Efficient Evaluation of Answer Set Programs with External Sources Based on External Source Inlining

Authors

  • Christoph Redl Technische Universität Wien

DOI:

https://doi.org/10.1609/aaai.v31i1.10672

Abstract

HEX-programs are an extension of answer set programming(ASP) towards external sources. To this end, external atomsprovide a bidirectional interface between the program and anexternal source. Traditionally, HEX -programs are evaluatedusing a rewriting to ordinary ASP programs which guess truthvalues of external atoms; this yields answer set candidateswhose guesses are verified by evaluating the source. Despitethe integration of learning techniques into this approach, whichreduce the number of candidates and of necessary verificationcalls, the remaining external calls are still expensive. In thispaper we present an alternative approach based on inliningof external atoms, motivated by existing but less general approaches for specialized formalisms such as DL-programs. External atoms are then compiled away such that no verification calls are necessary. To this end, we make use of supportsets, which describe conditions on input atoms that are sufficient to satisfy an external atom. The approach is implementedin the DLVHEX reasoner. Experiments show a significant performance gain.

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Published

2017-02-12

How to Cite

Redl, C. (2017). Efficient Evaluation of Answer Set Programs with External Sources Based on External Source Inlining. Proceedings of the AAAI Conference on Artificial Intelligence, 31(1). https://doi.org/10.1609/aaai.v31i1.10672

Issue

Section

AAAI Technical Track: Knowledge Representation and Reasoning