Joost Vennekens Johan Wittocx Maarten Mariën Marc Denecker Predicate Introduction for Logics with Fixpoint Semantics. Part II: Autoepistemic Logic. 209-227 2007 79 Fundam. Inform. 1-2 http://iospress.metapress.com/openurl.asp?genre=article&issn=0169-2968&volume=79&issue=1&spage=208 db/journals/fuin/fuin79.html#VennekensWMD07a