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