Consider the following premises. p -> p_2. p_2. p or ~p_2. Can we infer p from them? If possible, name the inference rules being used at each step.
 From p or ~p_2 we can infer p_2 -> p via rewriting. From p_2 -> p, p -> p_2 we can infer p_2 <-> p via biconditional introduction. From p_2 <-> p we can infer p_2 -> p via biconditional elimination. Finally, from p_2 -> p, p_2 we can infer p via modus ponens. Therefore, the answer is yes.