Consider the following premises. w -> p_11. ~p_8. p_11 <-> t_1. p_11 -> w. p_8 <-> w. Can we infer t_1 from them?
 From p_11 -> w, w -> p_11 we can infer p_11 <-> w. From p_8 <-> w, ~p_8 we can infer ~w. From p_11 <-> w, ~w we can infer ~p_11. Finally, from p_11 <-> t_1, ~p_11 we can infer ~t_1, which contradicts t_1. Therefore, the answer is no.