Consider the following premises. p_6 or ~s. p_6 -> p. p -> s. Can we infer s <-> p_6 from them? If possible, name the inference rules being used at each step.
 From p_6 -> p, p -> s we can infer p_6 -> s via transitivity. From p_6 or ~s we can infer s -> p_6 via rewriting. Finally, from s -> p_6, p_6 -> s we can infer s <-> p_6 via biconditional introduction. Therefore, the answer is yes.