November 2025 - Categories - categories.org.au

Lecture notes by Bill Lawvere
by Michael Barr, Prof. 23 Apr '26

23 Apr '26

I got a request from someone named C. Muster who is searching for a set of lecture notes by Bill that he gave at U. Laval in 1974. Does anyone have a copy that they would be willing to send to him. 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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Subject: Dedicated to R. H. Street’s 80
by George Janelidze 16 Mar '26

16 Mar '26

Dear Colleagues, In honor of the 80th birthday of Professor Ross Howard Street, we are pleased to announce a special issue of Journal of Pure and Applied Algebra dedicated to celebrating his remarkable contributions to category theory and mathematics in general. Topics of interest include (but are not limited to) all areas of pure and applied category theory. The Guest Editors are: Jiří Adámek Maria Manuel Clementino Marino Gran George Janelidze Stephen Lack We are sending this message now so that you can begin to plan for possible submissions. The deadline will be 31 July 2026, and we will write again with further information about submissions once the journal’s website is ready. George Janelidze, on behalf of the Guest Editors Disclaimer - University of Cape Town This email is subject to UCT policies and email disclaimer published on our website at https://www.uct.ac.za/main/email-disclaimer or obtainable from +27 21 650 9111. If this email is not related to the business of UCT, it is sent by the sender in an individual capacity. Please report security incidents or abuse via https://csirt.uct.ac.za/report-incident 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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7th Workshop on Formal Topology (7WFTop)-( first annoucement)
by Maria Emilia Maietti 12 Feb '26

12 Feb '26

================================== 7th Workshop on Formal Topology (7WFTop). >From topology to dynamic constructivism, and back. (first announcement) > ------------------------------ The 7th Workshop on Formal Topology will take place in Venice, Italy, on April 13-17, 2026 at Convento di San Francesco della Vigna. This is the seventh of a series of successful meetings on the development of Formal Topology and its connections with related approaches. The first six have been held in Padua (1997), Venice (2002), Padua (2007), Ljubljana (2012), Stockholm (2015), and Birmingham (2019). The meeting is supported by Dipartimento di Matematica “Tullio Levi-Civita” (Università di Padova). ------------------------------ Dynamic constructivism is a new approach to the foundation of mathematics proposed by Giovanni Sambin starting from the 90s and whose forthcoming book is a first organic exposition. The main claim is that mathematics is the result of a dynamic, human process, which stems from the interplay between the construction of mathematical entities, by abstraction and by idealization, and their selection according to their effectiveness in applications to reality and in the organization of mathematics itself. Pointfree topology in the form of Formal Topology and the more recent Positive Topology provides a key tool to link the effective content of mathematics with its ideal one, and thus achieve a synthesis of computation and visual intuition. A careful management of information within a dynamic view "back and forth" from mathematics to its foundation inevitably leads to accepting a plural vision of mathematics, thus enlightening connections between different constructive or even classical approaches to it. INVITED SPEAKERS: Steve Awodey, Andrej Bauer, Ingo Blechschmidt, Francesco Ciraulo, Maria Manuel Clementino, Thierry Coquand, Laura Crosilla, Tom de Jong, Martín Escardó, Hugo Herbelin, Hajime Ishihara, Tatsuji Kawai, Ansten Klev, Takako Nemoto, Michael Rathjen, Giovanni Sambin, Göran Sundholm, Mark van Atten, Steve Vickers, David Wärn, Joshua Wrigley. CONTRIBUTED TALKS There will be room for some contributed talks. Information about abstract submission will appear soon in the website of the workshop. ACCOMODATION The organizers will be happy to help you find accommodation, given the peculiarities of the city of Venice, and are making agreements with some facilities to guarantee partecipants a convenient price for their stay. If you are interested, please write to the workshop email address 7wftop(a)math.unipd.it<mailto:7wftop@math.unipd.it> as soon as possible, indicating "accommodation" in the subject. Finding accommodation at a reasonable price will be difficult or virtually impossible after June-July 2025. REGISTRATION The registration form will be available soon on the workshop website https://events.math.unipd.it/7wftop/. Participation will require a registration fee. SCIENTIFIC COMMITTEE Ingo Blechschmidt (University of Antwerp) Thierry Coquand (Gothenburg University) Martín Escardó (University of Birmingham) Maria Emilia Maietti (University of Padua) Per Martin-Löf (Stockholm University) ORGANIZING COMMITTEE Cipriano Junior Cioffo (University of Pisa) Francesco Ciraulo (University of Padua) Maria Emilia Maietti (University of Padua) Samuele Maschio (University of Padua) Pietro Sabelli (Czech Academy of Science) Giovanni Sambin (University of Padua) CONTACTS For inquiries, please send an e-mail to: 7wftop(a)math.unipd.it<mailto:7wftop@math.unipd.it> 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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Octoberfest 2025
by Richard Blute 23 Nov '25

23 Nov '25

The Octoberfest 2025 website is now complete. You’ll find video of all the talks and slides for most of the talks. Thanks to all participants for making it such a successful event. Cheers Rick https://richardblute.ca/octoberfest-2025/ 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/groups/groupsubscription?source=EscalatedMess…> | Leave group<https://outlook.office365.com/groups/groupsubscription?source=EscalatedMess…> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>

