What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? ~R(a_2). forall x_2: R(x_2) <-> S_2(x_2).
forall x_2: R(x_2) -> S_2(x_2). forall x_2: S_2(x_2) -> R(x_2).