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