Dear Jaap, I was not closed to Thomas Streicher but I remember a warm person with a great passion for logic and category theory. His work with Martin Hofmann on the groupoid model of Martin-Lof type theory was a precursor of the homotopy models of Awodey-Warren and Voevodsky. He took seriously the work of Benabou on fibered categories and he applied it successfully to type theory. Jonathan Weinberger, his last student, has great contributions to simplicial homotopy theory. We will miss him. André Joyal ________________________________ De : Bernhard Reus <bernhard@sussex.ac.uk> Envoyé : 3 janvier 2025 09:36 À : Oosten, J. van (Jaap) <J.vanOosten@uu.nl>; categories@mq.edu.au <categories@mq.edu.au> Objet : Re: Thomas Streicher Thomas was not only a brilliant type theorist, category theorist and mathematician, as many already pointed out, he was also very generous with his time, happy to discuss any topic he was interested in. He was like a walking lexicon. I am devastated. It was him who introduced me to type theory and constructivism, changing the course of my PhD, eventually co-supervising it. Thomas had a massive impact on my life, more than he will ever know now. I am immensely grateful to have had the privilege to work with him. It was great fun writing papers with him, then afterwards going for a nice meal. Those were good times, back then in Passau and Munich in the 90es. As a PhD student, I remember going into his office to ask a question, coming out, hours later, with many new questions to think about. Amazed and bedazzled by what I just heard. His great sense of humour and passion for the subject was second to none. At conferences, there were always colleagues queueing to have a chat with him. When they made Thomas, they broke the mould. Like Jaap, I mourn a great friend. My heart goes out to Eva, his wife, and all his friends and family. Bernhard ________________________________ From: Oosten, J. van (Jaap) <J.vanOosten@uu.nl<mailto:J.vanOosten@uu.nl>> Sent: Friday, January 3, 2025 11:47 am To: categories@mq.edu.au<mailto:categories@mq.edu.au> <categories@mq.edu.au<mailto:categories@mq.edu.au>> Cc: Oosten, J. van (Jaap) <J.vanOosten@uu.nl<mailto:J.vanOosten@uu.nl>> Subject: Thomas Streicher I just received information that Thomas Streicher passed away yesterday. Thomas fell ill last September, when he could not attend Pino Rosolini's retirement party due to pneumonia; then it turned out he has metastases in the lungs from a pancreatic cancer. After several chemo treatments his situation suddenly worsened, and yesterday he died, peacefully, without pain. Thomas was 66 years old. In Thomas, we mourn a logician and category theorist of exceptional calibre. Let me just recall that in 2011, during an Oberwolfach meeting, Vladimir Voevodsky praised Thomas' work on type theory as a paradigm of precision. But I personally mourn a friend. A warm person with many interests. I wish strength to his wife Eva, and his family. Jaap van Oosten You're receiving this message because you're a member of the Categories mailing list group from Macquarie University. To take part in this conversation, reply all to this message. View group files | Leave group | Learn more about Microsoft 365 Groups You're receiving this message because you're a member of the Categories mailing list group from Macquarie University. To take part in this conversation, reply all to this message. View group files<https://outlook.office365.com/owa/categories@mq.edu.au/groupsubscription.ashx?source=EscalatedMessage&action=files&GuestId=6bf90c14-94d1-45b7-a0b5-9dd447734d27> | Leave group<https://outlook.office365.com/owa/categories@mq.edu.au/groupsubscription.ashx?source=EscalatedMessage&action=leave&GuestId=6bf90c14-94d1-45b7-a0b5-9dd447734d27> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>