Consider the following premises. q_11 or t. r. p_11 or ~q_11. t -> p_11. Can we infer ~p_11 from them? If possible, name the inference rules being used at each step.
 From p_11 or ~q_11 we can infer q_11 -> p_11 via rewriting. Finally, from q_11 -> p_11, t -> p_11, q_11 or t we can infer p_11 via disjunction elimination, which contradicts ~p_11. Therefore, the answer is no.