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)
  KBO Processor:
   argument filtering:
    pi(apply) = []
    pi(app) = [1]
    pi(app#) = 0
   weight function:
    w0 = 1
    w(app#) = w(app) = w(apply) = 1
   precedence:
    app# ~ app ~ apply
   problem:
    DPs:
     
    TRS:
     app(app(apply(),f),x) -> app(f,x)
   Qed