On Modal Logic, IF Logic, and IF Modal Logic.

Tero Tulenheimo Merlijn Sevenster On Modal Logic, IF Logic, and IF Modal Logic. 481-501 2006 conf/aiml/2006 Advances in Modal Logic http://www.aiml.net/volumes/volume6/Tulenheimo-Sevenster.ps db/conf/aiml/aiml2006.html#TulenheimoS06