SAT Live!

Call for Participation: QBFGallery 2026

Fri, 24 Apr 2026 00:00:00 +0200

========================= CALL FOR CONTRIBUTIONS =======================

We warmly encourage developers of QBF solvers to submit their work, even at early stages of development, as long as it fulfills some very simple requirements. We also welcome the submission of QBF formulas to be used for the evaluation. Researchers thinking about using QBF-based techniques in their area (e.g., formal verification, planning, knowledge representation & reasoning) are invited to contribute to the evaluation by submitting QBF instances of their research problems (see the requirements for instances). The results of the evaluation will be a good indicator of the current feasibility of QBF-based approaches and a stimulus for people working on QBF solvers to further enhance their tools.

Important Dates

2026-05-17: Submission of benchmarks 2026-05-17: Submission of solvers 2026-05-20: Feedback on solver submissions May, June 2026: evaluation runs 2026-07-19: presentation of results at the QBF 2026 Workshop

Organization

Cynthia Peyrer, Johannes Kepler University Linz
Luca Pulina, University of Sassari
Martina Seidl, Johannes Kepler University Linz

Second Call for Papers: 2nd Workshop on Machine Learning for Solvers and Provers (at FLoC 2026)

Fri, 24 Apr 2026 00:00:00 +0200

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The 2nd Workshop on Machine Learning for Solvers and Provers (ML4SP)

    July 18, 2026, Lisbon, Portugal

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Workshop page: https://ml4sp.github.io/

We warmly invite you to submit your work to the 2nd Workshop on Machine Learning for Solvers and Provers (ML4SP), organised as part of the 2026 Federated Logic Conference (FLoC 2026) at Lisbon, Portugal. The workshop will run during the first block of the conference, on July 18, 2026.

Topics

Machine learning (ML) has had a substantial impact on SAT/SMT and CP solvers, as well as automated theorem provers. Recent advances have demonstrated the power of ML to inform solver heuristics, guide proof search, and optimize algorithm portfolios. Despite growing interest in this direction, work on ML for solvers and provers is often scattered across multiple research communities – SAT, SMT, CP, theorem proving, formal methods, and machine learning – with few opportunities for focused interaction.

The ML4SP workshop aims to bring together researchers and practitioners working at the intersection of machine learning and formal reasoning systems. It provides a forum for the presentation of recent work, the exchange of ideas, and the fostering of collaboration between these communities.

Topics of interest include, but are not limited to, ML-driven approaches for:

Heuristics (branching, restarts, …) in CP, SAT, SMT, and MIP solvers
Tactic selection and proof guidance in automated and interactive theorem provers
Algorithm selection, parameter tuning and algorithm configuration, and portfolio solvers
End-to-end learning for solvers and provers
Benchmark generation and instance hardness prediction
Applications of ML-enhanced reasoning in verification, synthesis, planning, and related areas
Leveraging large language models (LLMs) for solver heuristics and proof guidance

Submission

We welcome submissions describing previously published work, ongoing research, and position papers and early-stage ideas intended to stimulate discussion.

Submission should be in PDF form, following the LIPIcs guidelines. They can be:

Extended abstracts (up to two pages, excluding references); or
Full papers (up to 15 pages, excluding references).

All submissions will be reviewed by the PC members. A presentation time slot will be given to each accepted submission.

Submission link: https://submissions.floc26.org/ml4sp/

Key Dates

Submission deadline: 15 May 2026 AoE
Result notification: 25 May 2026
Camera ready: 2 July 2026
Workshop day: 18 July 2026

Programme Committe

Shaowei Cai	Chinese Academy of Sciences
Quentin Cappart	Polytechnique Montréal
Wuyang Chen	Simon Fraser University
Pascal Fontaine	LORIA, INRIA, Université de Lorraine
Guy Katz	The Hebrew University of Jerusalem
Sean Holden	Cambridge University
Mikoláš Janota	Czech Technical University
Lars Kotthoff	University of St Andrews
Peter Nightingale	University of York
Martin Suda	Czech Technical University
Dimos Tsouros	University of Western Macedonia
Felix Ulrich-Oltean	University of York
Vijay Ganesh (chair)	Georgia Institute of Technology
Nguyen Dang (chair)	University of St Andrews

Organizers:

Vijay Ganesh, Georgia Tech, vganesh45@gatech.edu
Nguyen Dang, University of St Andrews, nttd@st-andrews.ac.uk

