Consider the following premises. u <-> t. w_3 <-> q_8. u <-> q_8. ~w_3. Can we infer t from them? If possible, name the inference rules being used at each step.
 From w_3 <-> q_8, ~w_3 we can infer ~q_8 via biconditional elimination. From u <-> q_8, ~q_8 we can infer ~u via biconditional elimination. Finally, from u <-> t, ~u we can infer ~t via biconditional elimination, which contradicts t. Therefore, the answer is no.