Long Mathematical Proofs?...

There is a Wikipedia page for them...

List of long proofs

Wish someone would organize a sensible collection of of Large Theories Common Sense problems, a bit like the TPTP collection. Also need to check out the Intuitionistic Logic benchmarks, the ILTP Library.

8th Workshop on Logical and Semantic Frameworks, with Applications (LSFA 2013)

The Workshop on Logical and Semantic Frameworks is a series of conferences in Brazil that I like to support.

As I read in their 'about us' page:

"LSFA is a series of Meetings on Logical and Semantic Frameworks with Applications. Logical and semantic frameworks are formal languages used to represent logics, languages and systems. These frameworks provide mathematical foundations for formal specification of systems and programming languages, supporting tool development and reasoning. The objective of this series is to put together theoreticians and practitioners to promote new techniques and results, from the theoretical side, and feedback on the implementation and use of such techniques and results, from the practical side."

It could've been be a bit less underspecified, methinks.

I have never been invited speaker or even invited for their programme committee, which is a surprise, as it is exactly my kind of work.
and many of the organizers are my long-standing friends...

But still I think the idea is a good one, so once again I "paid to work", instead of being paid to do it.
hmm, this is not strictly true, as I guess this is what the Brazilian CAPES funding agency  gave me a "Ciencia Sem Fronteiras" award for.
Vagaries of the Brazilian funding system and its implementation, perhaps.

I  talked about work that I did with mathematicians Charles Morgan and Samuel Gomes da Silva on Natural Numbers Objects in Dialectica Categories.

This is very interesting stuff, and the guys promised that they're writing up a more mathematical version of our content.
From my part I'd like to do the other two bits of work that we thought we would do; applications of the Dialectica construction
1. to cardinalities of the continuum and
2. to the 'laxification' of topological spaces.

Yep, I definitely need to write some of this work up and I need to put up, somewhere, all the dozens of other talks I've given that I have not written up. yet.
I guess discarded slides might end up being the notebooks of the scholars of the future.

Ilha Grande and All That....

Over the summer I went to this most wonderful place in Brazil, Ilha Grande. The meeting was called

Ilha Grande 2013: II Workshop on Logic and Semantics

and I talked about versions of constructive modal logics. The slides are here and the discussion was pretty good.

Type Theory at EACL, yay!

Another fun event announced this week. In Gothenburg:
http://clt.gu.se/event/2014-04-27/type-theory-workshop-eacl-2014
(they probably need a picture in their page, I chose one at random, as I've never been there...)

Belated Happy Halloween...

Spending a weekend in New York with my best friend was brilliant. We went to the theater, to the High Line Park and Chelsea Market, to lots of museums, where the highlight was the Frick Collection, with its amazing free audioguides spoken by the curators themselves. This was fantastic! the best museum experience ever.

Since I also had two papers accepted for the Global WordNet Conference in Estonia and one submitted for LREC in Iceland I should be feeling pretty stoked about work, shouldn't I? But I feel that it's going too slow, that we're not making progress as fast as we need to. Oh well, let me remind myself that I have been invited to review papers for LREC and that I've been invited to the Program Committee of the EACL 2014 Type Theory and Natural Language Semantics Workshop (TTNLS), whose deadline is 23rd January 2014. Got to get the stuff working and the papers written...

(Historical note on this photo: The Ladies of Trinity Hospital at Castle Rising, Norfolk, England taking afternoon tea over 100 years ago. Single ladies (spinsters) still live in this almshouse today, and it is a condition of their residency that they wear this 17th century costume on Sundays and Open Days. This is what they say in the ebay posting that allows you to buy the full picture for 5 dollars)

Peripatetic Seminar on Sheaves and Logic

[it's now 2020, instead of 2017 and because of the zulip for category theory guys were asking https://categorytheory.zulipchat.com/# I decided to try to complete this list, at least a bit.  I will produce the spreadsheet required, with  links later on. for the time being just adding Peter Johnstone compilation of the list until the 100th PSSL (Many thanks to Julia Goedecke for that!) and the few recent ones I could find easily online.

From the comments (by myself)
Probably should do something clever like a spreadsheet or something, but
PSSL 95, 26th and 27th of April 2014 Brno, Czech Republic, http://math.muni.cz/~bourkej/PSSL95. 

