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