After explaining some of the benefits of capturing uniqueness constraints, such as keys and functional dependencies in any object-centered data model, we consider a number of alternative semantics for concept constructors that could be introduced for this purpose in Description Logics. Most significantly, we show that Classic-the hitherto most expressive DL for which reasoning is tractable, can be extended with a version of constructors capturing functional dependencies (including keys) while still possessing subsumption and consistency checking algorithms that are sound, complete, and run in low-order polynomial time. The results continue to hold even when we introduce cycles in the part-of hierarchy.
展开▼
