NO Problem: F(D(x),y) -> F(D(x),G(G(y))) F(x,E(y)) -> F(G(x),E(y)) G(x) -> x H(I(x)) -> K(J(x)) J(x) -> K(J(x)) I(x) -> I(J(x)) J(x) -> J(K(J(x))) S(x,T(x)) -> T(x) Proof: Containment Processor: loop length: 1 terms: F(D(x),y) context: [] substitution: x -> x y -> G(G(y)) Qed