October 2023 - Categories - categories.org.au

Re: "First" use of 'Category theory' to describe our field
by David Roberts 24 Feb '24

24 Feb '24

Dear Ross, no, that's pretty good! It's mildly surprising that it took ~20 years for the name to 'stick', but maybe less so given that the field grew slowly to start. Thanks, David David Roberts Webpage: https://ncatlab.org/nlab/show/David+Roberts Blog: https://thehighergeometer.wordpress.com On Thu, 11 Jul 2019 at 08:21, Ross Street <ross.street(a)mq.edu.au> wrote: > > Dear David > > From memory, the Pure Mathematics Honours (USyd) course that Max Kelly taught in 1965 > was called ``Category Theory''. It concentrated on different kinds of morphisms > and factorizations in a category, and finished with adjoint functors. > Also John Gray's (UIllinois) 1968-69 graduate course had that name. > > From Eilenberg I heard that each person using categories should have their own category of expertise. > I told this to John Gray who said that was fine; the time had come for that category to be Cat. > > I would suggest that the first category theorists to think of themselves as such were Eilenberg's students at Columbia. > However, Mac Lane was definitely a category theorist. > > This is probably not the verifiable stuff you were seeking. > > Ross > > > On 10 Jul 2019, at 10:01 PM, David Roberts <droberts.65537(a)gmail.com> wrote: > > Hi all, > > the (idle) question is: when did the phrase 'category theory' catch on > for the field? Clearly it didn't leap from either of the heads of > Eilenberg or Mac Lane full-grown, since they used the phrase 'General > theory of natural equivalences'. There are the old 'Reports of the > Midwest Category Seminar' lecture notes (the first in 1967), which > hints that 'category theory' wasn't quite the name in use. > > Even more interesting: who was the first "category theorist", by that name? > > Answers referring to verifiable sources would be best. > > Thoughts? > > David > > > > David Roberts > Webpage: https://ncatlab.org/nlab/show/David+Roberts > Blog: https://thehighergeometer.wordpress.com > [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Thanks for this.
by Michael Barr, Prof. 07 Nov '23

07 Nov '23

Partly, I am responding to this to train my mailer, but also some information. After Marta Bunge her web site disappeared. I wrote to our chairman a month ago asking if this was department policy and would mine disappear when I did. He has not bothered to respond so I guess I know the answer. The site is math.mcgill.ca/barr and it contains essentially all my published papers and books including the two with Charles. There is one new thing added: my original thesis, retyped. It is really mainly of historical interest. The main result is the direct construction of the shuffle idempotents in dimensions 2,3,4. Since a later paper found an inductive definition for all n, this is probably not interesting. Any idea why Mount Alison shut down the list? Computer storage is so cheap these days it hardly seems worth the effort. Michael 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.as…> | Leave group<https://outlook.office365.com/owa/categories@mq.edu.au/groupsubscription.as…> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>

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Signing off
by Bob Rosebrugh 03 Nov '23

03 Nov '23

Dear Colleagues, >From March 1990 until recently it was my privilege to moderate the categories mailing list. For a couple of years it has been my intention to pass the list to a new moderator, but I was too slow to act. Changes to IT service at my former employer, Mount Allison University, abruptly made it impossible for me to continue running the list. Those changes were unexpected for me, but I have been away from the campus for over three years and was not aware. The IT staff at Mount Allison have always been very supportive of the list and I thank them for their more than three decades of generous assistance. It is a reassuring pleasure to know that the list is now in the capable hands of JS Lemay who kindly accepted the invitation to revive it. I am very grateful. Moreover, there is no one better suited to the role and our community is fortunate to have him moderating. I am also very happy that the new home of the list is Macquarie. Best wishes to everyone. I am hoping to see many of you in the not distant future, Bob Rosebrugh ---------- You're receiving this message because you're a member of the Categories mailing list group from Macquarie University. Leave group: https://outlook.office365.com/owa/categories@mq.edu.au/groupsubscription.as…

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Workshop on Fixed Points in Computer Science -- Call for Contributions
by JS Lemay 01 Nov '23

