YES O(n^2) TRS: {app(app(app(uncurry(), f), x), y) -> app(app(f, x), y)} Natural interpretation: Strict: {app(app(app(uncurry(), f), x), y) -> app(app(f, x), y)} Weak: {} Interpretation class: deltarestricted [uncurry](delta) = + 0 + 0*delta [app](delta, X1, X0) = + 0*X0 + 0*X1 + 0 + 1*X0*delta + 1*X1*delta + 1*delta app_tau_1(delta) = delta/(0 + 1 * delta)app_tau_2(delta) = delta/(0 + 1 * delta) Qed