Consider the following premises. exists x_3: W(x_3) -> Q_3(x_3). forall x_3: W(x_3) or P_3(x_3). forall x_3: P_3(x_3) <-> Q_3(x_3). Can we infer exists x_3: Q_3(x_3) from them?
 From forall x_3: P_3(x_3) <-> Q_3(x_3) we can infer forall x_3: P_3(x_3) -> Q_3(x_3). Finally, from exists x_3: W(x_3) -> Q_3(x_3), forall x_3: P_3(x_3) -> Q_3(x_3), forall x_3: W(x_3) or P_3(x_3) we can infer exists x_3: Q_3(x_3). Therefore, the answer is yes.