What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_3: S_2(x_3) <-> R(x_3). forall x_3: S_2(x_3) <-> R(x_3).
forall x_3: S_2(x_3) -> R(x_3). forall x_3: S_2(x_3) -> R(x_3). forall x_3: R(x_3) -> S_2(x_3). forall x_3: R(x_3) -> S_2(x_3).