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We show that for any constant \epsilon > 0 and p \ge 1, it is possible to distinguish functions f : \{0,1\}^n \to [0,1] that are submodular from those that are \epsilon-far from every submodular function in \ell_p distance with a constant number of queries.
More generally, we extend the testing-by-implicit-learning framework of Diakonikolas et al.(2007) to show that every property of real-valued functions that is well-approximated in \ell_2 distance by a class of k-juntas for some k = O(1) can be tested in the \ell_p-testing model with a constant number of queries. This result, combined with a recent junta theorem of Feldman and \Vondrak (2016), yields the constant-query testability of submodularity. It also yields constant-query testing algorithms for a variety of other natural properties of valuation functions, including fractionally additive (XOS) functions, OXS functions, unit demand functions, coverage functions, and self-bounding functions.
@InProceedings{blais_et_al:LIPIcs.ITCS.2017.33,
author = {Blais, Eric and Bommireddi, Abhinav},
title = {{Testing Submodularity and Other Properties of Valuation Functions}},
booktitle = {8th Innovations in Theoretical Computer Science Conference (ITCS 2017)},
pages = {33:1--33:17},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-029-3},
ISSN = {1868-8969},
year = {2017},
volume = {67},
editor = {Papadimitriou, Christos H.},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITCS.2017.33},
URN = {urn:nbn:de:0030-drops-81619},
doi = {10.4230/LIPIcs.ITCS.2017.33},
annote = {Keywords: Property testing, Testing by implicit learning, Self-bounding functions}
}