From topology to metric: modal logic and quantification in metric spaces.

Mikhail Sheremet Dmitry Tishkovsky Frank Wolter Michael Zakharyaschev From topology to metric: modal logic and quantification in metric spaces. 429-448 2006 conf/aiml/2006 Advances in Modal Logic http://www.aiml.net/volumes/volume6/Sheremet-Tishkovsky-Wolter-Zakharyaschev.ps db/conf/aiml/aiml2006.html#SheremetTWZ06