TRS: { f(X) -> g(n__h(n__f(X))), h(X) -> n__h(X), f(X) -> n__f(X), activate(n__h(X)) -> h(activate(X)), activate(n__f(X)) -> f(activate(X)), activate(X) -> X} POP* + Boolean Semantic Labelling: Normal positions: pi(activate_sl=1) = [1], pi(activate_sl=0) = [1], pi(h_sl=0) = [1], pi(f_sl=0) = [1] Safe positions: pi(h_sl=1) = [1], pi(f_sl=1) = [1], pi(n__f_sl=1) = [1], pi(n__f_sl=0) = [1], pi(n__h_sl=1) = [1], pi(n__h_sl=0) = [1], pi(g_sl=1) = [1], pi(g_sl=0) = [1] Precedence: h_sl=1 > n__h_sl=0, f_sl=1 > g_sl=0, f_sl=1 > n__h_sl=0, f_sl=1 > n__f_sl=0, f_sl=0 > g_sl=0, f_sl=0 > n__h_sl=0, f_sl=0 > n__f_sl=0, h_sl=0 > n__h_sl=0, activate_sl=1 > activate_sl=0, activate_sl=1 > h_sl=1, activate_sl=1 > h_sl=0, activate_sl=1 > f_sl=1, activate_sl=1 > f_sl=0 empty Interpretation: g^(1): 0 | 0 1 | 0 n__h^(1): 0 | 0 1 | 0 n__f^(1): 0 | 0 1 | 0 f^(1): 0 | 0 1 | 0 h^(1): 0 | 0 1 | 0 activate^(1): 0 | 0 1 | 1 Labelling: g^(1): 0 | 0 1 | 0 n__h^(1): 0 | 0 1 | 0 n__f^(1): 0 | 0 1 | 0 f^(1): 0 | 1 1 | 0 h^(1): 0 | 1 1 | 0 activate^(1): 0 | 1 1 | 0 Labelled predicative System: { f_sl=1(;X) -> g_sl=0(;n__h_sl=0(;n__f_sl=0(;X))), f_sl=0(X;) -> g_sl=0(;n__h_sl=0(;n__f_sl=0(;X))), h_sl=1(;X) -> n__h_sl=0(;X), h_sl=0(X;) -> n__h_sl=0(;X), f_sl=1(;X) -> n__f_sl=0(;X), f_sl=0(X;) -> n__f_sl=0(;X), activate_sl=1(n__h_sl=0(;X);) -> h_sl=1(;activate_sl=1(X;)), activate_sl=1(n__h_sl=0(;X);) -> h_sl=0(activate_sl=0(X;);), activate_sl=1(n__f_sl=0(;X);) -> f_sl=1(;activate_sl=1(X;)), activate_sl=1(n__f_sl=0(;X);) -> f_sl=0(activate_sl=0(X;);), activate_sl=1(X;) -> X, activate_sl=0(X;) -> X} Qed