Mustafa Hashmi, Guido Governatori, and Moe Thandar Wynn presented a paper entitled Modeling Obligations with the Event-Calculus, at RuleML 2014: International Web Rule Symposium, held 18-20 August 2014 in Prague.
Slides of the presentation are available at: http://www.nicta.com.au/pub?pslides=8116
Here is the abstract of the paper:
Time plays an important role in norms. In this paper we start from our previously proposed classification of obligations, and point out some shortcomings of Event Calculus (EC) to represent obligations. We propose an extension of EC that avoids such shortcomings and we show how to use it to model the various types of obligations.