April 2005 - Categories - categories.org.au

ICLP 2005: Call for Papers
by ICLP 2005 28 Apr '05

28 Apr '05

Call for Papers ------------------------------------------------------------ Twenty first International Conference on Logic Programming ICLP'05 2-5 October, 2005 Sitges (Barcelona) Spain Co-located with the International Conference on Principles and Practice of Constraint Programming (CP'05) ------------------------------------------------------------ http://www.iiia.csic.es/iclp2005/ [* Please note that ICLP'05 has a doctoral consortium for the first time as well as a special industrial paper session (details below). * Note that ICLP05's dates intersect with a solar eclipse visible in Barcelona ]. The Conference -------------- The 21st International Conference on Logic Programming will be held near Barcelona (Spain) from October 2nd to October 5th, 2005. ICLP'05 will be colocated with the International Conference on Principles and Practice of Constraint Programming (CP'05). Conference scope ---------------- Since the first conference held in Marseilles in 1982, ICLP has been the premier international conference for presenting research in logic programming. Contributions (papers and posters) are sought in all areas of logic programming including but not restricted to: Theory Implementation Semantic Foundations Compilation Formalisms Memory Management Nonmonotonic Reasoning Virtual Machines Knowledge Representation Parallelism Environments Alternative Paradigms Program Analysis Constraint Logic Programming Program Transformation Abductive Logic Programming Validation and Verification Inductive Logic Programming Debugging, Profiling Answer Set Programming Language Issues Applications Concurrency Semantic Web Objects Software Engineering Coordination Web Tools Mobility Internet Agents Higher Order Artificial Intelligence Types Deductive Databases Modes Natural Language Programming Techniques Specific attention will be given to work providing novel integrations of these different areas, and to new applications of logic programming in general. Contributions on applications will be assessed with an emphasis on their impact and synergy with other areas, as opposed to technical maturity. Applications of logic programming to the Semantic Web are especially encouraged. The technical program will include several invited talks and advanced tutorials, in addition to the presentations of the accepted papers and posters. A special session on industrial applications of logic programming is also planned and several workshops will be held in parallel with the conference. For the first time, a doctoral student consortium will be organized as part of ICLP. Invited Speakers ---------------- This year, ICLP will have the following invited speakers: Ian Horrocks, University of Manchester, UK Francesca Rossi, University of Padova, Italy Peter Stuckey, University of Melbourne, Australia Papers ------- Papers must describe original, previously unpublished research, and must not be simultaneously submitted for publication elsewhere. They must be written in English and not exceed 15 pages in Springer LNCS format. The authors are encouraged, although not obliged, to submit their papers already in Springer LNCS format. General information about the Springer LNCS series and the LNCS authors' instructions are available at the Springer LNCS/LNAI home page (http://www.springer.de/comp/lncs/index.html) Papers should express their contribution clearly, both in general and technical terms. It is essential to identify what was accomplished, describe its significance, and explain how the paper compares with and advances previous work. Authors should make every effort to make the technical content understandable to a broad audience. The primary means of submission will be electronic, in pdf format. If electronic submission is not possible, five hard copies should be sent to one of the program co-chairs. More information on the submission procedure will be available at http://www.easychair.org/ICLP2005/submit/ Industrial Papers ----------------- A special session on industrial applications of logic programming is also planned during the conference. Papers accepted in this session will describe innovative applications of logic programming to industrial problems. The application's innovativeness and industrial impact will be the main criteria used for judging the paper. Papers accepted