Consider the following premises. forall x_6: ~P_6(x_6) or U_4(x_6). forall x_6: ~Q_4(x_6). exists x_6: P_6(x_6) or T(x_6). forall x_6: T(x_6) <-> Q_4(x_6). Can we infer forall x_6: ~U_4(x_6) from them?
 From exists x_6: P_6(x_6) or T(x_6), forall x_6: ~P_6(x_6) or U_4(x_6) we can infer exists x_6: T(x_6) or U_4(x_6). From forall x_6: T(x_6) <-> Q_4(x_6), forall x_6: ~Q_4(x_6) we can infer forall x_6: ~T(x_6). Finally, from exists x_6: T(x_6) or U_4(x_6), forall x_6: ~T(x_6) we can infer exists x_6: U_4(x_6), which contradicts forall x_6: ~U_4(x_6). Therefore, the answer is no.