A four-valued semantics for terminological logics

摘要

An intuitive four-valued semantics can be used to develop expressively powerful terminological logics which have tractable subsumption. The subsumptions supported by the logic are a type of “structural” subsumption, where each structural component of one concept must have an analogue in the other concept. Structural subsumption captures an important set of subsumptions, similar to the subsumptions computed in kl-one and nikl. Thus the trade-off between expressive power and computational tractability which plagues terminological logics based on standard, two-valued semantics can be avoided while still retaining a useful and semantically supported set of subsumptions.