Working group Pole Algorithms and discrete structures Pole Automata, structures and verification Thematic team Automata and applications Thematic team Theory and algorithmics of graphs Manage talks Graphs and Logic Day, hour and place Wednesday at 1:30pm, room 3052 The calendar of events (iCal format). In order to add the event calendar to your favorite agenda, subscribe to the calendar by using this link. Contact(s) Hector Buffiere Giannos Stamoulis This working group aims to exchange and collaborate around problems linking model theory and structural graph theory. It is structured around a monthly seminar of two presentations and weekly working meetings on research questions. Next talk Graphs and Logic Wednesday April 30, 2025, 1:30PM, Salle 1021 Sylvain Schmitz (IRIF) Well quasi-orders and preservation theorems for First-Order Logic - Part II Continuation of part I. I intend to cover applications of WQOs in algorithmic graph theory, a focus on classes of graphs that are well-quasi-ordered by the induced subgraph ordering, along with Pouzet’s Conjecture, the generalisation to preservation properties in first-order logic. Previous talks Year 2025 Graphs and Logic Wednesday March 26, 2025, 1:30PM, salle 3052 Sylvain Schmitz; Giannos Stamoulis Well quasi-orders and preservation theorems for First-Order Logic; Some extensions of First-Order logic on graphs This will be a gentle tutorial on mostly standard results about well-quasi-orders (wqo) in a context of graph theory and algorithmic meta-theorems. I intend to cover a few basics of wqo theory, their applications in algorithmic graph theory, a focus on classes of graphs that are well-quasi-ordered by the induced subgraph ordering, along with Pouzet's Conjecture, and finally the generalisation to preservation properties in first-order logic. . In this tutorial we present a landscape of extensions of first-order logic (on graphs) and we discuss their expressive power and algorithmic results related to them. These extensions involve either additional predicates expressing different types of connectivity or the quantification over vertex sets that are (in a sense) of simple structure.