Consider the following premises. s -> p_6. p <-> s. ~p_6. p_6 -> s. Can we infer p from them? If possible, name the inference rules being used at each step.
 From p_6 -> s, s -> p_6 we can infer p_6 <-> s via biconditional introduction. From p_6 <-> s, ~p_6 we can infer ~s via biconditional elimination. Finally, from p <-> s, ~s we can infer ~p via biconditional elimination, which contradicts p. Therefore, the answer is no.