Consider the following premises. r_20 -> q_3. ~p or r_20. q_4 -> q_3. q and q_14. p or q_4. Can we infer ~q from them?
 From p or q_4, ~p or r_20 we can infer q_4 or r_20. Finally, from q and q_14 we can infer q, which contradicts ~q. Therefore, the answer is no.