June 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

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COMPSAC 2002 - call for participation
by Robert Hierons 26 Jun '02

26 Jun '02

Apologies for multiple copies. COMPSAC 2002 Call For Participation http://www.cse.dmu.ac.uk/COMPSAC Keeble College, Oxford, United Kingdom 26-29 August 2002 COMPSAC is a major international forum for researchers, practitioners, managers, and policy makers interested in computer software and applications. It was first held in Chicago in 1977 and has just celebrated its silver jubilee in the same city in 2001. This year's program includes a large number of original research papers, industrial case studies, participative workshops and discussion panels. The major theme for this conference is: PROLONGING SOFTWARE LIFE: DEVELOPMENT AND REDEVELOPMENT Keynote speakers: Sir Tony Hoare, FRS Dr. Terrence M.S. Heng Registration is now open, and both registration information and an advance program may be found at: http://www.cse.dmu.ac.uk/COMPSAC Please note that: a) the closing date for advanced registration is soon (26th July) b) there are a limited number of rooms and the accommodation reservation is on first-come-first-served basis. FURTHER INFORMATION Please refer to COMPSAC 2002 web site (http://www.cse.dmu.ac.uk/COMPSAC) and if necessary contact the program chair Hongji Yang Program Chair Software Technology Research Laboratory Faculty of Computing Sciences and Engineering De Montfort University Leicester, LE1 9BH, England Email: compsac2002(a)dmu.ac.uk or the following persons: Ian Sommerville, General Chair Computing Department Lancaster University, Lancaster, LA1 4YR, UK E-mail: is(a)comp.lancs.ac.uk Or Stephen S. Yau, Standing Committee Chair Computer Science and Engineering Department Arizona State University P.O. Box 875406, Tempe, AZ 85287-5406, USA E-mail: yau(a)asu.edu *********************************************************** Dr Robert M. Hierons Department of Information Systems and Computing, Brunel University, Uxbridge, Middlesex, UB8 3PH United Kingdom phone: +44 (0) 1895 816281 fax: +44 (0) 1895 251 686 email: rob.hierons(a)brunel.ac.uk homepage: http://www.brunel.ac.uk/~csstrmh/ ***********************************************************

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correction to my mail of 20th of June
by Thomas Streicher 25 Jun '02

25 Jun '02

In my reply to the question about large sites for toposes I made the WRONG claim that if Psh(C) is a topos then all slices of C are essentially small. As Peter Johnstone pointed out this is a sufficient condition and he asked me for an argument for the reverse direction. Alas, I couldn't find one but instead I came across the following counterexample. Let G be a large group (e.g. all permutations of the universe whose collection of non-fixpoints is small, see 1.96(10) of ``Cats & Alligators'') then Psh(G) is a locally small cocomplete topos although G is not even locally small. However, every slice of G is trivial. But if one takes for C the large group G augmented with a terminal object then Psh(C) is a locally small cocomplete topos, too, whereas C/1 is not essentially small. Thomas Streicher 27-Jun-2002 10:17:23 -0300,6734;000000000000-00000000

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CONCUR 2002 -- Call for Participation
by tony＠informatics.muni.cz 25 Jun '02