01 Nov '23

[[Sent on behalf of alexis.saurin(a)irif.fr -- the following message was sent to the old mailing email]] === Call for contributions === Workshop on Fixed Points in Computer Science 19 & 20 February 2024 https://www.irif.fr/users/saurin/fics2024/index.html<https://www.irif.fr/users/saurin/fics2024/index.html> This year, FICS workshop (Workshop on Fixed Points in Computer Science) will take place in Naples on the 19th and 20th of February, 2024, affiliated with CSL 2024 (https://csl2024.github.io/Home/<https://csl2024.github.io/Home>). == NEWS == * Program committee is announced below; * Workshop proceedings containing the extended abstracts will be published as an EPTCS volume; * CFP available at: https://www.irif.fr/users/saurin/fics2024/cfp.html;<https://www.irif.fr/users/saurin/fics2024/cfp.html;> * Easychair submission link: https://easychair.org/conferences/?conf=fics2024<https://easychair.org/conferences/?conf=fics2024> == Important dates and practical details== - Submission deadline for short and extended abstracts: 1 December 2023; - Notification: 21 December 2023; - Workshop: 19 and 20 February 2024. Submission link: https://easychair.org/conferences/?conf=fics2024<https://easychair.org/conferences/?conf=fics2024> Registration will be handled by CSL 2024 (details to come). Online participation will be possible with a reduced registration fees, but at least an author of each abstract will have to register with on-site fees. == About FICS workshop series == The goal is to bring together people from different subfields such as algebra/coalgebra, verification, logic, around the thematic of fixed points. Fixed points play a fundamental role in several areas of computer science. They are used to justify (co)recursive definitions and associated reasoning techniques. The construction and properties of fixed points have been investigated in many different settings such as: design and implementation of programming languages, logics, verification, databases. == Scope == Topics include, but are not restricted to: - fixed points in algebra and coalgebra - fixed points in formal languages and automata - fixed points in game theory - fixed points in programming language semantics - fixed points in proofs - fixed points in the mu-calculus and modal logics - fixed points in process algebras and process calculi - fixed points in functional programming and type theory - fixed points in relation to dataflow and circuits - fixed points in automated theorem proving, interactive theorem proving and logic programming - fixed points in finite model theory, descriptive complexity theory, and databases - fixed points in category theory for logic in computer science == Types of submissions == This year, we welcome two categories of submissions, short abstracts as well as extended abstracts: - Both types of submissions will be handled via Easychair and will be peer-reviewed by the PC. - In order to submit a short or extended abstract to FICS, please visit the following link: https://easychair.org/conferences/?conf=fics2024<https://easychair.org/conferences/?conf=fics2024> - A proceedings volume gathering the extended abstracts will be published by EPTCS shortly after the workshop (see details below). Here are details on each type of submission: - **short abstracts** are abstracts of **3 to 5 pages, references included**, describing the topic of the proposed contributed talk. They may contain (i) new completed results, (ii) work in progress or (iii) already (recently) published or submitted works. The submission can refer to a published paper or a preprint but the description given in the short abstract should be sufficiently detailed for the PC to judge the relevance of the proposed talk to the workshop program. - **extended abstracts** are papers of **6 to 10 pages, references excluded**, describing original results which have not been published nor are currently submitted elsewhere. The results must be presented in sufficient details to constitute a scientific publication. An appendix can provide additional details for the reviewer but will be read at the discretion of the reviewers. A volume of proceedings containing the **extended abstracts** will be published soon after the workshop by EPTCS: the authors of extended abstracts will be asked to submit a revised version few weeks after the event, allowing them to take into account the workshop discussions. Details will be released later. == Program Committee == - Zena Ariola (University of Oregon, USA) - Abhishek De (University of Birmingham, UK) - Zeinab Galal (UniversitÃ degli sutdi di Bologna, Italy) - Guilhem Jaber (UniversitÃ© de Nantes, France) - Ekaterina Komendantskaya (Heriot-Watt University, UK) - Denis Kuperberg (CNRS & ENS Lyon, France) - Martin Lange (University of Kassel, Germany) - Christine Paulin-Mohring (UniversitÃ© Paris Saclay, France) - Daniela Petrisan (UniversitÃ© Paris CitÃ©, France) - Alexis Saurin (CNRS & UniversitÃ© Paris CitÃ©, France), PC Chair - Thomas Studer (University of Bern, Switzerland) - Tarmo Uustalu (Reykjavik University, Iceland) - Yde Venema (University of Amsterdam, Netherland) == Journal publication == Depending on the number and quality of submissions, we will plan a subsequent special issue of a journal, as often done for previous editions of the workshop. == Contact == Alexis Saurin, alexis.saurin(a)irif.fr https://www.irif.fr/users/saurin/index<https://www.irif.fr/users/saurin/index>

