Consider the following premises. forall y: W_1(y) <-> W(y). t_3 -> W(i). forall y: ~W_1(y). Can we infer ~t_3 from them? If possible, name the inference rules being used at each step.
 From forall y: W_1(y) <-> W(y), forall y: ~W_1(y) we can infer forall y: ~W(y) via universal biconditional elimination. From forall y: ~W(y) we can infer ~W(i) via universal instantiation. Finally, from t_3 -> W(i), ~W(i) we can infer ~t_3 via modus tollens. Therefore, the answer is yes.