Date: Thu, 3 Mar 1994 22:12:02 +0400 (GMT+4:00)
Subject: Workshop on Teaching Formal Methods
Date: 02 Mar 1994 17:40:26 -0500
From: Philip Mulry
Dear Colleagues,
I wanted to bring to your attention the second announcement of a CS
workshop on the teaching of formal methods in an undergraduate
setting. My apologies that the original announcement did not appear
here. If you are interested or have any questions, drop me a note.
---
Philip Mulry
Dept of Computer Science
Colgate University
Hamilton N.Y. 13346
phil@cs.colgate.edu
**********************************************************************
TEACHING FORMAL METHODS
CURRICULUM DEVELOPMENT WORKSHOP
SECOND ANNOUNCEMENT
Hamilton College
Clinton, N.Y.
July 30 - Aug 5, 1994
sponsored by
The National Science Foundation
THE PURPOSE OF THE WORKSHOP is to develop modules and materials for
teaching formal methods in an undergraduate setting. Participants
will be asked to submit a module or position paper which they have
developed. While the particular form and length of the module is left
unspecified, modules should contain both expository material and
exercises or labs.
TOPICS for the modules may include(but are not limited to)
-- Propositional/ Predicate Calculus , with applications to
assertions/pre- and post-conditions
-- Loops and Invariants
-- Category Theory
-- Algorithm Design
-- Hardware Specification/Design/Verification
-- Parallel Constructs (eg. CSP, Hoare semantics)
-- Operational Semantics
-- Formal Methods with OOP
-- Applications of Mathematica
THE WORKSHOP itself will be devoted to the presentation, discussion
and revision of participant modules. We also anticipate inviting
several keynote speakers. After the workshop, participants will be
asked to submit full revised versions of their modules for
incorporation into a collection for dissemination to computer science
educators. Three of the principal investigators for the project,
Philip Mulry (Colgate University), Doug Troeger(CUNY) and Henry
Walker(Grinnell College), will be responsible for editing the
collection of materials with a view towards publication in the near
future. We plan to have a followup workshop in the summer of 1995,
in conjunction with the working group in Object Oriented Computing,
to evaluate the results to date and further disseminate the materials
developed. Participants will be encouraged to use draft versions of
the modules in their teaching for evaluation.
AN NSF GRANT will partially cover travel, room and board costs for
the workshop. Participants will receive a stipend of $150 for their
participation in the workshop and an additional $150 after submission
of their revised module.
THERE MAY BE LIMITED FUNDS to support attendance by individuals who
want to become involved with the project but do not have a module to
submit at this time. Please write to inquire.
TO APPLY: Send an abstract of your module or position paper and a
brief resume including your experience with formal methods to:
Philip Mulry
Formal Methods Workshop
Computer Science Department
Colgate University
13 Oak Drive
Hamilton, New York 13346
email:fmworkshop@cs.colgate.edu
ABSTRACTS should be no more than 5 pages in length, be clearly
written, and provide sufficient detail to allow the program committee
to assess the merits of the module. The preferred mode of submission
is via email. The preferred abstract format is latex. Submission of
abstracts should be received by March 20, 1994 by the program chair.
This is a firm deadline, late submissions will not be considered.
Participants will be notified of acceptance by April 1, 1994.
Accepted modules (in a specified format) will be due
July 1, 1994. A final revised module will be due November 1, 1994.
DATES:
Abstract Submission Deadline: March 20, 1994
Participation Notification: April 1, 1994
Draft Module Due: July 1, 1994
Conference: July 30 - August 5, 1994
Revised Module Due: November 1, 1994
FOR FURTHER INFORMATION, contact the Workshop Co-chairs:
Philip Mulry: phil@cs.colgate.edu
Doug Troeger: dtroeger@csfaculty.engr.ccny.cuny.edu
Henry Walker: walker@ac.grin.edu
Date: Sun, 6 Mar 1994 13:01:51 +0400 (GMT+4:00)
Subject: "Sketches: Outline with References"
Date: 4 Mar 1994 18:16:28 GMT
From: Charles Wells
My paper "Sketches: Outline with References" is now available in
both TeX dvi and postscript form by anonymous FTP from ftp.cwru.edu
in the directory math/wells in the file sketch.dvi or sketch.ps.
I have corrected some errors in the bibliography. The
corrections that were made are listed in the file skcorr.dvi or
skcorr.ps.
--
Charles Wells
Department of Mathematics, Case Western Reserve University
10900 Euclid Avenue, Cleveland, OH 44106-7058, USA
216 368 2893
Date: Tue, 8 Mar 1994 16:40:27 +0400 (GMT+4:00)
Subject: XY-pic v.2.7: Graphs and diagrams in TeX RELEASED!
Date: Tue, 8 Mar 1994 21:11:11 +1000
From: Kristoffer Rose
Reply to: kris@diku.dk
Dear XY-pic current, former, and potential XY-pic interestees,
This is to announce the release of a new version of my DIAGRAM DRAWING
PACKAGE, XY-pic: version 2.7. The release is slightly overdue (16
months late, in fact) but this is due to the ABUNDANCY OF NEW FEATURES
in the package.
Below I have attached the TRAILER of the package that gives some more
details and explains how to obtain it.
