May 2007 - Categories - categories.org.au

The policy of arXiv
by Marco Grandis 10 May '07

10 May '07

Dear Sirs, Before deciding of using arXiv in a systematic way, I would like that =20= there be a clear statement of its policy and commitments; a statement =20= which, likely, the organisers and many of us take as understood and =20 granted, but which I have been unable to find. To be more explicit, what about the possibility of the system being, =20 in future, exploited economically? What about the possibility of it =20 being sold to a commercial company? When downloading an article to the arXiv, the author is asked to =20 grant 'a perpetual, non-exclusive license to distribute this =20 article'. I think the author has a right to know that this license =20 will not be used, in the future, for goals which would be in contrast =20= with the present (understood) ones, or even opposite to them. Last year I wrote a message in this sense to the list =20 'categories' (categories@mta,ca), where arXiv has been frequently =20 proposed as a way of disseminating articles. In December 2006 there =20 was a discussion about these points in a blog kept by John Baez http://golem.ph.utexas.edu/category/2006/12/=20 arxiv_policy_statement.html This is part of a posting by John Baez, on this blog: "Many people like to have some idea of what an organization seeks to =20 do, or is committed to do, before they do business with it. For this reason, it=92s unusual for such an important entity as the =20 arXiv not to make a public statement about its goals and commitments. =20= Consider, for example, the Berlin Declaration on Open Access to =20 Knowledge in the Sciences and Humanities, and its many signatories, =20 or the statement by the Wellcome Trust supporting open access, or the =20= Wikimedia mission statement and bylaws, or the Google code of conduct =20= and privacy policy. " (end of citation) As far as I know, there still is no policy statement available. One =20 can only read, at the head of the 'arXiv Advisory Board' page: "Please note that all arXiv policy decisions are ultimately made by =20 Cornell University Library." Will the Cornell University Library make its arXiv policy public? With best regards Marco Grandis Dipartimento di Matematica Universit=E0 di Genova Via Dodecaneso, 35 16146 Genova Italy e-mail: grandis(a)dima.unige.it tel: +39 010 353 6805 http://www.dima.unige.it/~grandis/=

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Integrated Formal Methods 2007: Call for participation
by Jeremy.Gibbons＠comlab.ox.ac.uk 09 May '07

09 May '07

IFM2007: INTEGRATED FORMAL METHODS CALL FOR PARTICIPATION 2nd to 5th July 2007 St Anne's College, Oxford, UK www.ifm2007.org The design and analysis of computing systems presents a significant challenge: systems need to be understood at many different levels of abstraction, and examined from many different perspectives. Formal methods - languages, tools, and techniques with a sound, mathematical basis - can be used to develop a thorough understanding, and to support rigorous examination. Further research into effective integration is required if these methods are to have a significant impact outside academia. The IFM series of conferences seeks to promote that research, to bring together the researchers carrying it out, and to disseminate the results of that research among the wider academic and industrial community. This is the sixth IFM conference. It will be held in the historic university town of Oxford, at St Anne's College - one of the larger colleges of the University, with excellent new conference facilities. Oxford is easily reached from most UK cities, and is 70 minutes from the country's largest airport. Earlier conferences in the series were held at York (1999), Schloss Dagstuhl (2000), Turku (2002), Kent (2004), and Eindhoven (2005). The conference runs for three full days, 3rd to 5th July. Invited speakers include Jifeng He on "UTP Semantics for Web Services" and Daniel Jackson on "Recent Advances in Alloy"; a third invited speaker is yet to be confirmed. There are 32 contributed papers, including a special session on Unifying Theories of Programming. In addition, there are four satellite events, taking place on 2nd and 3rd July - three workshops: * Refinement Workshop * C/C++ Verification * MeMoT (Methods, Models and Tools for Fault Tolerance) and a tutorial: * KeY (Integrating OO Design and Deductive Verification of Software) The full programme is available at: http://www.ifm2007.org/programme-ifm.html Registration for the conference is now open, at: http://www.ifm2007.org/registration.html Special early-registration fees apply until 1st June 2007. For more information, visit the conference web page: http://www.ifm2007.org/ or contact the local organisers: Jim Davies http://www.softeng.ox.ac.uk/Jim.Davies Jeremy Gibbons http://www.softeng.ox.ac.uk/Jeremy.Gibbons

