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