25 Jun '02

*************************************************************************** *************************************************************************** ** ** ** C O N C U R 2 0 0 2 ** ** ** ** ** ** CALL FOR PARTICIPATION ** ** ** ** ** ** !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ** ** !!!! DO NOT MISS THE EARLY PAYMENT - DUE ON JULY 8 !!!! ** ** !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ** ** ** ** The 13th International Conference on Concurrency Theory ** ** ** ** August 20-23, 2002, Brno, Czech Republic ** ** ** ** http://www.fi.muni.cz/concur2002/ ** ** ** *************************************************************************** *************************************************************************** CONCUR 2002, the international conference on concurrency theory, will be organised by the Faculty of Informatics of Masaryk University in Brno, Czech Republic. The purpose of the CONCUR conferences is to bring together researchers, developers and students in order to advance the theory of concurrency, and promote its applications. Interest in this topic is continuously growing, as a consequence of the importance and ubiquity of concurrent systems and their applications, and of the scientific relevance of their foundations. CONCUR 2002 programme ********************* consists of five invited talks, two tutorials, and 32 contributed papers selected out of 101 submissions. CONCUR 2002 is accompanied by seven satellite workshops and a special event called `Tools day'. ** A Detailed schedule of talks is now available at the conference ** ** homepage. ** CONCUR 2002 Invited Talks: *************************** * Amir Pnueli (keynote) A Deductive Proof System for CTL* * Vaughan Pratt (keynote) Event-State Duality: The Enriched Case * Wan Fokkink Refinement and Verification Applied to an In-Flight Data Acquisition Unit * Alexander Rabinovich Expressive Power of Temporal Logics * Davide Sangiorgi Types, or: Where's the difference between CCS and pi? CONCUR 2002 Tutorials: *********************** * Julian Bradfield Introduction to modal and temporal mu-calculi * Andrew D. Gordon Types for Cryptographic Protocols CONCUR 2002 Affiliated Workshops: ********************************* * CMCIM'02 - Categorical Methods for Concurrency, Interaction, and Mobility * EXPRESS'02 - Expressiveness in Concurrency * FATES'02 - Formal Approaches to Testing of Software * FOCLASA'02 - Foundations of Coordination Languages and Software Architectures * INFINITY'02 - Verification of Infinite State Systems * MTCS'02 - Models for Time-Critical Systems * PDMC'02 - Parallel and Distributed Model Checking TOOLS DAY ********* gives a platform for presenting recent developments in the area of software tools for technology transfer, and offers an opportunity to discuss future trends and needs. THE LIST OF INVITED SPEAKERS of the affiliated events includes **************************** * Orna Grumberg (PDMC'02) * Kim G. Larsen (Tools Day) * Catuscia Palamidessi (EXPRESS'02) * Colin Stirling (INFINITY'02) * Moshe Y. Vardi (PDMC'02) * Igor Walukiewicz (EXPRESS'02) * Elaine Weyuker (FATES'02) SOCIAL PROGRAMME **************** * welcome reception * conference dinner will be held in hotel SANTON (a nice view over the Brno's dam) * trip to Moravian Karst (Macocha abyss, Punkva caves, a boat ride down the Punkva river,...) REGISTRATION: ************* There is only one registration form for the CONCUR 2002 conference and all of its affiliated events. Various optional discounts are available, which allow to participate at very low costs (especially suitable for PhD students). The www registration form with detailed instructions and explanations is available at http://www.fi.muni.cz/concur2002 DEDLINE FOR EARLY PAYMENT is July 8, 2002 ************************* CONTACT PERSONS: **************** Jan Staudek (OC), Antonin Kucera (PC) Address: CONCUR 2002 Faculty of Informatics Masaryk University Botanicka 68a 60200 Brno Czech Republic tel: ++420-5-4151 2339 fax: ++420-5-4121 2568 e-mail: {staudek,kucera}(a)fi.muni.cz MORE INFORMATION **************** * http://www.fi.muni.cz/concur2002/ * concur02(a)fi.muni.cz ************************************************************************** ************************************************************************** ** ** ** END OF THE MESSAGE ** ** ** ************************************************************************** ************************************************************************** 27-Jun-2002 10:17:23 -0300,2910;000000000000-00000000

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Interesting topos
by Michael Barr 24 Jun '02

24 Jun '02

John Kennison mentioned to me that a kind of dual of the Jonsson-Tarski topos is also a topos. The JT topos has as objects pairs (X,sigma), where sigma: X --> X x X is an isomorphism and compatible functions as arrows. This topos has as objects pairs (X,tau) where tau: X + X --> X is an isomorphism and compatible functions as arrows. Note that both categories are full subcategories of the topos of M-sets where M is the free monoid on 2 generators, described by requiring a certain arrow to be an isomorphism. The JT topos is, in fact, sheaves for the topology in which separated objects are ones for which the arrow X --> X x X is injective. This Kennison topos is different since it is not sheaves for a topology. In fact, the terminal object is not 1, but rather 2^N, the structure maps given by (a_0,a_1,...) |--> (0,a_0,a_1,...) and (a_0,a_1,...) |--> (1,a_0,a_1,...) which obviously gives an isomorphism of 2^N + 2^N to 2^N. Furthermore, it is quite easy to see that the Kennison topos is boolean, so that suggests looking at not-not sheaves in the topos M-set/2^N and that is correct. If we denote the two unary ops by u and v, then any X --> 2^N already has the property that uX is disjoint from vX. Given such an X and a subobject A, the not-not closure of A consists of all x in X for which there is a word w in M with wx in A. From this, it is easy to see that a not-not separated object is one for which u and v are both injective and also easy to see that the not-not closure of the union of uX and vX (which is a subobject of X) is all of X, so that a sheaf is one for which X + X --> X is an isomorphism. I guess the "two operator" case can be replaced by any number. Another point is that though boolean, this topos is not well-pointed. For example, it is easy to find an object (X,tau) for which u has no fixed point. But this makes it impossible for there to be an arrow 2^N --> X, since (0,0,...) is fixed by u. John has asked me to add the following, which is his description of the exponential (since it is boolean, Omega = 1 + 1 and 1 is described above): I might want to add the following description of the exponential objects: Given such a coalgebra (or set X with an equivalence between X+X and X) and given c in the Cantor Set C (which is 2^{Aleph0}) we define X(c) as the fibre of the unique coalgebra homo from X to C. Then given two coalgebras A,B we will construct M = B^{A}. The elements of M are pairs (m,c) with c in C and m a function from A(c) to B(c). If f is any unary operation, then f(m,c)=(n,d) where d=f(c) and n = fmg where f is f_{B} and g is the inverse of f_{A} which exists as f_{A} must be one-to-one, and which maps to the right place. 26-Jun-2002 16:17:34 -0300,1549;000000000000-00000000

