Consider the following premises. ~q. q_4 -> q. q_3 -> q_4. q -> q_3. Can we infer q_4 from them?
 From q -> q_3, q_3 -> q_4 we can infer q -> q_4. From q_4 -> q, q -> q_4 we can infer q_4 <-> q. Finally, from q_4 <-> q, ~q we can infer ~q_4, which contradicts q_4. Therefore, the answer is no.