Consider the following premises. u <-> q_8. q_8 <-> r. w <-> r. ~u. Can we infer w from them?
 From u <-> q_8, ~u we can infer ~q_8. From q_8 <-> r, ~q_8 we can infer ~r. Finally, from w <-> r, ~r we can infer ~w, which contradicts w. Therefore, the answer is no.