5 Dec 2013 18:01

### BX 2014: Paper deadline extended

Third International Workshop on Bidirectional Transformations (BX 2014)
Friday March 28th, 2014
Athens, Greece
co-located with EDBT/ICDT 2014

Web site:
http://bx-community.wikidot.com/bx2014:home

Submission site:
https://www.easychair.org/account/signin.cgi?conf=bx2014

Paper length: 3-8 pages, ACM format. In-progress work is highly encouraged, if limited to 4 pages.

Bidirectional transformations (bx) are a mechanism for maintaining the consistency of at least two
related sources of information. Such sources can be relational data, software models, documents,
graphs, trees, and so on. BX are an emerging topic in a wide range of research areas with prominent presence
at top conferences in different fields. However, much of the research in bx tends to get limited exposure
outside of a single field of study.

The purpose of this workshop series is not only to further research into bx, but to promote
cross-disciplinary research and awareness in the area. The first two instances of this workshop, BX'12
and BX'13, served as a dedicated venue for bx in all relevant areas, including:
- Databases
- Programming Languages
- Software Engineering
- Graph Transformation

This instance of the workshop is the first at a database venue. The workshop rotates between venues in
different areas to promote the cross-disciplinary nature of the work, as methodologies used for bx range


3 Dec 2013 21:15

### PhD opportunities at the University of Birmingham


Dear all,

We invite applications for PhD study at the University of Birmingham.

We are a group of (mostly) theoretical computer scientists who explore
fundamental concepts in computation and programming language
semantics. This often involves profound and surprising connections
between different areas of computer science and mathematics. From
category theory to lambda-calculus and computational effects, from
topology
to constructive mathematics, from game semantics to program
compilation, this is a diverse field of research that continues to
provide new insight and underlying structure.

See our webpage, with links to individual researchers, here:
http://www.cs.bham.ac.uk/research/groupings/theory/

Information about PhD applications may be found here:

very happy to discuss the opportunities available.

Best regards,
The Birmingham CS theory group

--

Martin Escardo    (topology, computation with infinite objects,


2 Dec 2013 13:57

### research positions

The Eduard Cech center had been established in 2005 and, since 2012,
it continues as the national research center focusing its attention
to interactions between algebra, geometry, and mathematical physics.
The participating institutions are Faculty of Science of Masaryk University
in Brno, Faculty of Mathematics and Physics of the Charles University
in Prague, Institute of Physics of the Academy of Sciences of the Czech
Republic and the Mathematics Institute of the Silesian University in Opava
(see http://eci.sci.muni.cz).

The Center invites applications for several research positions commencing
during the academic year 2014/2015 at the date depending on mutual agreement.
The positions are initially for one year with a possibility of extension.
The candidates must be recent PhD's and should submit a letter of application
accompanied by a CV, list of publications and an outline of their research
project to Professor Jiri Rosicky (rosicky <at> math.muni.cz) not later than

March 15, 2014.

They should also arrange for at least 2 letters of recommendation (one can
be from a Czech mathematician) to be mailed directly to rosicky <at> math.muni.cz
before March 15, 2014. The successful applicants will be notified as soon
as possible but not later than April 30, 2014.

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29 Nov 2013 17:06

### JLC Special Issue: Logics for Resources, Processes, and Programs

*********************************************************************************
Call for Papers

JOURNAL OF LOGIC AND COMPUTATION

Special Issue on Logics for Resources, Processes, and Programs

Editors: Didier Galmiche (Université de Lorraine --- LORIA) and
David Pym (UCL)

*********************************************************************************

AIMS AND SCOPE

We invite submissions to a Special Issue of the Journal of Logic and
Computation (JLC) devoted to the topic Logics for Resources,
Processes, and Programs'. This call follows on from the LRPP 2013
workshop held in association with Tableaux 2013. This Call is open
to all interested authors, irrespective of attendance at LRPP 2013.

Topics of interest include, but are not restricted to, the following:

- Logics for resources: semantics, model theory, and proof theory;
- Process calculi, concurrency, and resource-distribution;
- Reasoning about programs, systems, and behaviours (e.g., Separation
Logic and associated ideas);
- Extensions of logics: for example, with modalities;
- Languages of assertions, and languages based on resource logics


26 Nov 2013 11:11

### Re: preprint

Dear Jean,

Presheaves on all finite ordinals are called augmented simplicial sets.

As to 'directed space' I use now this term in a non-technical sense,
as referring to any topological structure suitable for directed
algebraic topology, like:

- preordered topological space,
-  d-space, i.e. space with distinguished paths,
-  c-space, i.e. space with distinguished cubes,
- etc.

See my book on 'Directed Algebraic Topology'. Thanks to Cambridge Un.

http://www.dima.unige.it/~grandis/BkDAT_page.html

(When I first used the term 'directed space', it was equivalent to d-
space; later I thought it was better to keep it for a more general
meaning.)

Best wishes   Marco

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22 Nov 2013 23:31

### 8th Scottish Category Theory Seminar: final programme

********************************************************************
***
***  8th Scottish Category Theory Seminar
***  Friday 29 November 2013, 13:30-17:30
***  International Centre for Mathematical Sciences
***  15 South College Street, Edinburgh, UK
***
***  http://homepages.inf.ed.ac.uk/als/SCT/sct131129.html
***
********************************************************************

We are pleased to announce the Eighth Scottish Category Theory
Seminar. Everyone is welcome. The final programme is:

1.30-2 COFFEE

2-3.00 Urs Schreiber: Higher toposes of laws of motion

3-3.30 Vincent Danos: Conditional expectation as a functor

3.30-4 COFFEE & PASTRIES

4-4.30 Ross Duncan: Quantum computing in (almost) any category: an
introduction to the ZX-calculus

4.30-5.30 Bart Jacobs: Program semantics, according to Heisenberg
and to Schroedinger

Abstracts will be available soon at the web address above.



