February 2002 - Categories - categories.org.au

Only two SMC structures on Cat?
by Jason C Reed 27 Jul '02

27 Jul '02

Power, A.J. and Robinson, E.P. Premonoidal categories and notions of computation (ftp://ftp.dcs.qmw.ac.uk/pub/lfp/edmundr/premoncat.ps.gz) in section 2 asserts that there is excatly one symmetric monoidal closed structure on Cat besides the cartesian one. Does anyone know [the location of] a proof? ---Jason

3 2

paperback announcement: Categorical Logic and Type Theory
by Bart Jacobs 15 Mar '02

15 Mar '02

Dear Colleague, I am happy to announce that Elsevier has now published a paperback version of my book B. Jacobs, Categorical Logic and Type Theory Studies in Logic and the Foundations of Mathematics 141, North Holland, Elsevier, 1999. 780 pages. The regular price of the paperback is NLG 150 / Euro 68.07 / US$ 74 Elsevier now offers a discount of 25% for this paperback if you order before 31 july 2001, using the attached form. In that case the price is: NLG 112.50 / Euro 51 / US$ 55.50. If you wish to use this special offer, please fill in the form, and send it in time to Andy Deelen at Elsevier (precise address at bottom of the form). Do not send it to me. The book gives a survey of categorical logic and type theory starting from the unifying concept of a fibration. Its intended audience consists of logicians, type theorists, category theorists and (theoretical) computer scientists. It contains the following chapters. Prospectus Introduction to fibred category theory Simple type theory Equational Logic First order predicate logic Higher order predicate logic The effective topos Internal category theory Polymorphic type theory Advanced fibred category theory First order dependent type theory Higher order dependent type theory References Notation index Subject index More information can be obtained from the authors webpage: http://www.cs.kun.nl/~bart/CLT/bookinfo.html Bart Jacobs, Dep. Comp. Sci., Univ. Nijmegen, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands. Email: bart(a)cs.kun.nl PS. Please pass this information on to your institute's librarian.

2 1

Studentships for PhD Study in Informatics at Edinburgh
by Diana Sisu 28 Feb '02

28 Feb '02

STUDENTSHIPS FOR PhD STUDY IN THE DIVISION OF INFORMATICS AT THE UNIVERSITY OF EDINBURGH Nine fully-funded research studentships are available for: * UK students * EU students * students worldwide Full funding means: we pay your fees - you study and tutor - you receive 8000 pounds to cover subsistence in your first year, rising in second and third years. An additional amount of 800 - 1200 pounds can be earned for tutoring and demonstrating each year. Payment of fees for overseas students is subject to successful competition for an Overseas Research Studentship. Partial funding is also available. Informatics --------------------------- Informatics is the study of information and computation, in both natural and artificial systems. It comprises a vast range of scientific and engineering endeavour and has enormous economic and social impact. The University's Division of Informatics brings together the former Departments of Artificial Intelligence, Cognitive Science and Computer Science, together with the Artificial Intelligence Applications Institute. The Division possesses a combination of breadth and strength unparallelled elsewhere in the UK and competitive world-wide; as an intellectual endeavour it is strikingly original. The Division is the only university grouping in the UK to have achieved the top 5*A rating in Computer Science in the UK government's 2001 Research Assessment Exercise round. With 87.1 research-active staff submitted for assessment, it is the UK's biggest research group in this area. We currently have around 160 students studying for PhD, and 80 for our MSc. PhD study --------------------------- PhD study is carried out within one of our six research Institutes: CISA the Centre for Intelligent Systems and their Applications IANC the Institute for Adaptive and Neural Computation ICCS the Institute for Communicating and Collaborative Systems ICSA the Institute for Computing Systems Architecture IPAB the Institute of Perception, Action and Behaviour LFCS the Laboratory for Foundations of Computer Science CISA undertakes basic and applied research and development in knowledge representation and reasoning. Through its applications institute AIAI, it works with others to deploy the technologies associated with this research. IANC fosters the study of adaptive processes in both artificial and biological systems; two themes are the study of artificial learning systems and the analysis and modelling of brain processes. ICCS pursues basic research into the nature of communication among humans and between humans and machines, using text, speech and graphics, and the design of interactive dialogue systems, using computational and algorithmic approaches. ICSA seeks development of a better understanding of systems components, both hardware and software, and their integration and interaction; this involves not only improving their raw performance and cost-effectiveness, but also making them more connectable and interoperable, more reliable, more usable and more applicable. The interests of IPAB are how to link computational perception, representation, transformation and generation processes to external worlds---whether real or virtual. The mission of LFCS is to achieve a foundational understanding of problems and issues arising in computation and communication through the development of appropriate and applicable formal models and mathematical theories. Further information --------------------------- About graduate study, the Division of Informatics, and the University as a whole is available at: http://www.informatics.ed.ac.uk/prospectus/graduate/ http://www.informatics.ed.ac.uk/ http://www.ed.ac.uk And you can mail queries to our Graduate Secretary, Mrs Betty Hughes: igs(a)informatics.ed.ac.uk. Admission Application Form can be downloaded from: http://www.postgrad.ed.ac.uk/applicat/Scieng.pdf MSc Study Further details of the MSc degrees on offer can be obtained from Judith Gordon, MSc Admissions Coordinator, Graduate School, 5 Forrest Hill, email msc-admissions(a)inf.ed.ac.uk. DEADLINE FOR RECEIPT OF APPLICATIONS FOR MSc and PhD IS 31ST MARCH 2002. Betty Hughes Admin Secretary Graduate School email: betty(a)cogsci.ed.ac.uk Tel. No. 650 4432 FAX No. 650 6626

