YES O(n^2) TRS: { p(m, n, s(r)) -> p(m, r, n), p(m, s(n), 0()) -> p(0(), n, m), p(m, 0(), 0()) -> m } DUP: We consider a non-duplicating system. Trs: { p(m, n, s(r)) -> p(m, r, n), p(m, s(n), 0()) -> p(0(), n, m), p(m, 0(), 0()) -> m } Matrix Interpretation: Interpretation class: triangular [0] [0] = [1] [X1] [1 1][X1] [1] [s]([X0]) = [0 1][X0] + [0] [X5] [X3] [X1] [1 0][X5] [1 1][X3] [1 0][X1] [0] [p]([X4], [X2], [X0]) = [0 1][X4] + [0 1][X2] + [0 1][X0] + [0] Qed