Consider the following premises. u_4. p_3 or ~s_2. u_4 -> s_2. Can we infer ~p_3 from them?
 From p_3 or ~s_2 we can infer s_2 -> p_3. From u_4 -> s_2, s_2 -> p_3 we can infer u_4 -> p_3. Finally, from u_4 -> p_3, u_4 we can infer p_3, which contradicts ~p_3. Therefore, the answer is no.