@inproceedings{ILPS-1993-OsorioJ,
	author        = "Mauricio Osorio and Bharat Jayaraman",
	booktitle     = "{Proceedings of the International Symposium on Logic Programming}",
	isbn          = "0-262-63152-0",
	pages         = "637",
	publisher     = "{MIT Press}",
	title         = "{Subset Assertions and Negation As Failure}",
	year          = 1993,
}