YES TRS: active(f(X)) -> mark(g(h(f(X)))) active(f(X)) -> f(active(X)) active(h(X)) -> h(active(X)) f(mark(X)) -> mark(f(X)) h(mark(X)) -> mark(h(X)) proper(f(X)) -> f(proper(X)) proper(g(X)) -> g(proper(X)) proper(h(X)) -> h(proper(X)) f(ok(X)) -> ok(f(X)) g(ok(X)) -> ok(g(X)) h(ok(X)) -> ok(h(X)) top(mark(X)) -> top(proper(X)) top(ok(X)) -> top(active(X)) max/plus interpretations on N: active_A(x1) = max{5, 11 + x1} active#_A(x1) = max{5, 11 + x1} f_A(x1) = max{4, 37 + x1} f#_A(x1) = max{4, 37 + x1} mark_A(x1) = max{26, 5 + x1} mark#_A(x1) = max{26, 5 + x1} g_A(x1) = max{2, 1 + x1} g#_A(x1) = max{2, 1 + x1} h_A(x1) = max{16, 4 + x1} h#_A(x1) = max{16, 4 + x1} proper_A(x1) = max{3, 3 + x1} proper#_A(x1) = max{3, 3 + x1} ok_A(x1) = max{48, 36 + x1} ok#_A(x1) = max{48, 36 + x1} top_A(x1) = max{49, 24 + x1} top#_A(x1) = max{49, 24 + x1} precedence: top > active > f = proper > g = h = ok > mark