Prioritizing Default Rules Embedded in Description Logic Knowledge Base

Description logic based semantic query needs complete information from sources of knowledge where available information is often incomplete. To solve such incomplete reasoning problem, this paper embedded default logic into the description logic knowledge base, meanwhile prioritized the default rules, which preferred more specific default rules over more general ones. Then, an original incomplete query could be transformed into a complete query relative to the extended knowledge base, by checking default satisfiability of complex concept in accord with the query. Furthermore, the default satisfiability can be detected through a new extended tableau algorithm.