CFP - LLMs meet Constraint Solving, 2nd Edition (LLM-Solve 2026)

Tue, 21 Apr 2026 00:00:00 +0200

CALL FOR PAPERS

LLM-Solve 2026: LLMs meet Constraint Solving (2nd Edition)
FLoC & CP 2026 Workshop
Sunday, July 19, 2026, at ISCTE, Lisbon, Portugal

IMPORTANT DATES

Submission deadline: May 15, 2026
Notification: May 25, 2026
Workshop: July 19, 2026

ABOUT

LLM-Solve 2026 is a workshop for researchers at the intersection of Large Language Models and Constraint Solving (CP, SAT, SMT, MIP, and related paradigms). LLMs now act as agentic systems that orchestrate multi-step reasoning and tool use, yet they struggle with reliability and formal correctness. Constraint solvers offer provable guarantees but require expertise to formalize problems and select suitable techniques. The opportunity is bidirectional. LLMs can help non-experts with modeling and interactive solving, while constraint solvers can provide execution, verification, and structured reasoning for LLM-driven agents.

TOPICS OF INTEREST (not restricted to)

LLMs and agentic systems for constraint modeling and acquisition
LLM-guided solver heuristics and search strategies
Hybrid approaches combining LLMs and constraint solvers
Constraint solvers for improving LLM reasoning and verification
SAT/CP-based methods for controlling or guiding LLM outputs
LLM-driven explanations and interactive constraint solving
Benchmarks, datasets, and evaluation methodologies for LLM-Constraint integration
Real-world applications combining constraint-solving and LLMs

SUBMISSIONS

Extended abstracts up to 2 pages (excluding references), with an optional appendix of up to 10 pages. Submissions may cover published work, original work, work in progress with preliminary results, or position papers. PDF following LIPIcs guidelines. All presenters and attendees must register for the FLoC workshop day.

Submit.

ORGANIZERS

Tias Guns (KU Leuven, Belgium)
Serdar Kadıoglu (Brown University, USA)
Stefan Szeider (TU Wien, Austria)
Dimos Tsouros (UOWM, Greece)

FLoC’26, CP’26

CFP - Soft Constraints, Discrete Optimization, and Machine Learning (SOFT'26)

Wed, 08 Apr 2026 00:00:00 +0200

This workshop aims to bring together researchers on constraint reasoning, optimization, and learning to present recent advances, share ongoing work, and discuss future directions for hybrid approaches that combine discrete optimization with machine learning and data mining.

Topics of Interest (but are not restricted to):

Max-SAT
Max-SMT
Markov Random Field
Pseudo-Boolean Optimization
Soft global constraints
Weighted CSP
Integer Programming
Combining discrete optimization with machine learning for better solver design.
Data-driven strategies to guide search heuristics, branching, or propagation.
Using machine learning and data mining techniques to guide search.
Integrating deep neural networks to improve solvers.

Submissions

The aim of this workshop is to provide a forum where researchers currently working in this area can exchange their ideas, discuss new developments and explore possible future directions. Therefore, we welcome and encourage three types of submission:

1) Work in progress and Original work. Submissions of an extended abstract or a full paper, up to 15 pages in the LIPIcs format (https://submission.dagstuhl.de/series/details/LIPIcs#author), about unpublished ideas will be reviewed by a double-blind process and if accepted and the authors agree the final version will be made available on the workshop website.

1) Already published work. Authors who are interested in giving a presentation to the workshop’s audience may submit their work non-anonymously while indicating where this work has been published. We will only accept work which has been published in the last calendar year (e.g., CPAIOR 2025, CP 2025, ECAI 2025, IJCAI 2025, AAAI 2026, and any journal or conference held after May 2025).

1) Papers not selected for the main CP conference. Decisions about acceptance of these papers will be based on their reviews.

Contributions should be submitted in the form of a PDF file, following LIPIcs guidelines, using the link https://submissions.floc26.org/soft/

The type of submission as defined above should be clearly stated during the submission. At least one author of each accepted paper must attend the workshop.

This workshop is open to all members of the FLoC community. All workshop participants must pay the workshop fee.

