What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? exists x: S_1(x) <-> P(x). forall x: S_1(x) <-> S(x). forall x: ~P(x).
forall x: S_1(x) -> S(x). exists x: S_1(x) -> P(x). forall x: S(x) -> S_1(x). exists x: P(x) -> S_1(x). exists x: ~S_1(x).