From MAILER-DAEMON Sun Apr 27 16:19:26 2003 Date: 27 Apr 2003 16:19:26 -0300 From: Mail System Internal Data Subject: DON'T DELETE THIS MESSAGE -- FOLDER INTERNAL DATA Message-ID: <1051471166@mta.ca> X-IMAP: 1049303059 0000000029 Status: RO This text is part of the internal format of your mail folder, and is not a real message. It is created automatically by the mail system software. If deleted, important folder data will be lost, and it will be re-created with the data reset to initial values. From rrosebru@mta.ca Wed Apr 2 12:57:04 2003 -0400 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 02 Apr 2003 12:57:04 -0400 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 190lRm-0000D6-00 for categories-list@mta.ca; Wed, 02 Apr 2003 12:50:46 -0400 Date: Wed, 2 Apr 2003 10:09:35 +0100 Message-Id: <200304020909.h3299Zi06981@calaf.crn.cogs.susx.ac.uk> From: Vladimiro Sassone To: categories@mta.ca Subject: categories: cfp: FGC: Foundations of Global Computing Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 1 =09=09 FGC: Foundations of Global Computing =09=09=09 2nd EATCS Workshop =09 =09=09 co-located with ICALP2003 =09 28-29 June 2003, Eindhoven, The Netherlands =09=09 Call for papers =09=09 ^^^^^^^^^^^^^^^^^ Aims and Scope Foundations of Global Computing focuses on foundational aspects of global computing, and invites submissions of original scientific work thereof. A non-exclusive list of topics includes: * calculi, models, and semantic theories of concurrent, distributed, mobile, global-computing systems; * languages, security, types, protocols and algorithms for global computing. Further points of specific interest are grid computing, peer-to-peer systems, game-theoretic approaches, protocol analysis, trust management, language-based security, ... The workshop proceedings will be published in the ENTCS series and a selection of papers will appear in a special issue of a leading Computer Science journal. It will be held as a ICALP2003 satellite event under the auspices of the EATCS. Invited Speakers C=E9dric Fournet (Microsoft Research) Robert Harper (CMU) Martin Hofmann (LMU Munich) Li Gong (SUN Microsystems) (joint speaker with twin SecCo`03) Programme Committee Luca Cardelli (Microsoft) Rocco De Nicola (Florence) Andrew D. Gordon (Microsoft) Jan van Leeuwen=09(Utrecht) John C. Mitchell (Stanford) Eugenio Moggi=09(Genoa) Ugo Montanari (Pisa) Greg Morrisett (Cornell) Mogens Nielsen (Aarhus) Don Sannella (Edinburgh) Vladimiro Sassone (Sussex) Vasco T. Vasconcelos (Lisbon) Martin Wirsing (LMU Munich) Important Dates Submission 27 Apr 2003 (midnight GMT-11 -- Samoa time) Notification 2 Jun 2003 PreFinal version 15 Jun 2003 Final version 31 Jul 2003 Submissions Authors are invited to submit an extended abstract of their papers, presenting original contributions to the workshop themes. Submissions should be in English and not exceed 15 standard pages. They should be sent as PS or PDF files to fgc@cogs.susx.ac.uk and be accompanied by a text-only message containing: title, abstract and keywords, the authors' full names, and address and e-mail for correspondence. Simultaneous submission to other meetings with published proceedings is not allowed. Organising Committee * Erik de Vink (Eindhoven) From rrosebru@mta.ca Fri Apr 4 20:08:48 2003 -0400 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Fri, 04 Apr 2003 20:08:48 -0400 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 191b7j-0001nV-00 for categories-list@mta.ca; Fri, 04 Apr 2003 20:01:31 -0400 Message-ID: <3E8C20E0.5DF09992@cwi.nl> Date: Thu, 03 Apr 2003 13:54:08 +0200 From: frb Organization: cwi X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.4.3-12 i686) X-Accept-Language: en MIME-Version: 1.0 To: mobij-list@cwi.nl Subject: categories: FMCO 2003: Call for Participation Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: cat-dist@mta.ca Precedence: bulk Status: RO X-Status: X-Keywords: X-UID: 2 (We apologize for the reception of multiple copies) ANNOUNCEMENT OF The Second International Symposium on Formal Methods for Components and Objects (FMCO 2003) DATES 4 - 7 November, 2003 PLACE Lorentz Center, Leiden University, Leiden, The Netherlands URL http://fmco.liacs.nl/fmco03.html OBJECTIVE The objective of this symposium is to bring together researchers and practioners in the areas of software engineering and formal methods to discuss the concepts of reusability and modifiability in component-based and object-oriented software systems. FORMAT The symposium is a four days event in the style of the former REX workshops,organized to provide an atmosphere that fosters collaborative work, discussions and interaction. The program consists of keynote and technical presentations, and contains an exquisite social event. Speakers' contributions will be published after the symposium in Lecture Notes in Computer Science by Springer-Verlag. KEYNOTE SPEAKERS Desmond D'Souza (Kinetium, Austin, USA) E. Allen Emerson (University of Texas at Austin, USA) Andrew D. Gordon (Microsoft Research, UK) Yuri Gurevich (Microsoft Research, USA) Tony Hoare (Microsoft Research, UK) David Parnas (University of Limerick, IE) Joseph Sifakis (Verimag, FR) TECHNICAL PRESENTATIONS Albert Benveniste (IRISA/INRIA - Rennes, FR) Frank de Boer (CWI, NL) Egon Boerger (Pisa University, IT) Werner Damm (University of Oldenburg, DE) Razvan Diaconescu (IMAR, RO) Gregor Engels (University of Paderborn, DE) Jose Luiz Fiadeiro (University of Leicester, UK) Jan Friso Groote (Eindhoven University of Technology, NL) Jean-Marc Jezequel (IRISA, Rennes, FR) Bengt Jonsson (Uppsala University, SE) Yassine Lakhnech (University of Grenoble, FR) Rob van Ommering (Philips Research Laboratories, NL) Amir Pnueli (The Weizmann Institute of Science, ISR) Willem-Paul de Roever (University of Kiel, DE) Jan Rutten (CWI, Amsterdam, NL) Philippe Schnoebelen (CNRS, Cachan, FR) Natalia Sidorova (Eindhoven University of Technology, NL) Heike Wehrheim (University of Oldenburg, DE) Jeannette Wing (Carnegie Mellon University, USA) REGISTRATION Participation is limited to about 80 people, using a first-in first-served policy. To register, please fill in the registration form at http://fmco.liacs.nl/fmco03.html. The EARLY registration fee (BEFORE September 15, 2003) is 375 euro for regular participants and 250 euro for students. It includes the participation to the symposium, a copy of the proceedings, all lunches and refreshments, and a social event (with dinner). ORGANIZING COMMITTEE F.S. de Boer (CWI and Utrecht University) M.M. Bonsangue (LIACS-Leiden University) S. Graf (Verimag) W.P. de Roever (CAU) For more information about participation and registration see the FMCO site above or consult either F.S. de Boer (frb@cwi.nl) or M.M. Bonsangue (marcello@liacs.nl). From rrosebru@mta.ca Sat Apr 5 15:25:36 2003 -0400 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sat, 05 Apr 2003 15:25:36 -0400 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 191tDn-0002Z9-00 for categories-list@mta.ca; Sat, 05 Apr 2003 15:20:59 -0400 From: Topos8@aol.com Message-ID: Date: Fri, 4 Apr 2003 14:02:52 EST Subject: categories: Models for infinitesimal analysis To: categories@mta.ca MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 3 In 1991 Springer published "Models for smooth infinitesimal analysis" by Moerdijk and Reyes. It is now out of print. Can anyone suggest a source from which I might obtain a used copy? I've tried Amazon which listed a used copy for sale but it turned out that it had been already sold. Carl Futia From rrosebru@mta.ca Mon Apr 7 10:59:03 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 07 Apr 2003 10:59:03 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 192X4X-0001Dp-00 for categories-list@mta.ca; Mon, 07 Apr 2003 10:54:05 -0300 Date: Mon, 07 Apr 2003 10:49:24 +0100 From: Steve Vickers User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.3) Gecko/20030312 X-Accept-Language: en-us, en MIME-Version: 1.0 To: categories-approval@mta.ca Subject: categories: change of address Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: cat-dist@mta.ca Precedence: bulk Message-Id: Status: O X-Status: X-Keywords: X-UID: 4 Dear Categories list, Please note my new email address at Birmingham University (no longer s.j.vickers@open.ac.uk): s.j.vickers@cs.bham.ac.uk All the best, Steve Vickers. From rrosebru@mta.ca Tue Apr 8 21:13:26 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 08 Apr 2003 21:13:26 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 19338U-0006zX-00 for categories-list@mta.ca; Tue, 08 Apr 2003 21:08:18 -0300 Mime-Version: 1.0 X-Sender: PTEvent@Janeway.Inf.TU-Dresden.DE (Unverified) Message-Id: Date: Tue, 8 Apr 2003 18:56:33 +0200 To: categories@mta.ca From: "Proof Theory, Computation and Complexity" Subject: categories: Proof Theory, Computation and Complexity - Announcement Content-Type: text/plain; charset="us-ascii" ; format="flowed" Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 5 Summer School and Workshop on Proof Theory, Computation and Complexity Technische Universitaet Dresden June 23-July 4, 2003 Preliminary Program and Call for Participation We plan the following courses and workshop for graduate students and researchers. Like for last year's events on Proof Theory and Computation (Dresden) and Proof, Computation, Complexity (Tuebingen), we aim at a meeting where people have plenty of time to exchange ideas. The summer school consists of eight advanced courses; the workshop takes place in the last two days. For