YES TRS: f(f(a())) -> f(g(n__f(a()))) f(X) -> n__f(X) activate(n__f(X)) -> f(X) activate(X) -> X max/plus interpretations on N: f_A(x1) = max{3, -4 + x1} f#_A(x1) = max{1, 3 + x1} a_A = 5 a#_A = 0 g_A(x1) = max{2, -2 + x1} g#_A(x1) = max{0, 6 + x1} n__f_A(x1) = max{1, -11 + x1} n__f#_A(x1) = max{3, 0} activate_A(x1) = max{0, 7 + x1} activate#_A(x1) = max{0, 15 + x1} precedence: activate > f > a = g = n__f