September 2015 - Categories - categories.org.au

Octoberfest Second Announcement
by Richard Blute 01 Oct '15

01 Oct '15

2015 Category Theory "Octoberfest" Workshop University of Ottawa, Ottawa, Canada October 31-November 1, 2015 SECOND ANNOUNCEMENT * * * The Category Theory "Octoberfest" is an (almost) annual workshop, traditionally held in October, bringing together researchers in category theory and its applications. This year's meeting will be hosted in the Department of Mathematics and Statistics at the University of Ottawa The scientific program starts on October 31, and consists of one and a half days of research talks. The Octoberfest website can be found at http://mysite.science.uottawa.ca/phofstra/Oct2015.html More details will appear as we get closer to the event. Research talks If you wish to give a talk please send a title and abstract to rblute(a)uottawa.ca by October 1. Time slots are limited, so please register early if you would like to be considered for a talk. Accommodations Information can be found at http://mysite.science.uottawa.ca/phofstra/Oct2015.html Registration If you would like to attend the meeting, please register by emailing rblute(a)uottawa.ca. There will be a reasonable on-site registration fee to cover workshop costs. We would appreciate it if you would let us know soon if you are probably going to attend. Rick Blute: rblute(a)uottawa.ca Pieter Hofstra: phofstra(a)uottawa.ca [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Intuitionistic Logic for Children, or: Planar Heyting Algebras for Children
by Eduardo Ochs 30 Sep '15

30 Sep '15

Hi list, I think (and hope) that the following seminar notes may be interesting to some people... "Intuitionistic Logic for Children, or: Planar Heyting Algebras for Children" http://angg.twu.net/math-b.html#zhas-for-children http://angg.twu.net/dednat6/tests/4.pdf Feedback VERY welcome! Cheers =), Eduardo Ochs [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Postdoc position at the ILLC
by Benno van den Berg 29 Sep '15

29 Sep '15

Dear all, There is a three-year postdoc position available at the ILLC, which is part of the University of Amsterdam. The deal is that applicants should also submit a proposal for a VENI-grant with NWO, the Dutch Science Organization, and should get a favorable review. This implies that only people who are eligible for the VENI can apply, which for most applicants means that they must have obtained their PhD in 2013, 2014 or 2015. The deadline for the application for the postdoc position is 1 November 2015, while the deadline for the VENI-application is 5 January 2016. More information is available here: http://www.uva.nl/en/about-the-uva/working-at-the-uva/vacancies/item/15-363… If you have any questions, feel free to contact me. Best, Benno [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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"Topos a l'IHES" - second announcement
by Olivia Caramello 28 Sep '15

28 Sep '15

Dear All, We are pleased to announce the following international conference on topos theory, which will take place at IHES from 23 to 27 November 2015. Everyone is welcome. Best regards, Olivia Caramello (on behalf of the Organizing Committee) ============================================================================ === TOPOS A L'IHES Call for participation 23-27 November 2015 Institut des Hautes Etudes Scientifiques https://indico.math.cnrs.fr/event/747/ * Scope * ------------ The conference aims to illustrate the fruitfulness and wide-ranging impact of the theory of Grothendieck toposes, by featuring presentations on new theoretical advances in the subject (including the theory of higher toposes) as well as on applications of toposes in different fields such as number theory, algebraic geometry, logic, functional analysis, topology, mathematical physics and computer science. The conference is preceded by a two-day introductory mini-course for the benefit of students and mathematicians who are not already familiar with topos theory. * Scientific Committee * ------------------------------- Olivia CARAMELLO Pierre CARTIER Alain CONNES Stephane DUGOWSON Anatole KHELIF * Tutorials * --------------- Olivia CARAMELLO (University Paris-Diderot) Andre' JOYAL (Universite' du Quebec, Montreal) * Invited speakers * -------------------------- Mathieu ANEL (University Paris-Diderot) Luca BARBIERI-VIALE (Università degli Studi di Milano) Jean BENABOU (University Paris 13) Denis-Charles CISINSKI (University Paul Sabatier, Toulouse) Caterina CONSANI (Johns Hopkins University, Baltimore) Thierry COQUAND (University of Goteborg) Simon HENRY (Radboud University, Nijmegen) Andre' JOYAL (Universite' du Quebec, Montreal) Mike PREST (University of Manchester) Urs SCHREIBER (Eduard Cech Institute for Algebra, Geometry and Physics, Prague) Carlos SIMPSON (University of Nice-Sophia-Antipolis) Bertrand TOEN (University of Montpellier 2) Michel VAQUIE' (University Paul Sabatier, Toulouse) * Short communications * --------------------------------- There is still room for a few short communications (20-25 minutes long); if you want to submit a one-page abstract for a short talk at the conference, please upload it while registering on the conference website before the 15th of October. * Registration and contact * ------------------------------------ More information is available at the conference website: https://indico.math.cnrs.fr/event/747/ If you have any queries please send them to the conference email address: topos(a)ihes.fr ============================================================================ === [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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ETAPS 2016 final call for papers
by Tarmo Uustalu 28 Sep '15

