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