May 2014 - Categories - categories.org.au

Partial functor
by David Leduc 17 Mar '15

17 Mar '15

Hi, A partial functor from C to D is given by a subcategory S of C and a functor from S to D. What is the appropriate notion of natural transformation between partial functors that would allow to turn small categories, partial functors and those "natural transformations" into a bicategory? The difficulty is that two partial functors from C to D might not have the same definition domain. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

7 6

ITRS 2014, Call for Participation
by Luca Paolini 30 May '14

30 May '14

======================================================================== CALL FOR PARTICIPATION **ITRS 2014** 7th Workshop on Intersection Types and Related Systems Vienna, Austria, July 18th, 2014 http://vsl2014.at/meetings/ITRS-index.html affiliated with RTA-TLCA 2014 in conjunction with FLoC 2014 at the Vienna Summer of Logic VSL http://vsl2014.at/ ======================================================================== ITRS 2014 is a venue for researchers working on both the theory and practical applications of systems based on intersection types and related approaches. You are cordially invited to participate. REGISTRATION: http://vsl2014.at/registration/ EARLY REGISTRATION is open and lasts until June 8th. WORKSHOP PROGRAMME: Invited Talk: * Luke Ong (University of Oxford, UK) Intersection Types, Game Semantics and Higher-Order Model Checking Contributed Talks: *Richard Statman A Finite Model Property for Intersection Types *Mario Coppo, Mariangiola Dezani-Ciancaglini, Ines Margaria and Maddalena Zacchi On Isomorphism of "Functional" Intersection and Union Types *Kentaro Kikuchi Uniform Proofs of Normalisation and Approximation for Intersection Types *Charles Grellois and Paul-Andr?? Melli??s Indexed linear logic and higher-order model checking *Marcin Benke, Viviana Bono and Aleksy Schubert Lucretia ??? intersection type polymorphism for scripting languages *M??rio Pereira, Sandra Alves and M??rio Florido Liquid Intersection Types *Ugo De Liguoro and Tzu-Chun Chen Semantic Types for Classes and Mixins *Jan Bessai, Boris D??dder, Andrej Dudenhefner and Moritz Martens Delegation-based Mixin Composition Synthesis -- Jakob Rehof Department of Computer Science Technische Universit??t Dortmund Lehrstuhl f??r Software Engineering, Otto-Hahn-Str. 14, 44227 Dortmund (Germany) http://www-seal.cs.tu-dortmund.de/seal/pages/people/rehof/index_en.shtml [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

1 0

New Paper: Cartesian differential storage categories
by Robert Seely 30 May '14

30 May '14

After some delays, the paper "Cartesian differential storage categories" (Blute-Cockett-Seely) is available on-line, at the ArXiv http://arxiv.org/abs/1405.6973 as well as on the third author's webpage http://www.math.mcgill.ca/rags/difftl/cart-diff-stor.pdf The abstact follows: Cartesian Differential Storage Categories by R. Blute, J.R.B. Cockett, and R.A.G. Seely Abstract Cartesian differential categories were introduced to provide an abstract axiomatization of categories of differentiable functions. The fundamental example is the category whose objects are Euclidean spaces and whose arrows are smooth maps. Tensor differential categories provide the framework for categorical models of differential linear logic. The coKleisli category of any tensor differential category is always a Cartesian differential category. Cartesian differential categories, besides arising in this manner as coKleisli categories, occur in many different and quite independent ways. Thus, it was not obvious how to pass from Cartesian differential categories back to tensor differential categories. This paper provides natural conditions under which the linear maps of a Cartesian differential category form a tensor differential category. This is a question of some practical importance as much of the machinery of modern differential geometry is based on models which implicitly allow such a passage, and thus the results and tools of the area tend to freely assume access to this structure. The purpose of this paper is to make precise the connection between the two types of differential categories. As a prelude to this, however, it is convenient to have available a general theory which relates the behaviour of "linear" maps in Cartesian categories to the structure of Seely categories. The latter were developed to provide the categorical semantics for (fragments of) linear logic which use a "storage" modality. The general theory of storage, which underlies the results mentioned above, is developed in the opening sections of the paper and is then applied to the case of differential categories. -- <rags(a)math.mcgill.ca> <www.math.mcgill.ca/rags> [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

