NO Problem: f(s(s(s(s(s(s(s(s(x)))))))),y,y) -> f(id(s(s(s(s(s(s(s(s(x))))))))),y,y) id(s(x)) -> s(id(x)) id(0()) -> 0() Proof: Unfolding Processor: loop length: 9 terms: f(s(s(s(s(s(s(s(s(x2029)))))))),y,y) f(id(s(s(s(s(s(s(s(s(x2029))))))))),y,y) f(s(id(s(s(s(s(s(s(s(x2029))))))))),y,y) f(s(s(id(s(s(s(s(s(s(x2029))))))))),y,y) f(s(s(s(id(s(s(s(s(s(x2029))))))))),y,y) f(s(s(s(s(id(s(s(s(s(x2029))))))))),y,y) f(s(s(s(s(s(id(s(s(s(x2029))))))))),y,y) f(s(s(s(s(s(s(id(s(s(x2029))))))))),y,y) f(s(s(s(s(s(s(s(id(s(x2029))))))))),y,y) context: [] substitution: y -> y x2029 -> id(x2029) Qed