December 1992 - Categories - categories.org.au

MFCS'93 second Call For Papers
by Wieslaw Pawlowski 21 Dec '92

21 Dec '92

SECOND AND FINAL CALL FOR PAPERS 18th International Symposium on MATHEMATICAL FOUNDATIONS OF COMPUTER SCIENCE Gdansk, Poland 30 August - 3 September 1993 SUBMISSION DEADLINE IS CLOSE ! 15 January 1993 The purpose of the symposia is to encourage high-quality research in all branches of Theoretical Computer Science and to provide an opportunity of bringing together specialists working actively in the area. The MFCS'93 symposium will be organized by the Institute of Computer Science of the Polish Academy of Sciences in Gdansk, Poland. Principal areas of interest of the symposium include: * software specification and development, * parallel and distributed computing, * semantics and logics of programs, * algorithms, complexity and computability, * database theory, * logic programming, * functional programming, * other related topics. The scientific programme will include invited lectures by - Krzysztof R. Apt (Amsterdam), - Andre Arnold (Bordeaux) - Rod M. Burstall (Edinburgh), - Volker Diekert (Stuttgart), - Matthew Hennessy (Brighton), - Furio Honsel (Udine), - Robin Milner (Edinburgh), - Andrew Pitts (Cambridge), - Vaughan Pratt (Stanford), - Grzegorz Rozenberg (Leiden), - Arto Salomaa (Turku), - Phil Wadler (Glasgow). The Programme Committee: J.Adamek (Prague), M.Bednarczyk (Gdansk), J.A.Bergstra (Amsterdam), A.Borzyszkowski (Gdansk), B.Courcelle (Bordeaux), H.-D.Ehrich (Braunschweig), I.Havel (Prague), G.Huet (Paris), N.Jones (Copenhagen), E.Moggi (Genova), V.Nepomniaschy (Novosibirsk), E.-R.Olderog (Oldenburg), F.Orejas (Barcelona), A.Poigne (St.Augustin), I.Sain (Budapest), D.Schmidt (Manhattan, Kansas), S.Sokolowski (Gdansk) and M.Wirsing (Munich). Authors are invited to submit 5 copies of a draft paper to S.Sokolowski The length of the final paper should not exceed 10 pages, size A4, at 12pt. Each contribution accompanied by a cover sheet containing eight-line abstract and detailed author's affiliation and address (fax, telex and e-mail are welcome). All the received contributions will be carefully refereed. The authors will be notified immediately. The accepted papers will be published in proceedings distributed at the conference. The publisher is Springer-Verlag, as usual for MFCS symposia. Submission deadline: 15 January 1993 Notification of the decision: 5 April 1993 Final versions due: 10 May 1993 The symposium is intended to be low budget. The organizers attempt to raise some financial support to partly cover the cost of attendance by the researchers from Central/Eastern Europe and from the former USSR. Any further information about the symposium may be obtained from Marek Bednarczyk, the Organizing Committee chairman, or from Stefan Sokolowski, the Programme Committee chairman, under the address: MFCS'93 Institute of Computer Science of the Polish Academy of Sciences ul. Jaskowa Dolina 31, P.O.Box 562, 80--252 Gdansk, Poland tel. ++48 58 419015 ext.26 or ++48 58 419034 ext.26 telex: 512233 pan pl, fax: ++48 58 416912 The organizers may also be contacted by e-mail under SSokolow(a)plearn.bitnet. Please DO NOT send contributions by e-mail!

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Recoltes et Semailles
by cxm7＠pop.cwru.edu 21 Dec '92

21 Dec '92

------------- I would very much like to read the first two parts of Grothendieck's _Recoltes et Semailles_, that is: Fatuite et Renouvellement and L'Enterrement I, ou la robe de L'Empereur de Chine These were already unavailable from the dept at Montpellier some years ago, when they did send me _l'Enterrement_ II and III and three smaller volumes. There was talk about them being published as a book, but I do not believe they have been. I would be grateful if any one could arrange to lend me a copy (or sell me one). Colin ==============================================================================

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More on amazing results
by barr＠triples.Math.McGill.CA 19 Dec '92

19 Dec '92

>From jean(a)saul.cis.upenn.edu Fri Dec 18 14:01:15 1992

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Amazing results
by CATEGORIES＠mta.ca 19 Dec '92

19 Dec '92

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Addendum to Kurt W.A.J.H.Y Riellag's
by Jean Gallier 19 Dec '92

19 Dec '92

Sorry, but I had missed the last page (wine bottle label) of his letter. 1. His results also show that Unconstrained logic deprogramming a is regressively nonproductive and self satisfied. 2. He intended to submit this aper to LICS, but missed the deadline. 3. I was informed by Diaconescu that most of his results are in fact folklore. Every Roumanian child knows about the undertopos. -- Jean ==============================================================================

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None
by barr＠triples.Math.McGill.CA 19 Dec '92

19 Dec '92

The following results are so amazing that I think they deserve widest possible circulation. --Mike >From jean(a)saul.cis.upenn.edu Fri Dec 18 11:45:25 1992

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SPECIAL TALK, AMAZING RESULTS!!!!!!!!!!!
by Jean Gallier 19 Dec '92

