Complexity of Recursive Normal Default Logic.

V. Wiktor Marek Anil Nerode Jeffrey B. Remmel Complexity of Recursive Normal Default Logic. 139-147 1997 32 Fundam. Inform. 2 db/journals/fuin/fuin32.html#MarekNR97 http://dx.doi.org/10.3233/FI-1997-32203