Implementing Stable-Unstable Semantics with ASPTOOLS and ClingoRemote
Normal logic programs subject to stable model semantics cover reasoning problems from the first level of polynomial time hierarchy (PH) in a natural way. Disjunctive programs reach one level beyond this, but the access to the underlying NP oracle(s) is somewhat implicit and available for the programmer using a so-called saturation technique. To address this shortcoming, stable-unstable semantics was proposed, making oracles explicit as sub-programs having no stable models. If this idea is applied recursively, any level of PH can be reached with normal programs only, in analogy to quantified Boolean formulas (QBFs). However, for the moment, no native implementations of stable-unstable semantics have emerged except via translations toward QBFs. In this work, we alleviate this situation with a translation of (effectively) normal programs that combines a main program with any number of oracles subject to stable-unstable semantics. The result is a disjunctive program that can be fed as input for answer set solvers supporting disjunctive programs. The idea is to hide saturation from the programmer altogether, although it is exploited by the translation internally. The translation of oracles is performed using translators and linkers from the ASPTOOLS collection and Clingo is used as the back-end solver.
Mon 17 JanDisplayed time zone: Eastern Time (US & Canada) change
10:20 - 12:00 | Languages, Methods and ToolsPADL at Directors Chair(s): Esra Erdem Sabanci University, Turkey Remote session chair | ||
10:20 25mTalk | Smart Devices and Large Scale Reasoning via ASP: Tools and ApplicationsRemote PADL Kristian Reale Department of Mathematics and Computer Science University of Calabria - DLVSystem S.r.l., Francesco Calimeri University of Calabria, Nicola Leone University of Calabria, Italy, Francesco Ricca University of Calabria, Italy | ||
10:45 25mTalk | Timed Concurrent Language for Argumentation: an Interleaving ApproachRemote PADL Stefano Bistarelli University of Perugia, Maria Chiara Meo University “G. d’Annunzio” of Chieti-Pescara, Carlo Taticchi University of Perugia | ||
11:10 25mTalk | Towards Dynamic Consistency Checking in Goal-directed Predicate Answer Set ProgrammingRemote PADL Joaquín Arias Universidad Rey Juan Carlos, Manuel Carro IMDEA Software Institute and T.U. of Madrid (UPM), Gopal Gupta The University of Texas at Dallas DOI Pre-print File Attached | ||
11:35 25mTalk | Implementing Stable-Unstable Semantics with ASPTOOLS and ClingoRemote PADL Tomi Janhunen Tampere University |