20 Nov 2013 00:42

### Re: Questions on compact closed categories

I don't know about the second question, but first let point out that that
is not the definition of a compact closed category.  A compact closed
category requires that A -o B = A*\otimes B.  This is true in finite
dimensional vector spaces (and the tensor unit is the dualizing object).
But the tensor unit is the dualizing object in Chu(Vect,K) where Vect is
the category of vector space and K is the ground field.  The dualizing
object and tensor unit is (K,K) but it is not compact.  It is, of course,
*-autonomous.

Michael

On Tue, 19 Nov 2013, Peterson Clayton wrote:

> Dear list members,
>
> I am currently working in categorical logic with something that might be called a "compact closed
deductive system", that is, a deductive system (in the sense of Lambek) defined as a compact closed
category (i.e., a *-autonomous category where the tensor unit is a dualizing object).
>
> I have two questions.
>
> First, it appeared to me that we can show in a compact closed deductive system that every arrow is an
isomorphism. Hence, if there is a deduction arrow from A to B, then A is isomorphic (logically equivalent)
to B. Is this result accurate? Does this generalize to any compact closed category?
>
> Secondly, I wonder what happens if we add an arbitrary arrow A --> B to the  category. Put differently, what
happens if we add A --> B as an axiom to a  compact closed deductive system? Does this also yield an
isomorphism between A and B (assuming that the first result is adequate)? Or is it possible to add some
axioms that are not necessarily isomorphisms?
>


19 Nov 2013 19:51

### subgroupoids of V-categories

Hi all,

For general V (closed symmetric monoidal, bicomplete), is there a general
way to construct the maximal subgroupoid of a V-category C?

I think I know how to *detect* the maximal subgroupoid. A map in C is an
isomorphism iff it is representably so: Writing 1 for the monoidal unit,
we say f : 1 -> C(x,y) is an iso iff the induced map f_* : C(z,x) ->
C(z,y) is an iso in V for all z. So we might say that a V-category G with
the same objects and C and an identity-on-objects local monomorphism G ->
C is the maximal subgroupoid provided that a morphism f factors through
G(x,y) -> C(x,y) just when f is an isomorphism.

In examples, this is probably good enough, but I still would feel better
if I had a general construction of the maximal subgroupoid. I feel like
this should be some sort of weighted limit, perhaps with some additional
structure on V?

Thanks,
Emily

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19 Nov 2013 15:50

### Special Session on Categorical Topology (AMS-MAA JMM, 2014)

Dear Colleagues,

There will be a Special Session on Categorical Topology at the AMS-MAA
Joint Mathematics Meetings in Baltimore, MD,  on Saturday January 18,
2014, from 8:00 to 18:00.

The following people will be giving talks:

Michael Barr (McGill University)
Hatim Boustique (Valencia College)
Jean Goubault-Larrecq (ENS Cachan)
Gábor Lukács (Halifax)
Frédéric Mynard (Georgia Southern University)
Gary Richardson (University of Central Florida)
Gavin Seal (EPFL)
Andrzej A Szymanski (University of Pennsylvania)
Walter Tholen (York University)

The schedule and further information can be found at:

http://jointmathematicsmeetings.org/meetings/national/jmm2014/2160_program_ss42.html.

We still have one or two 20-minute slots available if you are interested
<gavin.seal <at> fastmail.fm> or Frederic Mynard
<fmynard <at> georgiasouthern.edu>. Note however that because of the
conference deadlines, these talks will not appear in the official
program.

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19 Nov 2013 05:50

### Re: Difference and Duality

Hi, Posina,
I have downloaded "Conceptual Mathematics" and will look at it and your
question later, but in the meantime, I hope that others will respond more
quickly and directly to your question. However, in case you do not receive
adequate replies on Linked, may I suggest two other forums which may be more
fruitful.
http://mathematica.stackexchange.com/

and sometimes

Both require registration, but they are free and do not seem to generate spam.

David Reid

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18 Nov 2013 21:40

### Re: adjoints to lax-idempotent algebra structures

Thanks again to everyone who replied with examples and comments.  I've
created an nLab page which hopefully includes everything I learned:
http://ncatlab.org/nlab/show/continuous+algebra

On Sun, Nov 17, 2013 at 9:14 AM, Michael Shulman <shulman <at> sandiego.edu> wrote:
> On Sun, Nov 17, 2013 at 6:53 AM, Prof. Peter Johnstone
> <P.T.Johnstone <at> dpmms.cam.ac.uk> wrote:
>> What you can say about them in general
>> is contained in Corollary B1.1.15 of the Elephant (page 254): they
>> are exactly the retracts of free algebras (provided idempotent 2-cells
>> split in the underlying 2-category), and they all occur as coadjoint
>> retracts of free algebras.
>
> That's exactly the sort of thing I was looking for; thanks!
>
> Continuous categories are one of the examples I had in mind.  Another
> interesting almost-example is totally distributive categories.  And
> when T is a monad for coproducts, such a left adjoint seems to
> decompose every object into a coproduct of connected ones (although I
> have not analyzed this case carefully).
>
> T-continuous is a reasonable name, but it would also be nice for a
> name to suggest B1.1.15.  Is there a general name for algebras that
> are retracts of free ones?  In particular cases they are "projective"
> or "cofibrant", but it seems doubtful that either of those terms
> applies literally here.
>
> Mike

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`