Consider the following premises. s_2 -> q_3. ~p_5. q_3 -> s_2. p_5 <-> s_2. Can we infer q_3 from them?
 From p_5 <-> s_2, ~p_5 we can infer ~s_2. From q_3 -> s_2, s_2 -> q_3 we can infer q_3 <-> s_2. Finally, from q_3 <-> s_2, ~s_2 we can infer ~q_3, which contradicts q_3. Therefore, the answer is no.