Consider the following premises. ~s_1. s -> q_2. ~q_2. w -> s_1. s_1 -> w. Can we infer w from them?
 From w -> s_1, s_1 -> w we can infer w <-> s_1. Finally, from w <-> s_1, ~s_1 we can infer ~w, which contradicts w. Therefore, the answer is no.