selp: A Single-Shot Epistemic Logic Program Solver

Abstract

<jats:title>Abstract</jats:title><jats:p>Epistemic logic programs (ELPs) are an extension of answer set programming (ASP) with epistemic operators that allow for a form of meta-reasoning, that is, reasoning over multiple possible worlds. Existing ELP solving approaches generally rely on making multiple calls to an ASP solver in order to evaluate the ELP. However, in this paper, we show that there also exists a direct translation from ELPs into non-ground ASP with bounded arity. The resulting ASP program can thus be solved in a single shot. We then implement this encoding method, using recently proposed techniques to handle large, non-ground ASP rules, into the prototype ELP solving system “selp,” which we present in this paper. This solver exhibits competitive performance on a set of ELP benchmark instances.</jats:p>

Utilizing Treewidth for Quantitative Reasoning on Epistemic Logic Programs

“…2020) and to the best of our knowledge, our solver is the first implementation of solving ELPs that is guided by TDs. While the solver selp (Bichler et al . 2020) uses decompositions for breaking large rules into smaller ones, the solving itself is not guided by TDs.…”

“…EP-ASP (Son et al . 2017), selp (Bichler et al . 2020) and a very recent extension of clingo for ELPs, called eclingo (Cabalar et al .…”

Treewidth-aware reductions of normal ASP to SAT – Is normal ASP harder than SAT after all?

“…For ASP there is growing research on treewidth [64,44,41], which even involves grounding [11,14]. Algorithms of these works exploit structural restrictions (in form of treewidth) of a given program, and often run in polynomial time in the program size, while being exponential only in the treewidth.…”

Utilizing Treewidth for Quantitative Reasoning on Epistemic Logic Programs (Extended Abstract)

“…As a second contribution we present a new system tailored for quantitiative reasoning in ELPs. Although there has been progress in developing ELP solvers (e.g., EP-ASP [Son et al, 2017], selp [Bichler et al, 2020] and a very recent extension of clingo for epistemic logic programs, called eclingo [Cabalar et al, 2020]), these approaches basically rely on reducing ELP problems to standard ASP. Thus, these solvers typically materialize all world views, which is not necessary for quantitative reasoning.…”

“…Abstractions were also stipulated before, but in a different context [Hecher et al, 2020b;Saribatur and Eiter, 2021] or for establishing theoretical results [Ganian et al, 2017]. However, we improve an existing algorithm [Hecher et al, 2020a] and while the solver selp [Bichler et al, 2020] uses TDs for breaking-up rules, our solver is the first implementation of TD-guided solving for ELPs. Studies of measures different from treewidth have been conducted for LPs [Lonc and Truszczynski, 2003;Bliem et al, 2016;Fichte et al, 2019].…”