Consider the following premises. P_3(i_4) -> t_2. forall x: P_3(x) <-> T(x). q -> t_2. T(i_4) or q. Can we infer ~t_2 from them?
 From forall x: P_3(x) <-> T(x) we can infer forall x: T(x) -> P_3(x). From forall x: T(x) -> P_3(x) we can infer T(i_4) -> P_3(i_4). From T(i_4) -> P_3(i_4), P_3(i_4) -> t_2 we can infer T(i_4) -> t_2. Finally, from T(i_4) -> t_2, q -> t_2, T(i_4) or q we can infer t_2, which contradicts ~t_2. Therefore, the answer is no.