All Elephants are Bigger than All Mice


Sebastian Rudolph, Markus Krötzsch, Pascal Hitzler

All Elephants are Bigger than All Mice

Abstract. We introduce the concept product as a new expressive feature for description logics (DLs). While this construct allows us to express an arguably very common and natural type of statement, it can be simulated only by the very expressive DL SROIQ for which no tight worst-case complexity is known. However, we show that concept products can also be added to the DLs SHOIQ and SHOI, and to the tractable DL EL++ without increasing the worst-case complexities in any of those cases. We therefore argue that concept products provide practically relevant expressivity at little cost, making them a good candidate for future extensions of the DL-based ontology language OWL.

Published at DL-08 (Workshop paper)

Download PDF (last update: March 25 2008)

Citation details

  • Sebastian Rudolph, Markus Krötzsch, Pascal Hitzler. All Elephants are Bigger than All Mice. In Proceedings of the 21st International Workshop on Description Logics (DL-08). CEUR Workshop ProceedingsProperty "Publisher" has a restricted application area and cannot be used as annotation property by a user. 2008.

Talk slides

Dowload slides of the presentation at DL 2008.


The introduction of an earlier version of this paper contained a number of example statements that actually were no (obvious) examples for concept products. More suitable examples have been supplied now. All apologies for the confusion.


Description logics