Consider the following premises. w <-> t. q_12. t <-> q_4. w -> ~q_12. Can we infer ~q_4 from them? If possible, name the inference rules being used at each step.
 From w -> ~q_12, q_12 we can infer ~w via modus tollens. From w <-> t, ~w we can infer ~t via biconditional elimination. From t <-> q_4 we can infer q_4 -> t via biconditional elimination. Finally, from q_4 -> t, ~t we can infer ~q_4 via modus tollens. Therefore, the answer is yes.