Consider the following premises. p_8 -> q_8. p_8 -> q_8. ~p_8. q_8 -> p_8. Can we infer q_8 from them?
 From p_8 -> q_8, q_8 -> p_8 we can infer p_8 <-> q_8. From p_8 <-> q_8 we can infer q_8 -> p_8. From q_8 -> p_8, p_8 -> q_8 we can infer q_8 <-> p_8. Finally, from q_8 <-> p_8, ~p_8 we can infer ~q_8, which contradicts q_8. Therefore, the answer is no.