If you have lost interest in XY-pic then I apologise; otherwise I hope
that you'll find it worth the wait!
Regards,
Kristoffer Rose (.signature at the end below)
======================================================================
TRAILER: ANNOUNCING THE XY-pic version 2.7 DIAGRAM TYPESETTING PACKAGE
======================================================================
XY-pic is a package for typesetting a variety of graphs and diagrams
within TeX that works with most formats (including LaTeX 2.09, LaTeX2e
in compatibility mode, AMS-LaTeX, AMS-TeX, and plain TeX).
XY-pic version 2.7 has been a long time underway because it is a MAJOR
REWRITE of XY-pic. The reason is that the version 2.6 code has been
reorganised into a kernel and several orthogonal modules to make the
development of XY-pic 3 possible while maintaining backwards
compatibility. Therefore
* version 2.7 is a BETA TEST release in the sense that it is likely to
contain bugs in both documentation and code! If you are a version
2.6 user then PLEASE TEST this release with your existing diagrams
and REPORT PROBLEMS you encounter to the author: the intention is to
maintain full backwards compatibility but I need feed-back from
users in order to achieve this goal (see the `Incompatibilities'
appendix in the User's Guide for some known problems)!
* version 2.7 is an ALPHA TEST and RFC release of the forthcoming
XY-pic version 3 being developed by myself in collaboration with
Ross Moore while visiting Macquarie U, Sydney, until May 1994. It
will add special modes for convenient specification of at least the
following high-level diagram types Generalised trees, Planar graphs,
Commutative diagrams with 2-cells, and String and braid diagrams, as
well as provide special output drivers for at least PostScript
(eliminating the need for special fonts in this case). If you wish
to peek at the kind of diagrams we are working on then take a look
at the files available for ftp at ftp.mpce.mq.edu.au in
/pub/maths/tex/Quantum (and trough my WWW hyperlink cited below).
The package will also be provided as a LaTeX2e and LaTeX3 `package' as
soon as the guidelines for how to do this are available to the author.
----------------------------------------------------------------------
VERSION 2.7 FEATURES
----------------------------------------------------------------------
XY-pic version 2.7 provides two modes of specifying drawings:
* A matrix-like mode where the dimensions of the drawing are
automatically computed by aligning diagram entries in rows and
columns (this is also the `version 2 compatibility mode').
* A general `turtle graphic' drawing language for specifying graphs
with objects and connections between them in a manner independent of
orientation.
Both modes support the following specific features:
+ Positions can be given in variety of formats (extendable) including
user defined coordinates (x,y) and relative to previous positions,
objects, object edges, and points on connections.
+ Objects may be circular or rectangular (more shapes can be added)
and adjusted in several ways.
+ Large library of objects with mnemonic names.
+ Objects that orient themself along a connection when placed relative
to it, e.g., `\dir{|-}' is like \vdash but thus oriented.
+ Includes circle segments and arbitrary TeX text.
+ Connections are aligned between the reference points of objects but
start and end on the edges.
+ Any object can be used to build a connection (using `diagonal
filling'); library objects provide common line types.
+ Special notation for drawing arrows with tail, stem, and head build
from any object(s). Special support for arrows that cross each
other, arrows that `go by' other entries, combined arrows, and
arrows with n/8 bends.
+ Library of frames.
If you wish to check out the facilities (using a 300 dpi PostScript
printer), then you can print the file `xyguide.ps' that contains a
preformatted version of the User's Guide.
----------------------------------------------------------------------
AVAILABILTY
----------------------------------------------------------------------
XY-pic is available by anonymous ftp from at least the following sites:
ftp.diku.dk : /diku/users/kris/TeX/xy27run.tar.Z
ftp.mpce.mq.edu.au : /pub/maths/TeX/xy27run.tar.Z
The same locations also contains manuals formatted for printing on
300dpi PostScript printers in `xyguide.ps.Z' and `xyrefer.ps.Z' and a
special distribution for Textures (by ross@mpce.mq.edu.au) in
`xy27mac.sit.hqx'; check out the README files!
You can also use my WWW hyperlink cited below to retrieve the package.
Please note that XY-pic is `copyleft' under the terms of the GNU
General Public License.
----------------------------------------------------------------------
This is the end of the TRAILER. I hope you will enjoy XY-pic!