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Register before July 12: Advanced Functional Programming Summer School
by Johan Jeuring 24 Jun '02

24 Jun '02

Last registration date July 12. About 10 places left. -- Johan Jeuring Summer School and Workshop on Advanced Functional Programming St Anne's College, Oxford, UK 19th to 24th August 2002 http://www.functional-programming.org/afp/afp4 In conjunction with Summer School and Workshop on Generic Programming Call for participation This is the fourth school in a series on schools on Advanced Functional Programming. Previous schools were held in Baastad, Sweden (1995, LNCS 925), Olympia, Washington (LNCS 1129), and Braga, Portugal (LNCS 1608). We have recruited a group of excellent lecturers on advanced technologies in Functional Programming. ************ Lecturers ************ * Richard Bird (University of Oxford) and Jeremy Gibbons (University of Oxford): Arithmetic Coding with Folds and Unfolds * Manuel Chakravarty (University of New South Wales): Fast Arrays in Haskell * Matthias Felleisen (Northeastern University): Developing Interactive Web Programs in DrScheme * Cedric Fournet (Microsoft Research) and Fabrice Le Fessant (INRIA Rocquencourt): Jocaml3, a Language for Concurrent, Distributed and Mobile Programming * Paul Hudak (Yale University): Robots, Arrows and Functional Reactive Programming * Koen Claessen (Chalmers University of Tecnology) and Colin Runciman (University of York): Testing and Tracing Lazy Functional Programs * Philip Wadler (Avaya Labs): XQuery: A Typed Functional Language for Querying XML In addition, on the afternoon of Monday 19th August there will be a half-day Introduction to Functional Programming, presented by Graham Hutton (University of Nottingham). ************ Deadlines ************ For registration: 12th July 2002 ************ Organizers ************ Johan Jeuring (Utrecht University) Simon Peyton Jones (Microsoft Research) ************ Further information ************ Web: http://www.functional-programming.org/afp/afp4/info.html PDF poster: http://www.functional-programming.org/afp/afp4/afp-poster.pdf Email: afp-info(a)functional-programming.org Post: AFP, c/o Jane Ellory, Oxford University Computing Laboratory, Wolfson Building, Parks Road, Oxford OX1 3QD, United Kingdom. Fax: +44 1865 273839; mark "fao SSAFP (Jane Ellory)" 24-Jun-2002 19:03:33 -0300,3495;000000000001-00000000

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CTCS'02 (Expanded 2nd Call for Participation)
by P. Scott 24 Jun '02

