Consider the following premises. s -> q_11. q_11 -> s. ~w_1. w_1 <-> s. Can we infer ~q_11 from them?
 From s -> q_11, q_11 -> s we can infer s <-> q_11. From w_1 <-> s we can infer s -> w_1. From s -> w_1, ~w_1 we can infer ~s. Finally, from s <-> q_11, ~s we can infer ~q_11. Therefore, the answer is yes.