--
Kristoffer Hxgsbro ROSE Internet: kris@diku.dk
DIKU, U of Copenhagen, Universitetsparken 1, 2100 Kxbenhavn X, DANMARK
phone: +45 35321400 direct: +45 35321420 fax: +45 35321401
--
World Wide Web URL: file://ftp.diku.dk/diku/users/kris/WWW/home.html
Date: Thu, 10 Mar 1994 23:38:27 +0400 (GMT+4:00)
Subject: TLCA: First Call for Papers (Latex)
Date: Thu, 10 Mar 1994 13:27:09 +0000
From: Gordon Plotkin
\documentstyle{article}
\parindent 0cm
\pagestyle{empty}
\textwidth 18cm
\textheight 28cm
\topmargin -2.5cm
\oddsidemargin -1.2cm
\evensidemargin 0cm
\begin{document}
\begin{center}
{\LARGE First Call for Papers} \end{center}
\smallskip
\begin{center}
{\Huge Second International Conference on}
\end{center}
\begin{center}
{\Huge Typed Lambda Calculi and Applications}
\end{center}
\begin{center}
{\Huge TLCA}
\end{center}
\smallskip
\begin{center}
{\Large April 10--12, 1995, Edinburgh, Scotland}
\end{center}
\bigskip
The second international conference on Typed Lambda
Calculi and Applications will be held
April 10--12, 1995, at Edinburgh in
Scotland. The conference aims at providing a forum
for the presentation and discussion of recent
research in the following areas:\vspace{-1cm}
\begin{itemize}\begin{center}
\item[] \bf Proof theory of type systems \\
\item[] \bf Logic and type systems \\
\item[] \bf Typed lambda calculi as models of
(higher order) computation \\
\item[] \bf Semantics of type systems \\
\item[] \bf Proof verification via type systems \\
\item[] \bf Type systems of programming languages \\
\item[] \bf Typed term rewriting systems
\end{center}
\end{itemize}
\bigskip
\begin{minipage}[t]{8.5cm}
{\large \bf Program}
\smallskip
The program of TLCA will consist of about 30
selected presentations in plenary sessions.
The program committee for TLCA is
chaired by M.~Dezani and has the following
members: \smallskip
{\bf H.~Barendregt}~(Catholic University of Nijmegen) \\
{\bf M.~Dezani}~(Chairperson, University of Turin) \\
{\bf J-Y.~Girard}~(University of Marseilles) \\
{\bf R.~Hindley}~(University of Swansea) \\
{\bf F.~Honsell}~(University of Udine) \\
{\bf J.~W.~Klop}~(CWI) \\
{\bf G.~Longo}~(ENS) \\
{\bf A.~Meyer}~(MIT) \\
{\bf G.~Plotkin}~(University of Edinburgh) \\
{\bf P.~Scott}~(University of Ottawa) \\
{\bf J.~Smith}~(University of Gothenburg/Chalmers) \\
{\bf J.~Tiuryn}~(University of Warsaw) \\ \smallskip
{\large \bf Call for Papers}
\smallskip
Original contributions are solicited for TLCS;
they should be sent to the conference secretariat.
Electronic submission (PostScript only) is
preferred; hard copy (6 copies required) will
also be accepted. Papers should be clearly written
and allow the program committee to assess the
merits of the work. References and comparisons
with related work should be included.
Papers should not exceed 15 standard pages and
should be accompanied by a one-page abstract.
The deadline for submissions is September 8, 1994.
Authors will receive notification of acceptance by
November 12, 1994. Definitive versions of papers
will be due December 15, 1994.
\end{minipage} \hspace{1cm} \begin{minipage}[t]{8.5cm}
{\large \bf Proceedings}
\smallskip
It is intended to publish the accepted papers as a
volume of the Springer Verlag Lecture Notes in Computer
Science series.\smallskip\\
{\large \bf Organizing Committee}
\smallskip
{\bf G.~Cleland, P.~Gardner, M.~Lekuse,
G.~Plotkin} \\(University of Edinburgh) \\
{\large \bf Important Dates}
\smallskip
\vspace{-0.25cm}\begin{tabbing}
abcdefghijklmnop\=abcdefghijklmnop\kill
Sept. 8, 1994
\>Deadline for submissions \\
Nov. 12, 1994
\>Notification of acceptance \\
Dec. 15, 1994
\>Final version of paper \\
April 10, 1995
\>TLCA
\end{tabbing}
\vspace{0.1cm}\smallskip
{\large \bf TLCA Secretariat}
\smallskip
TLCA Secretariat \\
Professor M.~Dezani \\
Universit\'{a} di Torino \\
Dipartimento di Informatica \\
Corso Svizzera, 185\\
10149 Torino \\
ITALY\\
Tel: 39-11-7429232~~Fax: 39-11-751603\\
Email: dezani@di.unito.it \\
{\large \bf $\lambda$-Calculus Network Meeting}
\smallskip
Participants of TLCA are invited to attend a
$\lambda$-Calculus Network Meeting to be held
in the weekend before the conference.
\end{minipage}
\end{document}
Date: Thu, 10 Mar 1994 23:35:10 +0400 (GMT+4:00)
Subject: Correcting Typos in Lambek-Scott
Date: Thu, 10 Mar 94 09:30:45 EST
From: SCPSG@acadvm1.uottawa.ca
Dear Colleagues:
Cambridge University Press is going into the 4th printing
of our book "Introduction to Higher Order Categorical Logic"
by Jim Lambek and me, and have asked us for any typos
(major rewrites are not possible, alas).
If anyone knows of typos (there were many
in the first printing, due to CUP error, most were corrected
by the 3rd paperback) we would appreciate hearing about it.
You can write to me (Phil Scott) at the address below.
Thanks in advance,
Phil Scott
scpsg@acadvm1.uottawa.ca
Date: Thu, 10 Mar 1994 23:42:23 +0400 (GMT+4:00)
Subject: TLCA: First Call for Papers (Plain Text)
Date: Thu, 10 Mar 1994 13:27:13 +0000
From: Gordon Plotkin
First Call for Papers, TLCA
International Conference on Typed Lambda Calculi and Applications
April 10--12, 1995, Edinburgh, Scotland
The second international conference on Typed Lambda Calculi and
Applications will be held April 10--12, 1995, at Edinburgh in Scotland.
