Consider the following premises. forall z_3: T(z_3) -> W(z_3). forall z_3: W(z_3) -> T(z_3). exists z_3: T(z_3) -> W(z_3). Can we infer exists z_3: T(z_3) -> W(z_3) from them?
That is one of the premises. Therefore, the answer is yes.