Role Conjunctions in Expressive Description Logics

Decidability of Expressive Description Logics with Role Compositions

On Expressive Number Restrictions in Description Logics

We consider expressive Description Logics (ALCN) allowing for number restrictions on complex roles built with combinations of role construc-tors. In particular, we are mainly interested in Logics (called ALC N) allowing for the same kind of complex roles both in number and in value restrictions, which represent very expressive description languages and can be shown very useful for applications....

Classifying Description Logics

We describe a method for characterizing the expressive power of description logics. The method is essentially model-theoretic in nature, and it is applied to obtain expressiveness results for a wide range of logics in the well-known FL− and AL hierarchies. As a corollary we obtain a complete classification of the relative expressive power of these logics.

Restricted Role-value-maps in a Description Logic with Existential Restrictions and Terminological Cycles

In a previous paper we have investigated subsumption in the presence of terminological cycles for the description logic EL, which allows conjunctions, existential restrictions, and the top concept, and have shown that the subsumption problem remains polynomial for all three types of semantics usually considered for cyclic definitions in description logics. In this paper we show that subsumption...

Foreign Affairs and Trade

It is known that a theory in S5-epistemic logic with several agents may have numerous models. This is because each such model specifies also what an agent knows about infinite intersections of events, while the expressive power of the logic is limited to finite conjunctions of formulas. We show that this asymmetry between syntax and semantics persists also when infinite conjunctions (up to some...