Consider the following premises. q_2. s -> p_17. p_17 <-> t_4. ~t_4. Can we infer ~s and q_2 from them?
 From p_17 <-> t_4, ~t_4 we can infer ~p_17. From s -> p_17, ~p_17 we can infer ~s. Finally, from ~s, q_2 we can infer ~s and q_2. Therefore, the answer is yes.