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) -> P_2(x_3). exists x_3: U(x_3) <-> Q(x_3). forall x_3: Q(x_3) <-> P_2(x_3).
forall x_3: Q(x_3) -> P_2(x_3). exists x_3: U(x_3) -> Q(x_3). forall x_3: P_2(x_3) -> Q(x_3). exists x_3: Q(x_3) -> U(x_3).