28 Sep '15

****************************************************************** CALL FOR PAPERS: ETAPS 2016 19th European Joint Conferences on Theory And Practice of Software Eindhoven, The Netherlands, 2-8 April 2016 http://www.etaps.org/2016 ****************************************************************** -- ABOUT ETAPS -- ETAPS is the primary European forum for academic and industrial researchers working on topics relating to software science. ETAPS, established in 1998, is a confederation of five main annual conferences, accompanied by satellite workshops. ETAPS 2016 is the ninteenth event in the series. -- MAIN CONFERENCES (4-7 April) -- * ESOP: European Symposium on Programming (PC chair Peter Thiemann, Universität Freiburg, Germany) * FASE: Fundamental Approaches to Software Engineering (PC chairs Perdita Stevens, University of Edinburgh, UK, and Andrzej Wasowski, IT University of Copenhagen, Denmark) * FOSSACS: Foundations of Software Science and Computation Structures (PC chairs Bart Jacobs, Radboud Universiteit Nijmegen, The Netherlands, and Christof Löding, RWTH Aachen, Germany) * POST: Principles of Security and Trust (PC chairs Frank Piessens, Katholieke Universiteit Leuven, Belgium, and Luca Viganò, King's College London, UK) * TACAS: Tools and Algorithms for the Construction and Analysis of Systems (PC chairs Marsha Chechik, University of Toronto, Canada, and Jean-François Raskin (Université Libre de Bruxelles, Belgium) TACAS '16 hosts the 5th Competition on Software Verification (SV-COMP). -- INVITED SPEAKERS -- * Unifying speakers: Andrew D. Gordon (MSR Cambridge and University of Edinburgh, UK) Rupak Majumdar (MPI Kaiserslautern, Germany) * ESOP invited speaker: Cristina Lopes (University of California at Irvine, USA) * FASE invited speaker: Oscar Nierstrasz (Universität Bern, Switzerland) * POST invited speaker: Vitaly Shmatikov (University of Texas at Austin, USA) -- IMPORTANT DATES -- * 9 October 2015: Submission deadline for abstracts * 16 October 2015: Submission deadline for full papers * 2-4 December 2015: Author response period (ESOP and FoSSaCS only) * 18 December 2015: Notification of acceptance * 8 January 2016: Camera-ready versions due -- SUBMISSION INSTRUCTIONS -- ETAPS conferences accept two types of contributions: research papers and tool demonstration papers. Both types will appear in the proceedings and have presentations during the conference. ESOP and FoSSaCS accept only research papers. A condition of submission is that, if the submission is accepted, one of the authors attends the conference to give the presentation. Submitted papers must be in English presenting original research. They must be unpublished and not submitted for publication elsewhere. In particular, simultaneous submission of the same contribution to multiple ETAPS conferences is forbidden. The proceedings will be published in the Advanced Research in Computing and Software Science (ARCoSS) subline of Springer's Lecture Notes in Computer Science series. Papers must follow the formatting guidelines specified by Springer at the URL http://www.springer.de/comp/lncs/authors.html and be submitted electronically in pdf through the EasyChair author interface of the respective conference. Submissions not adhering to the specified format and length may be rejected immediately. FASE will try a light-weight double-blind review process (see http://www.etaps.org/2016/fase) - Research papers FASE, FOSSACS and TACAS have a page limit of 15 pp (excluding bibliography of max 2 pp) for research papers, whereas POST allows at most 20 pp (excluding bibliography of max 2 pp) and ESOP 25 pp (excluding bibliography of max 2 pp). Additional material intended for the referees but not for publication in the final version - for example, details of proofs - may be placed in a clearly marked appendix that is not included in the page limit. ETAPS referees are at liberty to ignore appendices and papers must be understandable without them. In addition to regular research papers, TACAS solicits also case study papers (at most 15 pp, excluding bibliography of max 2 pp). Both TACAS and FASE solicit also regular tool papers (at most 15 pp, excluding bibliography of max 2 pp). - Tool demonstration papers Submissions should consist of two parts: * The first part, at most 4 pages, should describe the tool presented. Please include the URL of the tool (if available) and provide information that illustrates the maturity and robustness of the tool. (This part will be included in the proceedings.) * The second part, at most 6 pages, should explain how the demonstration will be carried out and what it will show, including screen dumps and examples. (This part will be not be included in the proceedings, but will be evaluated. ESOP and FOSSACS do not accept tool demonstration papers. TACAS has a page limit of 6 pages for tool demonstrations. -- SATELLITE EVENTS (2-3 April, 8 April) -- Around 20 satellite workshops will take place before and after the main conferences. -- HOST CITY -- Eindhoven is located in the province of North Brabant in the south of the Netherlands. It is the fifth-largest city of the Netherlands. The city is well known for modern art, design and technology. The main airport of the Netherlands is the Amsterdam Airport, Schiphol. All major airlines fly to Schiphol, and Schiphol has a direct and very frequent train connection to Eindhoven. Eindhoven also has a small international airport, Eindhoven Airport, with direct connections to more than thirty destinations in Europe. -- HOST INSTITUTION -- ETAPS 2016 is hosted by Faculteit Wiskunde en Informatica, Technische Universiteit Eindhoven. -- ORGANIZERS * General chair: Jan Friso Groote * Workshops chairs: Erik de Vink and Julien Schmaltz * Publicity chair: Anton Wijs -- FURTHER INFORMATION -- Please do not hesitate to contact the organizers at j.f.groote(a)tue.nl, a.j.wijs(a)tue.nl. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Latest version of diagxy
by Michael Barr 27 Sep '15