The conference aims at providing a forum for the presentation and
discussion of recent research in the following areas:
Proof theory of type systems
Logic and type systems
Typed lambda calculi as models of (higher order) computation
Semantics of type systems
Proof verification via type systems
Type systems of programming languages
Typed term rewriting systems
The program of TLCA will consist of about 30 selected presentations in
plenary sessions. The program committee for TLCA is chaired by
M. Dezani and has the following members:
H. Barendregt (Catholic University of Nijmegen)
M. Dezani (Chairperson, University of Turin)
J-Y. Girard (University of Marseilles)
R. Hindley (University of Swansea)
F. Honsell (University of Udine)
J. W. Klop (CWI)
G. Longo (ENS)
A. Meyer (MIT)
G. Plotkin (University of Edinburgh)
P. Scott (University of Ottawa)
J. Smith (University of Gothenburg/Chalmers)
J. Tiuryn (University of Warsaw)
Call for Papers
Original contributions are solicited for TLCS; they should be sent to the
conference secretariat. Electronic submission (PostScript only) is
preferred; hard copy (6 copies required) will also be accepted. Papers
should be clearly written and allow the program committee to assess the
merits of the work. References and comparisons with related work
should be included. Papers should not exceed 15 standard pages and
should be accompanied by a one-page abstract. The deadline for
submissions is September 8, 1994. Authors will receive notification of
acceptance by November 12, 1994. Definitive versions of papers will
be due December 15, 1994.
Proceedings
It is intended to publish the accepted papers as a volume of the Springer
Verlag Lecture Notes in Computer Science series.
Organizing Committee
G. Cleland, P. Gardner, M. Lekuse, G. Plotkin (University of
Edinburgh)
Important Dates
Sept. 8, 1994 Deadline for submissions
Nov. 12, 1994 Notification of acceptance
Dec. 15, 1994 Final version of paper
April 10, 1995 TLCA
TLCA Secretariat
TLCA Secretariat
Professor M. Dezani
Universita di Torino
Dipartimento di Informatica
Corso Svizzera, 185
10149 Torino
ITALY
Tel: 39-11-7429232 Fax: 39-11-751603
Email: dezani@di.unito.it
Lambda-Calculus Network Meeting
Participants of TLCA are welcome to attend a Lambda-Calculus
Network Meeting to be held immediately before the conference.
Date: Fri, 11 Mar 1994 09:33:16 +0400 (GMT+4:00)
Subject: term rewriting and sesqui-categories
Date: Fri, 11 Mar 1994 11:18:20 +0000 (GMT)
From: "John G. Stell"
The following paper is available by anonymous ftp.
MODELLING TERM-REWRITING SYSTEMS BY SESQUI-CATEGORIES.
Abstract
It is well-known that a term rewriting system gives rise to a 2-category
in which the objects are finite sets of variables, the morphisms are
substitutions, and the 2-cells are rewrites. This paper demonstrates that
a generalization of a 2-category, called a sesqui-category, is a more
appropriate categorical model for a term rewriting system. This is
principally because, unlike the case of a 2-category, the sesqui-category
associated to a term rewriting system supports a notion of length on its
2-cells. This notion of length is used in developing definitions of local
confluence and critical pair in the context of an arbitrary sesqui-category
with length and certain additional structure. The relationship between
these abstract definitions and their usual term rewriting counterparts is
established. This provides some evidence that sesqui-categories may be an
appropriate vehicle for an abstract theory of rewriting capable of handling
critical pairs.
The paper can be obtained by
anonymous ftp from ftp.cs.keele.ac.uk
the file is pub/techreports/1994/tr94-02.ps
-------------------------------------------------------------------------
John Stell
Department of Computer Science email john@cs.keele.ac.uk
Keele University
Keele, Staffordshire, telephone +44 782 583260
ST5 5BG fax +44 782 713082
U. K.
-------------------------------------------------------------------------
Date: Sat, 12 Mar 1994 18:06:40 +0400 (GMT+4:00)
Subject: T. Wilson's query of Feb 2
Date: Fri, 11 Mar 1994 16:37:45 -0500 (EST)
From: MTHISBEL@ubvms.cc.buffalo.edu
... Mr. Wilson has asked a question
which was answered on page 14 of vol. 31 of Mathematica Scandinavica (1972)
(after the diagram). No. John Isbell
Date: Sat, 12 Mar 1994 18:12:08 +0400 (GMT+4:00)
Subject: Is Lawvere-Tierney complete?
Date: Sat, 12 Mar 1994 13:43:37 +0100
From: Todd Wilson
Has anyone proved that the elementary topos axioms are complete for
the first-order properties (in the language of categories) of
Grothendieck toposes?
--Todd Wilson
Date: Sat, 12 Mar 1994 23:36:40 +0400 (GMT+4:00)
Subject: Re: Is Lawvere-Tierney complete?
Date: Sat, 12 Mar 94 18:21:19 EST
From: Peter Freyd
The first-order properties of a Grothendieck topos include all of
first-order arithmetic, hence there can not be a complete
axiomization.
