This volume constitutes revised selected papers from the four workshops collocated with the 19th International Conference on Software Engineering and Formal Methods, SEFM 2021, held virtually during December 6-10, 2021. The 21 contributed papers presented in this volume were carefully reviewed and selected from a total of 29 submissions. The book also contains 3 invited talks. SEFM 2021 presents the following four workshops: CIFMA 2021 - 3rd International Workshop on Cognition: Interdisciplinary Foundations, Models and Applications;CoSim-CPS 2021 - 5th Workshop on Formal Co-Simulation of...