Consider the following premises. exists x_13: Q(x_13). forall x_13: Q_13(x_13) -> T_4(x_13). forall x_13: W(x_13) -> Q_13(x_13). forall x_13: T_4(x_13) -> ~Q(x_13). forall x_13: U(x_13) -> W(x_13). Can we infer exists x_13: ~U(x_13) from them?
 From forall x_13: W(x_13) -> Q_13(x_13), forall x_13: Q_13(x_13) -> T_4(x_13) we can infer forall x_13: W(x_13) -> T_4(x_13). From forall x_13: T_4(x_13) -> ~Q(x_13), exists x_13: Q(x_13) we can infer exists x_13: ~T_4(x_13). From forall x_13: U(x_13) -> W(x_13), forall x_13: W(x_13) -> T_4(x_13) we can infer forall x_13: U(x_13) -> T_4(x_13). Finally, from forall x_13: U(x_13) -> T_4(x_13), exists x_13: ~T_4(x_13) we can infer exists x_13: ~U(x_13). Therefore, the answer is yes.