Consider the following premises. exists x: S_1(x) and U_4(x). forall x: S_1(x) -> Q_4(x). Can we infer exists x: Q_4(x) from them?
 From exists x: S_1(x) and U_4(x) we can infer exists x: S_1(x). Finally, from forall x: S_1(x) -> Q_4(x), exists x: S_1(x) we can infer exists x: Q_4(x). Therefore, the answer is yes.