@conference {137,
	title = {Data Complexity in the {EL} Family of Description Logics},
	booktitle = {Logic for Programming, Artificial Intelligence, and Reasoning, 14th International Conference, LPAR 2007, Yerevan, Armenia, October 15-19, 2007, Proceedings},
	volume = {4790},
	year = {2007},
	month = {10/2007},
	pages = {333-347},
	publisher = {Springer},
	organization = {Springer},
	abstract = {We study the data complexity of instance checking and conjunctive query answering in the EL family of description logics, with a particular emphasis on the boundary of tractability. We identify a large number of intractable extensions of EL, but also show that in ELIf , the extension of EL with inverse roles and global functionality, conjunctive query answering is tractable regarding data complexity. In contrast, already instance checking in EL extended with only inverse roles or global functionality is EXPTIME-complete regarding combined complexity},
	doi = {10.1007/978-3-540-75560-9_25},
	url = {http://dx.doi.org/10.1007/978-3-540-75560-9_25},
	author = {Adila Krisnadhi and Carsten Lutz},
	editor = {Nachum Dershowitz and Andrei Voronkov}
}
@conference {138,
	title = {Data Complexity in the {EL} family of DLs},
	booktitle = {Proceedings of the 2007 International Workshop on Description Logics (DL2007), Brixen-Bressanone, near Bozen-Bolzano, Italy, 8-10 June, 2007},
	volume = {250},
	year = {2007},
	month = {06/2007},
	publisher = {CEUR-WS.org},
	organization = {CEUR-WS.org},
	url = {http://ceur-ws.org/Vol-250/paper_15.pdf},
	author = {Adila Krisnadhi and Carsten Lutz},
	editor = {Diego Calvanese and Enrico Franconi and Volker Haarslev and Domenico Lembo and Boris Motik and Anni-Yasmin Turhan and Sergio Tessaris}
}
