[News and Highlights] [Research] [Publications] [Activities] [Teaching]
I lead the
and Optimization Group
at the University of Helsinki.
Interested in a postdoc position in my group?
We are looking for a talented postdoc with proven potential and
a strong background in solver development, applications, and/or theory
related to SAT, constraints, optimization, mathematical programming,
formal verification, graphical models, and explainable AI.
Feel free to contact me by email for more details!
Looking for a research-oriented Master's thesis topic and/or a summer internship, with a possibility of
a part-time or full-time research assistant position?
We are always on the lookout for talented students with
- a CS background, especially in algorithms/machine learning;
- a Math / Operations Research background, especially in optimization/logic/complexity, with interest in algorithms; and/or
- strong implementation skills (C/C++) who are motivated by challenging programming tasks
to work with us on forefront research problems within the
and Optimization Group.
For more information, contact me by email.
Disclaimer: Apart from truly exceptional cases, internships are only available to
student locally in the Helsinki region. I am not able to respond to every international query about internship opportunities.
See also recent work for new publications.
M. Järvisalo, A. Van Gelder (eds.), LNCS 7962, Springer, 2013.
Boolean satisfiability and generalizations,
decision procedures, constraint satisfaction, combinatorial/discrete optimization,
automated reasoning, artificial intelligence, operations research,
knowledge representation, complexity of reasoning, computational aspects of argumentation,
probabilistic graphical models, structure discovery, ...
Awards and Honors
- 2019 IJCAI-JAIR Best Paper Prize
- University of Helsinki 2019 Doctoral Dissertation Award to my PhD student Jeremias Berg
- PGM 2018 Best Student Paper Award to my PhD student Kari Rantanen
- CP 2017 Distinguished Paper Award
- Invited paper at AAAI 2017 in the What's Hot track.
- IJCAI 2016 Early Career Spotlight
as one of 22 (6 within Europe) most active early career researchers in all representative areas of AI.
- ECAI 2016 Runner-Up Best Student Paper Award to my PhD student Andreas Niskanen
Best solver at MaxSAT Evaluation 2015 on industrial and crafted weighted partial MaxSAT instances
for our solver LMHS.
ICCMA 2015 Honorary Mention at
for our Cegartix solver
KR 2012 Distinguished Student Paper Prize
2011 Best Researcher Award at Department of Computer Science,
University of Helsinki.
CP 2007 runner-up for the CP'07 Best Paper Award
ICLP 2007 Best Student Paper Award
Declarative Boolean Optimization: Pushing the Envelope (9/2019-8/2023; PI)
funded by Academy of Finland (Academy project funding for early-career researchers)
- Symbolic Reasoning for Formally Verified and Explainable AI (2020-2022; PI)
funded by Academy of Finland (ICT 2023 Autonomous Everything)
Decision Procedures for the Polynomial Hierarchy,
Boolean Optimization, and Model Counting (9/2014-8/2019; PI),
funded by Academy of Finland (Academy Research Fellow funding scheme)
Harnessing Constraint Reasoning for Structure Discovery (2015-2018; PI),
Research Funds of the University of Helsinki (Three-year Research Projects
Extending the Reach of Boolean Constraint Reasoning
Academy of Finland
(Postdoctoral Project funding scheme)
A complete list of my publications with downloadable papers and bibtex entries
is available both
by year and
Some recent work
Google Scholar profile,
Orcid ID 0000-0003-2572-063X (incomplete data),
Scopus Author ID 23397451200 (incomplete data).
