YES TRS: a__f(f(a())) -> c(f(g(f(a())))) mark(f(X)) -> a__f(mark(X)) mark(a()) -> a() mark(c(X)) -> c(X) mark(g(X)) -> g(mark(X)) a__f(X) -> f(X) max/plus interpretations on N: a__f_A(x1) = max{2, 3 + x1} a__f#_A(x1) = max{15, 2 + x1} f_A(x1) = max{0, 3 + x1} f#_A(x1) = max{10, 12} a_A = 4 a#_A = 11 c_A(x1) = max{4, -8 + x1} c#_A(x1) = max{0, 1} g_A(x1) = max{3, 1 + x1} g#_A(x1) = max{13, 15} mark_A(x1) = max{0, x1} mark#_A(x1) = max{16, 14 + x1} precedence: mark > a__f > f > a = c = g