Consider the following premises. w -> ~t_4. ~q_13. p -> q_13. t_4. Can we infer ~w from them? If possible, name the inference rules being used at each step.
 From p -> q_13, ~q_13 we can infer ~p via modus tollens. Finally, from w -> ~t_4, t_4 we can infer ~w via modus tollens. Therefore, the answer is yes.