Consider the following premises. ~q_11. ~u or r_11. u or q_11. Can we infer ~r_11 from them?
 From u or q_11, ~u or r_11 we can infer q_11 or r_11. Finally, from q_11 or r_11, ~q_11 we can infer r_11, which contradicts ~r_11. Therefore, the answer is no.