Jan Willem Klop (19 December 1945 - 28 September 2025)

It is with deep sadness that we announce the passing of  Prof. dr. J.W. (Jan Willem) Klop at the age of 79 on 28 September 2025. 

Jan Willem Klop was a distinguished scientist renowned for his foundational work in various aspects of the theory of computation. Thanks to his efforts in 2003 a multi-authored 900-page book, 'Term Rewriting Systems,' appeared, of which he was the main author. The book's review in the Journal of Functional Programming noted that it is 'a compulsory reference for anyone working in the area.'