Dirk HofmannDirk Hofmann is an Assistant Professor at the University of Aveiro, Portugal. He received his PhD from the University of Bremen (Germany) in 1999. His research interests focus on the development and application of categorical methods in mathematics, rimarily in algebra and topology, but also in logic and computer science. Over the past ten years he has contributed significantly to the development of the theory presented in this book, and beyond. He is also well known for his contributions to duality theory. Read More Read Less