Consider the following premises. ~w or r_20. r_15 -> q_1. t_4 -> r_15. r_20 -> r_15. w or t_4. Can we infer q_1 or q from them?
 From w or t_4, ~w or r_20 we can infer t_4 or r_20. From t_4 -> r_15, r_20 -> r_15, t_4 or r_20 we can infer r_15. From r_15 -> q_1, r_15 we can infer q_1. Finally, from q_1 we can infer q_1 or q. Therefore, the answer is yes.