Consider the following premises. t_4 and q_5. ~q_11. s -> q_11. Can we infer t_4 and ~s from them? If possible, name the inference rules being used at each step.
 From s -> q_11, ~q_11 we can infer ~s via modus tollens. From t_4 and q_5 we can infer t_4 via simplification. Finally, from t_4, ~s we can infer t_4 and ~s via conjunction. Therefore, the answer is yes.