Consider the following premises. w_1 -> U(a_15). forall x: ~U(x). t_3 -> q_16. q_16 -> t_3. w_1 <-> t_3. Can we infer ~q_16 from them? If possible, name the inference rules being used at each step.
 From t_3 -> q_16, q_16 -> t_3 we can infer t_3 <-> q_16 via biconditional introduction. From forall x: ~U(x) we can infer ~U(a_15) via universal instantiation. From w_1 -> U(a_15), ~U(a_15) we can infer ~w_1 via modus tollens. From w_1 <-> t_3, ~w_1 we can infer ~t_3 via biconditional elimination. Finally, from t_3 <-> q_16, ~t_3 we can infer ~q_16 via biconditional elimination. Therefore, the answer is yes.