Consider the following premises. p or ~s. s or ~p. p <-> w. ~w. Can we infer ~s from them?
 From p <-> w, ~w we can infer ~p. From s or ~p we can infer p -> s. From p or ~s we can infer s -> p. From s -> p, p -> s we can infer s <-> p. Finally, from s <-> p, ~p we can infer ~s. Therefore, the answer is yes.