Consider the following premises. forall x: W_3(x) <-> T_4(x). forall x: T_4(x) -> W_3(x). forall x: ~W_3(x). Can we infer forall x: ~T_4(x) from them? If possible, name the inference rules being used at each step.
 From forall x: W_3(x) <-> T_4(x) we can infer forall x: W_3(x) -> T_4(x) via universal biconditional elimination. From forall x: W_3(x) -> T_4(x), forall x: T_4(x) -> W_3(x) we can infer forall x: W_3(x) <-> T_4(x) via universal biconditional introduction. Finally, from forall x: W_3(x) <-> T_4(x), forall x: ~W_3(x) we can infer forall x: ~T_4(x) via universal biconditional elimination. Therefore, the answer is yes.