27 Sep '15

I have just uploaded to CTAN the latest version of diagxy. It is also available from my own web site: http://www.math.mcgill.ca/barr/papers/. The main thing it does is work well with the beamer macro \uncover (and relatives) to allow you use the node and arrow mode to add arrows (or for that matter, nodes) as overlays on diagrams. It also solves a problem that one user reported to me that the registration on repeatedly laying down the same ink was not perfect and he claimed that his nodes were thickened. I never observed this but the same fix apparently fixes it. Also, I have added \hyperref to the diaxydoc file. Michael [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Spelling of "equaliser"
by Toby Bartels 26 Sep '15

26 Sep '15

[Note from moderator: This is not on topic, so no discussion please, but the poster may send one digest of responses.] Hello, I'd like to know who uses the spelling "equalizer" and who uses "equaliser". In English overall, the suffix "-ize" is catching on and displacing "-ise"[^note], and such Americanisms dominate scientific writing even more than most other fields. On the other hand, "-ise" remains especially common in Australia, and there sure are a lot of Australian category theorists, aren't there? While I probably don't need Americans confirming the use of "equalizer", I'd be interested to hear what people in other countries do (or any Americans who use "equaliser"), or anyone who uses "-ise" normally but adopts "equalizer" as a technical spelling (or the reverse), or anyone who distinguishes "equalizer" from "coequalizer" (that would be weird) or any other usage of both forms, or if you have useful information about this besides your own practice. (The disjunction "or" here is non-idempotent, like the multiplicative \par in linear logic, multiset sum, disjoint union of sets, etc; the more criteria you meet, the more I want your response.) If you want, you can look at <https://en.wikipedia.org/wiki/Talk:Equaliser_%28mathematics%29> for a discussion of this issue that suffers from a lack of data. --Toby Bartels [^note]: That is, when it is the suffix derived from Greek "-izein" or patterned on it; "-ise" is used even in the U.S. for other words, such as "advertise" and "exercise", in which it is not actually a suffix (and the less said about "-lyze", the better). [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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CFP iFM 2016 (integrated Formal Methods), 1 - 3 June 2016, Reykjavik
by Marieke Huisman 23 Sep '15

