It will be my great pleasure and honour to edit the Automata Column in the SIGLOG Newsletter. Here is my first proposal: an admireable article by Shaull Almagor on recent breakthrough results concerning determinisation of tropical weighted automata.
POPL (Principles of Programming Languages) took place from January 11 to 17 in Rennes, the capital city of Brittany in France, bringing together about 700 attendees from 38 countries over seven days. The conference took place at the Jacobins Convent in the city center of Rennes, a historic site that has been recently renovated and converted into a convention center.
Dear Colleagues, The letter from the chair this time comes from not one, but two chairs. This is because we are in the process of transition. Catuscia Palamidessi is stepping down from the role of SIGLOG chair after years of important service. As Catuscia reported in the January issue of this newsletter, the financial crisis that had preoccupied us for some time has been resolved with an agreement with ACM that balances the SIGLOG overhead charges with its income from the ACM digital library. With this difficulty behind us, it is time to look forward and rebuild SIGLOG. With this in mind, a nominating committee chaired by Moshe Vardi proposed Anuj Dawar for the role of chair and Prakash Panangaden for the role of vice-chair. They stepped into these roles in May 2026. Sandra Alves and Elaine Pimentel continue in their roles as Secretary and Treasurer respectively.
We survey the history of the determinizability problem for min-plus (tropical) weighted automata. Traditional automata accept or reject their input, and are therefore Boolean, in the sense that their language is a function L : Σ * → {0, 1}. They are well-understood, and have provided the theoretical basis for many applications, most notably in formal verification. However, today's rich systems and properties are often unsuitable to model with Boolean models, mostly due to the presence of quantitative elements, such as energy, probability, counters, etc.
April 2026 edition of SIGLOG Monthly, featuring deadlines, calls and community announcements.
In 2025, for the first time in their respective histories, the two leading ACM SIGPLAN venues—ICFP (the International Conference on Functional Programming) and SPLASH (Systems, Programming, Languages and Applications: Software for Humanity)—were co-located as a single joint event. ICFP/SPLASH 2025 took place from October 12 to 18, 2025, in Singapore, bringing together over 900 attendees from more than 40 countries over seven days—making it one of the largest SIGPLAN events in recent memory.
January 2026 edition of SIGLOG Monthly, featuring deadlines, calls and community announcements.
Cambridge University Press has recently published my book, "Proof Theory and Logic Programming: Computation as Proof Search" (December 2025). A preprint of the full text is available for download [1].
Dear SIGLOG Members, Happy New Year 2023! May the New Year fulfill your plans and dreams, and bring you success in your professional and personal life.
Approximation algorithm and limits of approximation is one of the major topics in algorithms, complexity theory, and computer science in general. The area uses multiple algorithmic techniques such as Semidefinite Programming (SDP), as well as advanced tools of proving inapproximabily, one of the most important of which is the PCP Theorem. The overall goal is, of course, to determine the best attainable approximability ration and provide an algorithm capable of achieving this ratio. Unconditional inapproximability results are generally very difficult, which prompted the use of the Unique Games Conjecture (UGC) introduced by S.Khot that posits the inapproxibality of a certain basic problem. The UGC, as well as the majority of the problems researchers are focusing on can be formulated withing the general framework of the Constraint Satisfaction Problem (CSP).
It is a great pleasure to introduce this paper by my old friend Glynn Winskel. Game semantics has been growing vigorously since the early 2000's with the breakthrough work of Abramsky, Jagadeesan and Malacaria and Hyland and Ong as well as Hanno Nickau on capturing the notion of sequentiality in functional programming languages. Many extensions appeared in the following years capturing concepts like nondeterminism, state and control flow. More recently Abramsky and his collaborators have developed the notion of game comonads and made connections with complexity theory; this was the subject of an earlier article in this column.
The 44th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2024) was held during the period of December 16–18, 2024, in Gujarat, India. The venue was the 400-acre campus of Indian Institute of Technology Gandhinagar, situated on a bank of the Sabarmati river, opposite to the city of Gandhinagar situated on the other bank of the river. During the conference, the participants could enjoy pleasant sunny weather, and very hospitable reception of the local organisers. Great thanks to the organising team at IIT Gandhinagar for their fantastic work, especially to the Chair, Neeldhara Misra.
This article discusses distributed/concurrent games and strategies, their past and possible future developments in computation, logic and game theory.
April 2025 edition of SIGLOG Monthly, featuring deadlines, calls and community announcements.
The 5th Ph.D. School in the series of Foundations of Programming and Software Systems took place in Copenhagen from October 14 to October 18, 2024 under the title "Probability in Computer Science". This week-long event brought together around 75 participants, including PhD students and leading experts from computer science, but also from other fields such as mathematics and engineering, to explore relevant topics in various areas in computer science that encounter probabilities. Organized by Joost-Pieter Katoen from RWTH Aachen University, and Andrzej Wasowski and Raúl Pardo from the IT University of Copenhagen, the school combined a rich academic program with engaging social activities, allowing the participants to connect, exchange ideas, and discuss various research topics.
January 2025 edition of SIGLOG Monthly, featuring deadlines, calls and community announcements.
Constraint Satisfaction Problems (CSPs) have long been a central topic in theoretical computer science, offering a rich and historically significant field of study, particularly from the perspectives of checking satisfiability in polynomial time and designing approximation algorithms. This survey explores past and recent advances in understanding the approximability of CSPs, highlighting key breakthroughs and challenges that have emerged along the way. We discuss the connections approximability of CSPs share with other areas of mathematics, such as combinatorics, analysis, and algebra. Finally, this article provides open questions and future directions in the area of approximation of CSPs and closely related problems.
October 2024 edition of SIGLOG Monthly, featuring deadlines, calls and community announcements.
The Women in Logic Workshop (WiL) aims to increase awareness of the valuable contributions made by women in logic. Its primary goal is to promote excellent research led by women, ultimately increasing their visibility and representation within the community.