19 Dec '92

__ __ __ | / \ / | / | | | | _ | | |___ \__/ \__/ | \__ A N D __ __ ___ ___ ___ . __ / / \ |\ /| | \ | | | /\ | | / \ |\ | | | | | V | |__/ | | | /__\ | | | | | \| \__ \__/ | | | |__| | / \ | | \__/ | | T H E S E M I N A R Thursday, December 31, 1992 nidnight University of Pennsylvania DDDDLL 44E-7817 Linear Logic is nonregressively productive and not self-realizable, Nonmonotonic Logic is regressively nonproductive and self satisfied. Kurt W.A.J.H.Y Riellag Auspices de Beaune ABSTRACT: The amazing results quoted in the title are proved. They have unprecedented and unpredictable consequences such as: 1. Linear logic being nonregressively productive, no matter how good a theorem you produce, a harder and better one is waiting out there. 2. Linear logic is never satisfied with itself, which means that it is an infinite source of new results. In contrast, 3. Nonmonotonic logic being regressively nonproductive, no matter how bad a result you produce, there is a worse one waiting out there. 4. This does not matter anyway, since nonmonotonic logic is self satisfied. There are other incredible consequences of these results. For example, the discontinuum hypothesis is independent of NMZF (nonmonotonic ZF), and Riemann's Hypothesis gives in. The proof techniques are the most revolutionary aspect of this work. The main new concept is that of an FBI sheaf. To define an FBI sheaf, it was necessary to define a variant of Grothendieck topologies, named undercover agents. Then, an undertopos is like a topos, except that it has a subobject declassifier. An FBI site is a category with undercover agents. FBI sheaves cannot be glued, but they can be shredded. By iterating sheaf shredding long enough, we get an FBI sheaf sufficiently small that, it splits (et oui!). This is why the French say: "Voila le topo(s)". The most amazing of all is that in fact, using Freyd undercovers and the fact that A => A is intuitionistically provable, we get that every FBI sheaf over a big site is nonregressive. This is because all undercover agents eventually split. It it then an easy matter to get our fundamental results. They explain a lot, in particular about funding. Note from the moderator: I received (hard)-mail from Kurt W.A.J.H.Y Riellag late last night. Kurt W.A.J.H.Y Riellag is an illegitimate descendant of the well known Bourbaki. He has been working on these results for many years while bottling wine in the caves at Beaune. Amazingly enough, Kurt W.A.J.H.Y Riellag has no diplommas whatsoever, but he knows his wines (and cheese). Unfortunately, I learned this morning that Kurt W.A.J.H.Y Riellag went for his annual retreat at some unknown mountain winery. This means that someone here at Penn will have to give the talk if we want to hear it. I did receive a large stack of wine bottle labels containing the entire paper scribbled on them. --Jean And by the way, MERRY CHRISTMAS, and HAPPY NEW YEAR!!!!!!! The next talk after Kurt W.A.J.H.Y Riellag will be on January 18. Speaker: Ross Street. ==============================================================================

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JOB: category theory and/or the semantics of computation
by cbj＠dcs.ed.ac.uk 09 Dec '92

09 Dec '92

A message from Birmingham, England follows, which seems relevant here. ------- Forwarded Message

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temporary lectureship in computer science
by Aaron Sloman 08 Dec '92

08 Dec '92

We recently advertised a two year temporary lectureship, to replace someone who has been granted leave to work on a research fellowship. We've had quite a lot of applicants, some of them quite impressive, but what we'd most like is someone whose research can build in existing work here in category theory and/or the semantics of computation So if you know of an RA coming to the end of a job, or nearly finished research student, who might welcome an appointment, please ask him/her to get in touch with me as soon as possible (preferably by Monday 14th Dec) with CV, names of referees and full details of research interests, etc. It must be someone really good for the area of reserch to outweigh the quality of other applicants. The preferred start date is beginning of April, but a shortish delay could be tolerated for the right person. The job will involve teaching, and the person should be a good communicator, but we expect to provide time for research also. Unfortunately I shall be away Thursday till Sunday, so may not respond immediately. Thanks for your help. Aaron Aaron Sloman, School of Computer Science, The University of Birmingham Edgbaston Birmingham B15 2TT England EMAIL A.Sloman(a)cs.bham.ac.uk or A.Sloman(a)bham.ac.uk Phone: Office +44-(0)21-414-3711 Fax: +44-(0)21-414-4281 ------- End of Forwarded Message From: SMTP%"CATEGORIES" 18-DEC-1992 16:38:45.85 To: rrosebrugh(a)macc2.mta.ca CC: Subj: Amazing results

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Lemma on fibrations
by mxh＠dcs.ed.ac.uk 08 Dec '92

08 Dec '92

I'm looking for a reference for the following lemma on composition of fibrations Let p:E->B and r:B->A be fibrations and D be a subcategory of A-> stable under pullback. If r has indexed products along morphisms in D and if p has indexed products along all cartesian maps above something in D then the composition rp has indexed products along D, too and the Beck-Chevalley condition holds. Martin Hofmann, Edinburgh ==============================================================================

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