The Seminaire Itinerant des Categories, 17 mai 2014, http://sites.uclouvain.be/bcts/sic2014/. 

Lastly Peripatetic Seminar on Sheaves and Logic PSSL 96. October 11-12, 2014, University of Palermo, Italy. http://math.unipa.it/metere/PSSL96/

so ok, we got the websites for PSSL 105 https://sites.google.com/view/pssl-105.
 and PSSL 104 https://mysite.science.uottawa.ca/phofstra/PSSL18.html. 

 Looks like we're out of luck with PSSL 103. Google only found "Masaryk University will host the 103rd edition of PSSL. We look forward to see you in Brno! all the relevant informations are on the conference website." but he conference website gives me a 404. 

I had more luck with PSSL 102, https://www.usc.es/regaca/pssl102/ 

Finally we get http://www1.maths.leeds.ac.uk/~pmtng/PSSL/pssl101.html.]


I've been trying to find the records of the Peripatetic Seminar on Sheaves in Logic. Gavin Wraith provided a very nice collection with all the the titles and speakers from  1976 till 1999 (PSSL 70). What  has happened since?

The categories mailing list  conference page seems to have most (missing only PSSL81?) of the announcements of  PSSLs. Maybe this list should be in the opposite order to facilitate additions, but here it goes.

Peripatetic Seminar on Sheaves and Logic PSSL 71 The 71st meeting of the PSSL was held in Louvain-la-Neuve on the weekend of 16-17 October 1999.PeripateticSeminar on Sheaves and Logic 71 (I couldn't find the webpage.)

Category Theory Symposium (PSSL 72) A "PSSL-like" meeting on category theory was held in Brussels, April 8-9. Please check out the webpage http://www.vub.ac.be/CLEA/BobWS2000.html  
Bob Coecke's old webpage has the program for PSSL72.

Peripatetic Seminar on Sheaves and Logic PSSL 73 The 73rd meeting of the seminar was held at the Department of Theoretical Computer Science of the Technical University in Braunschweig, Germany, over the weekend of April 29-30, 2000. Contact: Jurgen Koslowski, koslowj@iti.cs.tu-bs.de , the program is in Jurgen's webpage.

The 74th PSSL was held in Cambridge on the weekend of 4/5 November 2000. Also an opportunity for anyone who hasn't been in Cambridge recently to see the new Mathematics building.

Peripatetic Seminar on Sheaves and Logic (PSSL 75) The 75th meeting of the Peripatetic Seminar on Sheaves and Logic was held at the Institut Mittag-Leffler, Stockholm, on the week-end of 9-10 June 2001. The meeting may be seen as a satelitte event of the Logic Year, which is taking place at the Mittag-Leffler Institute in the context of the Logic Year.
Anders Kock, Erik Palmgren, Dana Scott 
The 75th PSSL webpage is here.


Peripatetic Seminar on Sheaves and Logic PSSL 76 The 76th meeting of the Peripatetic Seminar on Sheaves and Logic was held at the IT-University of Copenhagen over the weekend 2-3 March, 2002. For information: www.it-c.dk/research/theory/Seminars/pssl76.html 

Peripatetic Seminar on Sheaves and Logic PSSL 77 The 77th meeting of the seminar was held at the Department of Theoretical Computer Science of the Technical University in Braunschweig, Germany, over the weekend of October 5/6, 2002. For information: http://www.iti.cs.tu-bs.de/TI-INFO/koslowj/PSSL77.html

Peripatetic Seminar on Sheaves and Logic PSSL 78 The 78th meeting of the PSSL was held in Strasbourg over the weekend of 15-16 February 2003. Contact:
crans@math.u-strasbg.fr 

Peripatetic Seminar on Sheaves and Logic PSSL 79 A PSSL was organized by the University of Utrecht on the weekend of the 28th and 29th of June, 2003.

Peripatetic Seminar on Sheaves and Logic PSSL 80 A PSSL was held on the weekend of 3rd and 4th April, 2004 in Cambridge, UK, organized by Eugenia Cheng. The program is  in http://cheng.staff.shef.ac.uk/pssl80/

Peripatetic Seminar on Sheaves and Logic PSSL 81
was held in the  Department of Mathematics, University of Coimbra, PORTUGAL in 9-10 April, 2005. More information, including the program can be found at http://www.mat.uc.pt/~categ/events/pssl.html.