1 0

[Fwd: NASSLLI '02, Stanford, CA]
by Peter McBurney 28 Feb '02

28 Feb '02

WITH APOLOGIES FOR MULTIPLE POSTINGS ******** NASSLLI'02 The first North American Summer School in Logic, Language, and Information and LLC11 The eleventh Logic, Language, and Computation Colloquium at CSLI June 24-30, 2002 Stanford University Stanford, California, USA http://www.stanford.edu/group/nasslli ********* We are pleased to announce that the first North American Summer School in Logic, Language, and Information (NASSLLI) will take place at Stanford University from the 24th to the 30th of June. It will be followed by the eleventh Logic, Language, and Computation Colloquium (LLC) at CSLI, the program of which will be integrated with the school. The thematic focus of NASSLLI is modeled on that of its European sister event, ESSLLI. As it is customary with schools of this nature, the classes will run from foundational and introductory to advanced. Each lecturer will give a set of five one hour lectures on a topic suitable for a broad audience interested in the interface of logic, language, and computation. NASSLLI is ideal for graduate and advanced undergraduate students in linguistics, computer science, philosophy, mathematics and psychology, as well as postdoctoral students, IT professionals, and faculty seeking to extend their knowledge of the field. We wish to extend you an invitation to join us here at Stanford between June 24 and June 30, 2002, in order to experience cutting edge research carried out by some of the finest teachers in North America and Europe. Our program to date: - Martin Abadi (CS, UCSC) [Computer Security] - Samson Abramsky (CS, Oxford) [Games in Computer Science] - Sergei Artemov (CS, CUNY New York) [Proof Polynomials] - Patrick Blackburn (INRIA Lorraine) [Lectures on Hybrid Logic] - Craig Boutilier (CS, University of Toronto) [Logical and Statistical Methods in AI] - Joan Bresnan (Linguistics, Stanford) [Optimality Theory] - Paul Dekker (Philosophy, Amsterdam) [Dynamics, Semantics, Pragmatics] - R.E. Jennings (Philosophy, Simon Fraser University) [Logicalization] - Ed Keenan (Linguistics, UCLA) [A Mathematical Theory of Grammatical Theories] - Phokion Kolaitis (CS, UCSC) [Constraint Satisfaction, Complexity, and Logic] - Larry Moss (Math, Indiana) [Dynamic Epistemic Logic] - Marc Pauly and Mike Wooldridge (Liverpool) [Modal Logic and Agents] - Fernando C.N. Pereira (Computer and Information Science, UPenn) [Machine Learning in Natural Language Processing] - Frank Veltman (Logic & Cognitive Science, Amsterdam) [Logic in AI] - Dag Westerstahl (Philosophy, Stockholm) and Stanley Peters (Linguistics, Stanford) [Generalized Quantifiers] In addition to lectures, the event will include workshops, evening lectures by distinguished researchers, as well as sporting events, party and more. There will be a limited number of scholarships awarded to eligible students. Please visit http://www.stanford.edu/group/nasslli/ for more information. On behalf of the organizing committee, David Anderson Publicity Coordinator **************************************************************** Peter McBurney Department of Computer Science University of Liverpool Liverpool L69 7ZF U.K. Tel: + 44 151 794 6760 Email: P.J.McBurney(a)csc.liv.ac.uk Web page: www.csc.liv.ac.uk/~peter/ ****************************************************************