1 0

Announcing ACM's new Special Interest Group on Logic and Computation
by prakash 30 May '14

30 May '14

Dear Colleague, I am delighted to announce the formation of a new special interest group focussed on logic and computation. The new SIG will be called SIGLOG. The officers are: Prakash Panangaden (Chair), Luke Ong (vice-Chair), Natarajan Shankar (Treasurer), Alexandra Silva (Secretary). The officers will be assisted by an executive committee and an advisory committee. The formation of this SIG has taken a long time with a lot of effort put in by many people. The idea of such a SIG was first mooted in 2007 by Moshe Vardi and Dana Scott and the first draft proposals were written by Vardi with input from Martin Abadi, Rajeev Alur and Phokion Kolaitis. For a long time the logic and computation community has functioned without a unifying organization. It has, nevertheless, grown in numbers and diversity and there are now many conferences that testify to the vitality of the community. Indeed the FLoC cluster of conferences this Summer in Vienna is expected to attract 1500 participants. There are, however, many ways in which a community-wide organization can serve the community that a single-conference-based organization cannot. SIGLOG aims to serve a broad range of interests. The flagship conference will be the ACM-IEEE Symposium on Logic in Computer Science. SIGLOG will actively seek association agreements with other conferences in the field. A SIGLOG newsletter is planned to be published quarterly in an electronic format with community news, technical columns, members? feedback, conference reports, book reviews and other items of interest to the community. An important activity of SIGLOG will be advocating for the importance of logic in the undergraduate computer science curriculum. Another important activity will be the establishment of prizes to recognize the outstanding contributions made by leading members of the community. Several members of the community have won Turing prizes, but there is room for much more recognition, especially for younger researchers. SIGLOG will collaborate closely with EATCS and EACSL as well as other organizations, for example the G?del Society. SIGLOG will maintain close ties with the ACM Transactions on Computational Logic. The upcoming Federated Logic Conferences in Vienna (part of the Vienna Summer of Logic) will feature a SIGLOG launch event. SIGLOG seeks to be an inclusive and diverse organization. We are committed to encouraging the participation of women in computing and are pleased to note that there are many outstanding women leaders in the research areas covered by SIGLOG. We actively seek members from all geographical regions and from a broad variety of research interests. It is possible to join SIGLOG as soon as today by filling the form at http://www.acm.org/membership/sig-pdfs/SIGLOG.pdf . One can join SIGLOG without joining ACM (the SIGLOG membership fee is $25 and $15 for students). Yours sincerely, Prakash Panangaden SIGLOG Chair [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

1 0

postdoc in Seville
by Fernando Muro 29 May '14

29 May '14

Dear fellow categorists, The previously announced postdoc position is now open: https://www.imus.us.es/es/noticia/590 Best, Fernando Muro -- Fernando Muro Universidad de Sevilla, Departamento de ??lgebra http://personal.us.es/fmuro [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

1 0

Reminder: The European Master's Program in Computational Logic: Application until 31 May 2014
by Tobias Philipp 27 May '14

27 May '14

Dear all, I'd like to draw your attention to the fact that applications for the European Master's Program in Computational Logic are still possible UNTIL 31 May 2014. A limited number of small scholarships is available. More details are given below. Please spread this information as wide as possible among friends and colleagues, at your old universities and the places, where you currently live and work. Many thanks -- Steffen ******************************************************************************************************* The European Master's Program in Computational Logic We are glad to announce to you the possibility to join our European Master's Program of Computational Logic. This program is offered jointly at the Free-University of Bozen-Bolzano in Italy, the Technische Universit??t Dresden in Germany, the Universidade Nova de Lisboa in Portugal and the Technische Universit??t Wien in Austria. Within this program you have the choice to study at two /three of the four European universities. In addition, you can do your project work at the National ICT of Australia (NICTA). You will graduate with a MSc in Computer Science and obtain a joint degree. Information on the universities and the program including the application procedure is provided here: http://www.emcl-study.eu/home.html Language of instruction is English. Tuition fees are 3.000 EUR (for non-European students) and 1.000 (for European students) per year. A limited number of small scholarships is available. (see: http://www.emcl-study.eu/fileadmin/emcl_booklet_tree/mss_jc_scholarship_sch…) Do not hesitate to contact us if you have any further questions. Kind regards -- Steffen H??lldobler Prof. Dr. Steffen Hoelldobler International Center for Computational Logic Technische Universit??t Dresden 01062 Dresden, Germany phone: [+49](351)46 33 83 40 fax: [+49](351)46 33 83 42 email: sh(a)iccl.tu-dresden.de [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

