Hi! I haven't organised a seminar for today. However, tomorrow morning Ryuya Hora will be back at LIPN to present some of his work, which is both topos-theoretic and involves monoid actions. Here are the details: Salle B107, bâtiment B, Université de Villetaneuse 05/06/2025 10:30 - 12:00 Titre: Local state classifier for automata theory Résumé : The notion of a local state classifier was introduced in the context of Lawvere's first open problem in topos theory. Although this problem itself has already been resolved, the idea of local state classifiers -- defined as colimits of all monomorphisms -- has potential applications in more general categorical frameworks beyond topos theory. In this talk, I will not delve into the technical details of topos theory. Instead, I will focus on explaining the definition and core idea of the local state classifier through simple examples. At the end of the presentation, I will briefly introduce my research on a topos-theoretic approach to automata theory, which is based on the fact that the local state classifier of the category of word actions PSh(\Sigma*) is given by word congruences. The BBB link will be the following: https://bbb.lipn.univ-paris13.fr/b/sei-eer-t24 code accès: 757416 See you tomorrow if you can make it! Morgan