Consider the following premises. s_1 -> q_11. w. p_3 -> ~w. ~q_11. Can we infer ~s_1 and ~p_3 from them? If possible, name the inference rules being used at each step.
 From s_1 -> q_11, ~q_11 we can infer ~s_1 via modus tollens. From p_3 -> ~w, w we can infer ~p_3 via modus tollens. Finally, from ~s_1, ~p_3 we can infer ~s_1 and ~p_3 via conjunction. Therefore, the answer is yes.