Date: Sun, 13 Mar 1994 11:31:59 +0400 (GMT+4:00)
Subject: mail aliases
Date: March 12, 1994
From: Bob Rosebrugh
Mike Barr has mentioned that a large mail alias list is maintained on the
triples machine at McGill, and that anyone is free to use it. For example,
I can be reached by sending mail to
rosebrugh@triples.math.mcgill.ca
The triples list contains several hundred names of interest to readers of
categories. Like Vaughan Pratt's structures directory, the triples list
uses surnames, with single initials where necessary as in asmith, bsmith.
Date: Tue, 15 Mar 1994 21:40:01 +0400 (GMT+4:00)
Subject: PSSL: 2nd announcement
Date: Tue, 15 Mar 1994 12:33:58 +0000 (GMT)
From: Edmund Robinson
SECOND ANNOUNCEMENT 54TH PSSL
As previously announced, the 54th meeting of the Peripatetic Seminar
on Sheaves and Logic will be held over the weekend of the 26th-27th
March 1994 at the University of Sussex. As usual, we welcome talks on
topics in logic, category theory and related areas.
The meeting will be held in Stage I of the Maths and Physics Building,
in lecture theatre PB1A6, starting at 9.30 on the Saturday morning.
On the Friday evening, from 7.30 to about 10.00 there will be a
gathering in the COGS common room in Stage II of the Maths and Physics
Building, at which the program for the meeting will be
finalised. Light refreshments will be available.
Information about travel, local accommodation, participants and talks
offered has been placed in the Sussex anonymous ftp archive
(ftp.cogs.sussex.ac.uk, subdirectory pub/pssl) and will continue to be
updated as necessary. There is also a mailbox pssl@cogs.sussex.ac.uk,
specifically for conference mail. If you have problems with arranging
travel or accommodation, please feel free to contact us (please note
that we have not arranged accommodation for participants, unless
specifically requested).
We look forward to seeing you in Sussex. The local organizers,
Carolyn Brown,
Chris Mulvey,
Edmund Robinson,
Gavin Wraith
Date: Wed, 16 Mar 1994 17:16:32 +0400 (GMT+4:00)
Subject: holomorph
Date: Wed, 16 Mar 94 10:42:28 +0100
From: Pierre Ageron
Thank you to all people who contributed to the discussion about Cantor-
Bernstein. I learnt many interesting things, although what I had I mind was
rather the general categorical structure underlying the proof. A similar
question could be asked about the "elementary" proof of the following theorem :
if there is an injection from A to B, then there is injection from 2A to 2B.
Another question. The construction of the holomorph of a group is well-known :
Hol(G) = G x Aut(G) .
Similar constructions can be done for graphs, categories, sketches, ...
Has anyone seen anything about that ?
Pierre Ageron
Date: Thu, 17 Mar 1994 11:48:53 +0400 (GMT+4:00)
Subject: holomorph
Date: Thu, 17 Mar 1994 08:37:35 +0000
From: "Prof R. Brown"
In reply to Pierre Ageron's question:
A nice way to regard the holomorph is as follows. The category (groups) is
embedded in the category Gd=(groupoids), which is cartesian closed. So Gd
has an internal endomorphism and also automorphism object AUT(-) (the
maximal internal subgroup object of END(-)). So if G is a group, then AUT(G)
is a group-groupoid, also known as a cat^1-group. As a group it is
isomorphic to the holomorph of G. (See for example, J Shrimpton, JPAA 72
(1991) 303-318 for background.) Under the correspondence between
group-groupoids and crossed modules, the holomorph of G corresponds to the
crossed module G--> Aut(G) given by the inner automorphism map. Shrimpton
gets an analogous crossed module Q(\Gamma) --> Aut(\Gamma) when \Gamma is a
directed graph, and this has an associated group-groupoid, which can be
called the holomorph of \Gamma.
So the holomorph should be regarded as simply the internal automorphism
object (in the appropriate category). If the objects don't form a cartesian
closed category to start with, then something must be done about it (like
turning groups into groupoids).
Maybe you can only form a monoidal closed category. Then you have problems
with group objects. See Brown and Gilbert Proc London Math Soc (3) 59 (1989)
51-73 for an example of what can be done (in this case with the category of
crossed modules, where the cartesian closed structure is not the really
interesting one).
The area is interesting, in view of the widespread use of groups in maths
and science. What are and what should be "groups"? If S is a structure, how
can and should Aut(S) be structured?
Ronnie Brown
Prof R. Brown Tel: +44 248 382474
School of Mathematics Fax: +44 248 355881
Dean St email: mas010@uk.ac.bangor
University of Wales
Bangor
Gwynedd LL57 1UT
UK
Date: Sat, 19 Mar 1994 16:17:52 +0400 (GMT+4:00)
Subject: Typing and CC
Date: Fri, 18 Mar 1994 15:30:29 +0100 (MET)
From: Clemens Cap
I have two questions, which I hope, someone has the answer or a pointer
where I could obtain some hints:
Question 1:
Let C be a CCC, which not necessarily is a free CCC. Is there a reasonable
way of typing C ?
