What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall z: T(z) <-> R_4(z). forall z: ~T(z). exists z: U(z) <-> S_4(z). forall z: U(z) -> R_4(z). forall z: R_4(z) -> U(z).
forall z: U(z) <-> R_4(z). forall z: R_4(z) <-> U(z). forall z: T(z) -> R_4(z). exists z: U(z) -> S_4(z). forall z: R_4(z) -> T(z). exists z: S_4(z) -> U(z). forall z: ~R_4(z).