Consider the following premises. w_3. p_18 or ~q_18. p_18 -> ~w_3. q. Can we infer q_18 from them? If possible, name the inference rules being used at each step.
 From p_18 or ~q_18 we can infer q_18 -> p_18 via rewriting. From p_18 -> ~w_3, w_3 we can infer ~p_18 via modus tollens. Finally, from q_18 -> p_18, ~p_18 we can infer ~q_18 via modus tollens, which contradicts q_18. Therefore, the answer is no.