What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall y_3: Q_2(y_3) -> Q_4(y_3). forall y_3: Q_4(y_3) -> Q_2(y_3). forall y_3: Q_1(y_3). forall y_3: Q_1(y_3) -> U(y_3). forall y_3: U(y_3) -> Q_4(y_3).
forall y_3: U(y_3). forall y_3: Q_1(y_3) -> Q_4(y_3). forall y_3: U(y_3) -> Q_2(y_3). forall y_3: Q_2(y_3) <-> Q_4(y_3). forall y_3: Q_4(y_3) <-> Q_2(y_3).