Foundations of Software Science and Computation Structures 20th International Conference, FOSSACS 2017, Held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2017, Uppsala, Sweden, April 22-29, 2017, Proceedings - Esparza, Javier; Murawski, Andrzej S. (Springer Berlin Heidelberg : Imprint: Springer, 2017)