Consider the following premises. p_11 -> q_17. p_11 or w. s <-> p_2. w <-> q_17. p_2 -> ~q_17. Can we infer ~s from them?
 From w <-> q_17 we can infer w -> q_17. From p_11 -> q_17, w -> q_17, p_11 or w we can infer q_17. From p_2 -> ~q_17, q_17 we can infer ~p_2. Finally, from s <-> p_2, ~p_2 we can infer ~s. Therefore, the answer is yes.