What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? exists x: Q_3(x) or ~U(x). forall x: U(x) <-> Q_3(x).
exists x: U(x) -> Q_3(x). forall x: U(x) -> Q_3(x). forall x: Q_3(x) -> U(x).