YES

Problem:
 app(app(apply(),f),x) -> app(f,x)

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