Consider the following premises. ~r. s_4 -> r_6. s_1 <-> r. p -> r_6. s_4 or p. Can we infer r_6 and ~s_1 from them?
 From s_1 <-> r, ~r we can infer ~s_1. From s_4 -> r_6, p -> r_6, s_4 or p we can infer r_6. Finally, from r_6, ~s_1 we can infer r_6 and ~s_1. Therefore, the answer is yes.