Consider the following premises. w -> t_2. t_2 -> t. ~w. t -> w. Can we infer t_2 from them? If possible, name the inference rules being used at each step.
 From t_2 -> t, t -> w we can infer t_2 -> w via transitivity. From t_2 -> w, w -> t_2 we can infer t_2 <-> w via biconditional introduction. Finally, from t_2 <-> w, ~w we can infer ~t_2 via biconditional elimination, which contradicts t_2. Therefore, the answer is no.