for this session will be published in the proceedings as shorter, (up to) 10 pages papers. Posters ------- Posters provide a forum for presenting work in an informal and interactive setting. They are ideal for discussing current work not yet ready for publication, for PhD thesis summaries and research project overviews. Accepted posters will also get a 10 minute slot for presentation during the conference. Extended abstract (2 pages) of each accepted poster will be published in the proceedings. Posters must be submitted electronically. More information on the submission procedure will be available at http://www.easychair.org/ICLP2005/submit/ Doctoral Student Consortium --------------------------- The Doctoral Consortium will provide an opportunity for students pursuing their doctoral thesis in logic programming and related areas to explore their research interests under the guidance of a panel of distinguished experts in the field. The Doctoral Consortium will also offer invited speakers and discussion groups. The Consortium will allow participants to interact with established researchers and with other students, through presentations, question-answer sessions, panel discussions, and invited presentations. A separate call-for-participation will be issued for the doctoral consortium. About 6 to 8 students will be selected for the consortium. Selected students will also present their research in the poster session. The abstract of the poster will be published in the conference proceedings. Financial support for selected students may be available. Publication ----------- The proceedings of the conference will be published by Springer-Verlag in the LNCS series. The proceedings will include the accepted papers and the abstracts of accepted posters. Sponsoring and prizes --------------------- The conference is sponsored by the Association for Logic Programming. The ALP has funds to assist financially disadvantaged participants. The ALP is planning to sponsor two prizes for ICLP'05: for the best technical paper and for the best application paper. Important dates --------------- POSTERS PAPERS Abstract submission deadline: 30 April Submission deadline: 1 June 6 May Notification of authors: 1 July 24 June Camera-ready copy due: 15 July 15 July Organization ------------ Conference Co-Chairs: Pedro Meseguer (IIIA-CSIC, Spain) Javier Larrosa (Technical University of Catalonia, Spain) Program Co-Chairs: Maurizio Gabbrielli (University of Bologna, Italy) Gopal Gupta (University of Texas at Dallas, USA) Workshop Chair: Hai-Feng Guo (University of Nebraska at Omaha, USA) Doctoral Consortium Chair: Enrico Pontelli (New Mexico State University, USA) Publicity Chair: Felip Manya (IIIA-CSIC, Spain) Program Committee: Roberto Bagnara University of Parma, Italy Maurice Bruynooghe KU Leuven, Belgium Giorgio Delzanno University of Genova, Italy Stefan Decker Digital Enterprise Research Institute, Ireland Thom Fruehwirth University of Ulm, Germany Maurizio Gabbrielli University of Bologna, Italy (Program Co-Chair) Gopal Gupta University of Texas at Dallas, USA (Program Co-Chair) Patricia Hill University of Leeds, UK Joxan Jaffar University of Singapore, Singapore Bharat Jayaraman SUNY Buffalo, USA Javier Larrosa Technical University of Catalonia, Spain (Conference Co-Chair) Michael Leuschel University of Dusseldorf, Germany Massimo Marchiori University of Venice, Italy and W3C, MIT, USA Pedro Meseguer IIIA-CSIC, Spain (Conference Co-Chair) Juan J. Moreno Navarro Technical University of Madrid, Spain Gopalan Nadathur University of Minnesota, USA Ilkka Niemela Helsinki U. of Tech. Finland Catuscia Palamidessi INRIA, France Enrico Pontelli New Mexico State Univeristy, USA I.V. Ramakrishnan SUNY Stony Brook, USA Vitor Santos Costa Federal U. of Rio de Janeiro, Brazil Harald Sondergaard University of Melbourne, Australia Peter Stuckey University of Melbourne, Australia Frank Valencia University of Uppsala, Sweden Contact addresses ----------------- Conference Chairs: Pedro Meseguer Javier Larrosa IIIA-CSIC Dep. LSI, UPC Campus UAB Jordi Girona 1-3 08193 Bellaterra, Spain 08034 Barcelona, Spain Program Co-chairs: iclp05-chairs(a)cs.unibo.it Maurizio Gabbrielli Gopal Gupta Department of Computer Science Department of Computer Sciences MS EC31 University of Bologna The University of Texas at Dallas Mura A. Zamboni 7 2601 N. Floyd Rd 40127 Bologna, Italy Richardson, TX 78050, USA

