Consider the following premises. ~u_4 or r_11. u_4 or t. ~t. r_11 -> t_3. Can we infer t_3 from them?
 From u_4 or t, ~u_4 or r_11 we can infer t or r_11. From t or r_11, ~t we can infer r_11. Finally, from r_11 -> t_3, r_11 we can infer t_3. Therefore, the answer is yes.