A Complexity Dichotomy for Semilinear Target Sets in Automata with One Counter I will introduce a generalised reachability problem in automata with one counter with a variety of semantics. The goal of the presentation is to outline what features of target sets makes reachability easy or (NP-)hard. About joint work with Yousef Shakiba and Georg Zetzsche. Automata in the Wild 2025 University of Warwick, UK Henry Sinclair-Banks, 01/04/25