What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall x_3: U(x_3) -> S(x_3). forall x_3: S(x_3) -> U(x_3). q_3 -> S(a_7). ~U(a_7).
forall x_3: U(x_3) <-> S(x_3). forall x_3: S(x_3) <-> U(x_3).