Unifying Theories of Programming 7th International Symposium, UTP 2019, Dedicated to Tony Hoare on the Occasion of His 85th Birthday, Porto, Portugal, October 8, 2019, Proceedings - Ribeiro, Pedro; Ribeiro, Pedro; Sampaio, Augusto; Sampaio, Augusto (Springer International Publishing : Imprint: Springer, 2019)