What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall z: W(z) -> U_3(z). forall z: U_3(z) -> W(z). exists z: W(z) -> U_3(z).
forall z: W(z) <-> U_3(z). forall z: U_3(z) <-> W(z). exists z: W(z) <-> U_3(z). exists z: U_3(z) <-> W(z).