YES TRS: a__f(f(a())) -> a__f(g(f(a()))) mark(f(X)) -> a__f(mark(X)) mark(a()) -> a() mark(g(X)) -> g(X) a__f(X) -> f(X) max/plus interpretations on N: a__f_A(x1) = max{2, 12 + x1} a__f#_A(x1) = max{14, 11 + x1} f_A(x1) = max{5, 12 + x1} f#_A(x1) = max{7, 13} a_A = 2 a#_A = 6 g_A(x1) = max{6, -9} g#_A(x1) = max{0, 1 + x1} mark_A(x1) = max{1, 8 + x1} mark#_A(x1) = max{15, 8 + x1} precedence: mark > a__f > f > a = g