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). forall z: R(z) <-> W_4(z). forall z: R(z) -> W_4(z).
forall z: R(z) -> W_4(z). forall z: W_4(z) -> R(z). forall z: ~W_4(z).