Consider the following premises. q. ~w or r_2. w. s -> ~q. Can we infer r_2 from them? If possible, name the inference rules being used at each step.
 From w we can infer w or s via addition. From s -> ~q, q we can infer ~s via modus tollens. From w or s, ~w or r_2 we can infer s or r_2 via resolution. Finally, from s or r_2, ~s we can infer r_2 via disjunctive syllogism. Therefore, the answer is yes.