August 1997 - Categories - categories.org.au

Applications for Category Theory
by Daniel J. Yoder 28 Aug '97

28 Aug '97

My name is Daniel Yoder. I am very interested in learning about Category Theory -- I have in fact purchased a little booklet by a Benjamin C. Pierce entitled "Basic Category Theory for Computer Scientists" -- as part of a software engineering project I am working on. The project started out as an attempt to address my frustrations with existing commercial object-oriented programming tools, like those for Smalltalk and C++. I had been developing the outlines of a "methodology" for describing logical domain models, which could perhaps be loosely compared to an (explicitly) object-oriented version of the Z language. I say loosely because my formal algebra background is very weak. At any rate, eventually I began translating these abstractions into a C++ library and I wanted to see if there wasn't a more formal basis to proceed from. This idea was particularly compelling because I am dealing with a synthesis of functional programming abstractions, a rich object model (which includes my own conception of a category which appears to be vaguely related to the formal one), and graphs (which I was using for representing the model). Presently, my goals are quite modest but I have found it difficult to develop an approach based on existing research because I lack the appropriate mathematical background. So the question is: are there any attempts to map category theory (or type theory or set theory -- I am not sure where the boundaries are) to applications (versus theory per se), roughly analagous to Z or VDM, that might be comprehensible to somewhat without the formal framework? If not, is there a sequence of study you would recommend for proceeding? I have an undergraduate degree and have done some reading about formal algebra and category theory, but I am not sure of the path from the former to the latter, or if that is, in fact, the appropriate path. Any assistance would be greatly appreciated. Thank you for your consideration. - Dan (founder of Tazent Software)

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Reviews of books on category theory in c.s.
by Charles Wells 28 Aug '97

28 Aug '97

A year or two ago someone wrote a comparative review of several books in the area of category theory in computer science. I would appreciate finding out where it is available. Thanks, Charles Wells, Department of Mathematics, Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH 44106-7058, USA. EMAIL: charles(a)freude.com. OFFICE PHONE: 216 368 2893. FAX: 216 368 5163. HOME PHONE: 440 774 1926. HOME PAGE: URL http://www.cwru.edu/artsci/math/wells/home.html "In theory, there is no difference between theory and practice, but in practice, there is."

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e-address change
by J. R. Otto 26 Aug '97

26 Aug '97

Dear People, My e-address has changed from otto(a)triples.math.mcgill.ca to quant(a)mcs.com Thanks, Jim Otto

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Is cut semantical?
by Vaughan R. Pratt 26 Aug '97

26 Aug '97

Cut-free proofs correspond more or less to dinatural transformations, suitably strengthened to require invariance under logical relations when necessary. Is there a semantical counterpart in this sense to proofs with cut? Or is the chaotic nature of cut incompatible with this sort of syntax-semantics correspondence? Vaughan Pratt

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Re: Applications for Category Theory (Yoder)
by Philip Wadler 25 Aug '97

25 Aug '97

You might find Burstall and Rydeheard's book useful -- they implement much of category theory in Standard ML. It's published by Prentice Hall, in the series edited by Tony Hoare. -- P

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Chair in Computing Science at Uppsala University
by Bengt Jonsson 25 Aug '97

25 Aug '97

Could you please post the following announcement on the Category Theory Mailing list? Thank you Bengt Jonsson Uppsala University **************************************************************** UPPSALA UNIVERSITY invites applications for a tenured CHAIR (FULL PROFESSOR) IN COMPUTING SCIENCE at the Faculty of Science and Technology. Ref no. 3603/97 Applicants must demonstrate scientific excellence and pedagogical proficiency. The successful candidate is expected to pursue an active research program, perform graduate and undergraduate teaching, and supervise graduate students. The chair is placed in the division for mathematics and computer science, which is nicely located on a campus area for mathematics and information technology (http://www.mic.uu.se/) at Uppsala University. The campus houses chairs and graduate programs in areas including automatic control, computerized image analysis, computer systems, computing science, mathematical logic, mathematical statistics, mathematics, numerical analysis, signal processing, and systems analysis. Information about computer science in the division can be found at the home page of the department of computing science (http://www.csd.uu.se/datalogi/) of computer systems (http://www.docs.uu.se/) or of scientific computing (http://www.tdb.uu.se/) For additional information about the position, consult the dean of mathematics and computer science, prof. Ewert Bengtsson, tel no +46-18-183467 (after June 28 +46-18-4714367), e-mail Ewert.Bengtsson(a)cb.uu.se. Prospective candidates must contact the office of the faculty in order to receive the full announcement with instructions on how to apply. Please use fax no +46-18-181999 (after June 28 +46-18-4711999), e-mail: Christina.Lindberg(a)uadm.uu.se, or retrieve the announcement from http://www.csd.uu.se/datalogi/positions97/chair.shtml. Applications must be received on September 10, 1997, at the latest. The faculty wishes to establish a more equal proportion amongst female and male professors, and applications from women are encouraged.

