Conversational Human-Aware Technology for Optimisation

Things we underestimated while developing the CPMpy constraint modelling library

Author(s): Tias Guns, Dimosthenis Tsouros
Published in: The 22nd workshop on Constraint Modelling and Reformulation, 2023
Publisher: online: https://modref.github.io/ModRef2023.html

Holy Grail 2.0: From Natural Language to Constraint Models

Author(s): Dimosthenis Tsouros, Helene Verhaeghe, Serdar Kadioglu, Tias Guns
Published in: Progress Toward the Holy Grail workshop at CP2023, 2023
Publisher: Online: https://freuder.wordpress.com/progress-towards-the-holy-grail-workshops/pthg-23-the-sixth-workshop-on-progress-towards-the-holy-grail/
DOI: 10.48550/arxiv.2308.01589

Sudoku Assistant - An AI-powered app to help solve pen-and-paper Sudokus

Author(s): Tias Guns, Milan Pesa, Maxime Mulamba, Ignace Bleukx, Emilio Gamba, and Senne Berden
Published in: BNAIC/BeNeLearn AI & ML conference for Belgium, Netherlands & Luxembourg, 2022
Publisher: Benelux Association for Artificial Intelligence (BNVKI)

Learning to Learn in Interactive Constraint Acquisition

Author(s): Dimosthenis Tsouros, Senne Berden, Tias Guns
Published in: Proceedings of the AAAI Conference on Artificial Intelligence, Issue 8, 2024, Page(s) 8154-8162
Publisher: AAAI Press
DOI: 10.1609/aaai.v38i8.28655

Efficient Modeling of Half-reified Global Constraints

Author(s): Bleukx, Ignace; Verhaeghe, Hélène; Tsouros, Dimos; Guns, Tias
Published in: The 23rd workshop on Constraint Modelling and Reformulation, 2024
Publisher: online: https://modref.github.io/ModRef2024.html

Exploiting Symmetries in MUS Computation

Author(s): Ignace Bleukx, Hélène Verhaeghe, Bart Bogaerts, Tias Guns
Published in: Proceedings of the AAAI Conference on Artificial Intelligence, Issue 39, 2025, Page(s) 11122-11130, ISSN 2374-3468
Publisher: Association for the Advancement of Artificial Intelligence (AAAI)
DOI: 10.1609/aaai.v39i11.33209

Learning Preferences over Unsatisfiable Subsets

Author(s): Gamba, Emilio; Foschini, Marco; Mandi, Jayanta; Bogaerts, Bart; Guns, Tias
Published in: PTHG-24: The Seventh Workshop on Progress Towards the Holy Grail, 2024
Publisher: PTHG

Improving Reduction Techniques in Pseudo-Boolean Conflict Analysis.

Author(s): Orestis Lomis; Jo Devriendt; Hendrik Bierlee; Tias Guns
Published in: 28th International Conference on Theory and Applications of Satisfiability Testing (SAT 2025); 2025; Vol. 28th International Conference on Theory and Applications of Satisfiability Testing (SAT 2025), Issue 1, 2025
Publisher: Schloss Dagstuhl – Leibniz-Zentrum für Informatik

CPMpy_* submissions to the XCSP3 competition

Author(s): Guns, Tias; Vanroose, Wout; Sergeys, Thomas; Bleukx, Ignace; Devriendt, Jo; Tsouros, Dimos; Verhaeghe, Hélène
Published in: Proceedings of the 2024 XCSP3 Competition, 2024
Publisher: Arxiv: https://arxiv.org/abs/2412.00117

Towards Step-wise Explanations Of Large Search Trees

Author(s): Bleukx, Ignace; J. Stuckey, Peter; Guns, Tias
Published in: 32nd International Conference on Principles and Practice of Constraint Programming, 2026
Publisher: Schloss Dagstuhl -- Leibniz-Zentrum fuer Informatik

CPMpy_* submissions to the XCSP3 competition

Author(s): Guns, Tias; Sergeys, Thomas; Bleukx, Ignace; Tsouros, Dimos; Bierlee, Hendrik
Published in: Proceedings of the 2025 XCSP3 Competition, 2025
Publisher: Arxiv: https://arxiv.org/abs/2511.06918

Unified Programmatic Access to CO Benchmarks, to Connect Constraint Solving Communities

