Consider the following premises. ~w_1. p_1 <-> t. p_1 -> q_8. w_1 <-> q_8. Can we infer ~t from them? If possible, name the inference rules being used at each step.
 From w_1 <-> q_8, ~w_1 we can infer ~q_8 via biconditional elimination. From p_1 -> q_8, ~q_8 we can infer ~p_1 via modus tollens. Finally, from p_1 <-> t, ~p_1 we can infer ~t via biconditional elimination. Therefore, the answer is yes.