YES
O(n^2)
TRS:
 {     g(a()) -> g(b()),
          b() -> f(a(), a()),
  f(a(), a()) -> g(d())}
 DUP: We consider a non-duplicating system.
  Trs:
   {     g(a()) -> g(b()),
            b() -> f(a(), a()),
    f(a(), a()) -> g(d())}
  Matrix Interpretation:
   Interpretation class: triangular
         [0]
   [d] = [0]
   
       [X3]  [X1]    [1 0][X3]   [1 0][X1]   [2]
   [f]([X2], [X0]) = [0 0][X2] + [0 0][X0] + [1]
   
         [0]
   [a] = [3]
   
         [3]
   [b] = [1]
   
       [X1]    [1 2][X1]   [0]
   [g]([X0]) = [0 0][X0] + [0]
   
   
   Qed