participating in the summer school we ask for a small fee (currently undetermined). We are looking into the possibility of providing grants to participants who ask for them. Registration is requested, please send an email to , making sure you include a very brief bio (5-10 lines) stating your experience, interests, home page, etc. We will select applicants in case of excessive demand. We will provide assistance in finding an accommodation in Dresden. Week 1, June 23-27: courses on Denotational Semantics of Lambda Calculi Achim Jung (Birmingham, UK) Proof Theory with Deep Inference Alessio Guglielmi (Dresden, Germany) Five Lectures on Proof-Analysis Sara Negri (University of Helsinki and Academy of Finland) Mass Problems Stephen Simpson (Penn State, USA) Week 2, June 30-July 2: courses on Natural Deduction: Some Recent Developments Jan von Plato (Helsinki, Finland) Semantics and Cut-elimination for Church's (Intuitionistic) Theory of Types, with Applications to Higher-order Logic Programming Jim Lipton (Wesleyan, USA) Dependent Type Theories Peter Aczel (Manchester, UK) Term-rewriting and Termination in Proof Theory Roy Dyckhoff (St Andrews, Scotland) July 3-4: workshop (consult the web site for details) Dresden, on the river Elbe, is one of the most important art cities of Germany. You can find world-class museums and wonderful architecture and surroundings. We will organize trips and social events. This program is still subject to variation, please check the web site. Please distribute this message broadly. From rrosebru@mta.ca Wed Apr 9 11:16:48 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 09 Apr 2003 11:16:48 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 193GK8-0002xh-00 for categories-list@mta.ca; Wed, 09 Apr 2003 11:13:12 -0300 Message-Id: <200304090526.h395PxC26942@math.u-strasbg.fr> Date: Wed, 9 Apr 2003 07:25:59 +0200 (MEST) From: Philippe Gaucher Subject: categories: preprint : Homotopy branching space and weak dihomotopy To: categories@mta.ca X-Mailer: dtmail 1.3.0 @(#)CDE Version 1.4.2 SunOS 5.8 sun4u sparc Content-Type: text X-Sun-Text-Type: ascii X-Antivirus: scanned by sophos at u-strasbg.fr Sender: cat-dist@mta.ca Precedence: bulk Status: RO X-Status: X-Keywords: X-UID: 6 Author : Philippe Gaucher Title : Homotopy branching space and weak dihomotopy Abstract : The branching space of a flow is the topological space of germs of its non-constant execution paths beginning in the same way. However, there exist weakly S-homotopy equivalent flows having non weakly homotopy equivalent branching spaces. This topological space is then badly behaved from a computer-scientific viewpoint since weakly S-homotopy equivalent flows must correspond to higher dimensional automata having the same computer-scientific properties. To overcome this problem, the homotopy branching space of a flow is introduced as the left derived functor of the branching space functor from the model category of flows to the model category of topological spaces. As an application, we use this new functor to correct the notion of weak dihomotopy equivalence, which did not identify enough flows in its previous version. Comments : 44 pages, 3 figures Url : http://www-irma.u-strasbg.fr/~gaucher/ or Arxiv : math.AT/0304112 From rrosebru@mta.ca Thu Apr 10 12:19:54 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 10 Apr 2003 12:19:54 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 193dlt-0003aC-00 for categories-list@mta.ca; Thu, 10 Apr 2003 12:15:25 -0300 Message-Id: <200304100232.h3A2WP703703@synaphai.kurims.kyoto-u.ac.jp> To: categories@mta.ca Subject: categories: preprint: a paper on *-autonomous categories and linear logic Date: Thu, 10 Apr 2003 11:32:25 +0900 From: Hasegawa Masahito Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 7 Dear colleagues, The following short paper Coherence of the Double Involution on *-Autonomous Categories by J.R.B. Cockett, M. Hasegawa and R.A.G. Seely available from the authors' pages http://www.kurims.kyoto-u.ac.jp/~hassei/papers/#STAR http://www.math.mcgill.ca/rags/ might be of some interest for those woking on proof theory/type theory and semantics of Linear Logic. It addresses the following "coherence" question. Many formulations of proof nets and sequent calculi for Classical Linear Logic (CLL) take it for granted that a type A is "identical" to its double negation A^{\bot\bot}. On the other hand, it has been assumed that *-autonomous categories are the appropriate semantic models of (the multiplicative fragment of) CLL. However, in general, in a *-autonomous category an object A is only "canonically isomorphic" to its double involution A^{**}. This raises the questions whether *-autonomous categories do not, after all, provide an accurate semantic model for these proof nets and whether there could be semantically non-identical proofs (or morphisms), which must be identified in any system which assumes a type is identical to its double negation. Fortunately, there is no such semantic gap: in this paper we provide a "coherence theorem" for the double involution on *-autonomous categories, which tells us that there is no difference between the up-to-identity approach and the up-to-isomorphism approach, as far as this double-negation problem is concerned. This remains true under the presence of exponentials and/or additives. Our proof is fairly short and simple, and we suspect that this is folklore among specialists, though we are not aware of an explicit treatment of this issue in the literature. Best, Robin Cockett Masahito Hasegawa Robert Seely From rrosebru@mta.ca Mon Apr 14 11:28:27 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 14 Apr 2003 11:28:27 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 1954pQ-0004NO-00 for categories-list@mta.ca; Mon, 14 Apr 2003 11:21:00 -0300 Date: Fri, 11 Apr 2003 05:28:59 +0100 Message-Id: <200304110428.h3B4Sxa15069@glory.dcs.ed.ac.uk> X-Authentication-Warning: glory.dcs.ed.ac.uk: als set sender to als+lics-junk@inf.ed.ac.uk using -f To: categories@mta.ca From: Alex Simpson Subject: categories: LICS 2003 - Call for Participation Reply-To: als+lics-junk@dcs.ed.ac.uk Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 8 Eighteenth Annual IEEE Symposium on LOGIC IN COMPUTER SCIENCE (LICS 2003) June 22 - 25, 2003, Ottawa, Canada http://www.dcs.ed.ac.uk/home/als/lics/lics03/ CALL FOR PARTICIPATION (early registration deadline is May 20, 2003) The LICS Symposium is an annual international forum on theoretical and practical topics in computer science that relate to logic in a broad sense. The conference is intended to emphasize the relevance of logic to computer science. The program of LICS 2003 features 4 invited talks, 2 invited tutorials, 34 contributed papers, and 14 short presentations. Invited Talks: - Erich Graedel (RWTH Aachen): "Will deflation lead to depletion? On non-monotone fixed point inductions" - John Harrison (Intel Corp.): "Formal verification at Intel" - Marta Kwiatkowska (U. Birmingham) "Model checking for probability and time: from theory to practice" - John McCarthy (Stanford U.) "Advice about nonmonotonic reasoning in AI" Invited Tutorials: - Martin Abadi (UC Santa Cruz): "Logic in Access Control" - Benjamin Pierce (U. Pennsylvania) "Types and Programming Languages: The Next Generation" The full program of LICS 2003 is available on the conference website http://www.dcs.ed.ac.uk/home/als/lics/lics03/ Affiliated Workshops: As in previous years, there will be a number of workshops affiliated with LICS 2003: - June 21: Probability in AI Organizer: Doina Precup - June 21: Typical Case Complexity and Phase Transitions, Organizers: Evangelos Kranakis and Lefteris Kirousis - June 26: Logic and Computational Linguistics Organizers: Gerald Penn and Leonid Libkin - June 26: Causality in Computer Science and Physics Organizer: Prakash Panangaden - June 26-27: Foundations of Computer Security Organizer: Iliano Cervesato - June 26-27 Implicit Computational Complexity Program chair: Anuj Dawar Pre-LICS Summer School: The Fields Institute Summer School on Logic and Foundations of Computation will be held at the University of Ottawa, June 2-20, 2003 For information, see the summer school web site at: http://www.mathstat.uottawa.ca/lfc/fields2003/ Registration: LICS 2003 registration and conference information is now available on the LICS 2003 website or directly at: http://www.mathstat.uottawa.ca/lfc/lics2003/ The DEADLINE FOR EARLY REGISTRATION is Tuesday, May 20, 2003. From rrosebru@mta.ca Tue Apr 15 16:47:13 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 15 Apr 2003 16:47:13 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 195WJs-0001TH-00 for categories-list@mta.ca; Tue, 15 Apr 2003 16:42:16 -0300 From: Peter Selinger Message-Id: <200304150324.h3F3O9R32103@quasar.mathstat.uottawa.ca> Subject: categories: Ottawa Summer School + Workshops: Call for Participation To: categories@mta.ca (Categories List) Date: Mon, 14 Apr 2003 23:24:09 -0400 (EDT) X-Mailer: ELM [version 2.5 PL3] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: cat-dist@mta.ca Precedence: bulk Status: RO X-Status: X-Keywords: X-UID: 9 Fields Institute Summer School and Workshops Logic and Foundations of Computation University of Ottawa, Canada June 2-20, 2003 http://www.mathstat.uottawa.ca/lfc/fields2003/ CALL FOR PARTICIPATION Dormitory registration deadline: April 25 Dear Colleagues: June will be theoretical computer science month at U. Ottawa! The Fields Institute is sponsoring a summer school in