What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x: ~S(x). forall x: S(x) <-> U_3(x). forall x: S(x) -> U_3(x).
forall x: S(x) -> U_3(x). forall x: U_3(x) -> S(x). forall x: ~U_3(x).