Working with events and states in PENG light

In this paper I discuss how the controlled natural language PENG Light can be modified so that it can serve as a high-level interface language to the Event Calculus. The Event Calculus is a narrative-based formal language for reasoning about events, their effects and timepoints, and can be used for various reasoning tasks where a representation of time is important. Using a scenario from a dynamic domain, I show what kind of modifications are necessary on the level of the controlled natural language to specify the background knowledge that is required to deal with direct and indirect effects of events and with continuous change in that domain. I discuss how the output of the controlled natural language processor of PENG Light that distinguishes between events and states can be aligned with the input language of the Event Calculus, and then be used for automated reasoning. Finally, I show how the Event Calculus can be used to support the question answering process and then evaluate its reasoning capabilities using a number of benchmark questions stated in controlled natural language.21 page(s