Consider the following premises. q_11 -> s_2. p_11 or ~s. p_11 -> q_11. s_2 -> r_1. Can we infer s -> r_1 from them?
 From p_11 -> q_11, q_11 -> s_2 we can infer p_11 -> s_2. From p_11 or ~s we can infer s -> p_11. From p_11 -> s_2, s_2 -> r_1 we can infer p_11 -> r_1. Finally, from s -> p_11, p_11 -> r_1 we can infer s -> r_1. Therefore, the answer is yes.