@inproceedings{LICS-1989-GaifmanS,
	author        = "Haim Gaifman and Ehud Y. Shapiro",
	booktitle     = "{Proceedings of the Fourth Annual Symposium on Logic in Computer Science}",
	doi           = "10.1109/LICS.1989.39158",
	isbn          = "0-8186-1954-6",
	pages         = "50--62",
	publisher     = "{IEEE Computer Society}",
	title         = "{Proof Theory and Semantics of Logic Programs}",
	year          = 1989,
}