Consider the following premises. t_3 or ~w_3. w_3 or q_11. q_11 -> t_3. r_1 -> p_2. p_2 -> ~t_3. Can we infer r_1 from them?
 From t_3 or ~w_3 we can infer w_3 -> t_3. From w_3 -> t_3, q_11 -> t_3, w_3 or q_11 we can infer t_3. From p_2 -> ~t_3, t_3 we can infer ~p_2. Finally, from r_1 -> p_2, ~p_2 we can infer ~r_1, which contradicts r_1. Therefore, the answer is no.