2 Aug 1999 12:22

### Re: universal property of tangent bundle


Spivak's Comprehensive Introduction... an abstract
characterization of the tangent bundle ( removed from the
main text in the second edition due to the pressure of public
distaste')

Kirill Mackenzie

>
> Given an object M in the normal'' category of finitely dimensional
> smooth manifolds Man (not in SDG sense), what it the universal property
> of the tangent bundle TM?
>
> So far, I found only the following:
>
> For every manifold M there is a functor F:I -> Man0, where Man0 is
> category of open areas in R^n and smooth mapping, such that M=Colim F,
> F corresponding to the atlas on M and M is represented as a result of
> gluing instances of R^n in the atlas. This functor can be trivially
> modified (by multiplying its values on objects on R^n and modifying
> morphisms appropriately) to get functor TF:I -> Man0, such that
> TM=Colim TF.
>
> But this doesn't seem satisfactory because:
>
> 1. Construction of TF follows one particular construction of TM as a
> set of triples (x,(U,f),h) where x \in U, (U,f) is in atlas and h \in
> R^n with appropriate points identified.
>


1 Aug 1999 13:55

### Pre-print announcement

The following pre-print is available:
-----------------------------------------------------------------------
Perceive This as That - Analogies, Artificial Perception, and Category
Theory

By Zippora Arzi-Gonczarowski

It is forthcoming in The Annals of Mathematics and Artificial
Intelligence'.
-----------------------------------------------------------------------

Please e-mail to   zippie <at> actcom.co.il   if you want to receive the
pre-print.

((((((((
This paper is a continuation of the project that started with two papers
that were already announced on this list:

<at> article{aaa98,
Author = "Z. Arzi-Gonczarowski and D. Lehmann",
title = "Introducing the Mathematical Category of Artificial
Perceptions",
journal = "Annals of Mathematics and  Artificial Intelligence",
volume = "23",
number = "3,4",
month = "November",
pages = "267--298",
publisher = "Baltzer Science Publishers",
year = "1998" }


6 Aug 1999 03:18

### CFP: Workshop on Real-Time Constraints (2nd Call)


International Workshop on "REAL-TIME CONSTRAINTS"
(RTC'99)

Second Call For Papers
http://www.iis.sinica.edu.tw/~eric/cp99-rtc/

A Post-Conference Workshop of
the 5th International Conference on Principles and Practice
of Constraint Programming (CP'99)

October 16, 1999, Alexandra, Virginia, USA

A CP'99 post-conference international workshop on REAL-TIME CONSTRAINTS is
being organized at CP'99. Real-time systems and applications all require
stringent timing constraints for correct operation. Such real-time constraints
are often difficult to design as well as verify. Varied techniques that deal
with real-time constraints have been proposed in various application domains.
This workshop will try to find a consensus in the various techniques that
appear in different domains related to real-time constraint specification,
programming, design, validation, and verification.

All topics related to real-time constraints are invited.
Topics of interest include, but are not limited to, the following:
- Specification of Real-Time Constraints   - Formal Methods
- Modeling of Real-Time Constraints        - Industrial Techniques
- Programming of Real-Time Constraints     - Case Studies
- Verification of Real-Time Constraints    - IP / Virtual Components
- Testing of Real-Time Constraints         - Embedded Systems
- Real-Time Constraint Tools               - Hardware-Software Coverification


6 Aug 1999 05:02

### New mailing list for universal algebra


Greetings:

I have finally established a mailing list for universal algebra.  (I have
been thinking about doing this for a long time.  At one time, I was going
to establish a mailing list for Beck modules, and a fair number of people on
this list expressed interest.)  The mailing list is at the onelist.com web
facility.

It is a moderated mailing list, for now, with me as the only moderator for
the time being.  (My policy will be that anything that isn't spam or harmful
to someone else will be accepted.)

To subscribe, you can register for the univalg list at on the web at
http://www.onelist.com, or send e-mail to univalg-subscribe <at> onelist.com.
Onelist.com may then ask you to confirm your subscription by e-mail.  To
submit a message to the list, either post it using the facilities at the
web site, or send it to univalg <at> onelist.com.

If you have any problems doing any of this, please send me e-mail at
rowan <at> crl.com.

The mailing list is set up so that replies to messages go out to the
whole list.  So, please bear this in mind.  If for some reason you subscribe,
and then change your mind, you can unsubscribe at the web site or send
e-mail to univalg-unsubscribe <at> onelist.com.

Bill Rowan



6 Aug 1999 12:41

		MONADIC COMPLETION OF ADJUNCTIONS

A famous theorem of Jon Beck says that an adjunction
A
^    |
|    |
F | -| | U
|    |
|    v
C

is monadic (equivalent to its category of Eilenberg--Moore algebras)
iff U satisfies a certain condition involving "U-split coequalisers".

Given any adjunction, of course one may "force" it to be monadic by
replacing the category A by the category of algebras for the monad U.F,
and there is a comparison functor.

(1) My question is this: is there an explicit account in the literature
somewhere of the construction obtained by "freely adding" the conditions
of Beck's theorem (the U-split coequalisers) to A?

(2) Further, has anyone considered what happens when one forces an adjunction

Steve Lack gave me a verbal answer to the second question, although he
hasn't shown me his notes:
(a) if we force U to be monadic, and then (the new) F to be comonadic,
(the third) U need NOT be monadic, but
(b) if we force U to be monadic again then (the fourth) F IS still comonadic.


