Consider the following premises. ~p_9. p_9 or s. s <-> t. Can we infer t from them? If possible, name the inference rules being used at each step.
 From p_9 or s, ~p_9 we can infer s via disjunctive syllogism. From s <-> t we can infer s -> t via biconditional elimination. Finally, from s -> t, s we can infer t via modus ponens. Therefore, the answer is yes.