Logic and Foundations of Computation, which will take place in the 3 weeks preceding the LICS conference at the University of Ottawa. This program will be hosted by the logic group in the Department of Mathematics and Statistics (Philip Scott, Richard Blute, and Peter Selinger), together with many distinguished visitors. The program consists of 2 weeks of courses, then a week of research workshops in several areas of theoretical computer science. Courses (Morning and Afternoons) Include: ========================================= Week 1: (i) Categorical Logic and (ii) Linear Logic (Taught by the Logic Group, with Guests: Thomas Ehrhard (Marseille), Robert Seely (McGill), Robin Cockett (Calgary), et al) Week 2: (i) Game Semantics and (ii) Concurrency Theory. The courses are given by Samson Abramsky and Guy McCusker for (i), and Glynn Winskel for (ii). Workshops: ========== June 15-16: Quantum Programming Languages (Org: P. Selinger) http://www.mathstat.uottawa.ca/lfc/fields2003/quantum.html June 17: Game Semantics (Org: S. Abramsky) http://www.mathstat.uottawa.ca/lfc/fields2003/games.html June 18-19: Mathematical Linguistics (Org: J. Lambek) http://www.mathstat.uottawa.ca/lfc/fields2003/linguistics.html June 19-20: Mobility Workshop (Org: G. Winskel) http://www.mathstat.uottawa.ca/lfc/fields2003/mobility.html The program culminates in the 18th annual IEEE Logic in Computer Science (LICS2003) meeting and LICS workshops, held from June 21-27 at U. Ottawa. For the latter, see http://www.dcs.ed.ac.uk/home/als/lics/. To register, please follow the links on our website to the Fields Institute, http://www.mathstat.uottawa.ca/lfc/fields2003/. PLEASE NOTE: Special Dorm Accommodations (2 bedroom apartment suites) must be prebooked by April 25, or they are lost and it's then on a first-come, first-served basis. For further information, please send mail to: fields@mathstat.uottawa.ca Sincerely, Philip Scott Richard Blute Peter Selinger Dept. of Mathematics & Statistics U. Ottawa From rrosebru@mta.ca Fri Apr 18 14:19:32 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Fri, 18 Apr 2003 14:19:32 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 196ZRz-0001fM-00 for categories-list@mta.ca; Fri, 18 Apr 2003 14:14:59 -0300 Date: Wed, 16 Apr 2003 16:41:53 -0400 (EDT) From: japaridze g Message-Id: <200304162041.QAA21398@monet.vill.edu> To: categories@mta.ca Subject: categories: Last call: Conference on Algebraic and Topological Methods in Non-Classical Logics Sender: cat-dist@mta.ca Precedence: bulk Status: RO X-Status: X-Keywords: X-UID: 11 INTERNATIONAL CONFERENCE ON ALGEBRAIC AND TOPOLOGICAL METHODS IN NON-CLASSICAL LOGICS Tbilisi, Georgia, 7 - 11 July 2003 The aim of this conference is to present some recent advances in the use of algebraic, order-theoretic, and topological methods in non-classical logics. We also hope to bring together researchers in the fields of non-classical logics, lattice theory, universal algebra, category theory, and general topology in order to foster collaboration and to get new ideas for further research. CONFERENCE TOPICS: Lattices with operators Topological semantics of modal logic Topological and topos semantics of intuitionistic logic Ordered topological spaces. INVITED SPEAKERS: Leo Esakia, Georgian Academy of Sciences Mai Gehrke, New Mexico State University John Harding, New Mexico State University Ramon Jansana, University of Barcelona Joachim Lambek, McGill University Daniele Mundici, Milan University Yde Venema, University of Amsterdam Michael Zakharyaschev, King's College Marek Zawadowski, University of Warsaw CALL FOR PAPERS: If you wish to speak at the conference, please send by email a title and abstract of your talk to Guram Bezhanishvili (gbezhani@nmsu.edu). The deadline for submissions is 1 May. We will let you know by 15 May if you will be invited to speak at the conference. The deadline to register for the conference is 1 June. LOCATION: Tbilisi State University, Tbilisi, Georgia WEB SITE: http://piscopia.nmsu.edu/morandi/TbilisiConference IMPORTANT DATES: Submission deadline: 1 May 2003 Notification of acceptance: 15 May 2003 Registration deadline: 1 June 2003 Conference: 7 - 11 July 2003 PROGRAM COMMITTEE: Guram Bezhanishvili, New Mexico State University Patrick Morandi, New Mexico State University Willem Blok, University of Illinois at Chicago Roberto Cignoli, University of Buenos Aires Josep Maria Font, University of Barcelona Dick de Jongh, University of Amsterdam Larisa Maksimova, Russian Academy of Sciences, Novosibirsk Hiroakira Ono, Japan Advanced Institute of Science and Technology Rohit Parikh, City University of New York Lazare Zambakhidze, Tbilisi State University ORGANIZATIONAL COMMITTEE: Merab Abashidze, Georgian Academy of Sciences Nick Arevadze, Georgian Academy of Sciences Nick Bezhanishvili, University of Amsterdam David Gabelaia, King's College Revaz Grigolia, Georgian Academy of Sciences Giorgi Japaridze, Villanova University Mamuka Jibladze, Georgian Academy of Sciences Ioseb Khutsishvili, Tbilisi State University Dimitri Pataraia, Georgian Academy of Sciences Levan Uridia, Tbilisi State University ORGANIZING INSTITUTIONS: New Mexico State University Tbilisi State University Georgian Academy of Sciences This conference is part of the activity of a grant funded by the Civil Research Development Fund and the Georgian Research Development Fund. For further information, contact Guram Bezhanishvili (gbezhani@nmsu.edu) orPat Morandi (pmorandi@nmsu.edu). From rrosebru@mta.ca Mon Apr 21 13:52:45 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 21 Apr 2003 13:52:45 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 197eTB-0004hz-00 for categories-list@mta.ca; Mon, 21 Apr 2003 13:48:41 -0300 Date: Mon, 21 Apr 2003 11:16:21 -0400 (EDT) From: Peter Freyd Message-Id: <200304211516.h3LFGLoB023897@saul.cis.upenn.edu> To: categories@mta.ca Subject: categories: Category Theorists in Montreal Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 12 [I thought it wise to share this announcement. -pjf] In the 12 days from June 30th to July 11 2003, Montreal will be the Categorization Capital of the Cognitive World. The latest developments in all aspects of categorization will be described and debated across the cognitive sciences spectrum: cognitive anthropology, computer science, linguistics, cognitive neuroscience, philosophy and psychology. The University of Quebec/Montreal will host this Cognitive Sciences Summer Institute. A sample of only a few of the over 50 speakers. For the full programme: http://www.unites.uqam.ca/sccog/liens/program.html Partial List: June 30th 2003 Categorization in cognitive sciences (all disciplines) Categorization in cognitive neuroscience, Stephen Grossberg, Boston University Categorization in psychology, Stevan Harnad, Universit=E9 du Qu=E9bec =E0 Montr=E9al Categorization in cognitive computer science, John F. Sowa, VivoMind LLC Categorization in linguistics, Pieter Muysken, Universiteit van Nijmegen Categorization in philosophy, Georges Rey, University of Maryland Discussant: On categorization in cognitive sciences, Anna Papafragou, University of Pennsylvania July 1st 2003 Semantic categories (anthropology, linguistics, philosophy, psychology) Emotions categories across languages, Jim Boster, University of Connecticut Semantic categorization, Brendan Gillon, McGill University Categorisation and conceptual change, Paul Thagard, University of Waterloo Color categories across languages, Paul Kay, University of California at Berkeley Discussant: On semantic categories, Seana Coulson, University of California at San Diego July 2nd 2003 Syntactic categories and category change (linguistics) A state of the art on syntactic categories, Arnold Zwicky, Stanford University Cross-categorial and multifunctional categories, Lisa Travis, McGill University Cross-categorial constructions, Rob Malouf, San Diego State University On category change, Ian Roberts, University of Cambridge Discussant: On syntactic categories, Pieter Muysken, Universiteit van Nijmegen July 3rd 2003 (linguistics and psychology) Categories in spoken and signed languages Syntactic categories in sign languages with particular reference to LSQ, Denis Bouchard and Colette Dubuisson, Universit=E9 du Qu=E9bec =E0 Montr=E9al Syntactic categories in sign languages with particular reference to ASL, Judy Kegl, University Southern Maine Syntactic categories in signed versus spoken languages, Diane Lillo-Martin, University of Connecticut Acquisition of categories A state of the art on the acquisition of syntactic categories in L1, Marie Labelle, Universit=E9 du Qu=E9bec =E0 Montr=E9al Syntactic categories in L2 acquisition, Lydia White, McGill University On categorisation and acquisition, Eve Clark, Stanford University July 4th 2003 Data mining for categories and ontologies (cognitive computer science, philosophy) Computer-aided categorization, Jean-Guy Meunier, Universit=E9 du Qu=E9bec =E0 Montr=E9al Discussant: On data mining for categories and ontologies, John F. Sowa, VivoMind LLC July 7th 2003 Neuroscience of categorization and category learning (psychology, philosophy) Neuropsychology of category learning, FG. Ashby, University of California at Santa Barbara Striatum and category learning, WT. Maddox, University of Texas at Austin Brain basis of category learning, John Gabrieli, Stanford University Brain damage and categorical speech perception and production, Susan Ravizza, University of Pittsburgh Neural network models of categorization: