Published online by Cambridge University Press: 22 September 2020
We describe eclingo, a solver for epistemic logic programs under Gelfond 1991 semantics built upon the Answer Set Programming system clingo. The input language of eclingo uses the syntax extension capabilities of clingo to define subjective literals that, as usual in epistemic logic programs, allow for checking the truth of a regular literal in all or in some of the answer sets of a program. The eclingo solving process follows a guess and check strategy. It first generates potential truth values for subjective literals and, in a second step, it checks the obtained result with respect to the cautious and brave consequences of the program. This process is implemented using the multi-shot functionalities of clingo. We have also implemented some optimisations, aiming at reducing the search space and, therefore, increasing eclingo ’s efficiency in some scenarios. Finally, we compare the efficiency of eclingo with two state-of-the-art solvers for epistemic logic programs on a pair of benchmark scenarios and show that eclingo generally outperforms their obtained results.
Partially supported by MINECO, Spain, grant TIC2017-84453-P. The second author is funded by the Alexander von Humboldt Foundation, Germany. The third author was partially supported by CITIC, Research Center of the Galician University System financed by the Consellería de Educación, Universidade e Formación Profesional (Xunta de Galicia) and co-financed 80% by the ERDF (Ref. ED431G 2019/01).