Consider the following premises. exists y_4: U(y_4) <-> S(y_4). forall y_4: W(y_4) -> Q_3(y_4). forall y_4: S(y_4) or ~Q_3(y_4). Can we infer exists y_4: W(y_4) -> U(y_4) from them?
 From forall y_4: S(y_4) or ~Q_3(y_4) we can infer forall y_4: Q_3(y_4) -> S(y_4). From exists y_4: U(y_4) <-> S(y_4) we can infer exists y_4: S(y_4) -> U(y_4). From forall y_4: Q_3(y_4) -> S(y_4), exists y_4: S(y_4) -> U(y_4) we can infer exists y_4: Q_3(y_4) -> U(y_4). Finally, from forall y_4: W(y_4) -> Q_3(y_4), exists y_4: Q_3(y_4) -> U(y_4) we can infer exists y_4: W(y_4) -> U(y_4). Therefore, the answer is yes.