Towards an axiom system for default logic
G Lakemeyer, HJ Levesque - PROCEEDINGS OF THE NATIONAL …, 2006 - aaai.org
Abstract Recently, Lakemeyer and Levesque proposed a logic of onlyknowing which 
precisely captures three forms of nonmonotonic reasoning: Moore's Autoepistemic Logic, 
Konolige's variant based on moderately grounded expansions, and Reiter's default logic.