 Joseph Gogan was a wonderful person and an amazing and inspirational advisor. He invented three major areas of computer science. One is what we call today the initial algebra semantics, which is also what K builds upon. Another is the theory of institutions, which allows you to take any logical system and regard it as an instance of a very general concept called an institution. And then you can build specifications and reason about them in a very general way using institutions. And another one is a security model that he created together with Jose Mezeguer, who is the creator of the mod language that is also a precursor of K. And not to mention that both of them, Gogan and Mezeguer, they created, together with other collaborators, they created the OBJ language, which was one of the first algebraic specifications languages out there. And if Gogan were alive now and he saw K, he would say, wow, this is like an OBJ++ sort of framework. So I owe a lot to Joseph Gogan. I learned many things from him, not necessarily always technical, sometimes even just how to do things, how to approach hard problems. And most importantly, I think what I learned from him is what not to work on, because it's very tempting to work on any problem that makes sense and you feel like you can solve it. And he had a big influence on me, on how I approach the problems I work on. Basically to go for the big fish all the time, think what is the biggest thing that you can do in your area, in what you work on. And once you crystallize it in your mind, then you start wondering why should I work on anything else? Then if this is the biggest thing that can happen and if I believe that I can do it, why should I work on anything else? And I keep thinking about it all the time. Each time I start working on a problem, which is tempting but not really important, I find the energy to put it aside and work on the important problem. And I remember those nights in San Diego, on the beach, in La Jolla beach, we were walking and talking and stopping once in a while in some cafes or restaurants. When he infused in my brain this idea of a universal language framework where programming languages should be nothing but mathematical theories, same like any other mathematical theory. You just have a syntax and you have some axioms and that's your theory. And you can reason about objects, mathematical objects in that theory using a general machinery. That's how we do proofs in first of the logic, in other logics. So programming languages should be no different. And I was sold. I like that so much. It was that aha moment when I realized that that's what I want to do if it were possible. Could be very hard. Maybe it's impossible to do now. But that's what I did actually since I started my post-doctoral career. I just tried to achieve this vision where you can have a universal framework for programming languages. Where programming languages are like mathematical theories and where program verification is like doing proofs in those mathematical theories, same like we did for thousands of years in mathematics. That inspired me and stayed with me all my life. And I would say that K would have never been there without his influence.