Consider the following premises. r_2 -> ~q_17. ~u_3. s <-> s_2. q_17. s <-> u_3. Can we infer s_2 from them?
 From r_2 -> ~q_17, q_17 we can infer ~r_2. From s <-> u_3, ~u_3 we can infer ~s. Finally, from s <-> s_2, ~s we can infer ~s_2, which contradicts s_2. Therefore, the answer is no.