Important Dates

Paper Submission deadline May 15th
Notification of acceptance May 28th
Early CP registration deadline June 1st
Final version deadline June 30th
Workshop Date July 24th

Organizers

Simon de Givry
INRAE MIAT, Toulouse, France.
Email: simon.de-givry @ inrae.fr
Web: https://miat.inrae.fr/degivry

Samir Loudni
DAPI, IMT Atlantique, Nantes, France.
Email: samir.loudni @ imt-atlantique.fr
Web: https://cv.hal.science/samir-loudni

Program Committee

Quentin Cappart, UCLouvain, Belgium and Polytechnique Montréal, Canada
Tias Gun, KU Leuven, Belgium
George Katsirelos, INRAE Paris Saclay, France
Elias B. Khalil, University of Toronto, Canada
Javier Larrosa, UPC, Barcelona, Spain
Jakob Nordström, University of Copenhagen, Denmark, and Lund University, Sweden
Albert Oliveras, UPC, Barcelona, Spain
Thomas Schiex, INRAE Toulouse, France
Sylvie Thiebaux, LAAS, Toulouse, France

CFP - Pseudo-Boolean Competition 2026

Wed, 08 Apr 2026 00:00:00 +0200

The 2026 edition of the competition for pseudo-Boolean solvers is organized under the aegis of the SAT 2026 conference. The Pseudo-Boolean Competition 2026 is also affiliated with the FloC Olympic Games.

All the details about this new edition of the competition are available at

https://www.cril.univ-artois.fr/PB26/

The deadline for both solvers and benchmarks submission is May 6, 2026.

Obviously, a competition cannot exist without solvers and benchmarks. So, if you have pseudo-Boolean solvers or benchmarks, please make a submission to the PB26 competition!

On behalf of the steering committee: Carlos Ansótegui, Johannes Klaus Fichte, Jakob Nordström, and Olivier Roussel

CFP - 3rd International Workshop on Highlights in Organizing and Optimizing Proof-logging Systems (WHOOPS'26)

Tue, 07 Apr 2026 00:00:00 +0200

The 3rd International Workshop on Highlights in Organizing and Optimizing Proof-logging Systems (WHOOPS ‘26) will be held on 19th July 2026 as part of the Federated Logic Conference (FLoC ‘26), immediately before the CP and SAT conferences.

The purpose of WHOOPS is to bring together researchers interested in certifying algorithms and proof logging for automated reasoning and combinatorial solving. As such, we solicit contributed talks that will be of interest to such an audience, on topics which could include:

the theory or practice of proof logging systems;
bringing proof logging to existing or new solving tools;
descriptions of challenges anticipated or encountered;
integrating proof logging into larger verification frameworks;
connections between proof logging and explainability;
speculation about or requests for future directions for proof logging and certification.

WHOOPS does not have full papers or proceedings, and presentations may cover work that is already published or that may be published elsewhere in the future. We ask only for a brief (<1 page) abstract, which can be submitted through the FLoC submissions system before the deadline of 15th May 2026.

Background and purpose

Modern automated reasoning has transformed large parts of industry and has also found numerous scientific applications. But many reasoning problems are computationally very challenging, or sometimes even undecidable. Because of this, the algorithms used are getting increasingly complex, and even the most mature tools currently available struggle with incorrect results. As these algorithms are increasingly being used autonomously, sometimes even in life-critical applications, it is urgent to ensure that what they compute is valid. Software testing, while important, has not been sufficient to resolve this problem, and formal verification methods are far from being able to scale to the level of complexity in modern algorithms.

During the last twenty years, the Boolean satisfiability (SAT) solving community has instead spearheaded the use of proof logging, meaning that the SAT solvers have to output, along the answer to a problem, a machine-verifiable proof that this answer is correct. Such solvers are also referred to as certifying algorithms. For a long time, attempts to extend proof logging to stronger paradigms in automated reasoning met with limited success. This has changed in the last few years, however, with proof logging techniques now being developed for a wide range of paradigms such as SAT-based and pseudo-Boolean optimisation, subgraph solving, constraint programming, automated planning, mixed integer linear programming, and even satisfiability modulo theories (SMT) solving and automated theorem proving.

These developments have been so fast that in 2024 the fairly spontaneous idea arose to celebrate the latest advances during an informal workshop, which—reflecting the rather improvised nature of the event—was named the 1st Workshop on Highlights in Organizing and Optimizing Proof-logging Systems (WHOOPS ‘24). The second edition WHOOPS ‘25 was held last autumn under the auspices of EuroProofNet.

The third instalment of the workshop series, to be held on 19th July 2026 as part of the Federated Logic Conference (FLoC ‘26), will continue to expand the range of topics beyond SAT and pseudo-Boolean proof logging to provide a forum for discussing certifying algorithms for automated reasoning more broadly. In addition to ensuring correctness of outputs for automated reasoning algorithms, we also hope to examine the use of proof logging to provide new tools for algorithm development and analysis, software debugging, and even research into explainability in the context of AI.