More precisely: If X is an object in a (not necessarily free) Cartesian
closed category, is it possible to tell, whether X is of the form
Y => Z or of the form Y x Z, with suitably chosen Y and Z ?
The problem I have is the following: Assume D is a free CCC constructed
over a set of constants. Now identify some of the objects in D to yield
the not-free CCC C. Now we could think of a situation, where an object
in C is of the form U x V and at the same time of the form W => R.
On the other hand, the restrictions on the identifications of D-objects,
which come from the requirement, that C again is a CCC, could prevent
that an object in C could have two possible forms.
Question 2:
What about the same problem in a symmetric monoidal closed category ?
Here things are a bit more complicated, since the bifunctor x no longer
is a product and there are no decomposing projection morphisms.
In fact, an object which has the form A x (B x C) could be
indistingusihable or even identical to an object of the form (A x B) x C.
What is known here ?
Can an object at the same time be of the form U x V and of the form
W => x ?? And what about identifications of products due to assoviativity
commutativity and neutrality ?
Please reply to cap@ifi.unizh.ch.
THANX A LOT FOR YOUR HELP.
--
* Prof. Clemens H. CAP cap@ifi.unizh.ch (email)
* Dept. of Computer Science +41-1-257 / 4326, 4331 (office voice)
* University of Zurich +41-1-363 00 35 (office fax)
* Winterthurerstr. 190 +41-1-362 97 11 (home; voice and fax)
* CH-8057 Zurich, Switzerland
* Motto: "Please do not read the last line of this signature".
Date: Sun, 20 Mar 1994 16:38:02 +0400 (GMT+4:00)
Subject: Re: Typing and CC
Date: Sat, 19 Mar 94 21:36:37 -0800
From: "John C. Mitchell"
Can an object at the same time be of the form U x V and of the form
W => x ??
Yes, since it is possible for these to have the same cardinality
(e.g., cpo's).
John Mitchell
Date: Sun, 20 Mar 1994 16:35:51 +0400 (GMT+4:00)
Subject: question of Clemens Cap
Date: Sat, 19 Mar 94 16:20:21 EST
From: Michael Barr
A propos question 1, there is always the example of a Scott monoid
which is a CCC with one object D such that (necessarily) D = D x D =
D ==> D. Ok, it is not quite a CCC, since it lacks an empty
product, but add one so you have two objects 1 and D with the above
properties.
This answers question 2 too, but in addition, Beck showed over 20
years ago that any monoidal category with a coherent associativity
isomorphism is equivalent, as a monoidal category, to a strictly
associative one.
Michael Barr
Date: Mon, 21 Mar 1994 10:37:16 +0400 (GMT+4:00)
Subject: Re: Typing and CC
Date: Mon, 21 Mar 1994 12:08:57 +0000 (GMT)
From: Edmund Robinson
Dear Prof Cap,
I just wanted to reinforce the replies of Mitchell and Barr. In any
Heyting algebra (cartesian closed poset) there is a great deal of
redundancy. In particular, 1 x U = U = 1 => U. And in Set,
0 x U = 0 = V => 0 for any non-empty V, since the empty-set is unique.
These are cartesian-closed, and hence a fortiori, monoidal closed, but
they are rather semantic models.
If you are thinking of presentations of categories as cartesian closed/
symmetric monoidal closed subject to certain equations, then I do not
know of any work on syntactic criteria for the equations which would
prevent the kind of identification you ask about. This is because a
category theorist would never write an equation between objects. Instead
they would introduce two maps between the objects (often one at least is
pre-existing) and specify that they are inverse isomorphisms. This is
not only more in line with "the spirit of category theory", but actually
gives you more information, since it tells you how the two structures
on the objects are related. In your case, it would tell you, for example,
just how a function could be looked at as an ordered pair. A simple
equality of objects will not do this.
best wishes
Edmund Robinson
Date: Wed, 23 Mar 1994 15:37:53 +0400 (GMT+4:00)
Subject: oriented homology
Date: Wed, 23 Mar 94 13:28:30 EST
From: Michael Barr
It is clear that the symmetric group on n + 1 letters acts on the
nth singular chain group by permuting the arguments of a simplex.
Suppose we divide out that action by identifying p(sigma) with
sgn(p).sigma for each permutation p. This gives a quotient of the
singular chain complex. Is it known if it is equivalent to it?
The standard argument in the simplicial case seems to break down
because two simplexes can have the same vertices without being
the same.
Michael Barr
Date: Wed, 23 Mar 1994 16:35:26 +0400 (GMT+4:00)
Subject: corrections to ctcs
Date: Wed, 23 Mar 94 15:16:13 EST
From: Michael Barr
There is going to be a new edition of CTCS (hooray!!) that incorporates
all known errata. So if any of you has a list of errors, now is the
time to let us know. Please compare against the list that appears
in my ftp directory on this computer under the name ctcsupd.tex before
sending to us.
It will a soft cover edition and may not include the solutions
since it is intended as a student edition. Although it seems there
will be some hard cover copies bound too.