philosophical issues, Pierre Poirier, Universit=E9 du Qu=E9bec =E0 Montr=E9al Discussant: On neuroscience of categorization and category learning, Henri Cohen, Universit=E9 du Qu=E9bec =E0 Montr=E9al July 8th 2003 Machine category learning (cognitive computer science, philosophy, robotics) Categories and conceptual spaces, Peter Gardenfors, Lund University Similarity in fuzzy categories, Didier Dubois and Henri Prade, Universit=E9 Paul Sabatier July 9th 2003 Categories in perception and inference (psychology, philosophy) Category representation, Rob Nosofsky, Indiana University Category learning, Rob Goldstone, Indiana University Categorization and inference, Arthur Markman, University of Texas at Austin Discussant: On categories in perception and inference, Seana Coulson, University of California at San Diego July 10th 2003 Grounding, recognition, and reasoning in categorization (psychology, philosophy) Neural networks and categorization, Robert Proulx, Universit=E9 du Qu=E9bec =E0 Montr=E9al Categorization and reasoning, Serge Robert, Universit=E9 du Qu=E9bec =E0 Montr=E9al Discussant: On grounding, recognition and reasoning in categorization, Stevan Harnad, Universit=E9 du Qu=E9bec =E0 Montr=E9al July 11th 2003 The naturalization of categories (philosophy) The social construction of categories, Luc Faucher, Universit=E9 du Qu=E9bec =E0 Montr=E9al A neurosemantic for categories, Chris Eliasmith, University of Waterloo Computer text analysis and categorization, Jean-Guy Meunier, Universit=E9 du Qu=E9bec =E0 Montr=E9al From rrosebru@mta.ca Tue Apr 22 15:29:46 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 22 Apr 2003 15:29:46 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 1982Sk-0006Om-00 for categories-list@mta.ca; Tue, 22 Apr 2003 15:25:50 -0300 Date: Tue, 22 Apr 2003 14:00:15 -0400 (EDT) From: Peter Freyd Message-Id: <200304221800.h3MI0Fab004612@saul.cis.upenn.edu> To: categories@mta.ca Subject: categories: Centenary Medal to Max Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 13 Copyright 2003 John Fairfax Publications Pty Ltd Sydney Morning Herald April 22, 2003 Tuesday SECTION: News And Features; Pg. 4 LENGTH: 292 words HEADLINE: A Plus For Unifying Maths BYLINE: Peter Munro BODY: Max Kelly, 72, is modest about his Centenary Medal for services to mathematics. He described it as an award for the little people. "It is a simple award for many common people, for little people. It's not an elite award," he said yesterday from his home in Pymble. "It's for the people in the world who help here and there." Mr Kelly helped by forming the Australian Category Theory Seminar in 1971. Category theory is a modern area of study that seeks to clarify mathematics by uniting its different theoretical streams. The seminar, run between Macquarie University and the universities of Sydney and NSW, is now one of the world's leading research centres on category theory. "Category theory sheds light on the relations between various aspects of mathematics and in doing so it brings unity and simplicity," Mr Kelly said. "It lights the way for the next lot of advances." He was pleased to be recognised on a list feat uring sportspeople, actors and politicians. "I am a bit surprised and rather pleased that they would take into account scientific achievements." Scientists in many fields were among the 4491 medal recipients from NSW: Brian Doyle, from West Pymble, was recognised for his contribution to the advancement of astronomy; Leslie Field, from Lane Cove, for services to organic chemistry; Victor Flambaum, from Coogee, for atomic and nuclear physics. Mr Kelly said it was important that scientific achievements were recognised as another form of community work. "Some people get recognition for helping the community in various ways but scientific advancement is also important to developing our country. "My gifts happen to be in this area. I cannot do anything special for meals on wheels, but I can in this area." From rrosebru@mta.ca Wed Apr 23 16:41:30 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 23 Apr 2003 16:41:30 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 198Q3R-00067n-00 for categories-list@mta.ca; Wed, 23 Apr 2003 16:37:17 -0300 To: categories@mta.ca Subject: categories: UWO/Fields program in homotopy theory From: Dan Christensen Date: Tue, 22 Apr 2003 15:57:28 -0400 Message-ID: Lines: 91 User-Agent: Gnus/5.090008 (Oort Gnus v0.08) Emacs/21.2 (i386-debian-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 14 Third Announcment Fields Institute Program on Homotopy Theory and its Applications University of Western Ontario London, Ontario September, 2003 http://www.math.uwo.ca/homotopy/ During the month of September, 2003, the Department of Mathematics at the University of Western Ontario will host a program on homotopy theory and its applications to other areas. Gunnar Carlsson, Paul Goerss, Ieke Moerdijk, Jack Morava and Fabien Morel will be in residence for parts of the month (see below). All of the events will take place in London, Ontario. The focus of the month will be a special 5 day version of the Ontario Topology Seminar, beginning on Saturday, September 20 in the morning and ending on Wednesday, September 24 in the afternoon. The speakers who have agreed to come are listed below. In addition, there will be six mini-courses at other times during the month given by the five longer-term visitors. Each will consist of two to three lectures. A tentative schedule is below. The organizers are Rick Jardine and Dan Christensen . If you think you might attend, please let one of us know (if you haven't already). The conference web page (see above) will be updated periodically. Hotel and travel information is available at http://jdc.math.uwo.ca/directions.html We recommend you book a hotel room right away, as the conference overlaps with homecoming weekend at Western. (You can always cancel later.) The conference is supported by the Fields Insitute, the NSF, and NSERC. Conference and mini-course speakers: Alejandro Adem, Wisconsin John Baez, Univ. of California, Riverside Paul Baum, Penn State Gunnar Carlsson, Stanford Wojciech Chacholski, Minnesota Bill Dwyer, Notre Dame Paul Goerss, Northwestern Jesper Grodal, Chicago Lars Hesselholt, MIT Mikhail Kapranov, Toronto Finnur Larusson, UWO Ib Madsen, Aarhus Peter May, Chicago Haynes Miller, MIT Ieke Moerdijk, Utrecht Jack Morava, Johns Hopkins Fabien Morel, Paris 7 Victor Snaith, Southampton Neil Strickland, Sheffield Bertrand Toen, Nice Mini-course schedule: The mini-courses will be held at the University of Western Ontario. Each course will be three hours long, either three one-hour lectures or two 90-minute lectures, except for Carlsson's second course, which will consist of two one-hour lectures. Rooms, times and abstracts will be announced later. Sept 8, 9, 10: Morava, "Recent developments in Galois theory" Sept 11, 12: Goerss, "Sheaves of modules and sheaves of spectra on the moduli stack of formal groups" Sept 15, 16, 17: Carlsson, "Galois theory and representations in K-theory" Sept 18, 19: Carlsson, "Algebraic topology and shape and feature recognition" Sept 17, 18, 19: Moerdijk, "Operads, Hopf algebras and homotopy theory" Sept 20-24: conference Sept 25, 26, 29: Morel, "Computation and conjectures on motivic stable homotopy groups of spheres" Here is when the minicourse speakers will be at Western: Gunnar Carlsson: Sept 14-23. Paul Goerss: Sept 7-13. Ieke Moerdijk: Sept 12-24. Jack Morava: Sept 5-10 and Sept 15-24. Fabien Morel: roughly Sept 20 to Oct 4. A list of all potential attendees can be found at http://www.math.uwo.ca/homotopy/attendees.html From rrosebru@mta.ca Wed Apr 23 16:41:30 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 23 Apr 2003 16:41:30 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 198Q4s-0006DD-00 for categories-list@mta.ca; Wed, 23 Apr 2003 16:38:46 -0300 Message-ID: <20030422214842.89385.qmail@web12203.mail.yahoo.com> Date: Tue, 22 Apr 2003 14:48:42 -0700 (PDT) From: Galchin Vasili Subject: categories: Kripke semantics and Alexandrov topology To: categories@mta.ca MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 15 Hello, I have been re-reading the chapter on intuitionism in Goldblatt's book, specifically the section on Kripke semantics. Am I wrong to say that Kripke semantics is based on the Alexandrov topology generated by the underlying poset? Regards, Bill From rrosebru@mta.ca Thu Apr 24 16:22:57 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 24 Apr 2003 16:22:57 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 198mGH-0007P4-00 for categories-list@mta.ca; Thu, 24 Apr 2003 16:20:01 -0300 Date: Thu, 24 Apr 2003 08:45:53 +0200 Subject: categories: Re: Kripke semantics and Alexandrov topology Content-Type: text/plain; charset=ISO-8859-1; format=flowed Mime-Version: 1.0 (Apple Message framework v551) To: categories@mta.ca From: Francois Lamarche In-Reply-To: <20030422214842.89385.qmail@web12203.mail.yahoo.com> Message-Id: <64F23624-7620-11D7-A908-0005024BFA15@loria.fr> Content-Transfer-Encoding: quoted-printable X-Mailer: Apple Mail (2.551) Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 16 YES, because, given a poset X, the category of sheaves over X equipped=20= with the Alexandrov topology is equivalent to the category of=20 *covariant* functors X --> Set. A very important, basic fact, which=20 is at the foundation of a lot of things in topos theory and computer=20 science. Cheers, Fran=E7ois > Hello, > > I have been re-reading