Consider the following premises. u_2. u -> q_10. ~q_10. u or t_1. Can we infer t_1 and u_2 from them?
 From u -> q_10, ~q_10 we can infer ~u. From u or t_1, ~u we can infer t_1. Finally, from t_1, u_2 we can infer t_1 and u_2. Therefore, the answer is yes.