Consider the following premises. p_9 -> p. q_3 or p_9. ~q_3 or r_7. p -> p_9. r_7 -> p. Can we infer ~p from them?
 From p_9 -> p, p -> p_9 we can infer p_9 <-> p. From q_3 or p_9, ~q_3 or r_7 we can infer p_9 or r_7. From p_9 <-> p we can infer p_9 -> p. Finally, from p_9 -> p, r_7 -> p, p_9 or r_7 we can infer p, which contradicts ~p. Therefore, the answer is no.