the chapter on intuitionism > in Goldblatt's book, specifically the section on > Kripke semantics. Am I wrong to say that Kripke > semantics is based on the Alexandrov topology > generated by the underlying poset? > > Regards, Bill > From rrosebru@mta.ca Thu Apr 24 16:22:57 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 24 Apr 2003 16:22:57 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 198mFK-0007Kj-00 for categories-list@mta.ca; Thu, 24 Apr 2003 16:19:02 -0300 Message-ID: <3EA7F033.3D207BE3@dsic.upv.es> Date: Thu, 24 Apr 2003 15:10:36 +0100 From: Salvador Lucas Reply-To: slucas@dsic.upv.es Organization: ELP MIME-Version: 1.0 To: categories@mta.ca Subject: categories: RDP'03 - Call for participation Content-Type: text/plain; charset=us-ascii; x-mac-type="54455854"; x-mac-creator="4D4F5353" Content-Transfer-Encoding: 7bit Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 17 [Apologies for multiple copies of this announcement] ****************************************************************** ****************** Call for participation ****************** ****************************************************************** Federated Conference on Rewriting, Deduction and Programming (RDP) including RTA - TLCA - FTP - IFIP WG 1.6 - RULE - UNIF - WFLP - WRS - WST http://www.dsic.upv.es/~rdp03 Valencia, Spain, June 8 - 14, 2003 ------------------------------------------------------------------ We are pleased to announce that the registration and hotel reservation procedures for attending RDP 2003 are open now. Please, follow this link http://www.dsic.upv.es/~rdp03/org/registration_info.html to formalize your registration. A number of rooms have been booked in various hotels near the Conference venue. Please remember that the number of rooms is limited. Requests will be processed on a first come first served basis and will be subject to space availability. Please, follow this link http://www.dsic.upv.es/~rdp03/org/hotel_info.html to eventually formalize your accomodation in one of such hotels. IMPORTANT: The deadline for early registration/accomodation is M a y 1 5, 2 0 0 3 RDP 2003 will take place at the ADEIT building of the "Fundacio Universitat Empresa de Valencia": Plaza Virgen de la Paz, 3 E-46001 Valencia Spain Please, look at the conference WWW site for further travelling information (available soon). The conference will be hosted by the Departamento de Sistemas Informaticos y Computacion (DSIC) at the Universidad Politecnica de Valencia. PARTICIPANTS 14th Int. Conf. on Rewriting Techniques and Applications, RTA'03 6th Int. Conf. on Typed Lambda Calculi and Applications, TLCA'03 4th Int. Workshop on First Order Theorem Proving, FTP'03 IFIP Working Group 1.6 on Term Rewriting 4th Int. Workshop on Rule Based Programming, RULE'03 17th Int. Workshop on Unification, UNIF'03 12th Int. Workshop on Functional and (Constraint) Logic Prog., WFLP'03 3rd Int. Workshop on Red. Strat. in Rewriting and Programming, WRS'03 6th Int. Workshop on Termination, WST'03 DATES RDP : June 8 - 14, 2003 RTA'03 : June 9 - 11 TLCA'03: June 10 - 12 FTP'03 : June 12 - 14 WG 1.6 : June 12 RULE'03: June 9 UNIF'03: June 8 - 9 WFLP'03: June 12 - 13 WRS'03 : June 8 WST'03 : June 13 - 14 ORGANIZERS The ELP group at the Universidad Politecnica de Valencia Officials: Salvador Lucas (chair of the organizing committee) Maria Alpuente (workshops chair) Jose Hernandez (local arrangements) Javier Oliver (secretary) Maria Jose Ramirez (local arrangements chair) German Vidal (publicity chair) CONTACT Salvador Lucas Departamento de Sistemas Informaticos y Computacion (DSIC) Universidad Politecnica de Valencia Camino de Vera, s/n E-46022 Valencia (Spain) phone: + 34 96 387 7353 (73531) fax: + 34 96 387 7359 e-mail: slucas@dsic.upv.es URL: http://www.dsic.upv.es/users/elp/slucas.html FURTHER INFORMATION RDP website: http://www.dsic.upv.es/~rdp03 The ELP group: http://www.dsic.upv.es/users/elp/elp.html ****************************************************************** From rrosebru@mta.ca Sat Apr 26 15:19:30 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sat, 26 Apr 2003 15:19:30 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 199UDU-0002kT-00 for categories-list@mta.ca; Sat, 26 Apr 2003 15:16:04 -0300 X-Mailer: exmh version 2.1.1 10/15/1999 To: categories@mta.ca Subject: categories: Re: Kripke semantics and Alexandrov topology Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Date: Thu, 24 Apr 2003 15:54:04 -0700 From: Vaughan Pratt Sender: cat-dist@mta.ca Precedence: bulk Message-Id: Status: O X-Status: X-Keywords: X-UID: 20 YES, because it doesn't matter. Bill's question is not well framed (besides the potential for ambiguity in the answer arising from "Am I wrong to say that"). Is the question is about intuitionistic logic/Heyting algebra itself, or its domain of discourse, ostensibly posetal Kripke structures? If the former, then the canonical models obtained by dualizing Heyting algebras are Stone(-Priestley(-Heyting)) spaces, whose topology is compact, the logic being finitary. If the latter, and if Stone topology is more bother than discrete topology (surely the case from a pedagogical standpoint), then the Alexandrov topology is preferable; this in general is not compact. But variations between topologies having the same specialization order describe only what points are approached in the (infinite) limit. Since intuitionistic logic is entirely finitary and does not concern itself with limiting processes, it doesn't matter what topology Kripke semantics is based on. Hence YES, Bill is wrong to imply that it does matter (other than for the secondary reasons discussed above). Best, Vaughan >YES, because, given a poset X, the category of sheaves over X equipped = >with the Alexandrov topology is equivalent to the category of = >*covariant* functors X --> Set. A very important, basic fact, which = >is at the foundation of a lot of things in topos theory and computer = science. > >Cheers, >Fran=E7ois >> >> I have been re-reading the chapter on intuitionism >> in Goldblatt's book, specifically the section on >> Kripke semantics. Am I wrong to say that Kripke >> semantics is based on the Alexandrov topology >> generated by the underlying poset? >> >> Regards, Bill From rrosebru@mta.ca Sat Apr 26 15:19:30 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sat, 26 Apr 2003 15:19:30 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 199UAr-0002dE-00 for categories-list@mta.ca; Sat, 26 Apr 2003 15:13:21 -0300 Date: Thu, 24 Apr 2003 23:15:01 +0300 (GMT) From: WAIT 2003 Reply-To: WAIT 2003 Subject: categories: WAIT 2003: Deadline approaching To: categories@mta.ca MIME-Version: 1.0 Content-Type: TEXT/plain; charset=us-ascii Content-MD5: Naht5lfDnfYDjUa8KZQ/ew== X-Mailer: dtmail 1.3.0 @(#)CDE Version 1.3.5 SunOS 5.7 sun4u sparc Sender: cat-dist@mta.ca Precedence: bulk Message-Id: Status: O X-Status: X-Keywords: X-UID: 21 ---------------------------------------------------------------------- CALL FOR PAPERS 32 JAIIO - WAIT 2003 Argentinian Workshop on Theoretical Computer Science Buenos Aires - Argentina September 1-5, 2003 Deadline for reception of papers: May 4 ---------------------------------------------------------------------- The Argentinian Workshop on Theoretical Computer Science (WAIT) has become an important Latin American forum for the exchange of ideas and the presentation of research in theoretical computer science and its applications. The workshop aims are to build a bridge between academic and applied research and to stimulate the exchange of ideas and experience between theory and practise in computer science. The meeting includes contributed and invited talks, and tutorials. Further, we are very pleased to announce that there will be a special issue of ENTCS (http://www.elsevier.nl/locate/entcs) dedicated to WAIT 2003 publishing a selection of outstanding contributions. WAIT 2003 (http://wait2003.famaf.unc.edu.ar), the 7-th workshop in the series, will be held in Buenos Aires during September 1-5 (2003) as part of the 32-nd Argentinian Conference on Informatics and Operations Research (32 JAIIO, http://www.jaiio2003.uade.edu.ar). Buenos Aires (http://www.buenosaires.gov.ar/areas/turismo/en/) is a cosmopolitan and modern urban centre easily accessible by plane from most mayor cities in the world. The city is characterised by the multiplicity of its artistic expressions, ranging from the great assortment of sculptures and monuments to streets and corners that surprise with their allegorical reliefs and murals. The climate of Buenos Aires ---oceanic and warm--- is mild all year round, allowing visitors to discover the city on foot in any season. The city offers all categories of accommodation, and food ---which is something of a cult--- is of high quality. TOPICS Submissions are welcome in all fields of Theoretical Computer Science. Specific topics of WAIT 2003 include (but are not limited to): * Logical and algebraic foundations of computer science (logics for computation, category theory, relation algebras, type theory); * Formal methods (formal specification of sequential and concurrent programs, analysis, verification and transformation of programs, model checking); * Algorithms and data structures (sequential, parallel, distributed and on-line computing, probabilistic algorithms); * Automata theory and computational complexity; * Symbolic and algebraic computation; * Quantum Computing; * Bioinformatics. Submissions are expected to contain original research and will be