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Call for papers and deadline extension for: TYPES 2023 post-proceedings
by Benno van den Berg 01 Nov '23

01 Nov '23

[WE HAVE EXTENDED THE DEADLINE FOR ABSTRACT AND PAPER SUBMISSION BY THREE WEEKS] TYPES is a major forum for the presentation of research on all aspects of type theory and its applications. TYPES 2023 was held from 12 to 15 June at ETSInf, Universitat Politècnica de València, Spain. The post-proceedings volume will be published in LIPIcs, Leibniz International Proceedings in Informatics, an open-access series of conference. Submission Guidelines Submission is open to everyone, also to those who did not participate in the TYPES 2023 conference. We welcome high-quality descriptions of original work, as well as position papers, overview papers, and system descriptions. Submissions should be written in English, and be original, i.e. neither previously published, nor simultaneously submitted to a journal or a conference. - Papers have to be formatted with the current LIPIcs style and adhere to the style requirements of LIPIcs. - The upper limit for the length of submissions is 20 pages for the main text (including appendices, but excluding title-page and bibliography). - Papers have to be submitted as PDF via the EasyChair interface, accessible at https://easychair.org/conferences/?conf=posttypes23 - Authors have the option to attach to their submission a zip or tgz file containing code (formalised proofs or programs), but reviewers are not obliged to take the attachments into account and they will not be published. Deadlines - Abstract Submission : 21 November 2023 (AoE) - Paper submission: 21 December 2023 (AoE) - Author notification: 31 March 2023 List of Topics The scope of the post-proceedings is the same as the scope of the conference: the theory and practice of type theory. In particular, we welcome submissions on the following topics: - Foundations of type theory; - Applications of type theory (e.g. linguistics or concurrency); - Constructive mathematics; - Dependently typed programming; - Industrial uses of type theory technology; - Meta-theoretic studies of type systems; - Proof assistants and proof technology; - Automation in computer-assisted reasoning; - Links between type theory and functional programming; - Formalising mathematics using type theory; - Homotopy type theory and univalent mathematics. Editors Eduardo Hermo Reyes, Formal Vindications, Spain Benno van den Berg, Universiteit van Amsterdam, The Netherlands Delia Kesner, Université Paris Cité, France Contact In case of questions, contact EMAIL postt...(a)easychair.org 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.as…> | Leave group<https://outlook.office365.com/owa/categories@mq.edu.au/groupsubscription.as…> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>

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Announcing the (virtual) 9th Mexican Workshop on Applied Geometry and Topology
by Antonio Rieser 31 Oct '23

31 Oct '23

Dear Colleagues, We are pleased to announce the 9th Mexican Workshop on Applied Geometry and Topology, which will take place virtually on gather.town on the mornings (Mexico City time) of November 10, 13-15, 2023. This year, our main topic is discrete and combinatorial homotopy theory, featuring a minicourse on Discrete Homotopy Theory by Chris Kapulkin from the University of Western Ontario and several related research talks, as well as research talks and poster presentations from other areas of applied geometry and topology. Registration to participate without a poster presentation is open until November 8th at the website https://9mwgeometrytopology.eventos.cimat.mx/home_9atd. To apply to present a poster, please register at the above website by November 6th and plan to submit your poster (by email to tda(a)cimat.mx<mailto:tda@cimat.mx>) by November 8th. The poster session will be on November 10th after the mini-course lecture. All submissions from any area of applied geometry and topology are welcome! We look forward to seeing you there! Yours truly, Antonio Rieser Jesús Rodríguez ================================== Centro de Investigación en Matemáticas Jalisco S/N Colonia Valenciana CP 36023 Guanajuato, GTO México ________________________________ La información y sus documentos adjuntos son susceptibles de estar clasificados en términos de la Ley General de Protección de Datos Personales en Posesión de Sujetos Obligados (LGPDPPSO). Si usted ha recibido este mensaje por error, por favor notifique al remitente respondiendo al correo, y elimine el mensaje original, así como sus documentos adjuntos como una medida de seguridad de carácter administrativo. This email and its attachments are confidential and may be privileged or protected by law. If you have received it in error, please notify us immediately, delete the email message, do not copy it, disclose its contents or use it for any purpose. ________________________________ 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.as…> | Leave group<https://outlook.office365.com/owa/categories@mq.edu.au/groupsubscription.as…> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>

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Categories vis-a-vis Naturality
by JS Lemay 30 Oct '23

