Affiliations: [a] Department of Mathematics and Computer Science, University of Calabria, Arcavacata di Rende, Italy. [email protected] | [b] Department of Informatics, Bioengineering, Robotics and Systems Engineering, University of Genova, Genova, Italy. [email protected]
Correspondence:
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Address for correspondence: Via Pietro Bucci 30/B, 87036 Rende (CS), Italy
Abstract: Many efficient algorithms for the computation of optimum stable models in the context of Answer Set Programming (ASP) are based on unsatisfiable core analysis. Among them, algorithm OLL was the first introduced in the context of ASP, whereas algorithms ONE and PMRES were first introduced for solving the Maximum Satisfiability problem (MaxSAT) and later on adapted to ASP. In this paper, we present the porting to ASP of another state-of-the-art algorithm introduced for MaxSAT, namely K, which generalizes ONE and PMRES. Moreover, we present a new algorithm called OLL-IN-ONE that compactly encodes all aggregates of OLL by taking advantage of shared aggregate sets propagators. The performance of the algorithms have been empirically compared on instances taken from the latest ASP Competition.
Keywords: Answer Set Programming, weak constraints, unsatisfiable core analysis
