Linkless Normal Form for ALC Concepts and TBoxes

In this paper we introduce a normal form for ALC concepts and TBoxes called linkless normal form. We investigate properties of concepts given in this normal form such as an efficient satisfiability test and the calculation of uniform interpolants. We further show a way to approximate a TBox by a concept in linkless normal form, which allows us to check certain subsumptions efficiently. This makes the linkless normal form interesting from the viewpoint of knowledge compilation. Furthermore, we show how to use the approximation of a TBox in linkless normal form to efficiently construct an approximation of a uniform interpolant of a TBox w.r.t. a given signature.