YES TRS: active(f(g(X),Y)) -> mark(f(X,f(g(X),Y))) active(f(X1,X2)) -> f(active(X1),X2) active(g(X)) -> g(active(X)) f(mark(X1),X2) -> mark(f(X1,X2)) g(mark(X)) -> mark(g(X)) proper(f(X1,X2)) -> f(proper(X1),proper(X2)) proper(g(X)) -> g(proper(X)) f(ok(X1),ok(X2)) -> ok(f(X1,X2)) g(ok(X)) -> ok(g(X)) top(mark(X)) -> top(proper(X)) top(ok(X)) -> top(active(X)) linear polynomial interpretations on N: active_A(x1) = 2 active#_A(x1) = 3 f_A(x1,x2) = x1 f#_A(x1,x2) = 2 g_A(x1) = x1 g#_A(x1) = 1 mark_A(x1) = 2 mark#_A(x1) = 0 proper_A(x1) = 1 proper#_A(x1) = 3 ok_A(x1) = 3 ok#_A(x1) = 0 top_A(x1) = x1 top#_A(x1) = x1 + 2 precedence: ok > top > active > f > mark > proper > g