Consider the following premises. forall x: W(x) -> T(x). forall x: T(x) -> W_2(x). forall x: W(x) or ~W_2(x). Can we infer forall x: W_2(x) <-> W(x) from them? If possible, name the inference rules being used at each step.
 From forall x: W(x) or ~W_2(x) we can infer forall x: W_2(x) -> W(x) via universal rewriting. From forall x: W(x) -> T(x), forall x: T(x) -> W_2(x) we can infer forall x: W(x) -> W_2(x) via universal transitivity. Finally, from forall x: W_2(x) -> W(x), forall x: W(x) -> W_2(x) we can infer forall x: W_2(x) <-> W(x) via universal biconditional introduction. Therefore, the answer is yes.