What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x: Q_2(x) <-> R_4(x). exists x: R_4(x) -> Q_2(x). forall x: ~R_4(x).
forall x: Q_2(x) -> R_4(x). forall x: R_4(x) -> Q_2(x). forall x: ~Q_2(x).