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) -> U(x). exists x: S(x) <-> U(x). forall x: U(x) -> W(x). forall x: W(x) -> S(x).
forall x: S(x) -> W(x). forall x: U(x) -> S(x). forall x: W(x) -> U(x). exists x: S(x) -> U(x). exists x: U(x) -> S(x).