1 0

Meeting on Quantales, Lisbon, July 16-18
by Pedro Resende 27 Feb '02

27 Feb '02

Dear friends and colleagues, A meeting devoted to the theory and applications of quantales will take place at the Department of Mathematics of Instituto Superior Técnico (IST) in Lisbon, from July 16 to 18, 2002. Quantales are lattice-ordered algebraic structures that generalize locales and also play the role of noncommutative spaces. They have been studied in several contexts, ranging from operator algebras and category theory to logic and computer science. The meeting is meant to be quite informal, and its aim is to bring together researchers who are interested in various aspects of quantales, in order to develop a broader understanding of the field both through talks and informal discussion. The meeting will be partially funded by the Fundação para a Ciência e Tecnologia (Portuguese Foundation for Science and Technology) through grant POCTI/1999/MAT/33018 ("Quantales") and through the Center for Logic and Computation of IST. Another announcement, including a registration form, will be sent out by the end of March 2002, but in the meantime any one interested in attending the meeting and in need of financial support is encouraged to contact us. Further announcements and information will also be available at the web site: http://www.math.ist.utl.pt/~pmr/Q-meeting/. Best regards, Chris Mulvey (c.j.mulvey(a)sussex.ac.uk) Pedro Resende (pmr(a)math.ist.utl.pt)

1 0

thanks
by maxk＠maths.usyd.edu.au 24 Feb '02

24 Feb '02

I was a bit embarrassed to learn that Ross Street had kindly informed this bulletin board of my heart bypass operation in January (which in fact followed two back operations in March and October of 2001); I didn't know how proper it was to use the system for such personal news. In fact I have been deeply touched by the large number of sympathetic letters I have received, both via Ross and directly, from so many colleagues, and even from some I have yet to meet in person. It is only a few that I have been able to thank in person, even of those closest to me; will the majority please accept this letter as expressing my gratitude for their kindness, and as recording the pleasure I have taken from the warmth of their messages? To bring the news up to date, the heart operation of 25 Jan went perfectly in itself, but the wound in the leg whence a vein was taken became infected a few days after my leaving the hospital. I had to return to hospital, and am now pretty much stuck at home while the thing heals slowly with antibiotics. Apparently healing can be slow unless one spends most of the time in bed, and most of the rest with the leg raised; which is pretty tedious. Anyway, my home email has now been restored after a problem at the university, so that I feel less cut off. I expect to be better after some weeks, and to meet many old friends at the Fields Institute in September. Once again, my sincere thanks, and my fond regards to many old friends. Max.

1 0

New book: Types and Programming Languages
by Benjamin C. Pierce 23 Feb '02

23 Feb '02

I'm pleased to announce the publication of a new graduate-level textbook on type systems and foundations of programming languages: Types and Programming Languages by Benjamin C. Pierce 8x9", 624 pp., 60 illus., cloth ISBN 0-262-16209-1 For more information (and a direct link for ordering from Amazon), please visit... http://www.cis.upenn.edu/~bcpierce/tapl A type system is a syntactic method for automatically checking the absence of certain erroneous behaviors by classifying program phrases according to the kinds of values they compute. The study of type systems--and of programming languages from a type-theoretic perspective--has important applications in software engineering, language design, high-performance compilers, and security. This text provides a comprehensive introduction both to type systems in computer science and to the basic theory of programming languages. The approach is pragmatic and operational; each new concept is motivated by programming examples and the more theoretical sections are driven by the needs of implementations. Each chapter is accompanied by numerous exercises and solutions, as well as a running implementation, available via the Web. Dependencies between chapters are explicitly identified, allowing readers to choose a variety of paths through the material. The core topics include the untyped lambda-calculus, simple type systems, type reconstruction, universal and existential polymorphism, subtyping, bounded quantification, recursive types, kinds, and type operators. Extended case studies develop a variety of approaches to modeling the features of object-oriented languages. Enjoy, -- Benjamin ----------------------------------------------------------------------------- BENJAMIN C. PIERCE, Professor Dept. of Computer & Information Science bcpierce(a)cis.upenn.edu University of Pennsylvania +1 215 898-2012 200 South 33rd St. Fax: +1 215 898-0587 Philadelphia, PA 19104, USA http://www.cis.upenn.edu/~bcpierce ----------------------------------------------------------------------------- 27-Feb-2002 14:04:34 -0400,2378;000000000001-00000000

1 0

PSSL 76: Reminder
by Carsten Butz 21 Feb '02

21 Feb '02

76th Peripatetic Seminar on Sheaves and Logic (PSSL 76) March 2-3, 2002 IT-University of Copenhagen http://www.it-c.dk/research/theory/Seminars/pssl76.html Dear friends and colleagues, Below you will find a list of people who have indicated that they will join us here in Copenhagen for the 76th PSSL. An asterix indicates that the participant will give a presentation. If you still want to join (and in particular, if you want to talk) please let us know as soon as possible. Best regards, Carsten Butz, butz(a)it-c.dk (on behalf of the organizers) ---------------------------------------------------- Participants of the 76th PSSL (as of Tuesday, 20-02-2002 at 20:02:02) *Adamek Jiri (Braunschweig) *Cheng Eugenia (Cambridge) Crans Sjoerd (Strasbourg) Hofstra Pieter (Utrecht) *Leinster Tom (Cambridge) *Menni Matias (Genova) *Milner Robin (Cambridge) *Porst Hans (Bremen) *Simpson Alex (Edinburgh) *Velebil Jiri (Braunschweig) Locals: Birkedal Lars (Copenhagen) *Butz Carsten (Copenhagen) Hildebrandt Thomas (Copenhagen) *Kock Anders (Aarhus) Torp-Smith Noah (Copenhagen) ------------------------------------------------------- 23-Feb-2002 14:58:24 -0400,2840;000000000001-00000000

