Consider the following premises. w -> u_2. p_4 -> w. p or ~u_2. Can we infer p_4 -> p from them?
 From p or ~u_2 we can infer u_2 -> p. From p_4 -> w, w -> u_2 we can infer p_4 -> u_2. Finally, from p_4 -> u_2, u_2 -> p we can infer p_4 -> p. Therefore, the answer is yes.