Consider the following premises. t_2 -> p. p_4 or w_2. ~p_4. w_2 -> t_2. Can we infer ~p from them?
 From w_2 -> t_2, t_2 -> p we can infer w_2 -> p. From p_4 or w_2, ~p_4 we can infer w_2. Finally, from w_2 -> p, w_2 we can infer p, which contradicts ~p. Therefore, the answer is no.