Consider the following premises. p_10 <-> p_22. ~q. s <-> q. p_22 -> ~q_22. q_22. Can we infer s from them? If possible, name the inference rules being used at each step.
 From p_22 -> ~q_22, q_22 we can infer ~p_22 via modus tollens. Finally, from s <-> q, ~q we can infer ~s via biconditional elimination, which contradicts s. Therefore, the answer is no.