Paul B Levy | 18 May 13:01 2016

Reminder: postdoc position in semantics and effects SUNDAY DEADLINE

Dear colleagues,

We are looking for a Postdoctoral Research Fellow to work on an
EPSRC-funded project "Recursion, Guarded Recursion and Computational

We shall be investigating fine-grained typed calculi and operational,
denotational and categorical semantics for languages that combine either
guarded or general recursion and type recursion with a range of
computational effects.  This will build on existing work such as
call-by-push-value and Nakano's guarded recursion calculus.

The successful candidate will have a PhD in programming language
semantics or a related discipline, and an ability to conduct
collaborative mathematical research.  Knowledge of operational and
denotational semantics, category theory, type theory and related
subjects are all desirable.

You will work with me (principal investigator) and Neelakantan
Krishnaswami (co-investigator) as part of the Theoretical Computer
Science group at the University of Birmingham.

The position lasts from 1 October 2016 until 30 September 2019.

You can read more and apply for the job at
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Peter Johnstone | 17 May 11:03 2016

PSSL history

Dear category-theorists,

Many of you will be aware that over the years I have kept a record
of all talks given at meetings of the Peripatetic Seminar on Sheaves
and Logic. I promised to make this publicly available on the
occasion of the hundredth meeting; and it has now been uploaded to
the website, at

Information on each talk is given in the form

Date; start time; speaker; current affiliation; title.

For reasons of space, when I started keeping the list (typed out in
hard copy in those days!) I omitted finishing times (so you have to
work out for yourself where the coffee-breaks came) and co-authors
of joint work. By the time I went over to using TeX it was too late
to reconstruct this information for the earlier meetings, so I
continued to omit it.

There are a number of gaps in the list (mostly missing titles or
affiliations); if anyone can help to fill in some of those gaps, or
correct any mistakes (of which I'm sure there are many), please
e-mail ptj <at>

Peter Johnstone

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Sam Staton | 14 May 22:20 2016

LICS 2016 Call for Participation

   5-8 July 2016, New York City, USA
   LICS 2016 will be hosted in New York City during July 5-8, 2016.
   This event also marks the thirtieth anniversary of LICS.
   Logic Mentoring Workshop
   LSB: 6th Workshop on Logic and Systems Biology
   NLCS: 4th Workshop on Natural Language and Computer Science.
   SR: 4th International Workshop on Strategic Reasoning.
   LOLA: Syntax and Semantics of Low-Level Languages.
   May 15, 2016 - Logic Mentoring Workshop and Student Volunteers
   June 3, 2016 - Early Registration Deadline
   July 5-8, 2016 - Conference
   July 9-10, 2016 - Workshops

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John MacDonald | 15 May 08:07 2016

FMCS2016 Fourth Announcement

                                  FMCS 2016
          24th Workshop on Foundational Methods in Computer Science
                    University of British Columbia, VANCOUVER, Canada
                            JUNE 2 - 5, 2016

                              FOURTH ANNOUNCEMENT

                                    * * *

The Department of Mathematics at the University of British Columbia
in cooperation with the Pacific Institute of Mathematical Sciences
is hosting the Foundational Methods in Computer Science workshop
on June 2-5, 2016, on the University of British Columbia
Campus in Vancouver, Canada


To register for FMCS send email to johnm <at> with the heading
"Registration" and a form will be emailed to you. If you plan to
attend and have not already registered, then please let us know as
soon as possible for planning purposes.

On campus accommodation is still available, as of May 14.

To book accommodation go to the webpage

Then go to accommodation section and click on the link "here". This opens
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Sam Dean | 12 May 09:55 2016

Free cocompletion

I would also be interested in whether someone has written down the proof in
the additive setting: for a preadditive category A the category of additive
functors  (A^op,Ab) is the free cocompletion of A with respect to additive

Maybe something general has been written somewhere.

Many thanks

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Paul B Levy | 11 May 15:08 2016

free cocompletion

Hi, the following result appears to be folklore:

Given a locally small category C, the full subcategory of [C^op,Set] on
small presheaves (i.e. those presheaves that are colimits of a small
diagram of representables) is a free cocomplete locally small category on C.

I've seen and heard this result in many places, and know how to prove
it, but is there a proof written out in the literature?  And where did
the statement first appear?



