Consider the following premises. t <-> q_12. u_3 or q_16. ~u_3 or t. q_16 -> q_12. Can we infer q_12 or q from them? If possible, name the inference rules being used at each step.
 From u_3 or q_16, ~u_3 or t we can infer q_16 or t via resolution. From t <-> q_12 we can infer t -> q_12 via biconditional elimination. From q_16 -> q_12, t -> q_12, q_16 or t we can infer q_12 via disjunction elimination. Finally, from q_12 we can infer q_12 or q via addition. Therefore, the answer is yes.