Michael Barr
Date: Thu, 24 Mar 1994 14:41:57 +0400 (GMT+4:00)
Subject: Re: oriented homology
Date: Wed, 23 Mar 1994 17:40:13 -0500
From: James Stasheff
seems to me that problem has a history
maybe Mac Lane would know??
jim
Date: Thu, 24 Mar 1994 15:50:32 +0400 (GMT+4:00)
Subject: TEMPUS summer school
The following announcement from the Theory Net looked relevant, Bob Rosebrugh
Date: Wed, 23 Mar 1994 12:34:55 PST
From: Pippo Scollo
First Announcement
We are pleased to announce a summer school concentrating on
ALGEBRAIC LOGIC AND THE METHODOLOGY OF APPLYING IT,
July 11-17, 1994, Budapest,
which is part of the
TEMPUS Summer School series for
Algebraic And Categorial Methods In Computer Science.
This will be the third one in the above mentioned series of summer
schools, attached to the TEMPUS project entitled "Algebraic and
Categorial Methods in Computer Science". The summer school is
sponsored by the European Community TEMPUS office.
Planned courses include:
Willem BLOK and Don PIGOZZI: General Algebraic Logic
Vaughan PRATT: Chu Spaces: Theory and Applications
Yde VENEMA: Boolean Algebras with Operators
Istvan NEMETI and Hajnal ANDREKA: Algebras of Relations of
Various Ranks & their Applications
Decidability issues and logics related to the dynamic trend
(workshop given by young researchers).
(For the time being, Yde Venema accepted our invitation only
tentatively.)
We plan to have classes from 10-12 in the mornings and 14-17 in the
afternoons from Monday to Friday and 10-12 on Saturday.
ACCOMMODATION: In double bedrooms in Summer Hotel Hill, for 14 DM/day.
The lectures will be in the same building. 25m swimming pool and
several other sport facilities will be available.
MEALS: Continental breakfast is available for 4 DM/day. Lunch is
available for 5,3 DM/day.
SOCIAL PROGRAMS: We plan a reception on Monday evening and a sight
seeing afternoon on Wednesday.
FEES: The registration fee is 120 DM.
REGISTRATION: Please send name, address (including e-mail, if
available) and gender to the organizing office by April 30, 1994 at
the latest, but send it as soon as you can. Please indicate if you
plan to bring a guest or indicate the name of participant with whom
you wish to share accommodation. Also indicate if you have any
special request (e.g. vegetarian meals). The second circular will be
sent only to those who have answered the first circular. The number
of participants is limited to 100 persons, therefore registrations
will be accepted in the order of receipt.
SCHOLARSHIPS: This year, unfortunately, the TEMPUS JEP is not allowed
to give any grant to students from EC countries for participation at
the summer school. All that they can offer is a grant for 1 professor
from each of the partner universities.
Grants for students from eastern partner universities are available
in a limited number. Please, apply for them to the organizing
committee.
ORGANIZING COMMITTEE:
Hajnal Andreka, Miklos Ferenczy, Istvan Nemeti and Ildiko Sain
ORGANIZING SECRETARY:
Corinna Farkas.
ADDRESSES:
Please send your correspondence to BOTH of the following two e-mail
addresses:
cora@ludens.elte.hu and h1468sai@ella.hu,
or to the following mailing address:
Ildiko Sain
Mathematical Institute Hung. Acad. Sci.
Budapest
Pf. 127
H-1364
Hungary
Fax: (36-1) 117-7166 (indicate: To Ildiko Sain)
PLEASE, DISTRIBUTE THIS ANNOUNCEMENT FREELY.
Hoping to hear from you,
Best regards from the
organizers.
Date: Fri, 25 Mar 1994 16:08:11 +0400 (GMT+4:00)
Subject: Reference wanted : Joyal, combinatorial functors
Date: Fri, 25 Mar 94 08:23:33 +0800
From: Michael FOURMAN
Greetings!
Apologies for broadcasting this, but I'm a bit isolated
(visiting here until June) and need a reference.
Can anyone supply a full reference for Andre Joyal's
monograph on combinatorial functors?
Many thanks,
Mike Fourman
Date: Fri, 25 Mar 1994 16:10:10 +0400 (GMT+4:00)
Subject: Math Report Hardcopies
Date: Fri, 25 Mar 1994 13:35:15 +1000
From: Ross Street
About 60 hardcopies of a 33 page preprint entitled
"The category of representations of the general linear groups
over a finite field"
by Andre Joyal and myself has just come back from the Macquarie
University printer. It is Macquarie Math Report # 93-141 (Dec 1993);
a full treatment of the subject of Section 4 of our paper
"Braided tensor categories" Advances in Math 102 (1993) 20-78.
Since this is a categorical treatment of a fairly specialized topic,
I do not intend to conduct a general mailing of the Report. However,
if you would like a copy, I'll send one if you email me at
and provide your precise postal address.
I believe Andre is having some hardcopies made at UQAM.
[The paper is stored in computers at UQAM & Macquarie and can be
sent via email, but requires my kinky software to decode.]
--Ross Street
Date: Thu, 31 Mar 1994 13:24:50 +0400 (GMT+4:00)
Subject: Michael Spivak
Date: Wed, 30 Mar 94 16:16:37 EST
From: Elaine Swan
Can anyone supply me with an email address for Michael Spivak or the
publishing company -- Publish or Perish Press?
