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Documents authored by McCreesh, Ciaran


Document
Proof Logging for Smart Extensional Constraints

Authors: Matthew J. McIlree and Ciaran McCreesh

Published in: LIPIcs, Volume 280, 29th International Conference on Principles and Practice of Constraint Programming (CP 2023)


Abstract
Proof logging provides an auditable way of guaranteeing that a solver has produced a correct answer using sound reasoning. This is standard practice for Boolean satisfiability solving, but for constraint programming, a challenge is that every propagator must be able to justify all inferences it performs. Here we demonstrate how to support proof logging for a wide range of previously uncertified global constraints. We do this by showing how to justify every inference that could be performed by the propagation algorithms for two families of generalised extensional constraint: "Smart Table" and "Regular Language Membership".

Cite as

Matthew J. McIlree and Ciaran McCreesh. Proof Logging for Smart Extensional Constraints. In 29th International Conference on Principles and Practice of Constraint Programming (CP 2023). Leibniz International Proceedings in Informatics (LIPIcs), Volume 280, pp. 26:1-26:17, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023)


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@InProceedings{mcilree_et_al:LIPIcs.CP.2023.26,
  author =	{McIlree, Matthew J. and McCreesh, Ciaran},
  title =	{{Proof Logging for Smart Extensional Constraints}},
  booktitle =	{29th International Conference on Principles and Practice of Constraint Programming (CP 2023)},
  pages =	{26:1--26:17},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-300-3},
  ISSN =	{1868-8969},
  year =	{2023},
  volume =	{280},
  editor =	{Yap, Roland H. C.},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CP.2023.26},
  URN =		{urn:nbn:de:0030-drops-190633},
  doi =		{10.4230/LIPIcs.CP.2023.26},
  annote =	{Keywords: Constraint programming, proof logging, extensional constraints}
}
Document
An Auditable Constraint Programming Solver

Authors: Stephan Gocht, Ciaran McCreesh, and Jakob Nordström

Published in: LIPIcs, Volume 235, 28th International Conference on Principles and Practice of Constraint Programming (CP 2022)


Abstract
We describe the design and implementation of a new constraint programming solver that can produce an auditable record of what problem was solved and how the solution was reached. As well as a solution, this solver provides an independently verifiable proof log demonstrating that the solution is correct. This proof log uses the VeriPB proof system, which is based upon cutting planes reasoning with extension variables. We explain how this system can support global constraints, variables with large domains, and reformulation, despite not natively understanding any of these concepts.

Cite as

Stephan Gocht, Ciaran McCreesh, and Jakob Nordström. An Auditable Constraint Programming Solver. In 28th International Conference on Principles and Practice of Constraint Programming (CP 2022). Leibniz International Proceedings in Informatics (LIPIcs), Volume 235, pp. 25:1-25:18, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2022)


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@InProceedings{gocht_et_al:LIPIcs.CP.2022.25,
  author =	{Gocht, Stephan and McCreesh, Ciaran and Nordstr\"{o}m, Jakob},
  title =	{{An Auditable Constraint Programming Solver}},
  booktitle =	{28th International Conference on Principles and Practice of Constraint Programming (CP 2022)},
  pages =	{25:1--25:18},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-240-2},
  ISSN =	{1868-8969},
  year =	{2022},
  volume =	{235},
  editor =	{Solnon, Christine},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CP.2022.25},
  URN =		{urn:nbn:de:0030-drops-166548},
  doi =		{10.4230/LIPIcs.CP.2022.25},
  annote =	{Keywords: Constraint programming, proof logging, auditable solving}
}
Document
Practical Bigraphs via Subgraph Isomorphism

Authors: Blair Archibald, Kyle Burns, Ciaran McCreesh, and Michele Sevegnani

Published in: LIPIcs, Volume 210, 27th International Conference on Principles and Practice of Constraint Programming (CP 2021)


Abstract
Bigraphs simultaneously model the spatial and non-spatial relationships between entities, and have been used for systems modelling in areas including biology, networking, and sensors. Temporal evolution can be modelled through a rewriting system, driven by a matching algorithm that identifies instances of bigraphs to be rewritten. The previous state-of-the-art matching algorithm for bigraphs with sharing is based on Boolean satisfiability (SAT), and suffers from a large encoding that limits scalability and makes it hard to support extensions. This work instead adapts a subgraph isomorphism solver that is based upon constraint programming to solve the bigraph matching problem. This approach continues to support bigraphs with sharing, is more open to other extensions and side constraints, and improves performance by over two orders of magnitude on a range of problem instances drawn from real-world mixed-reality, protocol, and conference models.