Author(s): Sergeys, Thomas; Bleukx, Ignace; Guns, Tias
Published in: 29th International Conference on Theory and Applications of Satisfiability Testing (SAT 2026), 2026
Publisher: Schloss Dagstuhl – Leibniz-Zentrum für Informatik GmbH, Dagstuhl Publishing

Simplifying Step-wise Explanation Sequences

Author(s): Ignace Bleukx, Jo Devriendt, Emilio Gamba, Bart Bogaerts, Tias Guns
Published in: Leibniz International Proceedings in Informatics (LIPIcs), Issue Volume 280, 2023, Page(s) 11:1 - 11:20
Publisher: Schloss Dagstuhl -- Leibniz-Zentrum fuer Informatik
DOI: 10.4230/lipics.cp.2023.11

Large Language Models for Explaining Unsatisfiable Constraint Satisfaction Problems

Author(s): Bleukx, Ignace; Guns, Tias
Published in: LLMs meet Constraint Solving 2026 - FLOC &CP 2026 Workshop, 2026
Publisher: Schloss Dagstuhl – Leibniz-Zentrum für Informatik GmbH, Dagstuhl Publishing

Preference Elicitation for Step-Wise Explanations in Logic Puzzles

Author(s): Marco Foschini, Marianne Defresne, Emilio Gamba, Bart Bogaerts, Tias Guns
Published in: Proceedings of the AAAI Conference on Artificial Intelligence, Issue 40, 2026, Page(s) 14225-14233, ISSN 2374-3468
Publisher: Association for the Advancement of Artificial Intelligence (AAAI)
DOI: 10.1609/aaai.v40i17.38436

Guided Bottom-Up Interactive Constraint Acquisition

Author(s): Dimosthenis Tsouros, Senne Berden, Tias Guns
Published in: Leibniz International Proceedings in Informatics (LIPIcs), 2023, Page(s) 36:1 - 36:20
Publisher: Schloss Dagstuhl -- Leibniz-Zentrum fuer Informatik
DOI: 10.4230/lipics.cp.2023.36

An Efficient Structured Perceptron for NP-Hard Combinatorial Optimization Problems

Author(s): Bastián Véjar, Gaël Aglin, Ali İrfan Mahmutoğulları, Siegfried Nijssen, Pierre Schaus, Tias Guns
Published in: Integration of Constraint Programming, Artificial Intelligence, and Operations Research, proceedings, 2024, Page(s) 253--262, ISBN 978-3-031-60599-4
Publisher: Springer Nature Switzerland
DOI: 10.1007/978-3-031-60599-4_17

Preference Elicitation for Multi-objective Combinatorial Optimization with Active Learning and Maximum Likelihood Estimation

Author(s): Marianne Defresne, Jayanta Mandi, Tias Guns
Published in: Proceedings of the Thirty-ThirdInternational Joint Conference on Artificial Intelligence, 2025, Page(s) 2583-2591
Publisher: International Joint Conferences on Artificial Intelligence Organization
DOI: 10.24963/ijcai.2024/288

Model-Based Algorithm Configuration with Adaptive Capping and Prior Distributions

Author(s): Ignace Bleukx, Senne Berden, Lize Coenen, Nicholas Decleyre, Tias Guns
Published in: Integration of Constraint Programming, Artificial Intelligence, and Operations Research. Lecture Notes in Computer Science, Issue volume 13292, 2022, Page(s) 64-73
Publisher: Springer
DOI: 10.1007/978-3-031-08011-1_6

From CP Modeling to Preference Elicitation in HMLV Assembly Problems

Author(s): Foschini, Marco; Gamba, Emilio; Kletzander, Lucas; Guns, Tias
Published in: 32nd International Conference on Principles and Practice of Constraint Programming (CP 2026), 2026
Publisher: Schloss Dagstuhl -- Leibniz-Zentrum fuer Informatik

Learning Constraint Programming Models from Data Using Generate-And-Aggregate

Author(s): Mohit Kumar, Samuel Kolb, Tias Guns
Published in: 28th International Conference on Principles and Practice of Constraint Programming (CP 2022). Leibniz International Proceedings in Informatics (LIPIcs), Issue Volume 235, 2022, Page(s) 29:1 - 29:16, ISBN 978-3-95977-240-2
Publisher: Schloss Dagstuhl – Leibniz-Zentrum für Informatik (lzi)
DOI: 10.4230/lipics.cp.2022.29