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obituary for Saunders Mac Lane
by moerdijk＠math.uu.nl 28 Apr '05

28 Apr '05

-------------------------------------------------------------------------= Dear Ms or Sir, On Tuesday I was asked by Maria Cleminson to write an obituary on Saunders Mac Lane, about 1000-1200 words long. Below, you find my proposed text. I have not written the standard closing paragraph, which I assume you will add yourself. I understand that an editor will go over it, but would ask you to show me the final version before I will give my consent to publish it. ... Yours sincerely, I. Moerdijk. ----------------------------------------------- Saunders Mac Lane, a former Professor at the University of Chicago and one of the most influential mathematicians of the twentieth century, died on April 14 in San Francisco, California. He is widely known as the creator, together with Samuel Eilenberg, of the language of CATEGORY THEORY, now an indispensable tool in many parts of mathematics, and having more and more applications in other fields, notably computer science and theoretical physics. Moreover, he was an inspiring teacher to many students, and served the mathematical community as a president of the American Mathematical Society, as a member of the National Science Board, and in various other important functions. He was awarded the National Medal of Science in 1989. During his productive life, he was strongly supported by his first wife Dorothy, with whom he had two daughters, Gretchen and Cynthia, and later, after Dorothy's death in 1985, by his second wife Osa Mac Lane-Skotting. Saunders Mac Lane was born on the 4th of August, 1909, in Norwich, Connecticut, as the son of a Congregetional minister, Donald Mac Lane, and a school teacher Winifred Saunders - Mac Lane. His father died when Saunders was only 15 years old, and after he graduated from high school in Leominster, Massachusetts, it was an uncle who in 1926 sent him to Yale. He graduated from Yale in 1930, and then moved to the University of Chicago where he obtained a Master's degree in 1931. During that year, he met Dorothy Jones who was reading economics at the same university, and whom he was to marry in 1933. Subsequently Mac Lane went to Goettingen in Germany, to work on a PhD thesis. In those days, it was not uncommon for talented mathematicians from the USA to study in Europe, and Goettingen was a world center of mathematics, where Mac Lane was able to attend lectures by the mathematical elite of the time, including David Hilbert, Gustav Herglotz, Hermann Weyl and Emmy Noether. One of the new developments that was taking place in Goettingen was the shaping of a "modern algebra", of which Emmy Noether was one of the main proponents. Mac Lane did not stay in Goettingen long. Pressed for time by the political climate in Germany, he hurried to complete his thesis in Mathematical Logic, under the supervision of Hermann Weyl and Paul Bernays. He returned to the US in the summer of 1933, to take a one year job at Yale. After working as an instructor at Harvard, Cornell and Chicago, he went to Harvard as an assistant professor in 1938, where he became full professor in 1946. In 1947, Mac Lane accepted an offer from the University of Chicago, where he was to spend the rest of his lon= g career. He served as Chairman of the Mathematics Department there from 1952 to 1958, and was appointed Max Mason Distinguished Service Professor in 1963, and Professor Emeritus in 1982. After his return from Germany to the US, Mac Lane's research interests had shifted from logic to algebra. Together with Garrett Birkhoff, he took it upon himself to spread the modern algebra of Emmy Noether on the American continent, and in 1941 Birkhoff and Mac Lane published their celebrated "Survey of Modern Algebra", the first English language text on the subject, a book which has seen many editions, and has influenced the lives of many generations of mathematics students in America and Europe alike. In his own research, Mac Lane had moved on and, together with Samuel Eilenberg and others, he developed an entirely new field of algebra, designed to provid= e the methods for a quantative, "algebraic" study of geometric objects, called homological algebra. They discovered a class of mathematical objects which combine algebraic and geometric features in a miraculous way, which are now known as Eilenberg-Mac Lane spaces, and which continue to play a central role in the field. In his work on homological algebra, Mac Lane showed the rare combination of being capable of doing long and complicated calculations (using new concepts to be developed simultaneously!), and of being a clear teacher and expositor at the same time. It was in the course of this work with Eilenberg, that the two mathematicians became increasingly aware of the lack of tools, even of a language, that would enable one to move from a domain like geometry, to another such as algebra, in a way which not only relates geometric objects to algebraic ones, but also translates - in an informative way - relations between different geometric objects into algebraic relations. This lead to their development of category theory. The first publication on category theory by Mac Lane and Eilenberg in 1945 was received by the mathematical community with mixed feelings, as it seemed just to express known facts in a new language. But gradually the force and wide applicability of the new language became clear, and now many important modern insights in mathematics cannot even be formulated without this language. Moreover, it turned out to be an effective vehicle, not only for exhibiting existing as well as newly discovered relations between different areas of mathematical research, but also between mathematics and other disciplines. Mac Lane wrote two influential text books on these subjects he partly created himself, "Homological Algebra" first published in 1963 and "Categories for the Working Mathematician", first published in 1971 and still the prevailing textbook in the field. Mac Lane was responsible for important breakthroughs in mathematical research, wrote several important books, and served the mathematical community in important functions. In addition, he was a gifted teacher, who was able at the same time to teach, to challenge and to listen to young students. He was a fervent hiker, leading the troops at mathematical conferences when he was already well into his seventies. Moreover, he had many interests besides mathematics, notably English poetry and philosophy. I was very fortunate to get to know him closely as a person and directly experience these qualities when in the late eighties we were collaborating on our joint book on topos theory, a field which - not surprisingly - uses categorical language to relate geometry to logic. We would have seemingly endless discussions about how (and how not!), to present mathematical concepts. Mac Lane would argue fiercely for his own point of view, but would always concentrate on the content of the matter, and never impose his authority or seniority. In the evenings, we would sit on the terrace of his weekend house in the Indiana Dunes overlooking Lake Michigan, and discuss philosophy, from Hegel and Heidegger to Kant and beyond, and Mac Lane would explain at length why Wittgenstein's view on the philosophy of mathematics was all wrong. Like many of his younger students and colleagues, I also had the privilege of listening to his colourful stories about how mathematics was before the war, about Hermann Weyl in Goettingen, or about his encounters with Bertrand Russell at a seminar at Harvard. We would go on long walks, on which he would lead the way at a brisk pace. It was only many years later,- when he would suggest I go alone on a walk while he would rest after lunch -, that his physical strength started to fade. Ieke Moerdijk. -------------------- Add standard form paragraph. ------------------- --=20 --=20 --=20 --=20 --=20 --=20 --=20 --=20 --=20 --=20

