@article {15929,
	title = {Circumscribing with sets},
	journal = {Artificial Intelligence},
	volume = {31},
	year = {1987},
	month = {1987/02//},
	pages = {201 - 211},
	abstract = {Sets can play an important role in circumscription{\textquoteright}s ability to deal in a general way with certain aspects of commonsense reasoning. A result of Kueker indicates that sentences that intuitively one would want circumscription to prove are nonetheless not so provable in a formal setting devoid of sets. Furthermore, when sets are introduced, first-order circumscription handles these cases very easily, obviating the need for second-order circumscription. The "Aussonderungs" axiom of ZF set theory plays an intuitive role in this shift back to a first-order language},
	isbn = {0004-3702},
	doi = {16/0004-3702(87)90020-8},
	url = {http://www.sciencedirect.com/science/article/pii/0004370287900208},
	author = {Perlis, Don}
}
