October 2013 - Categories - categories.org.au

Partial functor
by David Leduc 17 Mar '15

17 Mar '15

Hi, A partial functor from C to D is given by a subcategory S of C and a functor from S to D. What is the appropriate notion of natural transformation between partial functors that would allow to turn small categories, partial functors and those "natural transformations" into a bicategory? The difficulty is that two partial functors from C to D might not have the same definition domain. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Research positions
by Maria Manuel Clementino 26 Feb '14

26 Feb '14

5-YEAR RESEARCH POSITIONS The Centre for Mathematics of the University of Coimbra (CMUC) invites applications for five 5-year research positions in all areas of Mathematics. Applicants should have a PhD in Mathematics and at least three years of post-doctoral experience, with an international-level publication record and demonstrated ability to perform independent research. Preference will be given to candidates working in one of the areas in which the members of CMUC are currently active. A very good command of English is required. The appointments will be made for three years, renewable for two more. Successful applicants are expected to develop research within the areas of interest of CMUC. They should also contribute to graduate studies, supervising students from the Department of Mathematics. The basic salary is equivalent to the index 195 of the Portuguese research career (in the order of 42 500 euros a year), in accordance with the Ciência 2008 guidelines http://alfa.fct.mctes.pt/apoios/contratacaodoutorados/edital2008 Benefits include private health insurance and social security. Applicants should send • cover sheet (available from www.mat.uc.pt/cmuc/coversheet.pdf) including names and contact information of three persons who can provide a letter of recommendation • curriculum vitae (publication list included) • a 5-year research proposal (2 pages max), emphasizing their own research goals as pdf files to cmuc(a)mat.uc.pt. The subject of the e-mail message must include the job reference C2008 FCTUC CMUC v15-v19. The deadline for applications is *September 10, 2008.* ------------------------------ More information can be found at www.mat.uc.pt

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Joint 25th RTA & 12th TLCA: CALL FOR PAPERS
by Luca Paolini 31 Oct '13

31 Oct '13

Joint 25th International Conference on REWRITING TECHNIQUES AND APPLICATIONS and 12th International Conference on TYPED LAMBDA CALCULI AND APPLICATIONS July 14???17, 2014, Vienna, Austria http://vsl2014.at/rta-tlca ====================================== IMPORTANT DATES Abstract submission: January 28, 2014 Notification: April 9, 2014 Paper submission: February 4, 2014 Final version: April 29, 2014 Rebuttal period: March 19???21, 2014 ====================================== SUBMISSION and PUBLICATION --------------------------- Submissions presenting original work are expected at https://www.easychair.org/conferences/?conf=rtatlca2014. They should be at most 15 pages (10 for system descriptions) and follow http://www.springer.com/computer/lncs?SGWID=0-164-6-793341-0. The proceedings will be published in the LNCS Advanced Research in Computing and Software Science series of Springer. One author of each accepted paper is expected to present it at the conference. Topics ------ This joint RTA and TLCA conference is the major forum for the presentation of research on all aspects of rewriting and typed lambda-calculi. Areas of interest include but are not limited to: - Foundations: string rewriting; term rewriting; graph rewriting; lambdacalculi; higher-order rewriting; binding techniques; constrained rewriting and deduction; categorical and infinitary rewriting; stochastic rewriting; net rewriting; Petri nets; higher-dimensional rewriting; process calculi; explicit substitution; tree automata; confluence; termination; complexity; modularity. - Algorithmic aspects and implementation: strategies; matching; unification; anti-unification; narrowing; constraint solving; theorem proving; completion techniques; implementation techniques; parallel execution; certification of rewriting properties; abstract machines; automated (non)termination and confluence provers; automated complexity analysis; SMT solving; system descriptions. - Logic: proof theory; natural deduction; sequent calculi; proof assistants; cut elimination and normalization; propositions as types; linear logic and proof nets; equational logic; rewriting logic; rewriting calculi; proof checking; reasoning about programming languages and logics; homotopy type theory; type-theoretic aspects of complexity; implicit computational complexity. - Types: dependent types; polymorphism; intersection types and related approaches; subtyping; type inference and type checking; types in databases. - Semantics: denotational semantics; operational semantics; game semantics; realisability; domain theory; categorical models; universal algebra. - Programming: foundational aspects of functional programming, object oriented programming, and other programming paradigms; flow analysis of higher-type computation; program equivalence; program transformation; program optimization; program refactoring; rewriting models of programs; rule-based (functional and logic) programming; control operators; symbolic and algebraic computation; system synthesis and verification; XML queries and transformations; types in program analysis and verification; analysis of cryptographic protocols; systems biology; linguistics. Programme Committee -------------------- Andreas Abel (Gothenburg) Beniamino Accattoli (Bologna) Zena Ariola (Oregon) Steffen van Bakel (Imperial College) Pierre Clairambault (CNRS) Ugo Dal Lago (Bologna) Gilles Dowek (Inria) Santiago Escobar (Valencia) Amy Felty (Ottawa) Maribel Fernandez (King???s college) Adria Gascon (SRI International) Jeroen Ketema (Imperial College) Christopher Lynch (Clarkson) Masahito Hasegawa (Kyoto) Olivier Hermant (MINES ParisTech) Paul-Andre Mellies (CNRS) Alexandre Miquel (UdelaR) Cesar Munoz (NASA) Vivek Nigam (Para??ba) Luke Ong (Oxford) Brigitte Pientka (McGill) Femke van Raamsdonk (Amsterdam) Jakob Rehof (Dortmund) David Sabel (Frankfurt) Gernot Salzer (Wien) Sylvain Salvati (Inria) Aleksy Schubert (Warszawa) Peter Selinger (Dalhousie) Paula Severi (Leicester) Christian Sternagel (JAIST) Kazushige Terui (Kyoto) Mateu Villaret (Girona) Fer-Jan de Vries (Leicester) Harald Zankl (Innsbruck) Programme Chair --------------- Gilles Dowek Conference Chair ---------------- Gernot Salzer =============================================================== Luca Paolini, Sophie Tison RTA & TLCA publicity chairs [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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ICFP 2014: Call for Workshop & Co-located Event Proposals
by David Van Horn 31 Oct '13

