Consider the following premises. ~p_4. r_2 <-> q_13. p_4 or q_13. Can we infer ~r_2 from them?
 From r_2 <-> q_13 we can infer q_13 -> r_2. From p_4 or q_13, ~p_4 we can infer q_13. Finally, from q_13 -> r_2, q_13 we can infer r_2, which contradicts ~r_2. Therefore, the answer is no.