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