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Literature on Category Theory and Biology
by Deniz Kural 08 May '07

08 May '07

Hi, I was wondering if you are aware of any bibliographies, reviews, or papers relating category theory to biology - mathematical biology, systems biology, computational biology or bioinformatics. I would be interested in papers relating category theory to areas of knowledge representation or other areas of computer science used in abovementioned areas. Please feel free to email me in person if you wish not to overburden the mailing list. Regards, Deniz Kural

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PSSL 86 in Nancy: Preliminary Announcement
by Francois Lamarche 07 May '07

07 May '07

Fellow category theorists, The 86th edition of the Peripatetic Seminar on Sheaves and Logic will be held at the Institut Élie Cartan of the Université Henri Poincaré in Nancy, on the weekend of September 8-9 2007. More details will be announced later this summer, but interested people can start contacting me now. We intend to continue the PSSL tradition of informality, and scheduling talks pertaining to any aspect of category theory, with or without applications in natural science, logic, computer science, or other branches of mathematics. The fast TGV-Est train line will be inaugurated in June, and the Paris-Nancy trip will then take only 1h30m, with easy connections to the two Paris airports. The city of Nancy is right on the Paris- Munich train line, and also has good train connecftions with the north (Luxembourg, Brussels and Frankfurt via Metz) and the south (Lyon, Nice...). There is a local airport, 45 minutes away from downtown by minibus shuttle, and there are also two relatively close international airports, Luxembourg and Strasbourg, which often allow you to do the airport-dowtown Nancy trip in less than 2h30m. Nancy is of considerable interest for the mathematical tourist, being the birthplace of Henri Poincaré, and being intimately related to the career of Nicolas Bourbaki. It has two historical old towns: the medieval one, with the Renaissance palace of the Dukes of Lorraine, and the classical one, with UNESCO World heritage sites built by Duke Stanislas. It is can also boast one of the highest concentrations of Art Nouveau architecture in all of Europe, rivalling Prague and Barcelona. Hoping to see you in September, François Lamarche http://www.loria.fr/~lamarche

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Beck-Chevalley for presheaves on groupoids?
by John Baez 05 May '07

05 May '07

Hi - One of you must know the answer to this! Suppose we have a weak pullback (= pseudo-pullback) square of groupoids: G -> H | | v v K -> L Suppose we take presheaves on all four. We can get a square hom(G^{op},Set) -> hom(H^{op},Set) ^ ^ | | hom(K^{op},Set) -> hom(L^{op},Set) where the arrows pointing forward - in the same direction as the original arrows - are defined using pushforward, and the arrows pointing backward are defined using pullback. Does this square commute up to natural isomorphism? Do you know a reference somewhere? Some side remarks: 1) This seems related to the "Beck-Chevalley condition". 2) It may work for categories as well as groupoids, but I happen to need it only for groupoids. 3) I really need it with the category Vect replacing Set, so if you know a general result for any sufficiently nice category playing the role of Set here, that would be wonderful. Best, jb

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RDP'07 First Call for Participation
by Ralf Treinen 04 May '07

04 May '07

RDP 2007 - Call for Participation Federated Conference on Rewriting, Deduction, and Programming June 25 to 29, Paris, France http://www.rdp07.org ======================================================================== Online Registration is open unil May, 31. ======================================================================== RDP'07 is the fourth edition of the International Conference on Rewriting, Deduction, and Programming, consisting of two main conferences * Rewriting Techniques and Applications (RTA'07) * Typed Lambda Calculi and Applications (TLCA'07) a colloquium * From Type Theory to Morphologic Complexity: a Colloquium in Honor of Giuseppe Longo as well as the following workshops: * Higher Order Rewriting (HOR) * Proof Assistants and Types in Education (PATE) * Rule-Based Programming (RULE) * Security and Rewriting Techniques (SecReT) * Unification (UNIF) * Functional and (Constraint) Logic Programmming (WFLP) * Reduction Strategies in Rewriting and Programming (WRS) * Termination (WST) Invited Speakers: ================= Joint RTA/TLCA: * Frank Pfenning (Carnegie Mellon University) TLCA: * Patrick Baillot (CNRS, University Paris 13) * Greg Morrisett (Harvard University) RTA: * Xavier Leroy (INRIA Rocquencourt) * Robert Nieuwenhuis (Technical University of Catalonia) Celebratation of the 75th anniversary of the lambda calculus: * Henk Barendregt (Nijmegen University) Registration: ============= http://www.rdp07.org/registration.html Student Travel Grants: ====================== A limited number of travel grants for students is available. A call for applications will be issued separately. Information about travel grants will also be published on http://www.rdp07.org/grants.

