Consider the following premises. w or p. r <-> u. r -> ~r_11. w -> r_11. p -> r_11. Can we infer u from them?
 From w -> r_11, p -> r_11, w or p we can infer r_11. From r -> ~r_11, r_11 we can infer ~r. Finally, from r <-> u, ~r we can infer ~u, which contradicts u. Therefore, the answer is no.