refereed by international experts. Research papers must contain previously unpublished results. They will be judged on the base of originality and importance of their contributions and clarity of presentation. Papers should not exceed 12 pages, including figures and references. PROGRAM COMMITTEE: Martin Abadi (University of California at Santa Cruz) Gilles Barthe (INRIA Sophia-Antipolis) Gabriel Baum (Universidad de La Plata) Veronica Becher (Universidad de Buenos Aires) Vincent Danos (CNRS, Paris VII) Peter Dybjer (University of Gothenburg) Roberto Di Cosmo (PPS, Paris VII) Esteban Feuerstein (Universidad de Buenos Aires) Marcelo Fiore (Cambridge University) (co-chair) Daniel Fridlender (Universidad de Cordoba) (co-chair) Joos Heintz (Universidad de Buenos Aires) Gonzalo Navarro (Universidad de Chile) Peter O'Hearn (QMW, University of London) Alfredo Viola (Universidad de la Republica) IMPORTANT DATES: Deadline for reception of papers.................................May 4 Notification of acceptance.....................................June 27 Deadline for reception of the final version....................July 18 INSTRUCTIONS FOR AUTHORS: To facilitate the dissemination of papers and results, authors are invited to submit their papers in English. However, papers in Spanish or Portuguese are also welcome. Accepted contributions will be published in the Proceedings of the 32 JAIIO. Further, a selection of outstanding contributions will be invited to be published (in English) in a special issue of ENTCS dedicated to WAIT 2003. Papers should respond to ENTCS format (obtainable from http://math.tulane.edu/~entcs/) or similar, and must be submitted electronically in PostScript format (ghostview-readable) or PDF to the following e-mail address: wait2003@famaf.unc.edu.ar. Authors should communicate in a separate e-mail (in ASCII format) the title of the paper together with a short abstract, name and affiliation of all co-authors and their e-mail addresses, phone and FAX numbers. The message should also contain a list of keywords describing the area of the paper. ---------------------------------------------------------------------- From rrosebru@mta.ca Sat Apr 26 15:19:36 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sat, 26 Apr 2003 15:19:36 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 199UGZ-0002sm-00 for categories-list@mta.ca; Sat, 26 Apr 2003 15:19:15 -0300 Date: Fri, 25 Apr 2003 14:26:55 -0400 (EDT) From: Peter Freyd Message-Id: <200304251826.h3PIQtRn001255@saul.cis.upenn.edu> To: categories@mta.ca Subject: categories: equivalent varieties Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 22 Varieties of algebras when viewed as categories can be unexpectedly equivalent. For a reason explained at the end, I was looking at varieties of unital rings satisfying the equations p = 0 and x^p = x, one such variety for each prime integer p. The equivalence type of these categories is independent of p. The easiest way of establishing that is to show that each is equivalent to the category of Boolean algebras (a well-known fact when p = 2) and all the equivalences can by established by just one functor. Given a unital ring, R, define B(R) to be the boolean algebra of its central idempotents where the meet of a and b is ab and the join is a + b - ab. Then the restriction of B to the p'th variety described above is always an equivalence of categories. The fastidious will note (one would certainly hope) that B is not a functor in general (homomorphisms don't preserve centrality). But in a ring "without nilpotents" (that is, in which x^2 = 0 implies x = 0) all idempotents are central. The equations x^p = x, of course, imply the absence of nilpotents. (Given p the inverse functor to B can be described as follows: for a Boolean algebra C consider the set of "p-labeled partitions of unity", that is, the set of functions f:Z_p -> C whose values are pairwise disjoint and have unity as their join. Given two such, f and g, define their sum by setting (f+g)i to be the join of the set { fj ^ gk | j+k = i } and their product by setting (fg)i to be the join of { fj ^ gk | jk = i }.) I was looking for examples of equational theories with unique maximal consistent equational extensions. The best known example is the theory of lattices: every equation consistent with the theory of lattices is a consequence of distributivity. (Inconsistent in the equational setting means that all equations can be proved, or equivalently, the one equation x = y can be proved.) That is, the unique maximal consistent extension of the theory of lattices is the theory of distributive lattices (fortunately this is independent of your choice of whether top and/or bottom are considered to be part of the theory of lattices). A less-well-known example is the theory of Heyting algebras: every equation consistent with the theory of Heyting algebras is a consequence of the law of double-negation: (x -> 0) -> 0 = x. That is, the unique maximal consistent extension of the theory of Heyting algebras is the theory of Boolean algebras. This search for examples was sparked by what I consider a great example -- not to be described here -- in "algebraic real analysis". The only other examples I've found are the theories of unital rings of characteristic p, one such example for each prime p. To shift to the traditional language here, any polynomial identity consistent with characteristic p is a consequence of characteristic p and the identity x^p = x. A lot of examples. But, then again, maybe just one example. From rrosebru@mta.ca Sat Apr 26 19:02:27 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sat, 26 Apr 2003 19:02:27 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 199XiD-00077t-00 for categories-list@mta.ca; Sat, 26 Apr 2003 19:00:01 -0300 Date: Sat, 26 Apr 2003 15:27:35 -0300 (ADT) From: Bob Rosebrugh To: categories Subject: categories: Categories on vacation Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: cat-dist@mta.ca Precedence: bulk Status: RO X-Status: X-Keywords: X-UID: 24 Your Categories moderator will be out of email contact April 29-May 6, 2003. Postings submitted to Categories during that period will be distributed when I return. (If you were thinking of posting something and want it distributed sooner, you've got till Monday afternoon...) Best wishes, Bob From rrosebru@mta.ca Sun Apr 27 15:38:23 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 27 Apr 2003 15:38:23 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 199qyB-0003TR-00 for categories-list@mta.ca; Sun, 27 Apr 2003 15:33:47 -0300 Date: Sat, 26 Apr 2003 22:47:14 +0100 (BST) From: "Prof. Peter Johnstone" To: categories@mta.ca Subject: categories: Re: equivalent varieties In-Reply-To: <200304251826.h3PIQtRn001255@saul.cis.upenn.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Scanner: exiscan for exim4 (http://duncanthrax.net/exiscan/) *199XVr-0001II-3D*V.UUzKy7mOA* Sender: cat-dist@mta.ca Precedence: bulk Status: RO X-Status: X-Keywords: X-UID: 26 On Fri, 25 Apr 2003, Peter Freyd wrote: > Varieties of algebras when viewed as categories can be unexpectedly > equivalent. For a reason explained at the end, I was looking at > varieties of unital rings satisfying the equations p = 0 and > x^p = x, one such variety for each prime integer p. > > The equivalence type of these categories is independent of p. The > easiest way of establishing that is to show that each is equivalent to > the category of Boolean algebras (a well-known fact when p = 2) and > all the equivalences can by established by just one functor. Given a > unital ring, R, define B(R) to be the boolean algebra of its central > idempotents where the meet of a and b is ab and the join is > a + b - ab. Then the restriction of B to the p'th variety described > above is always an equivalence of categories. > > The fastidious will note (one would certainly hope) that B is not a > functor in general (homomorphisms don't preserve centrality). But in a > ring "without nilpotents" (that is, in which x^2 = 0 implies x = 0) > all idempotents are central. The equations x^p = x, of course, imply > the absence of nilpotents. > > (Given p the inverse functor to B can be described as follows: for > a Boolean algebra C consider the set of "p-labeled partitions of > unity", that is, the set of functions f:Z_p -> C whose values are > pairwise disjoint and have unity as their join. Given two such, f and > g, define their sum by setting (f+g)i to be the join of the set > { fj ^ gk | j+k = i } and their product by setting (fg)i to be the > join of { fj ^ gk | jk = i }.) > The equivalence of these varieties for all p is well known. It's best understood by seeing that they are all dual to the category of Stone spaces: given a Stone space, the ring of continuous Z_p-valued functions on it (where Z_p is given the discrete topology) is a ring satisfying p1=0 and x^p=x; conversely, given such a ring, its prime (=maximal) ideal spectrum is a Stone space. Not having my copy of "Stone Spaces" to hand as I write this, I can't remember whether this fact was in the book. But it certainly should have been. Peter Johnstone From rrosebru@mta.ca Sun Apr 27 15:40:42 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 27 Apr 2003 15:40:42 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 199r3H-0003h9-00 for categories-list@mta.ca; Sun, 27 Apr 2003 15:39:03 -0300 Date: Sun, 27 Apr 2003 09:16:25 -0400 (EDT) From: Peter Freyd Message-Id: <200304271316.h3RDGPnw015976@saul.cis.upenn.edu> To: