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