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alg-geom daily 9708010 received (over 1354 served) 976
by James Stasheff 08 Aug '97

08 Aug '97

has this already made it to your newsletter? ************************************************************ Until August 10, 1998, I am on leave from UNC and am at the University of Pennsylvania Jim Stasheff jds(a)math.upenn.edu 146 Woodland Dr Lansdale PA 19446 (215)822-6707 Jim Stasheff jds(a)math.unc.edu Math-UNC (919)-962-9607 Chapel Hill NC FAX:(919)-962-2568 27599-3250 ---------- Forwarded message ---------- Date: Fri, 8 Aug 1997 01:14:18 -0600 (MDT) From: send mail ONLY to alg-geom <no-reply(a)eprints.math.duke.edu> Reply-To: alg-geom(a)eprints.math.duke.edu To: alg-geom daily title/abstract distribution <rabble(a)xxx.lanl.gov> Subject: alg-geom daily 9708010 received (over 1354 served) 976 ALGEBRAIC GEOMETRY E-PRINTS DAILY MAILING received from Thu 7 Aug 97 00:00:10 GMT to Fri 8 Aug 97 00:00:11 GMT ------------------------------------------------------------------------------ \\ Paper: alg-geom/9708010 From: carlos(a)picard.ups-tlse.fr (Carlos Simpson) Date: Thu, 7 Aug 1997 16:31:55 +0000 (59kb) Title: Limits in $n$-categories Author: Carlos Simpson (CNRS, Universit\'e Paul Sabatier, Toulouse, France) Notes: Approximately 90 pages \\ We define notions of direct and inverse limits in an $n$-category. We prove that the $n+1$-category $nCAT'$ of fibrant $n$-categories admits direct and inverse limits. At the end we speculate (without proofs) on some applications of the notion of limit, including homotopy fiber product and homotopy coproduct for $n$-categories, the notion of $n$-stack, representable functors, and finally on a somewhat different note, a notion of relative Malcev completion of the higher homotopy at a representation of the fundamental group. \\ ( alg-geom/9708010 , 59kb) %-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%-%- %%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%%--%% %%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%---%%%--- The most recent addition to the conference page, at http://eprints.math.duke.edu/conferences/alg-geom.html is an announcement of the Opening Workshop of the Symplectic Geometry Year 1997/98, to be held at the University of Warwick, 1-12 September 1997. USEFUL INFORMATION ABOUT THIS SERVER Never `reply' to NO-reply(a)eprints.math.duke.edu; send all mail to alg-geom(a)eprints.math.duke.edu, with commands in the SUBJECT LINE. Use a single `get' to request multiple papers, `list macros' for available macro packages, and `help' for a list of available commands and other info. Information about submitting papers can be found at http://eprints.math.duke.edu/archive/alg-geom/submission.html and a list of conferences in algebraic geometry is at http://eprints.math.duke.edu/conferences/alg-geom.html

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Workshop on Internet Programming Languages: Call For Papers
by Christopher Colby 07 Aug '97

07 Aug '97

(Apologies for multiple postings of...) CALL FOR PAPERS Workshop on Internet Programming Languages In conjunction with the IEEE Computer Society 1998 International Conference on Computer Languages (http://www.math.luc.edu/iccl98) Loyola University Chicago, USA, 13 May, 1998 The Internet has long provided a global computing infrastructure but, for most of its history, there has not been much interest in programming languages tailored specifically to that infrastructure. More recently, the Web has produced a widespread interest in global resources and, as a consequence, in global programmability. It is now commonplace to discuss how programs can be made to run effectively and securely over the Internet. This workshop will provide a forum for the discussions of all aspects of computer languages for wide-area systems, including specification languages, programming languages, semantics, implementation technologies, and application experience. Papers are sought that describe theoretical results, language designs, implementation techniques, and experiences. Areas of particular interest include, but are not limited to: * Models of mobile computation * Semantic Frameworks * Programming constructs * Implementations * Run-time systems * Internet Models SUMBISSIONS Two categories of papers are requested: presentation papers and poster papers. Presentation papers should be at most 6 double-spaced pages (10 pt on 16 pt) in length. Poster papers should be at most 2 double-spaced page summaries (10 pt on 16 pt). Electronic submissions should be sent to wil98(a)eecs.tulane.edu. The submissions must be in Postcript form and must be viewable with Ghostview and printable on USletter. The deadline for submission is NOV 10, 1997. Authors will be notified by FEB 18, 1998. Participation in the workshop will be limited to only those who submit papers. ORGANIZING COMMITTEE Henri Bal Vrije Univ, The Netherlands bal(a)cs.vu.nl Boumediene Belkhouche Tulane Univ, USA bb(a)eecs.tulane.edu Luca Cardelli Digital SRC, USA luca(a)pa.dec.com

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ICCL'98 Call For Papers
by Christopher Colby 07 Aug '97