30 Oct '23

[[The following email is sent on behalf of posinavrayudu(a)gmail.com]] Dear All, Consider a category of objects (say, cats). Going by a naive understanding of the notion of category, every object of a category partakes in an essence/abstract general/theory that is characteristic of the category (cf. catness; whatever that might be). Doesn't it immediately follow from this commonplace understanding of category that morphisms of a category are necessarily natural transformations preserving the abstract essence characterizing the category (cf. playful cat ---> pensive cat). Of course, this is an informal paraphrasing of "Yoneda showed that maps in any category can be represented as natural transformations" (Lawvere & Schanuel, Conceptual Mathematics, p. 378). Isn't this reason enough to think of category theory as the theory of naturality? Happy Monday :) Thanking you, Yours truly, posina P.S. Given that all morphisms, beginning with functions between sets (https://conceptualmathematics.wordpress.com/2022/08/30/functions-are-natura…<https://conceptualmathematics.wordpress.com/2022/08/30/functions-are-natura…>), can be construed as natural transformations, one added value of baptizing category theory as the theory of naturality is that it brings into figural salience for all see that the constrasting notion is unnatural (as in miracles) and not social or culture (since they too don't change willy-nilly). To be clear, highlighting natural is not intended to belittle the categorical nature of our everyday experience (Kandel et al., Principles of Neural Science, pp. 621-637). On Mon, Oct 23, 2023 at 11:10 AM JS Lemay <js.lemay(a)mq.edu.au> wrote: > > Hello everyone! > > Welcome to the new category theory mailing list. > > Unfortunately, the old categories mailing list categories(a)mta.ca has gone permanently offline. > > Bob Rosebrugh, the old mailing list's moderator, reached out to me and asked me to set up a new mailing list. So thank you for your patience while we were getting this new mailing list up and running. (Big thanks to Richard, Steve, and Macquarie's IT team for helping me with this!) > > You are receiving this email because you were subscribed to the old categories mailing categories(a)mta.ca, and have been added as a member to this new one. > > All members from the old mailing list have been added, so this new mailing list is ready to go! Please feel free to start using this mailing list to advertise job postings, conferences, call for papers, questions, etc. > > Also, after 33 years of moderating the mailing list, Bob will be stepping down from mailing list responsibilities. So a big thank you to Bob for all these years running the mailing list! > > A general request email for the mailing list will soon be set up. In the meantime, if you have any questions regarding the mailing list, or would like to be removed, or know a colleague who would like to be added, feel free to email me at js.lemay(a)mq.edu.au > > Have a great day! > JS PL > > PS. We will try to send out emails from the old mailing list that we weren't sent out before it went offline. Unfortunately, some might be outdated. Apologies! > > > > > >

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Rosanna Cruciani
by Francis Borceux 30 Oct '23

30 Oct '23

It is with sadness that I let the categorical community know that Rosanna Cruciani passed this week-end. She has been a prominent figure of category theory in Rome. She was a reliable mathematician, a highly friendly person … and a very good cook. Her hospitality has always been very generous. We shall miss her. Our great sympathy goes to her daughter Raffaella and her son Giovanni. Her funerals will take place this Tuesday 31 at 9.30 in the church Nostra Signora di Coromoto in Rome. Francis Borceux ---------- You're receiving this message because you're a member of the Categories mailing list group from Macquarie University. Leave group: https://outlook.office365.com/owa/categories@mq.edu.au/groupsubscription.as…

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Higgs object
by Martin Escardo 30 Oct '23

30 Oct '23

Dear topos theorists, Recently I found myself coming across Higgs' object. I only know two references that mention it, the Elephant, and Freyd's paper "Choice and well-ordering". Is there an original paper by Denis Higgs, or at least a manuscript by him that you may have seen or have available? When was the first time the Higgs' object showed up in topos theory? References or recollections are welcome. Thanks, Martin ---------- You're receiving this message because you're a member of the Categories mailing list group from Macquarie University. Leave group: https://outlook.office365.com/owa/categories@mq.edu.au/groupsubscription.as…

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Re: Categories vis-a-vis Naturality
by Johnathon Taylor 29 Oct '23