23 Sep '15

============================================================ CALL FOR PAPERS iFM 2016 12th International Conference on integrated Formal Methods June 1-3, 2016, Reykjavik, Iceland http://en.ru.is/ifm/ ============================================================ === Important dates === Abstract submission: December 21, 2015 Paper submission: January 6, 2016 Paper notification: February 29, 2016 Final version: March 14, 2016 Conference: June 1-3, 2016 === Objectives and scope === Applying formal methods may involve the usage of different formalisms and different analysis techniques to validate a system, either because individual components are most amenable to one formalism or technique, because one is interested in different properties of the system, or simply to cope with the sheer complexity of the system. The iFM conference series seeks to further research into hybrid approaches to formal modeling and analysis; i.e., the combination of (formal and semi-formal) methods for system development, regarding both modeling and analysis. The conference covers all aspects from language design through verification and analysis techniques to tools and their integration into software engineering practice. Areas of interest include but are not limited to: - Formal and semi-formal modelling notations - Integration of formal methods into software engineering practice - Hybrid systems - Program verification - Program synthesis - Model checking - Static analysis - Runtime analysis, monitoring, performance evaluation - Decision procedures, SAT and SMT solving - Software engineering - Component-based systems (compositional, embedded, distributed, etc.) - Testing - Abstraction and refinement === Submission guidelines === iFM 2016 solicits high quality papers reporting research results and/or experience reports related to the overall theme of method integration. We solicit papers in the following categories: - research papers (max. 15 pages including bibliography) - regular tool papers (max. 15 pages including bibliography) - short tool papers (max. 8 pages including bibliography) - case study papers (max. 15 pages including bibliography) All submissions must be original, unpublished, and not submitted for publication elsewhere. Each paper will undergo a thorough review process. If necessary, a paper may be supplemented with a clearly marked appendix, which will be consulted at the discretion of the reviewers. Submissions should be made using the iFM 2016 Easychair site: https://www.easychair.org/account/signin.cgi?conf=ifm2016 Submissions must be in PDF format, using the Springer LNCS style files; we suggest to use the LaTeX2e package (the llncs.cls class file, available in llncs2e.zip and the typeinst.dem available in typeinst.zip as a template for your contribution). The conference proceedings will be published in Springer's Lecture Notes in Computer Science series. All accepted papers must be presented at the conference. Their authors must be prepared to sign a copyright transfer statement. At least one author of each accepted paper must register to the conference by the early date, to be indicated by the organizers, and present the paper. === Invited speakers === Marsha Chechik (University of Toronto, Canada) Laura Kovacs (Chalmers University of Technology, Sweden) Reiner Haehnle (Technical University Darmstadt, Germany) Edmund Clarke (Carnegie Mellon University, USA) === Workshops === iFM 2016 will be accompanied by a series of workshops. Further information is available from the conference website http://en.ru.is/ifm/ === Conference location === iFM 2016 is organized by the University of Reykjavik and will take place at the university campus in Reykjavik, the capital of Iceland. === Committees === General Chair: Marjan Sirjani (University of Reykjavik, Iceland) Program Chairs: Erika Abraham (RWTH Aachen University, Germany) Marieke Huisman (University of Twente, The Netherlands) Workshop Chair: Marcel Kyas (University of Reykjavik, Iceland) Program Committee: Wolfgang Ahrendt (Chalmers University of Technology, Sweden) Elvira Albert (Complutense University of Madrid, Spain) Bernd Becker (Albert-Ludwigs-University Freiburg, Germany) Clara Benac Earle (Universidad Politecnica de Madrid, Spain) Borzoo Bonakdarpour (McMaster University, Canada) Ferruccio Damiani (Universita di Torino, Italy) Frank de Boer (CWI, The Netherlands) Delphine Demange (University of Rennes 1/IRISA, France) Jan Friso Groote (Eindhoven University of Technology, The Netherlands) Dilian Gurov (KTH Royal Institute of Technology, Sweden) Holger Hermanns (Saarland University, Germany) Einar Broch Johnsen (University of Oslo, Norway) Peter Gorm Larsen (Aarhus University, Denmark) Martin Leucker (University of Lubeck, Germany) Dominique Mery (Universite de Lorraine, LORIA, France) Rosemary Monahan (Maynooth University, Ireland) Nadia Polikarpova (MIT, USA) Cesar Sanchez (IMDEA Software Institute, Spain) Sriram Sankaranarayanan (University of Colorado, USA) Ina Schaefer (Technische Universitaet Braunschweig, Germany) Gerardo Schneider (Chalmers, University of Gothenburg, Sweden) Emil Sekerinski (McMaster University, Canada) Armando Tacchella (University of Genoa, Italy) Mark Utting (University of the Sunshine Coast, Australia) Heike Wehrheim (University of Paderborn, Germany) Kirsten Winter (University of Queensland, Australia) [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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Re: Computability and Complexity of Categorical Structures
by Steve Vickers 22 Sep '15

