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