31 Oct '13

CALL FOR WORKSHOP AND CO-LOCATED EVENT PROPOSALS ICFP 2014 19th ACM SIGPLAN International Conference on Functional Programming August 31 – September 6, 2014 Gothenburg, Sweden http://icfpconference.org/icfp2014/ The 19th ACM SIGPLAN International Conference on Functional Programming will be held in Gothenburg, Sweden on August 31-September 6, 2014. ICFP provides a forum for researchers and developers to hear about the latest work on the design, implementations, principles, and uses of functional programming. Proposals are invited for workshops (and other co-located events, such as tutorials) to be affiliated with ICFP 2014 and sponsored by SIGPLAN. These events should be less formal and more focused than ICFP itself, include sessions that enable interaction among the attendees, and foster the exchange of new ideas. The preference is for one-day events, but other schedules can also be considered. The workshops are scheduled to occur on August 31 (the day before ICFP) and September 4-6 (the three days after ICFP). ---------------------------------------------------------------------- Submission details Deadline for submission: November 15, 2013 Notification of acceptance: December 15, 2013 Prospective organizers of workshops or other co-located events are invited to submit a completed workshop proposal form in plain text format to the ICFP 2014 workshop co-chairs (Sam Tobin-Hochstadt and Tom Schrijvers), via email to icfp2014-workshops(a)ugent.be by November 15, 2013. (For proposals of co-located events other than workshops, please fill in the workshop proposal form and just leave blank any sections that do not apply.) Please note that this is a firm deadline. Organizers will be notified if their event proposal is accepted by December 15, 2013, and if successful, depending on the event, they will be asked to produce a final report after the event has taken place that is suitable for publication in SIGPLAN Notices. The proposal form is available at: http://www.icfpconference.org/icfp2014/icfp14-workshops-form.txt Further information about SIGPLAN sponsorship is available at: http://acm.org/sigplan/sigplan_workshop_proposal.htm ---------------------------------------------------------------------- Selection committee The proposals will be evaluated by a committee comprising the following members of the ICFP 2014 organizing committee, together with the members of the SIGPLAN executive committee. Workshop Co-Chair: Sam Tobin-Hochstadt (Indiana University) Workshop Co-Chair: Tom Schrijvers (Ghent University) General Chair : Johan Jeuring (Utrecht University) Program Chair: Manuel Chakravarty (University of New South Wales) ---------------------------------------------------------------------- Further information Any queries should be addressed to the workshop co-chairs (Sam Tobin-Hochstadt and Tom Schrijvers), via email to icfp2014-workshops(a)ugent.be. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Equivariant Serre-Swan correspondence
by Johannes Huebschmann 29 Oct '13

29 Oct '13

Dear All Where in the literature can I find the equivariant Serre-Swan correspondence, spelled out for proper actions of a not necessarily compact topological or Lie group? Many thanks in advance Best Johannes [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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History of TAC
by David Roberts 25 Oct '13

25 Oct '13

[Note from moderator: the poster is correct; this is off topic. Please send any reply to the poster. Replies to the list will not be posted. It should be noted that some guesses below about this history are not correct. A published version of the story is at: http://www.ams.org/notices/201301/rnoti-p97.pdf Best to all] Hi all, I have been reading some back issues of this list, and there are several cryptic comments about JPAA winding up after TAC started publishing. I vaguely recall that TAC was founded by editors and former editors of JPAA in order to give category theorists a journal that was not in the clutches of a commercial publisher. Could anyone enlighten me about what happened in the mid-90s leading to TAC being founded? (I am aware of the general situation wrt publishing, costs and corporate mergers.) Clearly the discussions were behind closed doors and all that came out at the time was the public announcement http://www.mta.ca/~cat-dist/catlist/1999/elec-journal I would be happy with private replies, as I suspect that the moderator may find discussion about this off-topic; if so, I beg his indulgence in allowing this posting through. Regards, David Roberts [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Axiomatic Method and Category Theory
by andrei rodin 24 Oct '13