Program committee

Katalin Fazekas, TU Wien
Daniela Kaufmann, TU Wien
Ciaran McCreesh, University of Glasgow
Jakob Nordström, University of Copenhagen and Lund University
Michael Rawson, University of Southampton
Adrian Rebola-Pardo, TU Wien

Jakob Nordström, Professor University of Copenhagen and Lund University Phone: +45 28 78 38 11 / +46 70 742 21 98 https://jakobnordstrom.se

CFP - 17th International Workshop on Pragmatics of SAT (PoS 2026).

Thu, 02 Apr 2026 00:00:00 +0200

The aim of the Pragmatics of SAT (PoS) workshop series is to provide a venue for researchers working on designing and/or applying Boolean satisfiability (SAT) solvers and related solver technologies, including but not restricting to satisfiability modulo theories (SMT), answer set programming (ASP), and constraint programming (CP) as well as their optimization counterparts, to meet, communicate, and discuss latest results.

All information can be found on the workshop website:http://www.pragmaticsofsat.org/2026/

Important Dates

Paper submission deadline: May 7, 2026
Notification to authors: June 1, 2026
Workshop: July 19, 2026

CFP - 13th International Workshop on Quantified Boolean Formulas and Beyond

Wed, 11 Mar 2026 00:00:00 +0100

QBF 2026: CALL FOR PAPERS

International Workshop on Quantified Boolean Formulas and Beyond

19 July 2026

Affiliated to and co-located with: Int. Conf. on Theory and Applications of Satisfiability Testing (SAT 2026), 20-23 July

Quantified Boolean formulas (QBF) are an extension of propositional logic which allows for explicit quantification over propositional variables. The decision problem of QBF is PSPACE-complete, compared to the NP-completeness of the decision problem of propositional logic (SAT). Many problems from application domains such as model checking, formal verification or synthesis are PSPACE-complete, and hence could be encoded in QBF in a natural way. Considerable progress has been made in QBF solving throughout the past years. However, in contrast to SAT, QBF is not yet widely applied to practical problems in academic or industrial settings. For example, the extraction and validation of models of (un)satisfiability of QBFs has turned out to be challenging, given that state-of-the-art solvers implement different solving paradigms. The goal of the International Workshop on Quantified Boolean Formulas (QBF Workshop) is to bring together researchers working on theoretical and practical aspects of QBF solving and extensions like DQBF. In addition to that, it addresses (potential) users of QBF in order to reflect on the state-of-the-art and to consolidate on immediate and long-term research challenges.

The workshop also welcomes work on reasoning with quantifiers in related problems, such as dependency QBF (DQBF), quantified constraint satisfaction problems (QCSP), and satisfiability modulo theories (SMT) with quantifiers.

IMPORTANT DATES

13 May: Submission
27 May: Notification of acceptance
19 July: Workshop

Please see the workshop webpage for any updates:

https://qbf-workshop.github.io/dates/

CALL FOR CONTRIBUTIONS

The workshop is concerned with all aspects of current research on all formalisms enriched by quantifiers, and in particular QBF. The topics of interest include (but are not limited to):

Applications, encodings and benchmarks with quantifiers
QBF Proof theory and complexity results
Experimental evaluations of solvers or related tools
Case studies illustrating the power of quantifiers
Certificates and proofs for QBF, QCSP, SMT with quantifiers, etc.
Formats of proofs and certificates
Implementations of proof checkers and verifiers
Decision procedures
Calculi and their relationships
Data structures, implementation details and heuristics
Pre- and inprocessing techniques
Structural reasoning

SUBMISSION

We invite the submission of extended abstracts on work that has been published already, novel unpublished work, or work in progress. Submissions will be managed via HotCRP:

https://submissions.floc26.org/qbf/

More specifically, the following forms of submissions are solicited:

Proposals for short tutorial presentations on topics related to the workshop. Tutorial proposals will be reviewed by the PC. The number of accepted tutorials depends on the overall number of accepted papers and talks, with the aim to set up a balanced workshop program.
Talk abstracts reporting on already published work. Such an abstract should include an outline of the planned talk, and pointers to relevant bibliography.
Talk proposals presenting work that is unpublished or in progress.
Submissions which describe novel applications of QBF or related formalisms in various domains are particularly welcome. Additionally, this call comprises known applications which have been shown to be hard for QBF solvers in the past as well as new applications for which present QBF solvers might lack certain features still to be identified.