- Discovering Causal Graphs with Cycles and Latent Confounders: An Exact Branch-and-Bound Approach,
Int. J. Approximate Reasoning (2020)
- Finding Most Compatible Phylogenetic Trees over Multi-State Characters, AAAI 2020
- Deciding Acceptance in Incomplete Argumentation Frameworks, AAAI 2020
- Preprocessing in Incomplete MaxSAT Solving, ECAI 2020
- Learning Chordal Markov Networks via Stochastic Local Search, ECAI 2020
- Algorithms for Dynamic Argumentation Frameworks: An Incremental SAT-Based Approach, ECAI 2020
- Strong Refinements for Hard Problems in Argumentation Dynamics, ECAI 2020
- Synthesizing Argumentation Frameworks from Examples, J. Artificial Intelligence Research (2019)
- MaxSAT Evaluation 2019: New Developments and Detailed Results, J. Satisfiability, Boolean Modeling and Computation (2019)
- SAT Competition 2019, J. Satisfiability, Boolean Modeling and Computation (2019)
- Enumerating Potential Maximal Cliques via SAT and ASP, IJCAI 2019
- Centrality Heuristics for Exact Model Counting, ICTAI 2019
- Solving Graph Problems via Potential Maximal Cliques: An Experimental Evaluation of the Bouchitté-Todinca Algorithm,
ACM J. Experimental Algorithmics (2019) [pdf]
- Reasoning over Assumption-Based Argumentation Frameworks via Direct Answer Set Programming Encodings,
AAAI 2019 [pdf]
- Unifying Reasoning and Core-Guided Search for Maximum Satisfiability,
JELIA 2019 [pdf]
- Preprocessing Argumentation Frameworks via Replacement Patterns,
JELIA 2019 [pdf],
- Towards Transformational Creation of Novel Songs, Connection Science (2019)
- A Hybrid Approach to Optimization in Answer Set Programming,
KR 2018 [pdf]
- Extension Enforcement under Grounded Semantics in Abstract Argumentation,
KR 2018 [pdf]
Cautious Reasoning in ASP via Minimal Models and Unsatisfiable Cores, Theory and Practice of Logic Programming (2018)
Learning Optimal Causal Graphs with Exact Search, PGM 2018
SAT-based Approaches to Adjusting, Repairing, and Computing Largest Extensions of Argumentation Frameworks, COMMA 2018
- Premise Set Caching for Enumerating Minimal Correction Subsets, AAAI 2018
- A Preference-Based Approach to Backbone Computation with Application to Argumentation, SAC 2018
- Empirical Hardness of Finding Optimal Bayesian Network Structures:
Algorithm Selection and Runtime Prediction, Machine Learning (2018)
Editorial Board Memberships
Steering Committee Memberships
Program Committee Chairing, Guest Editorials, Senior PC Memberships
Program Committee Memberships
- Demo Track Chair, IJCAI-PRICAI 2020: 29th International Joint Conference on Artificial Intelligence and the 17th Pacific Rim International Conference on Artificial Intelligence, Yokohama, Japan (together with Jia Jia)
PC Chair, PoS 2020: 11th International Workshop on Pragmatics of SAT,
Alghero, Italy (together with Daniel Le Berre)
- Senior PC Member, IJCAI-PRICAI 2020: 29th International Joint Conference on Artificial Intelligence and the 17th Pacific Rim International Conference on Artificial Intelligence
PC Chair, PoS 2019: 10th International Workshop on Pragmatics of SAT,
Lisbon, Portugal (together with Daniel Le Berre)
- Senior PC Member, IJCAI 2019: 28th International Joint
Conference on Artificial Intelligence
- Senior PC Member, AAAI 2019: 33rd
AAAI Conference on Artificial Intelligence
PC Chair, PoS 2018: 9th International Workshop on Pragmatics of SAT, Oxford, UK
(together with Daniel Le Berre)
- Senior PC Member, IJCAI 2016: 25th International Joint
Conference on Artificial Intelligence
- Guest Editor, Journal of Satisfiability,
Boolean Modeling and Computation,
Special Issue on the SAT 2014 Competitions and Evaluations, 2015
PC Chair, SAT 2013: 16th International Conference on Theory and
Applications of Satisfiability Testing, Helsinki, Finland (together with Allen Van Gelder)
- Co-organizer, SAT Race 2019
- Co-organizer, MaxSAT Evaluation 2019
- Co-organizer, SAT Competition 2018
- Co-organizer, MaxSAT Evaluation 2018
- Co-organizer, SAT Competition 2017
- Co-organizer, MaxSAT Evaluation 2017
- Co-organizer, SAT Competition 2016
- Co-organizer, SAT Competition 2014
- Local Chair, SAT 2013:
Conference on Theory and
Applications of Satisfiability Testing, July 8-12, 2013, Helsinki, Finland
- Co-organizer, SAT Competition 2013
- Co-organizer, SAT-SMT Summer School 2013
- Co-organizer, SAT Challenge 2012
- Local organizer, SWAT 2012:
13th Scandinavian Symposium and Workshops on Algorithm Theory, July 4-6, 2012, Helsinki, Finland
- Co-organizer, SAT Competition 2011
- Local Chair, JELIA 2010:
12th European Conference on
Logics in Artificial Intelligence,
September 13-15, 2010, Helsinki, Finland
- Organizer, HIIT Seminar Kumpula research seminar, 2010-2011
Reviewed scientific manuscripts for
- Journal of Artificial Intelligence Research - 2019, 2017, 2015
- Journal of Universal Computer Science - 2019
- Artificial Intelligence - 2018, 2015, 2014, 2013, 2012, 2011, 2010
- Annals of Mathematics and Artificial Intelligence - 2018, 2014
- International Journal of Approximate Reasoning - 2017
- Theory and Practice of Logic Programming - 2017, 2016
- IEEE Intelligent Systems - 2016
- Information Sciences - 2015
- Journal of Automated Reasoning - 2015
- Journal of Experimental and Theoretical Artificial Intelligence - 2014, 2013
- Journal on Satisfiability, Boolean Modeling and Computation - 2012, 2011
- AI Communications - 2010
- Journal of Logic and Computation - 2008
To prospective students: If you're interested in conducting research
aiming at a thesis under my guidance, feel free to contact me
via email. To get a feel for possible topic areas, see my research
interests above. You can also have a look at my publications.
