What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall z: P(z) <-> Q_1(z). forall z: P(z) or S_2(z). forall z: Q_1(z) <-> S_2(z).
forall z: P(z) -> Q_1(z). forall z: Q_1(z) -> S_2(z). forall z: Q_1(z) -> P(z). forall z: S_2(z) -> Q_1(z).