categories@mta.ca Subject: categories: unique maximal consistent extensions Sender: cat-dist@mta.ca Precedence: bulk Status: O X-Status: X-Keywords: X-UID: 27 When looking for the examples I mentioned in my last post, I had in mind examples where the unique maximal consistent extension, of an equational theory is finitely axiomatizable If one drops that condition there are many more examples, and one of particular interest: the theory of lattice-ordered unital rings. This theory does have a unique maximal consistent extension but it is very much not finitely axiomatizable. For any integer polynomial, P, the non-existence of a root for P is equivalent with the equation 1 = (1 meet P^2). (Conversely, whether any equation holds -- indeed, whether any universally quantified sentence in this theory holds -- is equivalent to a Diophantine problem,) Vaughan has asked if one can determine a minimal theory whose unique maximal consistent extension is the theory of distributive lattices. To my surprise the answer is yes. Indeed, there are exactly two such theories (minimality not defined by number of equations but by their deductive strength). One is the set of five equations: x meet 1 = x, x meet 0 = 0, 1 join 1 = 1, 1 join 0 = 1, 0 join 0 = 0. The other, of course, is obtained my interchanging meet and join, 0 and 1. From rrosebru@mta.ca Sun Apr 27 15:44:51 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 27 Apr 2003 15:44:51 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 199r7O-0003ny-00 for categories-list@mta.ca; Sun, 27 Apr 2003 15:43:18 -0300 X-Authentication-Warning: triples.math.mcgill.ca: barr owned process doing -bs Date: Sat, 26 Apr 2003 15:44:31 -0400 (EDT) From: Michael Barr To: categories@mta.ca Subject: categories: Re: equivalent varieties In-Reply-To: <200304251826.h3PIQtRn001255@saul.cis.upenn.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: cat-dist@mta.ca Precedence: bulk Status: RO X-Status: X-Keywords: X-UID: 28 Two comments on Peter's posting. First the particular example he mentions was apparently first discovered by a French mathematician named Batbedat. Second, there is an example of an infinitary theory whose category of algebras is equivalent to the category of sets! Simply take the underlying functor to sets represented by an infinite set and prove it is tripleable using Beck's PTT (very easy). The theory has as n-ary operations all functions X --> X^n where X is the representing set. On Fri, 25 Apr 2003, Peter Freyd wrote: > Varieties of algebras when viewed as categories can be unexpectedly > equivalent. For a reason explained at the end, I was looking at > varieties of unital rings satisfying the equations p = 0 and > x^p = x, one such variety for each prime integer p. > > The equivalence type of these categories is independent of p. The > easiest way of establishing that is to show that each is equivalent to > the category of Boolean algebras (a well-known fact when p = 2) and > all the equivalences can by established by just one functor. Given a > unital ring, R, define B(R) to be the boolean algebra of its central > idempotents where the meet of a and b is ab and the join is > a + b - ab. Then the restriction of B to the p'th variety described > above is always an equivalence of categories. > > The fastidious will note (one would certainly hope) that B is not a > functor in general (homomorphisms don't preserve centrality). But in a > ring "without nilpotents" (that is, in which x^2 = 0 implies x = 0) > all idempotents are central. The equations x^p = x, of course, imply > the absence of nilpotents. > > (Given p the inverse functor to B can be described as follows: for > a Boolean algebra C consider the set of "p-labeled partitions of > unity", that is, the set of functions f:Z_p -> C whose values are > pairwise disjoint and have unity as their join. Given two such, f and > g, define their sum by setting (f+g)i to be the join of the set > { fj ^ gk | j+k = i } and their product by setting (fg)i to be the > join of { fj ^ gk | jk = i }.) > > I was looking for examples of equational theories with unique maximal > consistent equational extensions. The best known example is the theory > of lattices: every equation consistent with the theory of lattices is > a consequence of distributivity. (Inconsistent in the equational > setting means that all equations can be proved, or equivalently, the > one equation x = y can be proved.) That is, the unique maximal > consistent extension of the theory of lattices is the theory of > distributive lattices (fortunately this is independent of your choice > of whether top and/or bottom are considered to be part of the theory > of lattices). A less-well-known example is the theory of Heyting > algebras: every equation consistent with the theory of Heyting > algebras is a consequence of the law of double-negation: > (x -> 0) -> 0 = x. That is, the unique maximal consistent extension of > the theory of Heyting algebras is the theory of Boolean algebras. > > This search for examples was sparked by what I consider a great > example -- not to be described here -- in "algebraic real analysis". > The only other examples I've found are the theories of unital rings of > characteristic p, one such example for each prime p. To shift to the > traditional language here, any polynomial identity consistent with > characteristic p is a consequence of characteristic p and the > identity x^p = x. A lot of examples. But, then again, maybe just one > example. > > > From rrosebru@mta.ca Sun Apr 27 15:46:38 2003 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 27 Apr 2003 15:46:38 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 199r97-00042K-00 for categories-list@mta.ca; Sun, 27 Apr 2003 15:45:05 -0300 X-Authentication-Warning: triples.math.mcgill.ca: barr owned process doing -bs Date: Sun, 27 Apr 2003 09:19:31 -0400 (EDT) From: Michael Barr X-Sender: barr@triples.math.mcgill.ca To: Categories list Subject: categories: re: Equivalent varieties Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: cat-dist@mta.ca Precedence: bulk Status: RO X-Status: X-Keywords: X-UID: 29 To expand on what I said about equivalent varieties, a French mathematician named Batbedat showed many years ago that for any prime p, the category of p-rings (a p-ring satisfies px = 0 and x^p = x) is equivalent to the category of 2-rings, that is boolean rings. From rrosebru@mta.ca Sun Apr 27 16:20:58 2003 -0300 Status: X-Status: X-Keywords: Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 27 Apr 2003 16:20:58 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 199rfO-0005vP-00 for categories-list@mta.ca; Sun, 27 Apr 2003 16:18:26 -0300 Date: Sun, 27 Apr 2003 11:59:48 -0700 (PDT) From: jdolan@math.ucr.edu Message-Id: <200304271859.h3RIxmr06097@math-cl-n01.ucr.edu> To: categories@mta.ca Subject: categories: Re: equivalent varieties Sender: cat-dist@mta.ca Precedence: bulk peter johnstone wrote: |The equivalence of these varieties for all p is well known. It's best |understood by seeing that they are all dual to the category of Stone i think of these equivalences as sort-of "morita equivalences" between lawvere-style algebraic theories. for any finite k, the category of sets of cardinality a finite power of k has splitting-idempotents completion the category of finite sets. From rrosebru@mta.ca Sun Apr 27 19:13:33 2003 -0300 Status: X-Status: X-Keywords: Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 27 Apr 2003 19:13:33 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 199uLI-0001Ym-00 for categories-list@mta.ca; Sun, 27 Apr 2003 19:09:52 -0300 Date: Sun, 27 Apr 2003 12:27:31 -0700 (PDT) From: jdolan@math.ucr.edu Message-Id: <200304271927.h3RJRVx06368@math-cl-n01.ucr.edu> To: categories@mta.ca Subject: categories: Re: equivalent varieties Sender: cat-dist@mta.ca Precedence: bulk i wrote: |for any finite k, the category of |sets of cardinality a finite power of k has splitting-idempotents |completion the category of finite sets. non-empty, i guess. From rrosebru@mta.ca Mon Apr 28 09:06:53 2003 -0300 Status: X-Status: X-Keywords: Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 28 Apr 2003 09:06:53 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 19A7Nx-0006r9-00 for categories-list@mta.ca; Mon, 28 Apr 2003 09:05:29 -0300 Date: Sun, 27 Apr 2003 22:14:35 -0400 (EDT) From: F W Lawvere Reply-To: wlawvere@acsu.buffalo.edu To: categories@mta.ca Subject: categories: Re: equivalent varieties Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: cat-dist@mta.ca Precedence: bulk An invariant way to see the particular equivalence discussed is to note that the topos of presheaves on the category of finite sets is the classifying topos for p-algebras for any given p > 1. That is because any non-empty set is a retract of a finite power of p and because left-exactness is equivalent to preserving finite products in this particular case. This representation suggests a different interpretation from the usual "truth of properties" point of view concerning the essential content of Boolean algebra. Namely, it concerns finite partitions of a hypothetical whole and shuffling of these induced by arbitrary maps between the index sets for the partitions, nothing more. Coordinatizing the above shuffling of partitions using p = 3 has some advantages over p = 2, namely, the unary operations of the theory suffice to characterize ultrafilters, i.e. to insure that perceived points of a finite set are actually there; more formally, the contravariant