Henry Sinclair-Banks, a PhD student in the the Theory and Foundations (FoCS) Research Group and the Centre for Discrete Mathematics and its Applications (DIMAP), has won a Best Paper Award at ICALP 2023, the 50th EATCS International Colloquium on Automata, Languages and Programming. ICALP is the main conference and annual meeting of the European Association for Theoretical Computer Science (EATCS).

Henry's paper, co-authored with researchers from Germany and Poland: Marvin Künnemann, Filip Mazowiecki, Lia Schütze, and Karol Węgrzycki, addresses the coverability problem in vector addition systems (VASS), a well-known model of concurrent systems. Coverability is an algorithmic problem for the verification of "safety properties": whether the system always avoids a set of bad states. Henry and his co-authors determine how much time is required to solve this problem in the worst case. They develop an algorithm that improves upon the state of the art that has stood for forty years. They also prove that, in several settings, it is impossible to decide coverability substantially faster, unless there is also a faster algorithm for a classic problem such as Boolean satisfiability (SAT) and finding cycles of fixed length in graphs.

In total, 5 Warwick papers will appear at this year's ICALP:

• Michael Benedikt, Dmitry Chistikov, and Alessio Mansutti, "The complexity of Presburger arithmetic with power or powers",
• Sam Coy, Artur Czumaj, Peter Davies, and Gopinath Mishra, "Optimal (degree+1)-coloring in congested clique",
• Charilaos Efthymiou and Weiming Feng, "On the mixing time of Glauber dynamics for the hard-core and related models on G(n,d/n)",
• Marvin Künnemann, Filip Mazowiecki, Lia Schütze, Henry Sinclair-Banks, and Karol Węgrzycki, "Coverability in VASS revisited: Improving Rackoff's bound to obtain conditional optimality",
• Konstantinos Zampetakis and Charilaos Efthymiou, "Broadcasting with random matrices".

This July's ICALP will be the 50th edition of the conference.