Hans was part-time professor at iCIS within Software Science from 2007 until 2022. Additionally, he was an Associate Professor at the Technical University of Eindhoven.
Hans studied mathematics in Groningen and then obtained his Ph.D. in Amsterdam. After that, he worked for a while in industry and at the University of Utrecht before becoming an Associate Professor in Computer Science at TU Eindhoven in 2000. From 2007 until his retirement, he was a part-time professor at Radboud University,working one day a week.
Hans's expertise was in theoretical computer science: understanding and studying the mathematical structures that play a role in computer science. He was an internationally renowned researcher in the field of term rewriting and techniques and computer tools for automated theorem proving. In this area, he set up the course "Automated Theorem Proving" at Radboud University and taught it for many years, and he also redesigned and enthusiastically taught the course "Complexity." Hans was a sharp thinker who strived for clarity in definitions and mathematical proofs. Additionally, Hans had a great fondness for puzzles and games and how to model and program them with smart computer techniques. This led to the beautiful book "Playing with Infinity," published right after his retirement. He was an inspiring teacher who guided many students and made significant contributions to the field with his insights.
Our condolences go out to his wife Tineke, his children Marieke and Wouter, and other relatives. We wish them much strength.