Cite as

Blair Archibald, Kyle Burns, Ciaran McCreesh, and Michele Sevegnani. Practical Bigraphs via Subgraph Isomorphism. In 27th International Conference on Principles and Practice of Constraint Programming (CP 2021). Leibniz International Proceedings in Informatics (LIPIcs), Volume 210, pp. 15:1-15:17, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2021)


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@InProceedings{archibald_et_al:LIPIcs.CP.2021.15,
  author =	{Archibald, Blair and Burns, Kyle and McCreesh, Ciaran and Sevegnani, Michele},
  title =	{{Practical Bigraphs via Subgraph Isomorphism}},
  booktitle =	{27th International Conference on Principles and Practice of Constraint Programming (CP 2021)},
  pages =	{15:1--15:17},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-211-2},
  ISSN =	{1868-8969},
  year =	{2021},
  volume =	{210},
  editor =	{Michel, Laurent D.},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CP.2021.15},
  URN =		{urn:nbn:de:0030-drops-153068},
  doi =		{10.4230/LIPIcs.CP.2021.15},
  annote =	{Keywords: bigraphs, subgraph isomorphism, constraint programming, rewriting systems}
}
Document
Complications for Computational Experiments from Modern Processors

Authors: Johannes K. Fichte, Markus Hecher, Ciaran McCreesh, and Anas Shahab

Published in: LIPIcs, Volume 210, 27th International Conference on Principles and Practice of Constraint Programming (CP 2021)


Abstract
In this paper, we revisit the approach to empirical experiments for combinatorial solvers. We provide a brief survey on tools that can help to make empirical work easier. We illustrate origins of uncertainty in modern hardware and show how strong the influence of certain aspects of modern hardware and its experimental setup can be in an actual experimental evaluation. More specifically, there can be situations where (i) two different researchers run a reasonable-looking experiment comparing the same solvers and come to different conclusions and (ii) one researcher runs the same experiment twice on the same hardware and reaches different conclusions based upon how the hardware is configured and used. We investigate these situations from a hardware perspective. Furthermore, we provide an overview on standard measures, detailed explanations on effects, potential errors, and biased suggestions for useful tools. Alongside the tools, we discuss their feasibility as experiments often run on clusters to which the experimentalist has only limited access. Our work sheds light on a number of benchmarking-related issues which could be considered to be folklore or even myths.

Cite as

Johannes K. Fichte, Markus Hecher, Ciaran McCreesh, and Anas Shahab. Complications for Computational Experiments from Modern Processors. In 27th International Conference on Principles and Practice of Constraint Programming (CP 2021). Leibniz International Proceedings in Informatics (LIPIcs), Volume 210, pp. 25:1-25:21, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2021)


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@InProceedings{fichte_et_al:LIPIcs.CP.2021.25,
  author =	{Fichte, Johannes K. and Hecher, Markus and McCreesh, Ciaran and Shahab, Anas},
  title =	{{Complications for Computational Experiments from Modern Processors}},
  booktitle =	{27th International Conference on Principles and Practice of Constraint Programming (CP 2021)},
  pages =	{25:1--25:21},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-211-2},
  ISSN =	{1868-8969},
  year =	{2021},
  volume =	{210},
  editor =	{Michel, Laurent D.},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CP.2021.25},
  URN =		{urn:nbn:de:0030-drops-153165},
  doi =		{10.4230/LIPIcs.CP.2021.25},
  annote =	{Keywords: Experimenting, Combinatorial Solving, Empirical Work}
}