From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/10735 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Robin Cockett Newsgroups: gmane.science.mathematics.categories Subject: Re: Pieter Hofstra Date: Wed, 4 May 2022 21:11:10 +0000 Message-ID: References: Reply-To: Robin Cockett Mime-Version: 1.0 Content-Type: text/plain; charset="iso-2022-jp" Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="16686"; mail-complaints-to="usenet@ciao.gmane.io" To: Philip Scott , categories net Original-X-From: majordomo@rr.mta.ca Thu May 05 02:34:24 2022 Return-path: Envelope-to: gsmc-categories@m.gmane-mx.org Original-Received: from smtp2.mta.ca ([198.164.44.40]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nmPRo-00048G-EY for gsmc-categories@m.gmane-mx.org; Thu, 05 May 2022 02:34:24 +0200 Original-Received: from rr.mta.ca ([198.164.44.159]:59070) by smtp2.mta.ca with esmtp (Exim 4.80) (envelope-from ) id 1nmPQv-0006g8-8y; Wed, 04 May 2022 21:33:29 -0300 Original-Received: from majordomo by rr.mta.ca with local (Exim 4.92.1) (envelope-from ) id 1nmPQZ-0008K3-6N for categories-list@rr.mta.ca; Wed, 04 May 2022 21:33:07 -0300 In-Reply-To: Accept-Language: en-US Content-Language: en-US Precedence: bulk Xref: news.gmane.io gmane.science.mathematics.categories:10735 Archived-At: This is very sad news indeed. Pieter was a postdoc with me at Calgary 200= 5/6 before he moved (back) to Ottawa as a member of faculty. While in Cal= gary he developed with me the theory of Turing categories (abstract computa= bility). Subsequently, we kept in touch and he was a frequent visitor at = our home: I valued him not only as a colleague but also as a friend. Pieter was very popular amongst the mathematicians at Calgary as he gave in= credibly clear well-organized seminars on a wide variety of topics. He was= also, for the same reason, a very popular teacher. While at Calgary, Pieter supplemented his meager postdoc salary in a rather= unusual way. He would play poker on-line. He was incredibly disciplined = about it ... and invariably walked away with a profit. To him it all seem= ed very simple! When he moved to Ottawa he started a course in gaming whi= ch I understand was very popular (although I rather doubt whether his stude= nts could bring the same discipline to it as Pieter). I will miss him. -robin (Robin Cockett) ________________________________ From: Philip Scott Sent: Tuesday, May 3, 2022 12:32 PM To: categories@mta.ca Cc: Philip Scott Subject: categories: Pieter Hofstra [=1B$B"$=1B(BEXTERNAL] It is with great sadness that we announce that our dear friend and colleague Pieter Hofstra (1975-2022) passed away unexpectedly on May 1. Pieter obtained his PhD from Utrecht University, under Jaap van Oosten, studying realizability toposes. His research interests included general topos theory, realizability, inverse semigroups and groupoids, abstract computability, and homotopy type theory. Among his recent works, with J. Funk he introduced the notion of isotropy groups of toposes, which he was actively developing with students and colleagues. While Pieter was a brilliant researcher, a kind teacher and a caring supervisor, we will most remember him as a friend. When we have any details for a memorial service, we will pass them along. Richard Blute, Simon Henry, Philip Scott (University of Ottawa) [For admin and other information see: http://www.mta.ca/~cat-dist/ ]