Todd Schmidan Assistant Professor in the Computer Science Department of St. Mary's College of California. They are generally intereted in the algebraic, coalgebraic, and logical foundations of program semantics, and recently completed a PhD as a part of the PPLV group in the Computer Science Department of University College London. Today Todd joined us to talk about coequations, a fascinating (categorical) subject relating to the how we add algebraic structure to a space, how we think about relationships between spaces, and more. It turns out that coequations show up all over the place -- in DFAs, Markov chains, various PL concepts, etc. -- and so this is a place where the more abstract categorical stuff turns out to be really useful and illuminating for fairly concrete computer science ideas. Plus, coequations are just plain neat! We were really lucky to steal a little over an hour of Todd's time on this beautiful Saturday and we hope you enjoy the talk as much as we did.