Dear Category Theorists, In summer 2019, after a career in Mathematics and Computer Science spanning more than thirty years, our friend and colleague John Power will retire and return to Australia. John has advanced our understanding of many topics in his career, including coherence problems, algebraic theories, algebraic effects in computation, and logic programming. He has been instrumental in introducing and promulgating the effective use of categorical methods in computer science. As important as John’s academic qualities, he has also been a wonderful colleague. John has been an amazing mentor, supporter and friend to many of us and in particular to younger academics. We have all been touched by his kindness and his humour. To celebrate all of John’s achievements, and to inspire further work, we will hold a small informal workshop at the University of Bath where John has worked for the last decade, with confirmed attendance from several of his collaborators, including Martin Hyland, Ekaterina Komendantskaya, Paul Levy, Edmund Robinson and Pino Rosolini. We are looking for further talks and John has indicated he would particularly like to encourage younger members of the academic community to volunteer talks. Attendance is free. There is no formal registration process, but we do plan to supply tea and coffee, so to help us gauge numbers please follow the instructions below. Please, also forward to others who might be interested. Date: Thursday 27 June Location: University of Bath, England Action: Please send an email to Guy McCusker (g.a.mccusker@bath.ac.uk<mailto:g.a.mccusker@bath.ac.uk>) if you plan to attend and indicate if you would like to give a talk Details: We will update the web page http://www.cs.bath.ac.uk/~gam23/JohnPowerWorkshop/ All the best Guy McCusker and Neil Ghani [For admin and other information see: http://www.mta.ca/~cat-dist/ ]