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{6, x1} a__f#_A(x1) = max{6, x1} f_A(x1) = max{1, x1} f#_A(x1) = max{1, x1} a_A = 3 a#_A = 3 c_A(x1) = max{0, 1 + x1} c#_A(x1) = max{0, 1 + x1} g_A(x1) = max{4, x1} g#_A(x1) = max{4, x1} mark_A(x1) = max{6, x1} mark#_A(x1) = max{6, x1} precedence: a = c > mark > a__f > f > g