Consider the following premises. ~s <-> q_3. s <-> s_4. ~s_4. Can we infer ~q_3 from them?
 From s <-> s_4, ~s_4 we can infer ~s. From ~s <-> q_3 we can infer ~s -> q_3. Finally, from ~s -> q_3, ~s we can infer q_3, which contradicts ~q_3. Therefore, the answer is no.