What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x: Q_4(x) -> R_4(x). forall x: U(x) <-> R_4(x). forall x: Q_4(x) or ~U(x).
forall x: U(x) -> Q_4(x). forall x: U(x) -> R_4(x). forall x: R_4(x) -> U(x).