YES
O(n^4)
TRS:
 {
  app(app(plus(), app(s(), x)), y) -> app(s(), app(app(plus(), x), y)),
                      app(id(), x) -> x,
                  app(plus(), 0()) -> id()
 }
 DUP: We consider a non-duplicating system.
  Trs:
   {
    app(app(plus(), app(s(), x)), y) -> app(s(), app(app(plus(), x), y)),
                        app(id(), x) -> x,
                    app(plus(), 0()) -> id()
   }
  Matrix Interpretation:
   Interpretation class: triangular
         [0]
         [0]
   [s] = [0]
         [1]
   
         [1]
         [0]
   [0] = [1]
         [0]
   
            [0]
            [0]
   [plus] = [0]
            [0]
   
          [0]
          [0]
   [id] = [1]
          [0]
   
         [X7]  [X3]    [1 0 1 0][X7]   [1 0 0 0][X3]   [0]
         [X6]  [X2]    [0 0 0 0][X6]   [0 1 0 0][X2]   [0]
   [app]([X5], [X1]) = [0 0 1 1][X5] + [0 0 1 0][X1] + [0]
         [X4]  [X0]    [0 0 0 0][X4]   [0 0 0 1][X0]   [0]
   
   
   Qed