Consider the following premises. ~t. t or u_1. q_14. p_14 -> ~q_14. Can we infer u_1 from them? If possible, name the inference rules being used at each step.
 From p_14 -> ~q_14, q_14 we can infer ~p_14 via modus tollens. Finally, from t or u_1, ~t we can infer u_1 via disjunctive syllogism. Therefore, the answer is yes.