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