Consider the following premises. p_3 or w_4. ~p_18. p_3 -> u_1. p_18 <-> u_1. Can we infer ~w_4 from them?
 From p_18 <-> u_1 we can infer u_1 -> p_18. From u_1 -> p_18, ~p_18 we can infer ~u_1. From p_3 -> u_1, ~u_1 we can infer ~p_3. Finally, from p_3 or w_4, ~p_3 we can infer w_4, which contradicts ~w_4. Therefore, the answer is no.