Consider the following premises. exists x: T_4(x) -> Q_4(x). forall x: Q_4(x) -> T_4(x). forall x: ~T_4(x). Can we infer forall x: Q_4(x) from them?
 From exists x: T_4(x) -> Q_4(x), forall x: Q_4(x) -> T_4(x) we can infer exists x: T_4(x) <-> Q_4(x). From exists x: T_4(x) <-> Q_4(x) we can infer exists x: Q_4(x) -> T_4(x). Finally, from exists x: Q_4(x) -> T_4(x), forall x: ~T_4(x) we can infer exists x: ~Q_4(x), which contradicts forall x: Q_4(x). Therefore, the answer is no.