Consider the following premises. p_9 -> p_2. p_2 -> p. ~p. p_9 or ~p. Can we infer p_2 from them?
 From p_9 or ~p we can infer p -> p_9. From p -> p_9, p_9 -> p_2 we can infer p -> p_2. From p_2 -> p, p -> p_2 we can infer p_2 <-> p. Finally, from p_2 <-> p, ~p we can infer ~p_2, which contradicts p_2. Therefore, the answer is no.