Consider the following premises. exists x_13: R_13(x_13) -> S(x_13). forall x_13: Q_13(x_13) -> R_13(x_13). forall x_13: P_13(x_13) or Q_13(x_13). forall x_13: P_13(x_13) -> R_13(x_13). forall x_13: U_2(x_13) -> ~S(x_13). Can we infer forall x_13: U_2(x_13) from them?
 From forall x_13: P_13(x_13) -> R_13(x_13), forall x_13: Q_13(x_13) -> R_13(x_13), forall x_13: P_13(x_13) or Q_13(x_13) we can infer forall x_13: R_13(x_13). From exists x_13: R_13(x_13) -> S(x_13), forall x_13: R_13(x_13) we can infer exists x_13: S(x_13). Finally, from forall x_13: U_2(x_13) -> ~S(x_13), exists x_13: S(x_13) we can infer exists x_13: ~U_2(x_13), which contradicts forall x_13: U_2(x_13). Therefore, the answer is no.