Consider the following premises. p_1 or ~q_12. w_3 -> t. t or ~w. q_12 or w. p_1 -> w_3. Can we infer ~t from them?
 From t or ~w we can infer w -> t. From p_1 or ~q_12 we can infer q_12 -> p_1. From q_12 -> p_1, p_1 -> w_3 we can infer q_12 -> w_3. From q_12 -> w_3, w_3 -> t we can infer q_12 -> t. Finally, from q_12 -> t, w -> t, q_12 or w we can infer t, which contradicts ~t. Therefore, the answer is no.