Consider the following premises. q_6 -> p_4. r_3 -> q_6. r_3 or ~p_4. Can we infer ~(r_3 <-> p_4) from them?
 From r_3 -> q_6, q_6 -> p_4 we can infer r_3 -> p_4. From r_3 or ~p_4 we can infer p_4 -> r_3. Finally, from r_3 -> p_4, p_4 -> r_3 we can infer r_3 <-> p_4, which contradicts ~(r_3 <-> p_4). Therefore, the answer is no.