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