Conservative extensions in expressive description logics

摘要: The notion of a conservative extension plays central role in ontology design and integration: it can be used to formalize refinements, safe mergings two ontologies, independent modules inside an ontology. Regarding reasoning support, the most basic task is decide whether one another. It has recently been proved that this problem decidable 2ExpTime-complete if ontologies are formulated description logic ALC. We consider more expressive logics begin map out boundary between for which conservativity those not. prove extensions ALCQI, but undecidable ALCQIO. also show defined model-theoretically rather than terms consequence relation, they already