Glabbeek, Rob VanHofner, PeterHorne, Ross2025-05-232025-05-2397816654489561043-6871ORCID:/0000-0002-2141-5868/work/162369903http://www.scopus.com/inward/record.url?scp=85113902976&partnerID=8YFLogxKhttps://hdl.handle.net/1885/733752617We investigate how different fairness assumptions affect results concerning lock-freedom, a typical liveness property targeted by session type systems. We fix a minimal session calculus and systematically take into account all known fairness assumptions, thereby identifying precisely three interesting and semantically distinct notions of lock-freedom, all of which having a sound session type system. We then show that, by using a general merge operator in an otherwise standard approach to global session types, we obtain a session type system complete for the strongest amongst those notions of lock-freedom, which assumes only justness of execution paths, a minimal fairness assumption for concurrent systems.enPublisher Copyright: © 2021 IEEE.2021-06-2910.1109/LICS52264.2021.947053185113902976