Jörg Ernst, Grigoris Antoniou
Default logic (DL) (Reiter 1980) is one of the most prominent approaches to nonmonotonic reasoning. One of the main problems with its applicability is that it is computationally harder than classical logic (Gottlob 1992). (Cholewinski 1994,1995) introduced and studied stratification of default theories to increase the efficiency of default reasoning. The idea is to to split the knowledge into smaller parts, and to apply reasoning in a local way. This paper shows how stratification can work for some important variants of Default Logic. These variants are Justified Default Logic (JDL), Rational Default Logic (RDL), and Constrained Default Logic (CDL).