YES O(n^2) TRS: { g(a()) -> g(b()), b() -> f(a(), a()), f(a(), a()) -> g(d())} Natural interpretation: Strict: { g(a()) -> g(b()), b() -> f(a(), a()), f(a(), a()) -> g(d())} Weak: {} Interpretation class: deltarestricted [d](delta) = + 0 + 0*delta [f](delta, X1, X0) = + 0*X0 + 0*X1 + 0 + 2*X0*delta + 2*X1*delta + 0*delta [a](delta) = + 1 + 0*delta [b](delta) = + 0 + 5*delta [g](delta, X0) = + 0*X0 + 0 + 6*X0*delta + 0*delta f_tau_1(delta) = delta/(0 + 2 * delta)f_tau_2(delta) = delta/(0 + 2 * delta) g_tau_1(delta) = delta/(0 + 6 * delta) Qed