T. Lukasiewicz:
"Nonmonotonic Probabilistic Logics under Variable-Strength Inheritance with Overriding: Algorithms and Implementation in NMPROBLOG";
Report for TU Wien, Institut fuer Informationssysteme, INFSYS RR-1843-05-03; 2005; 23 pages.
http://publik.tuwien.ac.at/files/pub-inf_3530.pdf