مؤلف: Donald Sannella

The first author is a professor of computer science at the University of Edinburgh. His key research area is foundations for specification and formal development of modular software systems from specifications, with applications to computer security and programming languages; among other responsibilities, he is the Editor-in-Chief of the journal Theoretical Computer Science and Vice President of the European Association for Theoretical Computer Science. The second author is a professor of computer science at the University of Warsaw, and also at the Institute of Computer Science of the Polish Academy of Sciences. His research mainly concerns foundations for specification and formal development of modular software systems from specifications, semantics, and relevant aspects of logic, universal algebra and category theory; among other responsibilities, he is the Editor-in-Chief of the journal Information Processing Letters. They have each chaired major conferences in software engineering and theoretical computer science, and have served on the steering and program committees of the main events related to the topic of this book.