YES

Problem:
 app(app(app(compose(),f),g),x) -> app(f,app(g,x))

Proof:
 DP Processor:
  DPs:
   app#(app(app(compose(),f),g),x) -> app#(g,x)
   app#(app(app(compose(),f),g),x) -> app#(f,app(g,x))
  TRS:
   app(app(app(compose(),f),g),x) -> app(f,app(g,x))
  Subterm Criterion Processor:
   simple projection:
    pi(app#) = 0
   problem:
    DPs:
     
    TRS:
     app(app(app(compose(),f),g),x) -> app(f,app(g,x))
   Qed