What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall z: ~R_1(z). forall z: P(z) -> U(z). forall z: S_1(z) -> P(z). forall z: R_1(z) <-> S_1(z). forall z: U(z) -> S_1(z).
forall z: P(z) -> S_1(z). forall z: S_1(z) -> U(z). forall z: U(z) -> P(z). forall z: R_1(z) -> S_1(z). forall z: S_1(z) -> R_1(z). forall z: ~S_1(z).