Thank you in advance
Date: Thu, 31 Mar 1994 14:51:29 +0400 (GMT+4:00)
Subject: local homeomorphisms
Date: Thu, 31 Mar 94 13:08:53 EST
From: Peter Freyd
Peter Selinger, a student here at Penn, observes that the category of
topological spaces and local homeomorphisms fails to be complete only
because it fails to have a terminator. That is, every _non-empty_
small diagram has a limit. Who knows a reference for this?
Peter Freyd
Date: Thu, 31 Mar 1994 21:45:17 +0400 (GMT+4:00)
Subject: Second Announcement
Date: 31 Mar 94 14:17:00 EST
From: "NIEFIELD, SUSAN "
SECOND ANNOUNCEMENT UNION COLLEGE MATHEMATICS CONFERENCE
April 9-10, 1994
Please reply to this message, if you plan to attend and have not yet contacted
us.
FRIDAY EVENING RECEPTION: 9:00 - 11:00 PM (Bailey Hall 204)
SATURDAY
9:30 Registration, coffee, doughnuts (Bailey 204)
10:00 Parallel Sessions (Bailey Second Floor)
11:30 Invited Address I: Andre Joyal (Bailey 207)
12:30 Lunch (The College Center)
2:00 Parallel Sessions (Bailey Second Floor)
4:00 Coffee Break (Bailey 204)
4:30 Invited Address II: Peter May (Bailey 207)
5:30 Cocktails (Hale House Lower Lounge)
6:30 Banquet (Hale House Dining Room)
8:00 Dessert and Party (Milano Lounge)
SUNDAY (Bailey Hall 2nd Floor)
9:00 Coffee and doughnuts (Bailey 204)
9:30 Invited Address III: Zoltan Balogh (Bailey 207)
10:30 Parallel Sessions (Bailey Second Floor)
12:00 Lunch (The College Center)
1:00 Parallel Sessions (Bailey Second Floor)
3:30 Conference ends
CATEGORY THEORY SPEAKERS:
A. Joyal, University of Quebec at Montreal
"Money games"
M. Barr, McGill University
"Acyclic models"
R. Blute, University of Ottawa
"Linear Lauchli semantics"
M. Bunge, McGill University
"A characterization of Grothendieck toposes in Set-Modules"
P. Glenn, Catholic University of America
"Structures with a simplicially-defined higher dimensional composition"
M. Kleiner, Syracuse University
"Green correspondence for adjoint functors"
J. Lambek, McGill University
"Diagram chasing in Goursat categories"
H. Hu, York University
"Limits in free coproduct completions"
M. Mannucci, CUNY
"Modal geometric theories and their semantics"
W. Tholen, York University
"Locally split epis and effective descent"
ALGEBRAIC TOPOLOGY SPEAKERS:
J.P. May, University of Chicago
"Derived Categories in Algebra and Topology"
S. Costenoble, Hofstra University
"Some strange facts about ordinary equivariant homology"
T. Elmendorf, Perdue University Calumet
"Remarks on the Cyclotomic Structure of THH"
R. McCarthy, Brown University
"The Calculus of Homotopy Functors and Algebraic K-Theory"
R. Singer, Fordham University
"Just how much does one require to induce a map of Tor?"
SET-THEORETIC TOPOLOGY SPEAKERS:
Z. Balogh, Miami University of Ohio
"A solution to the small Dowker space problem"
T. LaBerge, Union College
"Forcing tightness in products of fans"
S. Hechler, Queens College
TBA
A. Zarach, East Stroudsburg University
"A model for ZF without power set"
ACCOMMODATIONS:
Blocks of rooms have been reserved at the Days Inn and the Holiday Inn in
Schenectady. To obtain one of these rooms at the rates listed below, mention
the Union College Mathematics Department when you call. Both are within easy
walking distance of the campus. The Ramada Inn is also within walking distance
of campus.
1. Holiday Inn (518) 393-4141
Single $55 Double $55
2. Days Inn (518) 370-0851
Single $45 Double $50
3. Ramada Inn (518) 370-7151
Single $63 Double $73
DIRECTIONS:
>From points South and East, take the New York Thruway to exit 25. Take I-890
to exit 7 (marked "NY 7 east to Troy"). Follow Route 7, turn left onto
Balltown Road (marked "to 146"), and then turn left at the first traffic light
onto Union Street. Follow Union Street and enter campus through Payne Gate on
the right. Bailey Hall is on the east side of campus, just west of the
athletic field.
>From points West, take the New York Thruway to exit 26, then I-890 to Erie
Boulevard (exit 4). Follow Erie Boulevard to Union Street, turn right onto
Union Street, and enter campus through Payne Gate on the left. Bailey Hall is
on the east side of campus, just west of the athletic field.
>From points North, take the Northway (I-87) to exit 9 (marked "146 Clifton
Park"). Turn right, follow 146 for about 6 miles to a traffic light, and turn
left onto Balltown Road (still 146). Follow Balltown Road over the Mohawk
River. Turn right onto Aqueduct Road (which becomes Van Vranken Avenue when it
enters Schenectady) and continue until it ends at the Union College campus
Nott Street gate. Bailey Hall is on the east side of campus, just west of the
athletic field.
Union College
Department of Mathematics
Schenectady, NY 12308
(518) 388-6246