24 Jun '02

Below is expanded Second Call for Participation, CTCS'02 (a wrong version was accidentally sent out earlier). Includes list of accepted papers & minicourse lecturers. ============================================================= CATEGORY THEORY AND COMPUTER SCIENCE (CTCS'02) AUGUST 15-17, 2002 GRADUATE STUDENT PRECONFERENCE AUGUST 12-14, 2002 University of Ottawa Ottawa, Ontario, Canada Second Call for Participation (Expanded Version) ********************************************* -------> ****NOTE: Early Registration ends June 30 ** <-------- ********************************************* -------> Included Below: List of Lecturers in Student Preconference and List of Accepted Papers. ***************************************************************************** CTCS'02 is the 9th Conference on Category Theory and Computer Science. The purpose of the conference series is the advancement of the foundations of computing using the tools of category theory. The emphasis is upon applications of category theory, but it is recognized that the area is highly interdisciplinary. Typical topics of interest include, but are not limited to, category-theoretic aspects of the following: coalgebras and computing concurrent and distributed systems constructive mathematics declarative programming and term rewriting domain theory and topology foundations of computer security linear logic modal and temporal logics models of computation program logics, data refinement, and specification programming language semantics type theory Previous meetings have been held in Guildford (Surrey), Edinburgh (twice), Manchester, Paris, Amsterdam, Cambridge, and S. Margherita Ligure (Genova). This is the first time CTCS will be held in North America. The proceedings of the conference will be published as a special issue of ENTCS (Electronic Notes in Theoretical Computer Science). Paper copies of the proceedings will be available to participants at the conference. The conference will have 4 invited speakers: Eric Goubault (CEA/Saclay) Guy McCusker (Sussex) Peter Selinger (Ottawa) Paul Syverson (Naval Research Laboratory) GRADUATE STUDENT PRECONFERENCE One new feature that CTCS will have this year is a "preconference" from August 12-14. This is supported in part by a grant from CRM, the Centre de Recherches Mathematiques (Univ. of Montreal). The goal is to prepare students for CTCS, through mini-courses in the basic areas underlying the fields of the conference. We anticipate offering courses in the following areas: Introduction to Category Theory (S. Niefield) Introduction to Categorical Logic (P. Scott) Coalgebras (J. Adamek) Communication and Concurrency (P. Selinger) Game Semantics (R. Cockett) Linear Logic (R. Blute) PROGRAMME COMMITTEE Rick Blute, Chair (Ottawa) Robin Cockett (Calgary) Thierry Coquand (Chalmers) Andrea Corradini (Pisa) Thomas Ehrhard (Luminy) Ryu Hasegawa (Tokyo) Martin Hofmann (Munich) Bart Jacobs (Nijmegen) Michael Johnson (Macquarie) Dusko Pavlovic (Kestrel Institute) Alex Simpson (Edinburgh) ORGANIZING COMMITTEE E. Moggi, Chair, (Genova) S. Abramsky (Oxford) P. Dybjer (Chalmers) B. Jay (Sydney) A. Pitts (Cambridge) LOCAL ORGANIZING COMMITTEE R. Blute (Ottawa) rblute(a)mathstat.uottawa.ca P. Scott (Ottawa) phil(a)site.uottawa.ca HOTEL INFORMATION We have arranged several special hotel rates. Both hotels are within walking distance of the conference. We request that you make hotel reservations yourself. If there are any problems, please contact one of the local organizers. (Note that all prices are in Canadian dollars.) 1) Ramada Hotel & Suites Ottawa (Use Group Code 2451 to get special rates.) 111 Cooper Street Ottawa, ONTARIO K2P 2E3 CANADA Tel: 1-613-238-1331 FAX: 1-613-230-2179 email: ramada(a)ramada-ottawa.com website: www.ramada.ca/ottsuit.html This is avalable from Wednesday, August 14, 2002 to Sunday, August 18, 2002 (departure on Monday). Rate: $109.00 single or double occupancy Deadline: July 14th, 2002 2) Novotel Ottawa Hotel (Use Contract # UNIV-814 to get special rates.) 33 Nicholas Street Ottawa, ONTARIO K1N 9M7 CANADA Phone:1-613-230-3033 or 1-800-668-6835 (Reservations worldwide-no charge dial) website: www.bestlodging.com/sites1/17534/index.shtml This is available from Wednesday, August 14, 2002 to Sunday, August 18, 2002 (departure on Monday). Rate: $129 single or double, $144 triple, $159 Quad Deadline: June 30th, 2002 We may also have a VERY limited number of university dorm rooms available at much cheaper rates. We will give them away on a first come, first served basis. Contact local organizers for this. CONFERENCE HOMEPAGE Updated information is available at http://www.mathstat.uottawa.ca/lfc/ctcs2002 . Registration forms are on the web site. For dormitory forms (for non students) please enquire by email to the organizers. Please register as soon as possible. (NOTE: CTCS is being held at U. Ottawa, but the conference registrar and coordinator is Ms. Gillian S. Murray, at Carleton University, as shown on the Registration Forms). ======================================================================= List of Accepted Papers 1) S. Abramsky & B. Coecke. Physical traces: Quantum vs. classical information processing 2) J. Adamek, S. Milius & J. Velebil. On rational monads and free iterative theories 3) S. Bloom & Z. Esik. Unique, guarded fixed points in an additive setting 4) P. Boudes. Non-uniform hypercoherences 5) M. Coccia, F. Gadducci & U. Montanari. GS-Lambda theories: A syntax for higher-order graphs 6) R. Cockett & L. Santocanale. Induction, coinduction and adjoints 7) E. Haghverdi, G. Pappas & P. Tabuada. Bisimulation relations for dynamical and control systems 8) M. Hasegawa. The uniformity principle on traced monoidal categories 9) J. Hughes & B. Jacobs. Factorization systems and fibrations 10) J. Koslowski. A monadic approach to polycategories 11) J. Laird. A categorical semantics of higher order store 12) F. Lamarche. Multiplicative linear logics and fibrations 13) P. Levy. Adjunction models for call-by-push-value with stacks 14) M. Maietti. Joyal's arithmetic universes via type theory 15) S. Milius. On iteratable endofunctors 16) L. Shroder. Classifying categories for partial equational logic 17) P. Taylor. Local compactness and the Baire category theorem in abstract Stone duality 18) K. Worytkiewicz. Paths and Simulations 24-Jun-2002 12:53:48 -0300,3252;000000000000-00000000

