Dear all, Like so many of you I am deeply saddened by Thomas’ passing. As part of his position in Darmstadt, he could always hire a PhD or postdoc, and from 2006 - 2011 I was the lucky one. I arrived just after finishing my PhD and through Thomas I discovered many new areas of logic and category theory. I could walk into his office at any time and start talking about anything and before you knew it, hours had passed and we had touched upon anything from mathematics to philosophy, politics, food, literature and life in general. You got the impression he had studied everything. And not just that, he had also developed his own distinctive opinion about the topic. He would be very fond of unorthodox ideas and would often start a discussion with ``It is probably a complete waste of time, but…’’ and then launch into another fascinating digression. I start this year with the feeling that I have lost a dear colleague and a dear friend. I will miss his deep knowledge of the areas of mathematics he was so fond of and I came to love as well. I will miss the diners, the drinks and the conversation. I am glad to have been given the opportunity to have spent all these happy times with Thomas, but also very sad to realise these have now come to the end. I offer my condolences to all his colleagues, friends and family, and especially his wife Eva. Best wishes, Benno Op zo 5 jan 2025 om 14:55 schreef Paul Levy <p.b.levy@bham.ac.uk<mailto:p.b.levy@bham.ac.uk>>: Correction: it was not Martin Escardo but Steve Awodey who said “He knew about univalence before it was called that.” Paul From: Paul Levy <p.b.levy@bham.ac.uk<mailto:p.b.levy@bham.ac.uk>> Date: Sunday, 5 January 2025 at 00:31 To: categories@mq.edu.au<mailto:categories@mq.edu.au> <categories@mq.edu.au<mailto:categories@mq.edu.au>> Subject: Re: Thomas Streicher This is really sad news. He was such a great person to talk to and made so many contributions. Martin Escardo said that Thomas knew about the Univalence axiom before it had a name. He also was the first to formulate a version of the WISC axiom: https://ncatlab.org/nlab/show/WISC I would also like to mention his work on control operators, with Martin Hofmann and Bernhard Reus, which I found illuminating in my PhD work. Paul From: Oosten, J. van (Jaap) <J.vanOosten@uu.nl<mailto:J.vanOosten@uu.nl>> Date: Friday, 3 January 2025 at 11:49 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 CAUTION: This email originated from outside the organisation. Do not click links or open attachments unless you recognise the sender and know the content is safe. 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>