5 Aug 1999 14:52

### on the coexponential question

Recently there was brought up the question whether duals of ccc's may have
significance and it has been pointed out by P. Levy and P. Selinger that a
good example is that of the Kleisli category for the continuation monad.

In a sense the dual of the Kleisli category is much neater as it is cc.
There is some odd'' structure there corresponding to some sort of
classical disjunction''. It is precisely this odd'' structure which is
used for constructing function spaces'' in the Kleisli category which,
however, aren't exponentials.
Actually, there can't exist proper function spaces for the following reason.
If C and its dual are both cartesian closed then C is a bi-Heyting algebra
as if C^op is cc then 1+(_) is a right adjoint and accordingly 1+1 ~= 1
form which it follows that C is posetal. This strengthens Joyal's Lemma''
saying that any c.c. with an involution is actually a Boolean algebra.

Thomas S.


9 Aug 1999 20:33

### Replacement Position at Saint Mary's University


SAINT MARY'S UNIVERSITY =20
MATHEMATICS AND COMPUTING SCIENCE DEPARTMENT

FULL TIME, LIMITED-TERM APPOINTMENT

The Department of Mathematics and Computing Science at Saint Mary's
University invites applications for a nine- to twelve-month replacement
position in Computing Science at the rank of Lecturer or Assistant
Professor, to begin September 1, 1999.

The successful candidate will have at least a M.Sc. but preferably a
Ph.D. in Computing Science, or possibly a degree in a related subject
with a very strong background in Computing Science. The successful
candidate will be expected to teach courses at the undergraduate level,
ideally including Artificial Intelligence, Information Retrieval, File
Structures, Advanced Architectures, and Linear Algebra. While there is
some flexibility in course assignment, a candidate who can teach all or
most of these courses will be preferred.

Salary will depend on qualifications and experience; teaching load (9
hours/week) will be standard for the department.  Applications,
including a curriculum vitae and the names and addresses of at least
three referees should be sent to:

Department of Mathematics and Computing Science
Attention: Chairperson of Search Committee
Saint Mary's University
Halifax, Nova Scotia
B3H 3C3


10 Aug 1999 19:27

### Re: WAIT99 (CFP - Preliminar)

                    -----------------------
CALL FOR PARTICIPATION
----------------------

28 JAIIO - WAIT'99

Argentinian Workshop on Theoretical Computer Science
Buenos Aires - Argentina
September 6-7, 1999

The 3rd Argentinean Workshop on Theoretical Computer Science (WAIT'99) will
be part on the 28th Argentinean Conference on Informatics and Operations
Research (28 JAIIO), to be held in Buenos Aires from September
6th to September 10th, 1999.

The goal of the workshop is bringing together researchers from academy
(from Argentinean and other uNiversities) and industry professionals in
order to discuss theoretical, empirical and experimental results on the
field of theoretical computer science.

This workshop will consist of two invited talks and seventeen technical
presentations in  the following areas of theoretical computer science:

* Logical and algebraic foundations for computer science

* Formal program construction

* Algorithms and data structures

* Computational complexity


12 Aug 1999 06:56

### TCS2000, call for papers


(Aplogies if you receive multiple copies)

call for papers
IFIP International Conference on Theoretical Computer Science
IFIP TCS2000
--- Exploring New Frontiers of Theoretical Informatics ---
August 17 - 19, 2000
Tohoku University, Sendai, Japan

IFIP TCS2000 is the first International Conference on Theoretical Computer
Science organized by the IFIP TC1 on Foundations of Computer Science. Major
topics of the conference are follows:

Track (1): Algorithms, Complexity and Models of Computation

analysis and design of algorithms --- algorithm experimentation ---
continuous algorithms and complexity --- computational complexity ---
descriptional complexity --- cellular automata and machines, automata
and formal languages --- hardware algorithms and parallel algorithms
--- computational learning theory --- algorithmic aspects in discovery
science --- cryptography --- combinatorics --- probabilistic and
randomized algorithms --- molecular computing and algorithmic aspects
of bioinformatics --- quantum computing --- neural network computing
--- evolutionary and genetic algorithms --- computational geometry ---
computational and mathematical finance --- bridging complexity and
semantics.

Track (2): Logic, Semantics, Specification and Verification



12 Aug 1999 20:59

### CADE-17 Preliminary Call For Papers


The 17th International Conference on Automated Deduction
June 17-20, 2000, Pittsburgh, Pennsylvania, USA
PRELIMINARY CALL FOR PAPERS

For the last 25 years CADE has been the major forum for the
presentation of research in automated deduction.  Original research
papers in all aspects of automated theorem proving, automated reasoning,
computer aided verification, formal methods and static analysis

PROGRAM CHAIR: David McAllester, AT&T Labs-Research
CONFERENCE CHAIR: Frank Pfenning, Carnegie Mellon University

PROGRAM COMMITTEE: Hubert Comon, David Dill, Ulrich Furbach, Harald Ganzinger,
Mike Gordon, Didier Galmiche, Tom Henzinger, Deepak Kapur, Ursula Martin,
Ken McMillan, Paliath Narendran,  David Plaisted, Robert Nieuwenhuis, Tobias Nipkow,
Hans de Nivelle, Larry Paulson, Amir Pnueli, Mark Stickel, Moshe Y. Vardi, Andrei Voronkov.