Consider the following premises. forall x: W_2(x) or U(x). exists x: Q_2(x) <-> U(x). forall x: W_2(x) -> Q_2(x). Can we infer exists x: Q_2(x) from them?
 From exists x: Q_2(x) <-> U(x) we can infer exists x: U(x) -> Q_2(x). Finally, from forall x: W_2(x) -> Q_2(x), exists x: U(x) -> Q_2(x), forall x: W_2(x) or U(x) we can infer exists x: Q_2(x). Therefore, the answer is yes.