Consider the following premises. p_9 or ~s. ~p. p_9 -> s. p <-> s. Can we infer ~p_9 from them?
 From p_9 or ~s we can infer s -> p_9. From p <-> s, ~p we can infer ~s. From p_9 -> s, s -> p_9 we can infer p_9 <-> s. Finally, from p_9 <-> s, ~s we can infer ~p_9. Therefore, the answer is yes.