Consider the following premises. q -> ~w_4. r_1. w -> ~r_1. w_4. Can we infer ~w and ~q from them? If possible, name the inference rules being used at each step.
 From w -> ~r_1, r_1 we can infer ~w via modus tollens. From q -> ~w_4, w_4 we can infer ~q via modus tollens. Finally, from ~w, ~q we can infer ~w and ~q via conjunction. Therefore, the answer is yes.