International Conference "Charles Ehresmann 100 ans" October 7 to 9, 2005, at the Universite de Picardie Jules Verne in Amiens.
Including the 82nd session of the PSSL "Peripatetic Seminar on Sheaves and Logic" and a session of the SIC (Seminaire Itinerant de Categories). See
http://perso.wanadoo.fr/vbm-ehr/ChEh

Peripatetic Seminar on Sheaves and Logic PSSL 83 A PSSL was held at Glasgow, Scotland, on 6-7 May, 2006. For information, see
http://www.maths.gla.ac.uk/~tl/pssl/ 

Peripatetic Seminar on Sheaves and Logic PSSL 84 A PSSL was held on the weekend of 14th and 15th October at the Department of Theoretical Computer Science of the Technical University in Braunschweig, Germany.  See  http://www.iti.cs.tu-bs.de/TI-INFO/koslowj/PSSL84.html 

Peripatetic Seminar on Sheaves and Logic PSSL 85. A PSSL was held on the weekend of 24th and 25th March, 2007 in Nice, organized by Eugenia Cheng, the schedule is http://cheng.staff.shef.ac.uk/pssl85/index.html#schedule.

Peripatetic Seminar on Sheaves and Logic PSSL 86. 8th and 9th September, 2007. Institut Élie Cartan of the Université Henri Poincaré in Nancy. Organizer: Francois Lamarche.
http://www.loria.fr/~lamarche/psslHomeEN.html 

Peripatetic Seminar on Sheaves and Logic PSSL 87. Honouring A. Kock, on the occasion of his 70th birthday, 22-23 March 2008. An extra session of invited talks on Friday 21 March with A. Joyal, F.W. Lawvere and G. Reyes. Organizer: Panagis Karazeris. See the web page:
http://www.math.upatras.gr/~pssl87 

Peripatetic Seminar on Sheaves and Logic PSSL 88. Honouring Martin Hyland and Peter Johnstone on the occasion of their 60th birthdays, 4th-5th April 2009. See the web page:
http://cheng.staff.shef.ac.uk/pssl88/ 

Peripatetic Seminar on Sheaves and Logic PSSL 89. 12th-13th December 2009 in Louvain-la-Neuve, Belgium. Information is available at http://homepages.vub.ac.be/~tvdlinde/pssl89.html 

Peripatetic Seminar on Sheaves and Logic PSSL 90. April 24-25, 2010 at the Department of Theoretical Computer Science of the Technical University Braunschweig, Germany. Information is available at http://www.iti.cs.tu-bs.de/TI-INFO/koslowj/PSSL90.html 

Peripatetic Seminar on Sheaves and Logic PSSL 91. November 27-28, 2010, Amsterdam. Information is available at http://staff.science.uva.nl/~ciancia/PSSL91/ 

Peripatetic Seminar on Sheaves and Logic PSSL 92. April 23-24, 2011, Oxford, UK.

Peripatetic Seminar on Sheaves and Logic PSSL 93. April 14-15, 2012, Cambridge, UK. See https://www.dpmms.cam.ac.uk/~jg352/PSSL93.html 

Peripatetic Seminar on Sheaves and Logic PSSL 94, 25-28 March, 2013, University of Sheffield, an event Eugenia Cheng  co-organised with David Jordan. The program is at http://cheng.staff.shef.ac.uk/pssl94/


By the way the picture is the Milky Way in Bear Valley, courtesy of Christian Le Cocq.

Ada Lovelace Day 2013...

So it seems that this was the fourth year that the interwebs celebrated Ada Lovelace's Day. I think this is a good thing and like to join in the celebrations...

Previous years I have posted about Karen Sparck-Jones and Christine Ladd-Franklin.
This year there was a suggestion of going and adding some more women scientists to Wikipedia and I'm planning to do so, as soon as I have a few spare minutes. Soon, very soon.

I  have also  tried to help  Catarina Dutilh Novaes and friends put online a directory of Women in Logic. (Anna Crouch did the boring job of finding the websites of the women already in the list, thanks Anna!)

Go on, friends, add yourselves in!

But meanwhile this year I think I've decided that it's best to celebrate the people that work in my favorite kind of mathematics, Category Theory. So here is Marta Bunge, looking very serious,  in a picture taken by Andrej Bauer.