Consider the following premises. ~w_3. ~u -> p. t <-> u. w_3 <-> t. Can we infer p from them?
 From w_3 <-> t we can infer t -> w_3. From t -> w_3, ~w_3 we can infer ~t. From t <-> u, ~t we can infer ~u. Finally, from ~u -> p, ~u we can infer p. Therefore, the answer is yes.