YES
O(n^3)
TRS:
 {
         first(0(), X) -> nil(),
  first(s(X), cons(Y)) -> cons(Y),
               from(X) -> cons(X)
 }
 DUP: We consider a non-duplicating system.
  Trs:
   {
           first(0(), X) -> nil(),
    first(s(X), cons(Y)) -> cons(Y),
                 from(X) -> cons(X)
   }
  Matrix Interpretation:
   Interpretation class: triangular
          [X2]    [1 0 0][X2]   [1]
   [from]([X1]) = [0 0 0][X1] + [0]
          [X0]    [0 0 0][X0]   [0]
   
       [X2]    [1 0 0][X2]   [0]
   [s]([X1]) = [0 0 1][X1] + [0]
       [X0]    [0 0 1][X0]   [0]
   
          [X2]    [1 0 0][X2]   [0]
   [cons]([X1]) = [0 0 0][X1] + [0]
          [X0]    [0 0 0][X0]   [0]
   
         [0]
   [0] = [0]
         [0]
   
           [X5]  [X2]    [1 0 0][X5]   [1 0 0][X2]   [1]
   [first]([X4], [X1]) = [0 1 1][X4] + [0 0 0][X1] + [0]
           [X3]  [X0]    [0 0 0][X3]   [0 0 0][X0]   [0]
   
           [0]
   [nil] = [0]
           [0]
   
   
   Qed