The Fourth Answer Set Programming Competition: Preliminary Report

Abstract

Answer Set Programming is a well-established paradigm of declarative programming in close relationship with other declarative formalisms such as SAT Modulo Theories, Constraint Handling Rules, PDDL and many others. Since its first informal editions, ASP systems are compared in the nowadays customary ASP Competition. The fourth ASP Competition, held in 2012/2013, is the sequel to previous editions and it was jointly organized by University of Calabria (Italy) and the Vienna University of Technology (Austria). Participants competed on a selected collection of benchmark problems, taken from a variety of research areas and real world applications. The Competition featured two tracks: the Model& Solve Track, held on an open problem encoding, on an open language basis, and open to any kind of system based on a declarative specification paradigm; and the System Track, held on the basis of fixed, public problem encodings, written in a standard ASP language.

Evaluating Answer Set Programming with Non-Convex Recursive Aggregates

“…The rewritings introduced in Section 3 have been implemented in a prototype system written in Python and available at the following URL: http://alviano.net/ software/f-stable-models/. The prototype accepts an input language whose syntax is almost conformant to ASP Core 2.0 [2]. It is a first-order language, meaning that propositional atoms are replaced by first-order atoms made of a predicate and a list or terms, where each term is an object constant, an object variable, or a composed term obtained by combining a function symbol with other terms.…”

“…In this problem, two vectors u and v of integers as well as an integer b are given, and the task is to decide whether the formula ∃x∀y(ux + vy = b) is true, where x and y are vectors of binary variables of the same length as u and v, respectively. For example, for u = [1,2], v = [2,3], and b = 5, the task is to decide whether the following formula is true:…”

Design and results of the Fifth Answer Set Programming Competition

“…We decided first to simplify the scoring system w.r.t. the last edition (see (Alviano et al 2013a)), and to improve it in the case of optimization problems.…”

Democratix: A Declarative Approach to Winner Determination

“…Answer-set programming (ASP) allows one to specify problems declaratively. Furthermore, powerful ASP solvers (e.g., [15,22]) are publicly available and the ASP community is constantly working on improving the performance (witnessed, for example, by the biennial ASP competition [1]). In the following we introduce ASP, thereby restricting ourselves to the syntax and semantics relevant in this work.…”

“…In Encoding 5 we first obtain the voters and the domain (positions and candidates) as in the previous encodings (rules [1][2]. In rules (3-4) we guess the shifts in the votes.…”