Consider the following premises. ~t_3 -> q. ~q_1. t_3 <-> q_1. Can we infer q from them? If possible, name the inference rules being used at each step.
 From t_3 <-> q_1, ~q_1 we can infer ~t_3 via biconditional elimination. Finally, from ~t_3 -> q, ~t_3 we can infer q via modus ponens. Therefore, the answer is yes.