Consider the following premises. q -> p_4. p_4 -> q. p_4 -> ~s. s. Can we infer ~q from them?
 From p_4 -> ~s, s we can infer ~p_4. From q -> p_4, p_4 -> q we can infer q <-> p_4. Finally, from q <-> p_4, ~p_4 we can infer ~q. Therefore, the answer is yes.