Dear Category Theorist: This is the final announcement for the Special Session on "Applied Categorical Structures" at the up-coming AMS Meeting in Toronto, Sept. 23&24. The Session will be held in Room 2173 of the Medical Sciences Building on the downtown campus of the University of Toronto. It will start on Saturday at 9am and finish on Sunday at 5pm. For comprehensive and continually updated meeting and program information, including accommodation in Toronto, see http://www.ams.org/meetings/ For the the program of the Session, see also the end of this message. There has been one change since Andre' Joyal is not able to attend, due to sudden unavoidable circumstances. There will be a WELCOME PARTY on Friday, September 22, starting at 7pm, for participants of the Session. With funds provided by York University we are pleased to be able to invite you and your spouse/friend to a complimentary buffet dinner (open till 10pm) in the Thai restaurant "Sawaddee" at 150 Avenue Road, Toronto, tel. (416) 921 9198. The restaurant is located at the north-west corner of the intersection of Avenue Road with Davenport, which is 7 (very short) blocks north of Bloor St. It's about a 15-minute walk from the UofT-campus, and less than 5 minutes from the Howard Johnson Inn which we mentioned in our previous message. The walk from the Days Inn on Carlton St would be about 30 minutes; a reasonable alternative to walking all the way or taking a short taxi ride would be walking westbound from the hotel on Carlton and College to Bay Street and taking the "Bay" bus no.6 north and to get off right at the intersection Avenue Rd/Davenport (subway token or exact fare $2 required). If coming by car to the restaurant, your best bet would be to search for spots on the streets in the area north west of the restaurant, success not guaranteed. In order for us to know the approximate number of participants, PLEASE LET US KNOW BY FRIDAY, SEPTEMBER 15, WHETHER YOU'LL BE COMING TO THE WELCOME PARTY, by e-mailing tholen@mathstat.yorku.ca (see form below). We look forward to seeing you in Toronto. Joan Wick Pelletier Walter Tholen ******************************************************************************* I shall be attending the "Welcome Party" on Friday, September 22: YES/NO I will be accompanied by my spouse/friend: YES/NO NAME: ********************** Send to tholen@mathstat.yorku.ca ********************** PROGRAMME Saturday, Sept. 23: 9:00 Matt Brin (see abstract below) 3:00 Stephen Awodey 9:30 Myles Tierney 3:30 Lars Birkedal 10:00 Jack Duskin 4:00 David Benson 10:30 Marco Grandis 4:30 John MacDonald 11:00 Enrico Vitale 5:00 Richard Wood Sunday, Sept. 24: 9:00 Marta Bunge 2:00 Joachim Lambek 9:30 Michael Makkai 2:30 James Madden 10:00 Robin Cockett 3:00 Gloria Tashjian 10:30 M. M. Mawanda 3:30 Robert Pare 11:00 F. William Lawvere 4:00 Jiri Rosicky 4:30 F. J. O. Souza All talks are 25 minutes long. The titles follow. The full abstracts may be seen at the web site cited above. Abstract # Title Authors Date Received 957-18-265 On the pivotal, symmetric case of involutory Hopf 13-jul-2000 objects. Fernando J. O. Souza*, fernando@math.uic.edu 957-18-235 Higher category theory. 12-jul-2000 Andre Joyal*, joyal@math.uqam.ca 957-06-218 Injective hulls of partially ordered monoids. 12-jul-2000 J. Lambek* 957-18-214 Modelling a sketch in an object in a 2-category. 11-jul-2000 Michael Johnson, mike@ics.mq.edu.au Robert Rosebrugh, rrosebru@mta.ca R. J. Wood*, rjwood@mathstat.dal.ca 957-18-204 Open problems on finiteness and their counting 11-jul-2000 measures. Mbila-Mambu Mawanda*, mm.mawanda@nul.ls 957-18-199 Monoreflections in categories of ordered rings. 10-jul-2000 James J Madden*, madden@math.lsu.edu 957-18-198 Nerves of Bicategories: Morphisms and Simplicial 10-jul-2000 Maps. John W Duskin*, duskin@math.buffalo.edu 957-18-157 A summary report on the state of our knowledge of 05-jul-2000 weak higher dimensional categories. Michael Makkai*, makkai@math.mcgill.ca 957-18-140 Dominances and Spread Completions. 04-jul-2000 Marta C Bunge*, bunge@math.mcgill.ca 957-18-132 Finitely productive classes of uniform spaces 03-jul-2000 which generate cartesian-closed categories. Gloria Tashjian* 957-68-123 Certain spans of sketches model problems of 29-jun-2000 complexity NP. David B Benson*, dbenson@eecs.wsu.edu 957-18-107 Flat covers and factorizations. 27-jun-2000 Jiri Rosicky*, rosicky@math.muni.cz 957-18-90 Free Double Categories and the Word Problem for 25-jun-2000 Groups. Robert Par\'e*, pare@mscs.dal.ca Robert MacG. Dawson, rdawson@husky1.stmarys.ca 957-18-77 A higher dimensional homotopy sequence. 22-jun-2000 Marco Grandis, grandis@dima.unige.it Enrico Vitale*, vitale@agel.ucl.ac.be 957-18-76 Some absolute pullbacks and pushouts in 22-jun-2000 $\boldsymbol{\Delta}$. Myles Tierney*, tierney@math.rutgers.edu 957-18-61 Monads and Structure. 16-jun-2000 John L. MacDonald*, johnm@math.ubc.ca 957-18-59 Relating realizability using sheaves. 16-jun-2000 Steve Awodey*, awodey@cmu.edu Andrej Bauer Dana S Scott 957-03-51 Relative and Modified Relative Realizability. 13-jun-2000 Lars Birkedal*, birkedal@itu.dk Jaap van Oosten, jvoosten@math.uu.nl 957-18-39 Higher fundamental functors in some categories of 07-jun-2000 presheaves. Marco Grandis*, grandis@dima.unige.it 957-18-30 Game theory revisited: categorical proof theories 31-may-2000 for games. J. Robin B. Cockett*, robin@cpsc.ucalgary.ca 957-18-19 Toposes and Continuum Microphysics. 22-may-2000 F. William Lawvere*, wlawvere@acsu.buffalo. NEW The chameleon groups of Richard J. Thompson: 09-sep-2000 categories with multiplication. Matt Brin*, matt@math.binghamton.edu.
----------------------------------------------------------------------------- Matt Brin: The chameleon groups of Richard J. Thompson: categories with mutliplication
Abstract:
We show that any category with a functoral multiplication has asociated to it a handful of groups that are strongly related to infinte, finitely presented groups discovered by Richard Thompson. To add weight to the connection between the multiplication and the groups, we prove that if associativity and commutativity equivalences are given, then they are are coherent (in the sense of MacLane) if and only if two of the groups turn out to be isomorphic to two of the groups discovered by Thompson. This is the beginning (low dimensional part) of the formalization of the already known relation between coherence questions and Thompson's groups.