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A Categorical Replacement for Replacement
by Paul Taylor 23 Nov '25

23 Nov '25

I gave an online lecture about this at ItaCa on Tuesday. I am going to repeat it, again online, in the Birmingham Theoretical Computer Science seminar series. Tomorrow, Friday, 21 November at 14:00 UTC. The abstract and zoom details are at researchseminars.org/seminar/TheoryCSBham and the slides are linked from my own webpage www.paultaylor.eu/ordinals/ I will have 50 minutes instead of 30 and the reason for repeating the talk is so that people can "cross examine" me on the proof. The idea (which I have been promising for many years) for the principle "in the native language of category theory" is that there be a reflection functor from the category of well founded coalgebras to the subcategory of extensional ones. The strength of this is that it is proposed for ANY endofunctor (instead of the powerset) and ANY factorisation system (instead of plain monos), subject to some conditions. I have finally learned how ZF works and how to use it. The lecture shows that the proposal is valid in ZF. I am still working on how constructions such as transfinite iteration of functors (in particular the von Neumann hierarchy) can be obtained from my proposal. The difficulty is that the constructive categorical theory of ordinals is intrinsically a mess. (Those who have followed my work for the past 30 years will be aware that I am not saying this for want of effort in trying to sort it out.) I will give another lecture (date and venue to be decided) about this and the recovery of ZF from my proposal. ---- I would like to ask the community two questions that are relevant to this: (1) Is the General Adjoint Functor Theorem of any use? I would think that if you can find a "solution set" or any of the other possible conditions for GAFT then you should be able to describe the adjoint directly. So the interesting situation is when the adjoint has to be obtained recursively (or corecursively). This is why I think well foundedness (in some form) has to be part of the method. (2) Are there examples in the literature of category theory or algebra more generally (but not set theory) where the official first order formulation of ZF and in particular Replacement is applied? Paul Taylor 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/groups/groupsubscription?source=EscalatedMess…> | Leave group<https://outlook.office365.com/groups/groupsubscription?source=EscalatedMess…> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>

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Conference in Santiago de Compostela dedicated to Manuel Ladra
by Xabier García Martínez 20 Nov '25

20 Nov '25

Dear colleagues, We are pleased to announce the conference "Categorical, homological and computational methods in Algebra. A conference honouring the mathematical contribution of Manuel Ladra, celebrating his 70th birthday". It will take place in Santiago de Compostela from the 24th until the 26th of June, 2026. For more information about the conference, please visit our website at https://mares.usc.es/chcma/ We hope to see you in Santiago de Compostela. Kind regards, The organising committee 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/groups/groupsubscription?source=EscalatedMess…> | Leave group<https://outlook.office365.com/groups/groupsubscription?source=EscalatedMess…> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>

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Postdoctoral Research Position, University of Birmingham
by Paul Levy 20 Nov '25

20 Nov '25

Dear all, Application deadline: 9 December 2025 The University of Birmingham invites applications for a fully funded postdoctoral research position in Theoretical Computer Science. The position is funded by the Engineering and Physical Sciences Research Council (UK) and provides support for up to 3.5 years of full-time research. The successful candidate will contribute to the project "New algebraic structures for computational effects", which aims to develop categorical and denotational semantics for general effects, for stateful effects in particular, and for polymorphism in effectful languages. The project will involve categorical structures, call-by-push-value and game semantics, so any background in these and related areas would be valuable. Although the earliest possible appointment date is 1 March 2026, a later start date can be arranged. To apply, use the following link to the University's Job Portal: https://edzz.fa.em3.oraclecloud.com/hcmUI/CandidateExperience/en/sites/CX_6… Please feel free to contact me with any informal enquiries. best regards, Paul 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/groups/groupsubscription?source=EscalatedMess…> | Leave group<https://outlook.office365.com/groups/groupsubscription?source=EscalatedMess…> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>

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TYPES 2025: Post-proceedings Final Call for Papers
by Fredrik Nordvall Forsberg 17 Nov '25

17 Nov '25

Dear all, this is a final invitation to submit to the TYPES 2025 post-proceedings. We have extended the abstract deadline until *Friday 21 November*, and the full paper deadline until *Friday 6 December*. ************************************************** TYPES 2025: Post-proceedings Final Call for Papers ************************************************** https://msp.cis.strath.ac.uk/types2025/postproceedings.html TYPES is a major forum for the presentation of research on all aspects of type theory and its applications. TYPES 2025 was held from 9 to 13 June at the University of Strathclyde, Glasgow, Scotland. The post-proceedings volume will be published in LIPIcs, Leibniz International Proceedings in Informatics, an open-access series of conference proceedings. Submission Guidelines --------------------- Submission is open to everyone, also to those who did not participate in the TYPES 2025 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. - Formatting: Papers have to be formatted with the current LIPIcs style and adhere to the style requirements of LIPIcs. - Page limits: The upper limit for the length of submissions is 20 pages for the main text (including appendices, but excluding title page and bibliography). - Supplementary material: 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. - Submission site: https://types-hotcrp.paris.inria.fr/types25-post/ . Deadlines --------- Submission of title and abstract: Friday 21 November 2025 AoE Submission of full paper: Friday 5 December 2025 AoE Author notification: 1 April 2026 Topics of interest ------------------ 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 ------- Fredrik Nordvall Forsberg, University of Strathclyde, Glasgow, Scotland James McKinna, Heriot-Watt University, Edinburgh, Scotland Contact ------- CIS_types2025-post(a)groups.strath.ac.uk 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/groups/groupsubscription?source=EscalatedMess…> | Leave group<https://outlook.office365.com/groups/groupsubscription?source=EscalatedMess…> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>

