What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? forall y: U_2(y) -> U_3(y). forall y: Q_4(y). forall y: Q_4(y) <-> U_3(y).
forall y: Q_4(y) -> U_3(y). forall y: U_3(y) -> Q_4(y).