Consider the following premises. p <-> q_6. q. q -> q_6. Can we infer q_6 from them? If possible, name the inference rules being used at each step.
 From p <-> q_6 we can infer p -> q_6 via biconditional elimination. From q we can infer q or p via addition. Finally, from q -> q_6, p -> q_6, q or p we can infer q_6 via disjunction elimination. Therefore, the answer is yes.