Consider the following premises. p_1 <-> w. p_1 or ~q_2. q_2 or w. Can we infer p_1 from them? If possible, name the inference rules being used at each step.
 From p_1 <-> w we can infer w -> p_1 via biconditional elimination. From p_1 or ~q_2 we can infer q_2 -> p_1 via rewriting. Finally, from q_2 -> p_1, w -> p_1, q_2 or w we can infer p_1 via disjunction elimination. Therefore, the answer is yes.