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functors in types: the constructor calculus
by Barry Jay 24 Jun '02

24 Jun '02

Announcing the availability of a new report titled The Constructor Calculus from http://www-staff.it.uts.edu.au/~cbj/Publications/constructors.ps The *constructor calculus* is a variant of the lambda-calculus that supports generic programming of functions for mapping, folding, equality, addition, etc. based on fresh approach to data types, their constructors, and pattern-matching. Its type system uses higher types to represent functors or, more precisely, data functors (like list X but not A->X). Aside from any general interest for readers of this list, there are some interesting open problems in the denotational semantics. Quantification over higher type variables and over kinds can be used to type polymorphic functions like mapping, e.g. map : forall a. forall X::a, Y::a, F::a->*. P(X->Y) -> FX -> FY where a is a kind variable (representing the number of sorts of data involved) X and Y are variable representing a tuple of types, F is a higher type variable representing a functor, and P is the finite product functor. The denotational semantics of functor polymorphism was addressed in an earlier system (Functorial ML, Jay,Bell\`e, Moggi, Journal of Functional Programming, 1998) but that of kind polymorphism has yet to be worked out. If F :: (*,*)->* is a data functor then its semantics could be a functor D x D -> D for some category D. More generally, a data functor of kind k -> * could be given by a functor D^k -> D What is the story when k is replaced by a variable a? What kind of category D has an object that represents the type scheme of map above? Perhap a self-enriched category is required. Has anyone considered self-enrichment in the effective topos? General comments, or suggestions about the denotational semantics are welcome. Yours, Barry Jay -- Associate Professor C.Barry Jay, Phone: (61 2) 9514 1814 Associate Dean (RPP), Faculty of IT www-staff.it.uts.edu.au/~cbj University of Technology, Sydney. CRICOS Provider 00099F 24-Jun-2002 12:52:45 -0300,7423;000000000000-00000000

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CTCS'02 (Aug. 15-17, U. Ottawa)
by P. Scott 22 Jun '02