22 Sep '15

Dear Noson - On 21/09/2015 14:42, Noson S. Yanofsky wrote: > Dear Steve, > > Thanks for taking the interest in the paper. > > Whether or not the colimit exists depends on which category you are > in. In my paper the colimit is taken in the category of small > categories where it does exist. Like you point out, (and David > Roberts pointed out in a previous post) ... (I don't seem to have David's post. Apologies if I'm repeating what he said.) > ... you might want to do some of > this stuff in other categories such as the effective topos etc where > this colimit would not exist. I do not know if the category of small > categories is "omniscient" or not, and if that is a good thing or a > bad thing, but the result stands. You seem to be shifting uncertainly between the category where colimits may or may not exist and a category (e.g. Set or a topos) that provides an ambient logic for your mathematics. Do you assume that 2 has all colimits? (Then the proof for the halting problem says take the colimit of the diagram H: ?? -> 2. You've parameterized that by x and y for program and data, but the essence of the argument can be seen even without those.) Or even those colimits of the specific form H? If so, then you are using a logical principle of your ambient mathematics, not pure category theory. > > (It is not a typo. Since 2 is indiscreet 0-->1 once the output goes > to 1 it must stay in 1. This is exactly what Halt(x,y,t) does. Once > it halts it stays halted. But all the outputs can remain 0.) "Indiscrete" means for each pair of objects x, y, there is a unique morphisms from x to y. From your definition on p.4, 2 is not indiscrete, since there is no morphism 1 -> 0. From the definition on p.14, ??_i is indiscrete. Suppose you have a functor H: ??_i -> 2. For any n you have H(0 -> n): H(0) -> H(n) and H(n -> 0): H(n) -> H(0). Hence, by antisymmetry in the poset 2, H(n) = H(0). What you are saying in words is captured by a functor from ?? (poset) to 2, not from ??_i to 2. Steve. > > All the best, Noson > > -----Original Message----- From: Steve Vickers > [mailto:s.j.vickers@cs.bham.ac.uk] Sent: Monday, September 21, 2015 > 6:10 AM To: Noson S. Yanofsky Cc: categories(a)mta.ca Subject: Re: > categories: Computability and Complexity of Categorical Structures > > Dear Noson, > > It seems to me it's an oversimplification to say that categories can > solve the Halting Problem. There's a logical principle involved. > > In your proof on p.23, the central step is that if H: ?? -> 2 is a > functor (where ?? and 2 are the posets of natural numbers and {0,1}), > then it has a colimit H': 1 -> 2. H(t) describes whether the > computation has halted by step t. (By the way, you use ??_i, the > indiscreet natural numbers, for the type of t. That's a typo, isn't > it? Since 2 is antisymmetric, that would imply H is constant.) > > Does the colimit exist? That's not a fact of pure category theory, > but a logical principle of "omniscience". If you go beyond classical > logic (and category theory facilitates this) then the colimit might > not exist. > > For example, it will not work in a topos. To find the colimit you > will need to embed 2 in ??, the poset on the subobject classifier. > There you still have the classical objects 0 and 1 (false and true), > but also intermediate objects corresponding to truth values of other > propositions such as "this computation halts". This switch from 2 to > ?? corresponds to relaxing decidability to semidecidability - and > semidecidability of the halting problem is trivial. > > If my calculations are correct, you can see this in the topos of > sheaves over the 1-point compactification of ??. This is the > classifying topos for functors H, and the generic H has no colimit. > > An alternative way to understand this is what you see in denotational > semantics. Here, when a map to 2 takes the value 0 ("bottom"), that > is interpreted as meaning that the assignment of result to argument > gets ensnared in a divergence. > > Regards, > > Steve. > [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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First World Congress on Analogy, Puebla, Mexico, November 4-6, 2015
by Universal Logic 22 Sep '15

22 Sep '15

First World Congress on Analogy, Puebla, Mexico, November 4-6, 2015 http://www.uni-log.org/analogy2015 This is the first world event dedicated to analogy in all its aspects. This event wants to promote interdisciplinary. It is of interest for all people dealing with analogy in one way or another: philosophers, logicians, mathematicians, artists, computer scientists, linguists, psychologists, etc. This is an event jointly sponsored by the University of Puebla in Mexico and the University Adam Mickiewicz in Poland. We invite submissions for contributions on all aspects of analogy in Science, Philosophy, Humanities and Art. Work of an interdisciplinary nature are particularly welcome. To submit a contribution send a one page abstract before September 30, 2015 to analogy2015(a)gmail.com [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

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