07 Aug '97

(Apologies for multiple postings of...) CALL FOR PAPERS IEEE Computer Society 1998 International Conference on Computer Languages Loyola University Chicago, USA, 14-16 May, 1998 (http://www.math.luc.edu/iccl98) Sponsored by the IEEE Computer Society Technical Committee on Computer Languages, in cooperation with ACM Special Interest Group on Programming Languages. This is the sixth in a series of conferences devoted to all aspects of computer languages, serving to bring together people broadly interested in machine processable descriptions. The hallmarks of ICCL are diversity, openness to a wide range of linguistic research, and international representation. The focus is on new ideas in languages and language technology which are innovative or experimental in nature. Papers are sought that describe significant new theoretical or experimental results in the design, evaluation or implementation of programming/specification languages. Areas of particular interest include but are not limited to: * Implementation/optimization * Theory/semantics * Abstract interpretation/Flow Analysis * Partial evaluation * Parallel/distributed languages * Object-oriented languages * Functional/logic languages * Multiparadigm languages * Real-time/fault-tolerant languages * Requirements/design/specification languages * Internet programming languages * Domain-specific languages Papers should be at most 20 double-spaced pages in length, should have an abstract of approximately 250 words, and a separate cover page indicating the title, authors, and a list of keywords. Papers will be judged on the basis of their relevance, significance, originality, correctness, and clarity. Accepted papers will appear in a full proceedings published by the IEEE Computer Society Press, for which authors will be expected to sign a copyright release form. Papers may be submitted electronically by sending an e-mail containing a platform-independent postscript file (which can be printed on A4 and/or on 8.5"x11" paper) to the address iccl98(a)csc.ncsu.edu, or by sending 5 copies of papers to Purush Iyer, program committee co-chair, at the address below. Submissions should be accompanied by a cover letter that includes a return mailing address, telephone number and email address. The papers are due by OCT 1, 1997. Authors will be notified of acceptance or rejection by JAN 20, 1998. Camera ready versions of accepted papers will be due FEB 15, 1998. On the day prior to the Conference, a workshop on internet programming languages is being planned by Henri Bal (bal(a)cs.vu.nl) and Boumediene Belkhouche (bb(a)eecs.tulane.edu) details for this and other pre-Conference activities will be publicized in a separate announcement and are also available at http://www.math.luc.edu/iccl98. PROGRAM COMMITTEE CO-CHAIRS Purush Iyer Young-il Choo Dept of Computer Science Gifford-Fong Associates North Carolina State University yic(a)gfa-genesis.com Raleigh, NC 27695-8206 +1 919-515-7291, purush(a)csc.ncsu.edu Fax: +1 919-515-2878 CONFERENCE CHAIR David Schmidt Computing and Info. Sciences Dept. Nichols Hall 234 Kansas State University Manhattan, KS 66506 +1 913-532-6350, schmidt(a)cis.ksu.edu Fax: +1 913-532-7353 PROGRAM COMMITTEE Henri Bal (Vrije University, NL) Boumediene Belkhouche (Tulane University, US) Young-il Choo (Gifford-Fong Associates, US) Radhia Cousot (CNRS & Ecole Polytechnique, FR) Pascal Fradet (IRISA, FR) Dan Friedman (Indiana University, US) Rajiv Gupta (University of Pittsburgh, US) Laurie Hendren (McGill University, CA) Fritz Henglein (DIKU, DK) Purush Iyer (NC State University, US) Joxan Jaffar (National University of Singapore, SG) Kim Marriott (Monash University, AU) Martin Odersky (Univ of South Australia, AU) Jens Palsberg (Purdue University, US) Uday Reddy (Univ of Illinois, Urbana, US) John Reppy (AT&T Research, US) Tom Reps (Univ of Wisconsin, US) Jeremy Gibbons (Oxford Brookes University, UK) Dave Schmidt (Kansas State University, US) Bernhard Steffen (Univ of Passau, DE) LOCAL ARRANGEMENTS CHAIR Konstantin Laufer Loyola University Chicago, IL STEERING COMMITTEE Joseph Urban (Chair), Arizona State Univ., USA Boumediene Belkhouche, Tulane University, USA Pei Hsia, University of Texas, Arlington, USA

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preprint
by Michael Batanin 07 Aug '97

07 Aug '97

The preprint " Finitary monads on globular sets and notions of computad they generate " is available as postscript files at http://www-math.mpce.mq.edu.au/~mbatanin/papers.html Abstract Consider a finitary monad on the category of globular sets. We prove that the category of its algebras is isomorphic to the category of algebras of an appropriate monad on the special category (of computads) constructed from the data of the initial monad. In the case of the free $n$-category monad this definition coincides with R.Street's definition of $n$-computad. In the case of a monad generated by a higher operad this allows us to define a pasting operation in a weak $n$-category. It may be also considered as the first step toward the proof of equivalence of the different definitions of weak $n$-categories.

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