What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall z: U(z) <-> R_2(z). forall z: ~R_2(z). exists z: W_2(z) <-> U(z). forall z: S(z) -> W_2(z).
forall z: U(z) -> R_2(z). exists z: W_2(z) -> U(z). forall z: R_2(z) -> U(z). exists z: U(z) -> W_2(z). forall z: ~U(z).