,
Wout Piessens
,
Tias Guns
,
Peter J. Stuckey
Creative Commons Attribution 4.0 International license
Global constraints are a central concept in Constraint Programming (CP), which allow modellers to compactly express complex relations, and which allow solvers to efficiently handle them. Table constraints have especially been well-studied as they can express arbitrary finite relations, and are extensively used in CP benchmarks. In this paper we study how to best deal with table constraints when using Integer Linear Programming (ILP) solvers. We study two paradigms: linear encodings, and a lazy cut generation approach. For the encoding we propose a novel MDD-based flow encoding. For the cut generation, in which lazy constraints are generated on-demand during branch-and-cut search, we investigate different ways of generating such integer and fractional cuts as well as how to strengthen them through shrinking and cut lifting. We experimentally compare the different approaches on CP competition instances with a wide variety of table constraints, showing clear benefits over the standard integer encoding.
@InProceedings{bierlee_et_al:LIPIcs.CP.2026.6,
author = {Bierlee, Hendrik and Piessens, Wout and Guns, Tias and Stuckey, Peter J.},
title = {{Table Constraints for Integer Programming}},
booktitle = {32nd International Conference on Principles and Practice of Constraint Programming (CP 2026)},
pages = {6:1--6:19},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-432-1},
ISSN = {1868-8969},
year = {2026},
volume = {379},
editor = {Beldiceanu, Nicolas},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CP.2026.6},
URN = {urn:nbn:de:0030-drops-266397},
doi = {10.4230/LIPIcs.CP.2026.6},
annote = {Keywords: Table constraints, integer programming, cut generation, modelling}
}
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