Democratix: A Declarative Approach to Winner Determination.

Computing the winners of an election is an important task in voting and preference aggregation. The declarative nature of answer-set programming ASP and the performance of state-of-the-art solvers render ASP very well-suited to tackle this problem. In this work we present a novel, reduction-based approach for a variety of voting rules, ranging from tractable cases to problems harder than NP. The encoded voting rules are put together in the extensible tool Democratix, which handles the computation of winners and is also available as a web application. To learn more about the capabilities and limits of the approach, the encodings are evaluated thoroughly on real-world data as well as on﾿random﾿instances.