1 0

strict, strong, pseudo, lax
by Keith Harbaugh 20 Feb '02

20 Feb '02

David Benson on 2002-02-08 wrote: Early on, John Gray and others noticed that functors ought not compose on-the-nose, but up-to-isomorphism, and (I believe) called the result <<pseudo-functors>>. Well, there is nothing <<pseudo>> about it and it is these latter entities that deserve the name <<functor>>, with the first 50 years of use then becoming XXX functor where XXX might be <<young>> or <<nasal>> or ... The issues here seem to be: What are the possible comparison methods for composition, identity, etc., how shall they be briefly named, and which shall be the default? The most conventional answers to these questions seem to be: . COMPARISON | SYSTEMS | USAGE EXAMPLES . | [E] [I] [M] | [E] [I] [M] . ___________ | ______ ______ ______ | ________ ________ ________ . equality | ------ strict strict | X strict X strict X . isomorphism | pseudo ------ strong | pseudo-X X strong X . morphism | lax lax ------ | lax X lax X X The leftmost column gives the three most common comparison methods. (morphism actually has two variants depending on the sense of the morphism.) Next come three different naming systems for the three comparison methods. [E], [I] and [M] designate both a system and a reference for it: [E] Kelly and Street, Review of the Elements of 2-Categories (1974), Section 1.5 [I] Blackwell, Kelly and Power, Two-Dimensional Monad Theory (1989), Section 1.2 [M] same reference as [E]; each reference provides examples, historical justification, and comparisons to alternative conventions (e.g., in the setting of bicategories, homomorphism for strong morphism). In each naming system the default comparison method has a '------' (the lack of a name) as its "name". Finally, in the USAGE EXAMPLES, for X take functor or morphism or (natural) transformation or algebra or .... The original quotation suggested taking up-to-isomorphism as the norm; that would seem to put it squarely in the [I] camp, making its XXX = <<strict>>. It would be interesting to expand the table to take into account other comparison methods and systems; also it would be in some ways be simpler if the isomorphism comparison could be denoted by a single term, but pseudo and strong have the advantage of clearly indicating where they stand relative to the norms in their respective systems. It has been stated that the notion of pseudo-functor originated with Grothendieck's study of fibrations (fibred categories) in the 1961 SGA Cat\'egories fibr\'ees et descente; perhaps Madame Ehreshmann or Monsieur Benabou might care to expand, confirm or comment on that... Keith 19-Feb-2002 11:36:18 -0400,2670;000000000001-00000000

2 1

CTCS02 Call for Students
by P. Scott 17 Feb '02

17 Feb '02

CATEGORY THEORY AND COMPUTER SCIENCE (CTCS'02) STUDENT PRECONFERENCE AUGUST 12-14, 2002 University of Ottawa Ottawa, Ontario, Canada Call for Student Participation In conjunction with the conference Category Theory and Computer Science (CTCS02), the University of Ottawa is offering a "preconference" from August 12-14. (Please see our website http://www.mathstat.uottawa.ca/lfc/ctcs2002/ for details of the conference.) The goal is to prepare graduate and advanced undergraduate students to attend CTCS02, through mini-courses in the basic areas underlying the fields of the conference. We anticipate offering minicourses in the following areas: Introduction to Category Theory Introduction to Categorical Logic Communication and Concurrency Game Semantics Linear Logic There will possibly be other minicourses offered as well, depending on the interests of the participants. We have also received funds from Centre de Recherches Mathematiques (CRM, Montreal) to reimburse some travel expenses and dormitory accomodations. To apply for this money, we ask that you contact us and include the following information: 1) A one-page email letter stating your background as well as why you are interested in attending. 2) The letter should also state whether you have access to any other funding to attend. 3) An email letter of reference from your supervisor or an appropriate other person. Preference will be given to students working in the areas covered by CTCS. All applications must be received by March 5. We will contact people shortly thereafter. Please send material to ctcs02(a)mathstat.uottawa.ca, or to one of us. Sincerely, Rick Blute (rblute(a)mathstat.uottawa.ca) Phil Scott (phil(a)site.uottawa.ca) Department of Mathematics and Statistics University of Ottawa 19-Feb-2002 11:36:24 -0400,5615;000000000000-00000000

1 0