Decision-Focused Learning: Through the Lens of Learning to Rank

Author(s): Jayanta Mandi, Víctor Bucarey, Maxime Mulamba Ke Tchomba, Tias Guns
Published in: Proceedings of the 39th International Conference on Machine Learning;, Issue Vol. 162, 2022, Page(s) 14935 - 14947
Publisher: PMLR

Table Constraints for Integer Programming

Author(s): Bierlee, Hendrik; Piessens, Wout; Stuckey, Peter; Guns, Tias
Published in: 32nd International Conference on Principles and Practice of Constraint Programming (CP 2026), 2026
Publisher: Schloss Dagstuhl -- Leibniz-Zentrum fuer Informatik

Using Certifying Constraint Solvers for Generating Step-wise Explanations

Author(s): Ignace Bleukx, Maarten Flippo, Bart Bogaerts, Emir Demirović, Tias Guns
Published in: Proceedings of the AAAI Conference on Artificial Intelligence, Issue 40, 2026, Page(s) 14192-14200, ISSN 2374-3468
Publisher: Association for the Advancement of Artificial Intelligence (AAAI)
DOI: 10.1609/aaai.v40i17.38432

Feasibility-Aware Decision-Focused Learning for Predicting Parameters in the Constraints

Author(s): Mandi, Jayanta; Defresne, Marianee; Berden, Senne; Guns, Tias
Published in: Advances in Neural Information Processing Systems 38 (NeurIPS 2025), 2025, ISSN 1049-5258
Publisher: Morgan Kaufmann Publishers

Mutational Fuzz Testing for Constraint Modeling Systems.

Author(s): Vanroose, Wout; Bleukx, Ignace; Devriendt, jo; Tsouros, dimos; Verhaeghe, hélène; Guns, tias
Published in: 30th International Conference on Principles and Practice of Constraint Programming (CP 2024), 2024, Page(s) 29:1--29:25, ISBN 978-3-95977-336-2
Publisher: "Schloss Dagstuhl -- Leibniz-Zentrum f{\""u}r Informatik"
DOI: 10.4230/lipics.cp.2024.29

Sudoku Assistant – an AI-Powered App to Help Solve Pen-and-Paper Sudokus

Author(s): Tias Guns, Emilio Gamba, Ignace Bleukx, Senne Berden, Milan Pesa
Published in: Proceedings of the AAAI Conference on Artificial Intelligence, Issue vol. 37 (13), 2023, Page(s) 16440-16442
Publisher: AAAI press
DOI: 10.1609/aaai.v37i13.27072

Contrastive Losses and Solution Caching for Predict-and-Optimize

Author(s): Maxime Mulamba, Jayanta Mandi, Michelangelo Diligenti, Michele Lombardi, Victor Bucarey, Tias Guns
Published in: Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence, 2021, Page(s) 2833-2840
Publisher: ijcai.org
DOI: 10.24963/ijcai.2021/390

Constraint Modelling with LLMs Using In-Context Learning.

Author(s): Michailidis, Kostis; Tsouros, Dimos; Guns, Tias
Published in: 30th International Conference on Principles and Practice of Constraint Programming (CP 2024), 2024, Page(s) 20:1--20:27, ISBN 978-3-95977-336-2
Publisher: "Schloss Dagstuhl -- Leibniz-Zentrum f{\""u}r Informatik"
DOI: 10.4230/lipics.cp.2024.20

Efficiently Explaining CSPs with Unsatisfiable Subset Optimization

Author(s): Emilio Gamba, Bart Bogaerts, Tias Guns
Published in: Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence, 2021, Page(s) 1381-1388
Publisher: ijcai.org
DOI: 10.24963/ijcai.2021/191

Solver-Free Decision-Focused Learning for Linear Optimization Problems

Author(s): Berden, Senne; Mahmutogullari, Irfan; Tsouros, Dimos; Guns, Tias
Published in: Advances in neural information processing systems, 2025, ISSN 1049-5258
Publisher: Morgan Kaufmann Publishers

Learning MAX-SAT Models from Examples Using Genetic Algorithms and Knowledge Compilation

