YES
O(n^4)
TRS:
 {
     g(empty(), d) -> d,
  g(cons(x, k), d) -> g(k, cons(x, d)),
     f(a, empty()) -> g(a, empty()),
  f(a, cons(x, k)) -> f(cons(x, a), k)
 }
 DUP: We consider a non-duplicating system.
  Trs:
   {
       g(empty(), d) -> d,
    g(cons(x, k), d) -> g(k, cons(x, d)),
       f(a, empty()) -> g(a, empty()),
    f(a, cons(x, k)) -> f(cons(x, a), k)
   }
  Matrix Interpretation:
   Interpretation class: triangular
          [X7]  [X3]    [1 0 0 0][X7]   [1 0 0 0][X3]   [0]
          [X6]  [X2]    [0 0 0 1][X6]   [0 1 0 0][X2]   [1]
   [cons]([X5], [X1]) = [0 0 0 0][X5] + [0 0 1 0][X1] + [0]
          [X4]  [X0]    [0 0 0 1][X4]   [0 0 0 1][X0]   [1]
   
       [X7]  [X3]    [1 1 0 0][X7]   [1 1 0 1][X3]   [0]
       [X6]  [X2]    [0 0 0 1][X6]   [0 1 1 0][X2]   [0]
   [f]([X5], [X1]) = [0 0 0 0][X5] + [0 0 0 0][X1] + [1]
       [X4]  [X0]    [0 0 0 1][X4]   [0 0 0 1][X0]   [0]
   
             [0]
             [1]
   [empty] = [1]
             [0]
   
       [X7]  [X3]    [1 1 0 0][X7]   [1 0 0 0][X3]   [0]
       [X6]  [X2]    [0 0 0 1][X6]   [0 1 0 0][X2]   [0]
   [g]([X5], [X1]) = [0 0 0 0][X5] + [0 0 1 0][X1] + [0]
       [X4]  [X0]    [0 0 0 1][X4]   [0 0 0 1][X0]   [0]
   
   
   Qed