Synsyta - Computing Fabrics - Model Driven Architecture

A Little Information about Description Logics
Summary and notes from Debra McGuinness

Description Logics [http://dl.kr.org] are a family of representation languages for representing structured knowledge and for accessing and reasoning with it in a principled and predictable way.

Description Logics can be seen to provide a unifying (and sound logical) framework for the commonly used frame-based systems, semantic networks, object-oriented representations, semantic data models, and type systems.

Recently, description logics have been receiving increased attention since they now provide a unifying framework and a well researched logical foundations for web languages.

The recent description logics

DAML+OIL [ http://www.w3.org/Submission/2001/12/] and OWL[http://www.w3.org/TR/owl-features/] have received increased attention and it is likely that OWL will be a World Wide Web Consortium Recommendation soon.

The OWL documents obtainable from the W3C Web Ontology working group page are in last call status now. See http://www.w3.org/2001/sw/WebOnt/

A few things about OWL are worthy of note.
- DAML+OIL and OWL semantics provide a formal foundation for the web languages XML and RDF and thus provide the logical foundation for information sharing. (This provides the link between the semantic web stack and the formal logic stack and also provides unambiguous descriptions of meaning thereby allowing connections to other "stacks" to be made as well.)
- There is a wealth of research on tractable reasoning of description logics. Different combinations of expressive power have been investigated and there is a formal understanding of the computational bounds of the languages. In practical terms, this means that if a project restricts itself to using only expressions that can be written in OWL, then efficient sound and complete reasoning algorithms can be written to provide deductions on the information.