Author(s): Senne Berden, Mohit Kumar, Samuel Kolb, Tias Guns:
Published in: 28th International Conference on Principles and Practice of Constraint Programming (CP 2022). Leibniz International Proceedings in Informatics (LIPIcs), Issue Volume 235, 2022, Page(s) 8:1-8:16, ISBN 978-3-95977-240-2
Publisher: Schloss Dagstuhl – Leibniz-Zentrum für Informatik (lzi)
DOI: 10.4230/lipics.cp.2022.8

Breaking Constraint Modelling Languages with Metamorphic Testing

Author(s): Bleukx, Ignace; Vanroose, Wout; Devriendt, Jo; Tsouros, Dimos; Verhaeghe, Helene; Guns, Tias
Published in: The 22nd workshop on Constraint Modelling and Reformulation, 2023
Publisher: online: https://modref.github.io/ModRef2023.html

Anytime Lexicographic Enumeration of the Pareto Front in Multi‐Objective Combinatorial Optimisation

Author(s): Marco Foschini, Dimos Tsouros, Bistra Dilkina, Tias Guns
Published in: Journal of Multi-Criteria Decision Analysis, Issue 33, 2026, ISSN 1057-9214
Publisher: John Wiley and Sons Ltd
DOI: 10.1002/mcda.70029

Probability Estimation and Structured Output Prediction for Learning Preferences in Last Mile Delivery

Author(s): Rocsildes Canoy, Victor Bucarey, Jayanta Mandi, Maxime Mulamba, Yves Molenbruch, Tias Guns
Published in: Computers & Industrial Engineering, Issue 189, 2023, Page(s) 109932, ISSN 0360-8352
Publisher: Pergamon Press Ltd.
DOI: 10.2139/ssrn.4363937

Perception-based constraint solving for sudoku images

Author(s): Maxime Mulamba, Jayanta Mandi, Ali İrfan Mahmutoğulları, Tias Guns
Published in: Constraints, Issue 29, 2024, Page(s) 112-151, ISSN 1383-7133
Publisher: Kluwer Academic Publishers
DOI: 10.1007/s10601-024-09372-9

Decision-Focused Learning: Foundations, State of the Art, Benchmark and Future Opportunities

Author(s): Jayanta Mandi, James Kotary, Senne Berden, Maxime Mulamba, Victor Bucarey, Tias Guns, Ferdinando Fioretto
Published in: Journal of Artificial Intelligence Research, Issue 80, 2024, Page(s) 1623-1701, ISSN 1076-9757
Publisher: Morgan Kaufmann Publishers, Inc.
DOI: 10.1613/jair.1.15320

Learn and route: learning implicit preferences for vehicle routing

Author(s): Rocsildes Canoy, Víctor Bucarey, Jayanta Mandi, Tias Guns
Published in: Constraints, Issue vol. 28; iss. 3, 2023, Page(s) 363 - 396, ISSN 1383-7133
Publisher: Kluwer Academic Publishers
DOI: 10.1007/s10601-023-09363-2

Efficiently Explaining CSPs with Unsatisfiable Subset Optimization

Author(s): Emilio Gamba, Bart Bogaerts, Tias Guns
Published in: Journal of Artificial Intelligence Research, Issue 78, 2023, Page(s) 709-746, ISSN 1076-9757
Publisher: Morgan Kaufmann Publishers, Inc.
DOI: 10.1613/jair.1.14260

Generalizing Constraint Models in Constraint Acquisition

Author(s): Dimos Tsouros, Senne Berden, Steven Prestwich, Tias Guns
Published in: Proceedings of the AAAI Conference on Artificial Intelligence, Issue 39, 2025, Page(s) 11362-11371, ISSN 2374-3468
Publisher: Association for the Advancement of Artificial Intelligence (AAAI)
DOI: 10.1609/aaai.v39i11.33236

CP-Bench: Evaluating Large Language Models for Constraint Modelling

Author(s): Kostis Michailidis, Dimos Tsouros, Tias Guns
Published in: Frontiers in Artificial Intelligence and Applications, ECAI 2025, 2025
Publisher: IOS Press
DOI: 10.3233/faia250890

Minimizing Surrogate Losses for Decision-Focused Learning Using Differentiable Optimization

Author(s): Jayanta Mandi, Ali İrfan Mahmutoğulları, Senne Berden, Tias Guns
Published in: Frontiers in Artificial Intelligence and Applications, ECAI 2025, 2025
Publisher: IOS Press
DOI: 10.3233/faia251273

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