Consider the following premises. t or ~q_6. p_6 -> q_6. p_6. Can we infer ~t from them?
 From p_6 -> q_6, p_6 we can infer q_6. From t or ~q_6 we can infer q_6 -> t. Finally, from q_6 -> t, q_6 we can infer t, which contradicts ~t. Therefore, the answer is no.