Consider the following premises. T_4(a_5) <-> t_2. forall x: ~Q_2(x). forall x: T_4(x) -> Q_2(x). Can we infer t_2 from them? If possible, name the inference rules being used at each step.
 From forall x: T_4(x) -> Q_2(x), forall x: ~Q_2(x) we can infer forall x: ~T_4(x) via universal modus tollens. From forall x: ~T_4(x) we can infer ~T_4(a_5) via universal instantiation. Finally, from T_4(a_5) <-> t_2, ~T_4(a_5) we can infer ~t_2 via biconditional elimination, which contradicts t_2. Therefore, the answer is no.