Paul Blain Levy
School of Computer Science, University of Birmingham

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Andree EHRESMANN | 10 May 08:22 2016

Online publication of the Cahiers and of Charles Ehresmann's Works

We are pleased to announce that the issues of the 

Cahiers de Topologie et Geometrie Differentielle Categoriques, 

from Volume L (2009) to LV (2014) included, are now freely downloadable from the internet site of the

through the hperlink on Recent Volumes. 

In the future the issues of the Cahiers will become freely available on the site of the Cahiers two years
after their paper publication. We recall that papers published up to Volume XLIX are accessible on the
NUMDAM site.

Moreover, the 7 volumes of 

Charles Ehresmann: Oeuvres completes et commentees 

(edited by A. Ehresmann from 1980-83 as Supplements to the Cahiers) are now also freely downloadable from
the site        

These 2 sites are included in the site of Andree Ehresmann

and they can also be accessed through hyperlinks on its first page.

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Julia Goedecke | 8 May 23:22 2016

PSSL100: Last Reminder

Dear Category Theorists,

This is a last reminder about PSSL100 which is happening in Cambridge on
21/22 May, celebrating 40 years since the start of this series of
conferences. You can see all relevant information on the conference website.

The deadline to propose a talk has now passed; Peter Johnstone will
soon inform speakers about who's talk can be accommodated in the programme.

The deadline to sign up to the conference dinner in Newnham College is
Monday 9 May. [Sorry for short notice: my first message sent a few days
ago did not get through.]

We hope to see some more last minute sign-ups for this momentous
occasion. If you have any questions, or need help finding accommodation,
please do not hesitate to contact me (Julia Goedecke, jg352 at

Best wishes,



Dr Julia Goedecke
DPMMS, Centre for Mathematical Sciences
University of Cambridge
Wilberforce Road

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Chris Heunen | 4 May 17:18 2016

QPL 2016 Call for Participation

The 13th International Conference on Quantum Physics and Logic will be
taking place next month, 6–10 June at the University of Strathclyde.
There is an excellent line-up of talks, including invited lectures and
tutorials from:

  Krysta Svore (Microsoft)
  Stephanie Wehner (Delft)
  Tom Leinster (Edinburgh)
  Elham Kashefi (Edinburgh)
  Daniel Oi (Strathclyde)
  Conor McBride (Strathclyde)
  Ognyan Oreshkov (Brussels)
  Peter Selinger (Dalhousie)
  Kohei Kishida (Oxford)
  Aleks Kissinger (Nijmegen)

as well as a full programme of contributed talks. Registration is FREE
for students and 40 pounds for others. For full details, including
registration, see:

We hope to see you in Glasgow!

Kind regards,
Ross Duncan, Chris Heunen, and Daniel Oi (local organisers)


The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.
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pjf | 3 May 14:57 2016

Major New York Times article about Eugenia Cheng!

                    Using the top 3/4 of the the first page of the
                        New York Times's weekly Science Section:

          It can also be a piece of pie, or custard ??? so says a professor
            author who spreads the magic of numbers through dessert

                                   by Natalie Angier
                                      May 2, 2016

         She is a theoretical mathematician who works in a rarefied field
         category theory, which is so abstract that ???even some pure
         think it goes too far,??? Dr. Cheng said.

         At the same time, Dr. Cheng is winning fame as a math
         convinced that the pleasures of math can be conveyed to the
legions of
         numbers-averse humanities majors still recovering from high
         algebra. She has been featured on shows like ???Late Night With
         Colbert,??? and her online math tutorials have been viewed more
than a
(Continue reading)

Paoli, Simona (Dr. | 29 Apr 17:44 2016

YaMCATS 7 University of Leicester 10 May 2016

Dear Colleagues,

  the next meeting of the Yorkshire and Midlands Category Seminar will take place at the University of
Leicester on Tuesday 10 May 2016. This meeting will consist of a mini-course with one speaker, as follows:

Speaker: Mark Weber (Macquarie University)
Title:  Towards a direct algebraic understanding of homotopy types.

Further details of the meeting are available at the YaMCATS website

The meeting is open to all and everybody is welcome.

Best regards,

The YaMCATS organizers

Nicola Gambino (University of Leeds)
Nick Gurski (University of Sheffield)
Simona Paoli (University of Leicester)

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