What's in an Attribute? Consequences for the Least Common Subsumer

06/01/2011
by   A. Borgida, et al.
0

Functional relationships between objects, called `attributes', are of considerable importance in knowledge representation languages, including Description Logics (DLs). A study of the literature indicates that papers have made, often implicitly, different assumptions about the nature of attributes: whether they are always required to have a value, or whether they can be partial functions. The work presented here is the first explicit study of this difference for subclasses of the CLASSIC DL, involving the same-as concept constructor. It is shown that although determining subsumption between concept descriptions has the same complexity (though requiring different algorithms), the story is different in the case of determining the least common subsumer (lcs). For attributes interpreted as partial functions, the lcs exists and can be computed relatively easily; even in this case our results correct and extend three previous papers about the lcs of DLs. In the case where attributes must have a value, the lcs may not exist, and even if it exists it may be of exponential size. Interestingly, it is possible to decide in polynomial time if the lcs exists.

READ FULL TEXT

page 1

page 2

page 3

page 4

research
01/01/1997

Improved Heterogeneous Distance Functions

Instance-based learning techniques typically handle continuous and linea...
research
04/24/2014

Gradual Classical Logic for Attributed Objects

There is knowledge. There is belief. And there is tacit agreement.' 'We ...
research
11/26/2009

A Semantic Similarity Measure for Expressive Description Logics

A totally semantic measure is presented which is able to calculate a sim...
research
04/20/2011

On the evolution of the instance level of DL-lite knowledge bases

Recent papers address the issue of updating the instance level of knowle...
research
03/10/2018

Face2Text: Collecting an Annotated Image Description Corpus for the Generation of Rich Face Descriptions

The past few years have witnessed renewed interest in NLP tasks at the i...
research
02/27/2013

Probabilistic Description Logics

On the one hand, classical terminological knowledge representation exclu...
research
06/17/2011

On the expressive power of unit resolution

This preliminary report addresses the expressive power of unit resolutio...

Please sign up or login with your details

Forgot password? Click here to reset