  This volume contains the proceedings of EXPRESS/SOS 2019: the Combined 26th
International Workshop on Expressiveness in Concurrency and the 16th Workshop
on Structural Operational Semantics, which was held on August 26, 2019, in
Amsterdam (The Netherlands), as an affiliated workshop of CONCUR 2019, the 30th
International Conference on Concurrency Theory.
  The EXPRESS/SOS workshop series aims at bringing together researchers
interested in the formal semantics of systems and programming concepts, and in
the expressiveness of computational models.
