
  DPs:
   f#(f(a(),a()),x) -> f#(a(),f(a(),a()))
   f#(f(a(),a()),x) -> f#(x,f(a(),f(a(),a())))
   f#(f(a(),a()),x) -> f#(f(x,f(a(),f(a(),a()))),a())
  TRS:
   f(f(a(),a()),x) -> f(f(x,f(a(),f(a(),a()))),a())
  EDG Processor:
   DPs:
    f#(f(a(),a()),x) -> f#(a(),f(a(),a()))
    f#(f(a(),a()),x) -> f#(x,f(a(),f(a(),a())))
    f#(f(a(),a()),x) -> f#(f(x,f(a(),f(a(),a()))),a())
   TRS:
    f(f(a(),a()),x) -> f(f(x,f(a(),f(a(),a()))),a())
   graph:
    f#(f(a(),a()),x) -> f#(x,f(a(),f(a(),a()))) ->
    f#(f(a(),a()),x) -> f#(a(),f(a(),a()))
    f#(f(a(),a()),x) -> f#(x,f(a(),f(a(),a()))) ->
    f#(f(a(),a()),x) -> f#(x,f(a(),f(a(),a())))
    f#(f(a(),a()),x) -> f#(x,f(a(),f(a(),a()))) ->
    f#(f(a(),a()),x) -> f#(f(x,f(a(),f(a(),a()))),a())
   SCC Processor:
    #sccs: 1
    #rules: 1
    #arcs: 3/9
    DPs:
     f#(f(a(),a()),x) -> f#(x,f(a(),f(a(),a())))
    TRS:
     f(f(a(),a()),x) -> f(f(x,f(a(),f(a(),a()))),a())
    Usable Rule Processor:
     DPs:
      f#(f(a(),a()),x) -> f#(x,f(a(),f(a(),a())))
     TRS:
      
     Bounds Processor:
      bound: 1
      enrichment: match
      automaton:
       final states: {5}
       transitions:
        f{#,1}(4,11) -> 5*
        f{#,1}(11,11) -> 5*
        f1(9,10) -> 11*
        f1(9,9) -> 10*
        a1() -> 9*
        f{#,0}(4,4) -> 5*
        f0(4,4) -> 4*
        a0() -> 4*
      problem:
       DPs:
        
       TRS:
        
      Qed