1 0

CT2014: early bird registration deadline
by Julia Goedecke 26 May '14

26 May '14

Dear Category Theorists, This is a reminder that the early bird registration with lower conference fee closes on Thursday 29 May (UK time). So if you have not registered, do consider registering before this date. http://www.ct2014.dpmms.cam.ac.uk/ As for pre-reserved rooms (which you can book in the registration process), we have approximately 10 ensuite rooms in Jesus college left and approximately 10 standard rooms in Fitzwilliam College. When these are full (or for people who are bringing guests), people will have to find their own rooms, but there are suggestions on the conference website. Please bear in mind that the Tour de France is coming to Cambridge on the 7th of July, so rooms might be harder to get. And on the 7th of July, many roads will be closed (in case you are staying that long). Julia (for the organisers) - -- Dr Julia Goedecke Graduate Education Officer DPMMS, Centre for Mathematical Sciences University of Cambridge Wilberforce Road CB3 0WB jg352(a)cam.ac.uk [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

1 0

K.A. Hardie
by Marcum, Howard 25 May '14

25 May '14

________________________________________ From: marcum.1(a)osu.edu Sent: Wednesday, May 21, 2014 10:57 AM To: pwitbooi(a)uwc.ac.za Subject: RE: K.A. Hardie Dear Peter, I am deeply saddened by this news. Please convey my sincere condolences to Keith's family. I first met Keith in 1978, with the first of several visits to Cape Town in 1986. On two occasions I stayed for extended periods in his homes (once in Rondebosch and once in Melkbosstrand). There was always lots of walking on beaches. We worked variously on Whitehead products, Hopf invariants and generalizations of Toda brackets (often jointly with Nobuyuki Oda and Heiner Kamps). He was trained in classical homotopy theory methods but eagerly embraced newer approaches. Beyond our professional association he was a good friend. It was a joy and privilege to have known him. Cordially, Howard Marcum [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

1 0

K.A. Hardie
by Peter Witbooi 25 May '14

25 May '14

Colleagues It is with deep sadness that I inform you of the passing away of Keith A. Hardie yesterday, 19 May 2014, at his home in Muizenberg, Cape Town. Keith has, among other things, made great contributions on homotopy in categories of pairs of topological spaces. The last of his 5 PhD students, I completed just as Keith was retiring from the university. This put me in the privileged default position for continued collaborative work. I treasure the relationship I had with him as my teacher, coworker and friend. Just the same he will be sorely missed by his collaborators, colleagues, close friends and many others. My condolences are with the bereaved family. Peter Witbooi Prof PJ Witbooi Dept. Math & Applied Math University of the Western Cape Private Bag X17 Bellville 7530 South Africa Ph, Office (+27) 021 9593027 Home 021 9489406 [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

6 5

Functoriality of pullbacks of sets
by Colin McLarty 25 May '14

25 May '14

It seems to me that Peter Freyd remarked it is easy to define pullbacks in ZF (maybe with with global choice?) so that pullback along one side is functorial, but hard to make it functorial on both sides. In other words we can easily make base change functorial in the bases, but not easily make it functorial in the bases at the same time as in the total spaces. Can anyone direct me to a reference to that work? thanks, Colin [For admin and other information see: http://www.mta.ca/~cat-dist/ ]

4 4