24 Oct '13

Dear List, here is my newly published monograph on the history and philosophy of category theory and some other related matters: http://www.springer.com/philosophy/book/978-3-319-00403-7 http://www.amazon.com/Axiomatic-Method-Category-Synthese-Library/dp/3319004… The main thesis of the book: Categorical logic brings us back to Euclid leaving Hilbert at the margins (I'm talking here about Hilbert's version of axiomatic method, not about his legacy as a whole). Table of Contents (Category theory doesn't appear in the book before Chapter 4): Introduction.- Part I A Brief History of the Axiomatic Method.- Chapter 1. Euclid: Doing and Showing.- Chapter 2. Hilbert: Making It Formal.- Chapter 3. Formal Axiomatic Method and the 20th Century Mathematics.- Chapter. 4 Lawvere: Pursuit of Objectivity.- Conclusion of Part 1.- Part II. Identity and Categorification.- Chapter 5. Identity in Classical and Constructive Mathematics.- Chapter 6. Identity Through Change, Category Theory and Homotopy Theory.- Conclusion of Part 2.- Part III. Subjective Intuitions and Objective Structures.- Chapter 7. How Mathematical Concepts Get Their Bodies. Chapter 8. Categories versus Structures.- Chapter 9. New Axiomatic Method (instead of conclusion).- Bibliography. A draft version is on arXiv. I hope some of you may enjoy it and I'll be most grateful for any critique and any comment. best regards, AR [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Subobject classifier algorithm
by Venkata Rayudu Posina 23 Oct '13

23 Oct '13

Dear All, In continuation of the discussion we had sometime ago regarding algorithms for finding truth value objects, I am wondering if the following constitutes an algorithm for calculating subobject classifiers. The basic idea is to use the correspondence between parts of an object and maps to truth value object from the object to find the truth value object. In general we start with an object (of "simplest" shape such as initial and gradually going to less simple ones), enumerate its parts, and then look for objects to which the number of maps from the object is equal to the number of parts of the object. In the case of the category of sets, we start with the initial object, which has one part. Since there is exactly one function from empty set to every set, this doesn't help in identifying the truth value set. So we move to [the next] sigleton set, which has two parts. The set to which there are exactly two maps from the singleton set is a two-element set, which we take as [candidate] truth value set. Finally we verify that the two-element set is indeed the truth value set by way of checking parts of an object = maps to truth value object from the object in the case of [the set after sigleton set] two-element set. (For now I'm ignoring the question of how many more objects do we have to check.) The above method does give the correct truth value object in the categories of maps, graphs, and dynamical systems in addition to the aforementioned case of the category of sets. In the category of [set] maps, we only have to look at two objects before we get to the terminal object, which lets us identify the truth value object w: D --> C where D = {false, u, true} and C = {false, true} with w(false) = false, w(u) = true, w(true) = true (see Sets for Mathematics, pp. 114 - 9). To give one more illustration, in the case of graphs, we have to go little beyond terminal object to the generic arrow, whose five parts correspond to the five graph maps from the generic arrow to the truth value object of graphs (please see bottom-left corner of the cover of Conceptual Mathematics). In all these case we begin with [the simplest] initial object and go to next [less simple] object, and at each stage we use number of parts of an object = number of maps to truth value object from the object to identify (and then verify) the truth value object. All the more important is that we have to examine the above correspondence at a few simple shapes only (beginning with the initial object) to find the truth value object. Would you be kind enough to let me know if there's something wrong in using the above method to find the truth value object (when there's one) of a category in general. Thanking you, Yours sincerely, posina http://conceptualmathematics.wordpress.com/ [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Preprint available
by Anders Kock 22 Oct '13

22 Oct '13

My preprint "Projective lines as groupoids with projection structure" is now available at arXiv. A projection structure on a groupoid consists in giving, for each pair (A,B) of distinct objects in it, a bijection between the set hom(A,B), and the set of objects distinct from A and B. Groupoids with such structure occur naturally in projective geometry over a field. - The present note investigates when, conversely, an abstractly given groupoid with projection structure comes about from a field, constructed out of the groupoid. http://arxiv.org/abs/1310.5357 Anders [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Workshop on Categorical Methods in Algebra and Topology
by Categorical Methods in Algebra and Topology 19 Oct '13

19 Oct '13

Dear colleagues, A Workshop on Categorical Methods in Algebra and Topology, in honour of Manuela Sobral on the occasion of her seventieth birthday, will be held in Coimbra, January 24-26, 2014. We would be very glad to welcome you at the workshop, as a participant and/or contributor to the scientific program. Important dates: Registration deadline: November 30, 2013 Abstract submission deadline: December 13, 2013. More information about the workshop can be found at the workshop webpage: www.mat.uc.pt/~wcmat14 The Organizers: Maria Manuel Clementino Jorge Picado Lurdes Sousa [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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