22 Jun '02

CATEGORY THEORY AND COMPUTER SCIENCE (CTCS'02) AUGUST 15-17, 2002 GRADUATE STUDENT PRECONFERENCE AUGUST 12-14, 2002 University of Ottawa Ottawa, Ontario, Canada Second Call for Participation ***************************************************************************** CTCS '02 is the 9th Conference on Category Theory and Computer Science. The purpose of the conference series is the advancement of the foundations of computing using the tools of category theory. The emphasis is upon applications of category theory, but it is recognized that the area is highly interdisciplinary. Typical topics of interest include, but are not limited to, category-theoretic aspects of the following: coalgebras and computing concurrent and distributed systems constructive mathematics declarative programming and term rewriting domain theory and topology foundations of computer security linear logic modal and temporal logics models of computation program logics, data refinement, and specification programming language semantics type theory Previous meetings have been held in Guildford (Surrey), Edinburgh (twice), Manchester, Paris, Amsterdam, Cambridge, and S. Margherita Ligure (Genova). This is the first time CTCS will be held in North America. The proceedings of the conference will be published as a special issue of ENTCS (Electronic Notes in Theoretical Computer Science). Paper copies of the proceedings will be available to participants at the conference. The conference will have 4 invited speakers, and they are: Eric Goubault (CEA/Saclay) Guy McCusker (Sussex) Peter Selinger (Ottawa) Paul Syverson (Naval Research Laboratory) GRADUATE STUDENT PRECONFERENCE One new feature that CTCS will have this year is a "preconference" from August 12-14. This is supported in part by a grant from CRM, the Centre de Recherches Mathematiques (Univ. of Montreal). The goal is to prepare students for CTCS, through mini-courses in the basic areas underlying the fields of the conference. We anticipate offering courses in the following areas: Introduction to Category Theory Introduction to Categorical Logic Coalgebras Communication and Concurrency Game Semantics Linear Logic PROGRAMME COMMITTEE Rick Blute, Chair (Ottawa) Robin Cockett (Calgary) Thierry Coquand (Chalmers) Andrea Corradini (Pisa) Thomas Ehrhard (Luminy) Ryu Hasegawa (Tokyo) Martin Hofmann (Munich) Bart Jacobs (Nijmegen) Michael Johnson (Macquarie) Dusko Pavlovic (Kestrel Institute) Alex Simpson (Edinburgh) ORGANIZING COMMITTEE E. Moggi, Chair, (Genova) S. Abramsky (Oxford) P. Dybjer (Chalmers) B. Jay (Sydney) A. Pitts (Cambridge) LOCAL ORGANIZING COMMITTEE R. Blute (Ottawa) rblute(a)mathstat.uottawa.ca P. Scott (Ottawa) phil(a)site.uottawa.ca HOTEL INFORMATION We have arranged several special hotel rates. Both hotels are within walking distance of the conference. We request that you make hotel reservations yourself. If there are any problems, please contact one of the local organizers. (Note that all prices are in Canadian dollars.) 1) Ramada Hotel & Suites Ottawa (Use Group Code 2451 to get special rates.) 111 Cooper Street Ottawa, ONTARIO K2P 2E3 CANADA Tel: 1-613-238-1331 FAX: 1-613-230-2179 email: ramada(a)ramada-ottawa.com website: www.ramada.ca/ottsuit.html This is avalable from Wednesday, August 14, 2002 to Sunday, August 18, 2002 (departure on Monday). Rate: $109.00 single or double occupancy Deadline: July 14th, 2002 2) Novotel Ottawa Hotel (Use Contract # UNIV-814 to get special rates.) 33 Nicholas Street Ottawa, ONTARIO K1N 9M7 CANADA Phone:1-613-230-3033 or 1-800-668-6835 (Reservations worldwide-no charge dial) website: www.bestlodging.com/sites1/17534/index.shtml This is available from Wednesday, August 14, 2002 to Sunday, August 18, 2002 (departure on Monday). Rate: $129 single or double, $144 triple, $159 Quad Deadline: June 30th, 2002 We may also have a VERY limited number of university dorm rooms available at much cheaper rates. We will give them away on a first come, first served basis. Contact local organizers for this. CONFERENCE HOMEPAGE Updated information is available at http://www.mathstat.uottawa.ca/lfc/ctcs2002 . Registration forms are on the web site. For dormitory forms (for non students) please enquire by email to the organizers. Please register as soon as possible. (NOTE: CTCS is being held at U. Ottawa, but the conference registrar and coordinator is Ms. Gillian S. Murray, at Carleton University, as shown on the Registration Forms). A complete list of accepted papers will appear in the second call for participation. 24-Jun-2002 12:52:45 -0300,2833;000000000000-00000000

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preprint: Cubical sets and their site
by grandis＠dima.unige.it 20 Jun '02

20 Jun '02

The following preprint is available M. Grandis - L. Mauri, Cubical sets and their site, Dip. Mat. Univ. Genova, Preprint 452 (Jun 2002), 26 p. Abstract. Extended cubical sets (with connections and interchanges) are presheaves on a ground category, the extended cubical site K, corresponding to the (augmented) simplicial site, the category of finite ordinals. We prove here that K has characterisations similar to the classical ones for the simplicial analogue, by generators and relations, or by the existence of a universal symmetric cubical monoid; in fact, K is the classifying category of a monoidal algebraic theory of such monoids. Analogous results are given for the restricted cubical site I of ordinary cubical sets (just faces and degeneracies) and for the intermediate site J (including connections). We also consider briefly the reversible analogue, !K. Available at: ftp://www.dima.unige.it/Home/grandis/public/CubSet.dvi ftp://www.dima.unige.it/Home/grandis/public/CubSet.ps Marco Grandis 20-Jun-2002 12:20:43 -0300,1593;000000000000-00000000

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