Lectured (teacher-in-charge of) the following courses at the University of Helsinki:
- Bachelor's Thesis Project, spring 2020 (supervisor)
- Seminar on Model Checking (5 ECTS), autumn 2019
- Automated Logical Reasoning (5 ECTS), spring 2019
- Seminar on Discrete Algorithms (5 ECTS),
spring 2019 (with Juha Kärkkäinen and Veli Mäkinen)
- Combinatorial Optimization (5 ECTS), autumn 2018
- Seminar on Automated Planning (5 ECTS), autumn 2018
- Seminar on Applied Discrete Algorithms A (5 ECTS),
spring 2018 (with Juha Kärkkäinen and Veli Mäkinen)
- Bachelor's Thesis Project, spring 2018 (supervisor)
- Seminar on Computational Social Choice (3 ECTS),
MSc-level seminar course based on the recent Handbook of Computational Social Choice. Topics included voting theory,
fair allocation, coalition formation (matchings and hedonic games), and automated theorem discovery.
- Satisfiability, Boolean Modeling and Computation (5 ECTS),
Central computational aspects of SAT, focusing on techniques that are important for modern real-world applications of SAT. Topics included: basics of propositional logic and computation; modern SAT solver algorithms and search techniques; preprocessing; modelling real-world problems as SAT; building complex SAT-based procedures for Boolean optimization and other search problems beyond NP.
Seminar on Tractability (3 ECTS),
MSc-level seminar course based on the recent book Tractability: Practical Approaches to Hard Problems.
Fundamental concepts and state-of-the-art techniques to tame intractability. Topics included: tractability in terms of graphical structures underlying problems, language restrictions, approximation algorithms, and kernelization methods, as well as utilizing heuristics in modern SAT-solvers.
Satisfiability, Boolean Modeling and Computation (3 ECTS),
intensive course in May 2015
Central computational aspects of Boolean satisfiability (SAT), focusing on techniques that are important for modern real-world applications of SAT.
Constraint Solving Meets Machine Learning and Data Mining (3 ECTS),
A snapshot into the current state of forefront research in the intersection of constraint solving, machine learning and data mining.
Discrete Optimization Project (2 ECTS),
Independent hands-on project work in the areas of constraint satisfaction and discrete optimization, involving problem modelling, algorithm implementation, and/or practical performance evaluation of search and optimization algorithms within a chosen topic.
Discrete Optimization (3 ECTS),
Combinatorial search spaces and optimization problems. Exhaustive and heuristic methods. Linear and integer programming.
Seminar on Boolean Constraint Reasoning (3 ECTS),
Theoretical and applied aspects of Boolean satisfiability, SAT
solvers and their extensions.
Previously, I've been involved as TA on:
Advanced Course in Computational Logic,
Helsinki University of Technology, spring 2009,
Modal logics, applications of temporal logics (LTL, CTL) in concurrent and
Computational Complexity Theory,
Helsinki University of Technology, autumn 2008,
NP-completeness, randomized algorithms, cryptography, approximation
algorithms, parallel algorithms, polynomial hierarchy, PSPACE-completeness
Logic in Computer Science: Foundations,
Helsinki University of Technology,
Propositional logic and predicate logic, proof theory and
Introduction to Theoretical Computer Science Y,
Helsinki University of Technology,
Introduction to Theoretical Computer Science T
Finite automata and regular languages, context-free grammars and pushdown
automata, Turing machines
Seminar on Theoretical Computer Science,
Helsinki University of Technology,
Propositional Satisfiability Checking Techniques
Basic Course in Programming L1,
Helsinki University of Technology, autumn 2001