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RHPL@FSTTCS 2025: Call for Participation
by Abhisekh Sankaran 17 Nov '25

17 Nov '25

======================= Call for Participation ======================= ============================================================= RHPL@FSTTCS 2025: Workshop on Research Highlights in Programming Languages + Website: https://fmindia.cmi.ac.in/rhpl2025/ + Dates: December 17 - 19, 2025 + Venue: BITS Pilani, K K Birla Goa Campus, co-located with FSTTCS 2025 + Early registration deadline: November 30, 2025 + Registration page: https://fmindia.cmi.ac.in/rhpl2025/registration ============================================================= =================== About the Workshop =================== RHPL 2025 is the fourth edition of the Workshop on Research Highlights in Programming Languages (RHPL) organized by the Indian Association for Research in Computing Science (IARCS). The focus of the workshop is on all areas of Programming Languages (PL), including but not limited to: + Applied formal methods + Automated and interactive theorem provers + Compilers + Concurrency and memory models + Domain and type theories + Program analysis and verification + Program sketching, synthesis and repair + Programming language design and semantics Further, in view of the increasing role of Artificial Intelligence (AI) and Machine Learning (ML) in PL theory and practice, the workshop also includes in its scope themes pertaining to the influences of AI/ML concepts and tools on the mentioned PL topics, and vice-versa; for instance, probabilistic programming languages. The objective of RHPL is to foster interactions between the attendees of the workshop, and more broadly, between researchers working on Programming Languages and the traditional FSTTCS community of researchers working on Theoretical Computer Science and Formal Methods. RHPL 2025 will be held at BITS Pilani, K K Birla Goa Campus as a co-located workshop of FSTTCS 2025. RHPL 2025 website: https://fmindia.cmi.ac.in/rhpl2025/ ================= Panel Discussion ================= + Theme: Bridging PL Theory and Practice in the Age of AI + Panelists: - Uday Khedker (IIT Bombay) - Pavithra Prabhakar (Kansas State University) - Subhajit Roy (IIT Kanpur) - R Venkatesh (TCS Research) =========================== Accepted Talks and Posters =========================== The list of accepted talks and posters of RHPL 2025 can be found at the link below. https://fmindia.cmi.ac.in/rhpl2025/accepted_proposals ============== Registration ============== The registration for RHPL 2025 is open. - Early registration deadline: *November 30, 2025* - Registration page: https://fmindia.cmi.ac.in/rhpl2025/registration ================== Local Information ================== - Local information page: https://fmindia.cmi.ac.in/rhpl2025/local_information ===================== Organising Committee ===================== - Abhisekh Sankaran (TCS Research) (co-Chair) - Divyesh Unadkat (Synopsys) (co-Chair) - Deepak D'Souza (IISc Bangalore) - Uday Khedker (IIT Bombay) - Kumar Madhukar (IIT Delhi) - Kartik Nagar (IIT Madras) - Sumanth Prabhu (TCS Research) - Ganesan Ramalingam (Microsoft) - Abhik Roychoudhury (National University of Singapore) ========= Contact ========= Feel free to write to us with any queries at the following email addresses. - abhisekh.sankaran(a)tcs.com<mailto:abhisekh.sankaran@tcs.com> - divyesh.unadkat(a)synopsys.com<mailto:divyesh.unadkat@synopsys.com> We look forward to seeing you in Goa. Best regards, RHPL 2025 Organising Committee RHPL 2025 Website: https://fmindia.cmi.ac.in/rhpl2025/ 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/groups/groupsubscription?source=EscalatedMess…> | Leave group<https://outlook.office365.com/groups/groupsubscription?source=EscalatedMess…> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>

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ItaCa Fest - 18th of November
by Giacomo Tendas 14 Nov '25

14 Nov '25

Dear all, On Tuesday the 18th of November, we will meet for the last ItaCa Fest of 2025. We will start at 3:00 PM (Italian time). As usual, you can find all the relevant information (schedule, abstracts, and Zoom link) at the following page: https://progetto-itaca.github.io/fests/fest25.html Here is the list of speakers for this episode: • Paul Taylor – A Categorical Replacement for Replacement; • Umberto Tarantino – Ultracategories via Kan extensions of relative monads; • Ettore Aldrovandi – Biextensions and Monoidal (2-)Categories. Best wishes, Giacomo 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/groups/groupsubscription?source=EscalatedMess…> | Leave group<https://outlook.office365.com/groups/groupsubscription?source=EscalatedMess…> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>

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