@inproceedings{PLDI-1990-Jacobs,
	author        = "Dean Jacobs",
	booktitle     = "{Proceedings of the 11th Conference on Programming Language Design and Implementation}",
	doi           = "10.1145/93542.93563",
	editor        = "Bernard N. Fischer",
	isbn          = "0-89791-364-7",
	pages         = "165--173",
	publisher     = "{ACM}",
	title         = "{Type Declarations as Subtype Constraints in Logic Programming}",
	year          = 1990,
}