Submissions must be prepared in English. There is no mandatory format. Authors can choose any reasonable format for their submissions. Plans for dissemination: The outcomes of the discussions will be summarized in a workshop report, which will be made publicly available as a technical report. Extended abstracts of the talks will also be included in the technical report.

Authors of accepted contributions are expected to give a talk at the workshop.

PROGRAM COMMITTEE

Leroy Chew, Czech Institute of Informatics, Robotics and Cybernetics, CTU Prague, Czech Republic
Lea Kasche, University of Jena, Germany
Franz-Xaver Reichl, University of Freiburg, Germany
Tony Tan, University of Liverpool, United Kingdom

ModRef 2026 Call for Papers

Tue, 10 Feb 2026 00:00:00 +0100

We invite you to submit your work to ModRef 2026, the 25th workshop on Constraint Modelling and Reformulation, which will be held on 19th July 2026 in Lisbon, Portugal, as part of FLOC26.

The purpose of ModRef is to be a forum for all kinds of work in modelling for CP, MIP, SAT, SMT, and other general-purpose solvers, including:

new models or new modelling ideas for any amenable problem (whether a new application or a classic benchmark),
reformulation techniques to improve the performance of models when solved by general-purpose solvers, and
automated modelling techniques, tools, and languages.

We solicit original papers that contribute to the understanding of modelling or model reformulation.

This year ModRef will again accept paper submissions. In addition to the presentation of research results, we especially welcome submissions of novel (ongoing) work, recent breakthroughs, future directions, and descriptions of interesting aspects of existing systems.

There are three types of paper submissions:

Extended abstracts: at most two pages
Short papers: at most eight pages.
Long papers: at most fifteen pages.

References are not part of the page limit. We also accept (and encourage) non-traditional electronic submissions, such as interactive works/tool demonstrations. In this case, please contact the chairs to discuss the suitability of your submission for ModRef.

Papers should be submitted through HotCRP as PDF files following LIPIcs guidelines. There is no requirement for papers to be anonymised before submission.

All submissions will be reviewed, and those that are well-written and make a worthwhile contribution to the topic of the workshop will be allowed a time slot for a presentation at the workshop. Accepted papers will be included in non-archival electronic workshop proceedings, which will be available on ModRef’s web site. You can see some of the past accepted papers to give you an idea of the kind of contributions shared over recent years.

For more information, please see our web site https://2026.modref.org/

If you have any questions, please contact us at jordicoll@udg.edu and felix.ulrich-oltean@york.ac.uk

Jordi Coll and Felix Ulrich-Oltean Co-chairs

Call for papers: 2nd Workshop on Machine Learning for Solvers and Provers (at FLoC 2026)

Tue, 10 Feb 2026 00:00:00 +0100

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The 2nd Workshop on Machine Learning for Solvers and Provers (ML4SP)

    July 18, 2026, Lisbon, Portugal

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Workshop page: https://ml4sp.github.io/

Topics

Topics of interest include, but are not limited to, ML-driven approaches for:

Heuristics (branching, restarts, …) in CP, SAT, SMT, and MIP solvers
Tactic selection and proof guidance in automated and interactive theorem provers
Algorithm selection, parameter tuning and algorithm configuration, and portfolio solvers
End-to-end learning for solvers and provers
Benchmark generation and instance hardness prediction
Applications of ML-enhanced reasoning in verification, synthesis, planning, and related areas
Leveraging large language models (LLMs) for solver heuristics and proof guidance

Submission

We welcome submissions describing previously published work, ongoing research, and position papers and early-stage ideas intended to stimulate discussion.

Submission should be in PDF form, following the LIPIcs guidelines. They can be:

Extended abstracts (up to two pages, excluding references); or
Full papers (up to 15 pages, excluding references).

All submissions will be reviewed by the PC members. A presentation time slot will be given to each accepted submission.

Submission link: https://submissions.floc26.org/ml4sp/

Key Dates

Submission deadline: 15 May 2026 AoE
Result notification: 25 May 2026
Camera ready: 2 July 2026
Workshop day: 18 July 2026

Organizers:

Vijay Ganesh, Georgia Tech, vganesh45@gatech.edu
Nguyen Dang, University of St Andrews, nttd@st-andrews.ac.uk