Consider the following premises. q_10 -> t. ~q_10 -> s_1. ~t. t -> q_10. Can we infer s_1 from them? If possible, name the inference rules being used at each step.
 From t -> q_10, q_10 -> t we can infer t <-> q_10 via biconditional introduction. From t <-> q_10, ~t we can infer ~q_10 via biconditional elimination. Finally, from ~q_10 -> s_1, ~q_10 we can infer s_1 via modus ponens. Therefore, the answer is yes.