29 Oct '23

This is not the way that one should consider basic introductory category theory. It should be thought about as the fundamental tool. All the things we naturally care to do in basic category theory has natural transformations in the definition itself. An equivalence of categories, of which isomorphism is an example of, is defined using natural transformations. Adjunctions, monads, Monoidal categories, Kan extensions, etc... all are defined using natural transformations. Naturality is one of the tools used but there are other things we care about and need to be considered. On Sat, Oct 28, 2023, 5:34 PM Johnathon Taylor <jmt240(a)case.edu<mailto:jmt240@case.edu>> wrote: Sorry for that. I had it tagged I thought originally and then had to go fix something. Thanks, Johnathon On Sat, Oct 28, 2023, 5:29 PM JS Lemay <js.lemay(a)mq.edu.au<mailto:js.lemay@mq.edu.au>> wrote: Hi Johnathon, Your email was only sent to myself. If you’d like to send this reply to the new mailing list: please use categories(a)mq.edu.au<mailto:categories@mq.edu.au> and include posinavrayudu(a)gmail.com<mailto:posinavrayudu@gmail.com> as well. Thanks! Have a great weekend JS PL On Oct 29, 2023, at 8:25 AM, Johnathon Taylor <jmt240(a)case.edu<mailto:jmt240@case.edu>> wrote: This is not the way that one should consider basic introductory category theory. It should be thought about as the fundamental tool. All the things we naturally care to do in basic category theory has natural transformations in the definition itself. An equivalence of categories, of which isomorphism is an example of, is defined using natural transformations. Adjunctions, monads, Monoidal categories, Kan extensions, etc... all are defined using natural transformations. Naturality is one of the tools used but there are other things we care about and need to be considered. On Sat, Oct 28, 2023, 4:47 PM JS Lemay <js.lemay(a)mq.edu.au<mailto:js.lemay@mq.edu.au>> wrote: [[The following email is sent on behalf of posinavrayudu(a)gmail.com<mailto:posinavrayudu@gmail.com>]] Dear All, Consider a category of objects (say, cats). Going by a naive understanding of the notion of category, every object of a category partakes in an essence/abstract general/theory that is characteristic of the category (cf. catness; whatever that might be). Doesn't it immediately follow from this commonplace understanding of category that morphisms of a category are necessarily natural transformations preserving the abstract essence characterizing the category (cf. playful cat ---> pensive cat). Of course, this is an informal paraphrasing of "Yoneda showed that maps in any category can be represented as natural transformations" (Lawvere & Schanuel, Conceptual Mathematics, p. 378). Isn't this reason enough to think of category theory as the theory of naturality? Happy Monday :) Thanking you, Yours truly, posina P.S. Given that all morphisms, beginning with functions between sets (https://conceptualmathematics.wordpress.com/2022/08/30/functions-are-natura…) can be construed as natural transformations, one added value of baptizing category theory as the theory of naturality is that it brings into figural salience for all see that the constrasting notion is unnatural (as in miracles) and not social or culture (since they too don't change willy-nilly). To be clear, highlighting natural is not intended to belittle the categorical nature of our everyday experience (Kandel et al., Principles of Neural Science, pp. 621-637). On Mon, Oct 23, 2023 at 11:10 AM JS Lemay <js.lemay(a)mq.edu.au<mailto:js.lemay@mq.edu.au>> wrote: > > Hello everyone! > > Welcome to the new category theory mailing list. > > Unfortunately, the old categories mailing list categories(a)mta.ca<mailto:categories@mta.ca> has gone permanently offline. > > Bob Rosebrugh, the old mailing list's moderator, reached out to me and asked me to set up a new mailing list. So thank you for your patience while we were getting this new mailing list up and running. (Big thanks to Richard, Steve, and Macquarie's IT team for helping me with this!) > > You are receiving this email because you were subscribed to the old categories mailing categories(a)mta.ca<mailto:categories@mta.ca>, and have been added as a member to this new one. > > All members from the old mailing list have been added, so this new mailing list is ready to go! Please feel free to start using this mailing list to advertise job postings, conferences, call for papers, questions, etc. > > Also, after 33 years of moderating the mailing list, Bob will be stepping down from mailing list responsibilities. So a big thank you to Bob for all these years running the mailing list! > > A general request email for the mailing list will soon be set up. In the meantime, if you have any questions regarding the mailing list, or would like to be removed, or know a colleague who would like to be added, feel free to email me at js.lemay(a)mq.edu.au<mailto:js.lemay@mq.edu.au> > > Have a great day! > JS PL > > PS. We will try to send out emails from the old mailing list that we weren't sent out before it went offline. Unfortunately, some might be outdated. Apologies! > > > > > > 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.as…> | Leave group<https://outlook.office365.com/owa/categories@mq.edu.au/groupsubscription.as…> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>

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