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3rd announcement of (same) paper
by Michael Makkai 04 May '07

04 May '07

The paper "Computads and 2 dimensional pasting diagrams" has been re-posted on my website http://www.math.mcgill.ca/makkai/. The paper is in a single pdf. It incorporates fresh corrections with respect to the second announcement on April 26th. With greetings: Michael Makkai

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Announcement of paper
by Michael Makkai 03 May '07

03 May '07

The paper "Computads and 2 dimensional pasting diagrams" has been posted on my website http://www.math.mcgill.ca/makkai/. The paper is in several pdf files. With greetings: Michael Makkai

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ADDCT'07: LAST CFP: Abstract Submission Deadline May 4
by Ashish Tiwari 03 May '07

03 May '07

LAST CALL FOR PAPERS Automated Deduction: Decidability, Complexity, Tractability (ADDCT'07) Workshop affiliated with CADE-21 Bremen, Germany, 15 July, 2007 For complete information- http://www.mpi-inf.mpg.de/~sofronie/addct07.html Important Dates --------------- 4 May 2007: Abstract submission 9 May 2007: Paper submission 5 June 2007: Notification 15 July 2007: Workshop Topics of interest for ADDCT include (but are not restricted to): ----------------------------------------------------------------- - Decidability: - decision procedures based on logical calculi such as: resolution, rewriting, tableaux, sequent calculi, or natural deduction - decidability in combinations of logical theories - Complexity: - complexity analysis for fragments of first- (or higher) order logic - complexity analysis for combinations of logical theories (including parameterized complexity results) - Tractability (in logic, automated reasoning, algebra, ...) - Application domains for which complexity issues are essential (verification, security, databases, ontologies, ...) Submissions are encouraged in one of the following categories: -------------------------------------------------------------- - Original research papers (up to 15 pages, LNCS style, including bibliogra= phy); - Work in progress (up to 6 pages, LNCS style, without bibliography). - Presentation-only papers Submission of papers is via EasyChair at http://www.easychair.org/ADDCT2007= / Organizers and Chairs --------------------- Silvio Ghilardi (U. Milano) Ulrike Sattler (U. Manchester) Viorica Sofronie-Stokkermans (MPI,Saarbr=FCcken) Ashish Tiwari (Menlo Park) Program Committee ----------------- Matthias Baaz (T.U.Wien) Maria Paola Bonacina (U. Verona) Christian Ferm=FCller (T.U.Wien) Silvio Ghilardi (U. Milano) Reiner Haehnle (Chalmers U.) Felix Klaedtke (ETH Zurich) Sava Krstic (Intel Corporation) Viktor Kuncak (EPFL Lausanne) Carsten Lutz (TU Dresden) Christopher Lynch,(Clarkson U.) Silvio Ranise (LORIA/INRIA-Lorraine) Ulrike Sattler (U. Manchester) Renate Schmidt (U. Manchester) Viorica Sofronie-Stokkermans (MPI,Saarbr=FCcken) Ashish Tiwari (SRI) Luca Vigano (U. Verona) Contact For further informations please send an e-mail to Viorica Sofronie-Stokkermans sofronie(a)mpi-inf.mpg.de

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C*-algebras
by Bas Spitters 03 May '07

03 May '07

It seems hard to find references to a categorical treatment of C*-algebras. Concretely, there are several tensor products on C*-algebras. Which one is `the right one' from a categorical perspective? Thanks, Bas Spitters

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