Consider the following premises. ~r or q. p_11 <-> p. r or p_11. p or ~q. Can we infer p from them?
 From p_11 <-> p we can infer p_11 -> p. From r or p_11, ~r or q we can infer p_11 or q. From p or ~q we can infer q -> p. Finally, from p_11 -> p, q -> p, p_11 or q we can infer p. Therefore, the answer is yes.