Consider the following premises. ~Q_3(b). forall x: T_3(x) <-> Q_3(x). T_3(b). Can we infer t_3 from them?
 From forall x: T_3(x) <-> Q_3(x) we can infer T_3(b) <-> Q_3(b). From T_3(b) we can infer T_3(b) or t_3. From T_3(b) <-> Q_3(b), ~Q_3(b) we can infer ~T_3(b). Finally, from T_3(b) or t_3, ~T_3(b) we can infer t_3. Therefore, the answer is yes. Notice, however, that the premises were contradictory, so we can infer anything from them.