functor represented by 3 from finite sets to M-sets is full where M is the 27-element monoid of these unary operations. ************************************************************ F. William Lawvere Mathematics Department, State University of New York 244 Mathematics Building, Buffalo, N.Y. 14260-2900 USA Tel. 716-645-6284 HOMEPAGE: http://www.acsu.buffalo.edu/~wlawvere ************************************************************ From rrosebru@mta.ca Mon Apr 28 09:06:53 2003 -0300 Status: X-Status: X-Keywords: Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 28 Apr 2003 09:06:53 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 19A7Ov-0006vs-00 for categories-list@mta.ca; Mon, 28 Apr 2003 09:06:29 -0300 Date: Mon, 28 Apr 2003 11:50:59 +0100 (BST) From: "Prof. Peter Johnstone" To: categories@mta.ca Subject: categories: Re: equivalent varieties In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Scanner: exiscan for exim4 (http://duncanthrax.net/exiscan/) *19A6Ds-0000od-DP*O/rXfW8/Lfk* Sender: cat-dist@mta.ca Precedence: bulk On Sat, 26 Apr 2003, Prof. Peter Johnstone wrote: > The equivalence of these varieties for all p is well known. It's best > understood by seeing that they are all dual to the category of Stone > spaces: given a Stone space, the ring of continuous Z_p-valued functions > on it (where Z_p is given the discrete topology) is a ring satisfying > p1=0 and x^p=x; conversely, given such a ring, its prime (=maximal) > ideal spectrum is a Stone space. > > Not having my copy of "Stone Spaces" to hand as I write this, I can't > remember whether this fact was in the book. But it certainly should have > been. > Yes, it is there -- Exercise V 2.6, page 186. Peter Johnstone From rrosebru@mta.ca Mon Apr 28 19:46:57 2003 -0300 Status: X-Status: X-Keywords: Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 28 Apr 2003 19:46:57 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 19AHLD-0005rN-00 for categories-list@mta.ca; Mon, 28 Apr 2003 19:43:19 -0300 Date: Mon, 28 Apr 2003 12:12:45 -0400 (EDT) From: Peter Freyd Message-Id: <200304281612.h3SGCjjT028244@saul.cis.upenn.edu> To: categories@mta.ca Subject: categories: correction Sender: cat-dist@mta.ca Precedence: bulk Vaughan has noticed that I hadn't broken the commutative habit. So let me start again. He asked if one can determine a minimal equational theory with the theory of distributive lattices as its unique maximal consistent extension. Yes, here's an example: x meet 1 = x, x meet 0 = 0, 1 join 1 = 1, 1 join 0 = 1, 0 join 1 = 1, 0 join 0 = 0. (I was missing the penultimate equation.) There is a Klein-group's worth of variations. One operation simultaneously interchanges meet and join, 0 and 1. Another operation simultaneously interchanges the arguments of the operators. I'll hazard that the resulting four theories are the only ones that do the trick. From rrosebru@mta.ca Wed May 7 14:18:51 2003 -0300 Status: R X-Status: X-Keywords: Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 07 May 2003 14:18:51 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 19DSSk-0006b7-00 for categories-list@mta.ca; Wed, 07 May 2003 14:12:14 -0300 Message-ID: <2169.130.39.83.205.1051574312.squirrel@webmail.math.lsu.edu> Date: Mon, 28 Apr 2003 18:58:32 -0500 (CDT) Subject: categories: a question about equational classes From: "James J. Madden" To: categories@mta.ca X-Mailer: SquirrelMail (version 1.4.0 RC1) MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 X-Priority: 3 Importance: Normal Sender: cat-dist@mta.ca Precedence: bulk There are many examples of functors between equational classes F:V -> W that are defined by letting F(A) be the free W-algebra on the elements of A modulo an equivalence generated by certain expressions of the form: w(v(a)) = w'(v'(a)). Here, w, w' are tuples of W-words, v(a) and v'(a) are tuples of V-words that we fill in in all possible ways with elements of A. A nice example is Joyal's definition of the "spectrum" functor from commutative rings to distributive lattices. Here, F(A) is the free distributive lattice on the underlying set of A, modulo the relations: 1 = top, 0 = bottom, a*b = a inf b, a+b sup a sup b = a sup b. (Under strong enough set-theoretic assumptions, F(A) is the distributive lattice of compact opens in the spectrum of A, and if we let 'a' stand for the element of F(A) corresponding to an element a from A, then 'a' may be identified the "cozero" set of a.) Several similar examples of spectrum functors defined by generators and relations appear in Johnstone's book on Stone spaces. There are many other examples, e.g., free group over a monoid, group rings, booleanization of a lattice. There are also examples from K-theory (the Steinberg group, I believe---but now I'm recalling very old stuff so don't pin me down). Less well-known, there a kind of universal valuation that I've been interested in, which is a functor from commutative rings to lattice-ordered monoids defined by letting F(A) be the free commutative, totally distributive lattice-ordered-monoid with infinity on A modulo: 1_A = 0_F(A), 0_A = infinity, a *_A b = a +_F(A) b, a +_A b geq a sup_F(A) b. (These, of course, are equational versions of the usual conditions for a valuation.) My question is, has there ever been an attempt to make a general theory about functors of this kind? Any relevant references that anyone knows about? -- James J. Madden Department of Mathematics Louisiana State University Baton Rouge LA 70803-4918 From rrosebru@mta.ca Wed May 7 14:19:26 2003 -0300 Status: R X-Status: X-Keywords: Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 07 May 2003 14:19:26 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 19DSWx-0007AH-00 for categories-list@mta.ca; Wed, 07 May 2003 14:16:35 -0300 Message-ID: <3EAFD970.2090400@it-c.dk> Date: Wed, 30 Apr 2003 16:10:56 +0200 From: Thomas Hildebrandt User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.4.1) Gecko/20020314 Netscape6/6.2.2 X-Accept-Language: en-us MIME-Version: 1.0 To: categories@mta.ca Subject: categories: 2nd CFP: Workshop on Categorical Methods for Concurrency, Interaction, and Mobility Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-MailScanner: Found to be clean Sender: cat-dist@mta.ca Precedence: bulk 2nd Call for Papers: [ Apologies for multiple copies ] Workshop on CATEGORICAL METHODS FOR CONCURRENCY, INTERACTION, AND MOBILITY Marseille, France, 6 September, 2003 affiliated with CONCUR 2003 and held together with GETCO 2003 (See also: http://www.mcs.le.ac.uk/events/cmcim03) Aims and Scope: The aim of the workshop is to bring together researchers applying category theory to concurrency, interaction, or mobility. Topics of interest include, but are not limited to: categorical algebras of processes categorical methods in game semantics and geometry of interaction categorical models of term/graph rewriting or rewriting logic Chu spaces coalgebras, bialgebras, coinduction comparing models of concurrency enriched categories of processes interaction categories presheaf models GETCO'03: Due to the close relation between geometric and topological methods on the one hand and categorical methods on the other hand, CMCIM'03 will be held jointly with the workshop on Geometric and Toplogical Methods in Concurrency Theory (GETCO'03). Both workshops will be on the same day with their talks not overlapping. Invited Lecture: Glynn Winskel Programme Committee: Marcelo Fiore (Cambridge) Eric Goubault (Paris) Thomas Hildebrandt (Copenhagen) Alexander Kurz (Leicester) Ugo Montanari (Pisa) John Power (Edinburgh) Jan Rutten (Amsterdam) Peter Selinger (Ottawa) Glynn Winskel (Cambridge) Important dates: Deadline for submission: June 1 Notification of acceptance: July 7 Final version due: July 27 Workshop dates: September 6 Location: The workshop will be held in Marseille. It is a satellite workshop of CONCUR 2003. For venue and registration see the CONCUR web page at http://concur03.univ-mrs.fr Submissions: It is planned to publish the proceedings of the meeting as a volume in Elsevier's ENTCS series. Papers must contain original contributions. Papers should be submitted as PostScript files by email to cmcim03@mcs.le.ac.uk , containing `CMCIM-submission' in the subject. A separate message should also be sent (subject: CMCIM-abstract), containing authors, title, and a text-only abstract. Workshop organizers: Thomas T. Hildebrandt Theory Department, IT University of Copenhagen Glentevej 67, 2400 Copenhagen NV, Denmark Alexander Kurz Department of Mathematics and Computer Science, University of Leicester, University Road, Leicester, LE1 7RH. Email: cmcim03@mcs.le.ac.uk Further information at http://www.mcs.le.ac.uk/events/cmcim03 From rrosebru@mta.ca Thu May 8 13:25:52 2003 -0300 Status: X-Status: X-Keywords: Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 08 May 2003 13:25:52 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.10) id 19DoBP-0003nP-00 for categories-list@mta.ca; Thu, 08 May 2003 13:23:47 -0300 Date: Tue, 29 Apr 2003 12:28:05 -0700 (PDT) From: Galchin Vasili Subject: categories: Hacking through topos theory ... internal language To: cat group MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: cat-dist@mta.ca Precedence: bulk Message-Id: Hello, I have started reading the stuff on internal language in McLarty's book and also in the Lambek/Scott book. I am trying to short circuit my learning a little (in a vast and humbling subject!) What are the models for topos logic? The class of Heyting algebras? Regards, Bill