I am deeply saddened to learn that Håkan Kjellerstrand passed away on February 10. Håkan, a dedicated professional software engineer, played an important role in shaping the Picat language and system from its earliest days. He wrote more than a thousand Picat programs, and contributed countless suggestions and bug reports. He also co-authored several publications on Picat, including the book "Constraint Solving and Planning with Picat". In addition, he generously provided timely and thoughtful responses to questions on the newsgroup. His passing is a tremendous loss to the Picat community, and he will be remembered for his contributions, generosity, and passion.
Best regards,
Neng-Fa