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Advisory Committee on CT conferences
by Prof. Peter Johnstone 27 Apr '05

27 Apr '05

This message is to announce the formal inauguration of an international Advisory Committee on Category Theory conferences. The members of the Committee are as follows: Bill Lawvere <wlawvere(a)acsu.buffalo.edu> (chairman) Peter Johnstone <ptj(a)dpmms.cam.ac.uk> (vice-chairman) Jiri Adamek <adamek(a)iti.cs.tu-bs.de> Francis Borceux <borceux(a)math.ucl.ac.be> Ross Street <street(a)ics.mq.edu.au> Walter Tholen <tholen(a)pascal.math.yorku.ca> Richard Wood <rjwood(a)mscs.dal.ca> The Committee has been established in order to promote continuity in the organization of major international conferences in category theory, with the general aim of ensuring that such meetings take place on a regular basis. It does not intend to dictate the precise form of such meetings (and indeed has no power to do so), but it intends to offer help and advice to would-be organizers of conferences, based on the experience of those who have organized previous meetings. To achieve this, the Committee will regularly solicit proposals from individuals who may be interested in organizing such meetings. It will advise potential organizers on the timing of meetings, with the aim of avoiding undesirable clashes. It will also maintain records of past meetings, and will serve as a channel whereby their organizers can pass on their experience to organizers of future conferences, if requested. It should be emphasized that the Committee sees its role as relating only to major international meetings covering the whole of category theory (i.e. the sequence of which the three most recent terms are Coimbra 1999, Como 2000, Vancouver 2004 ...). It will not become involved with regional meetings such as the Peripatetic Seminar or the Octoberfest, nor with meetings on specialized topics within category theory. In keeping with the procedure outlined above, the Committee now wishes to invite proposals for future meetings. We are particularly interested to hear from people who may be planning a meeting in summer 2006, but those with plans for the longer-term future are also welcome to contact us. Initial contact may be made (in person or by e-mail) with any member of the Committee. 27-Apr-2005 13:04:19 -0300,4243;000000000000-0000001f

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research positions
by Jiri Rosicky 27 Apr '05

27 Apr '05

Eduard Cech center is a newly established national research center focusing its attention to interactions between algebra, geometry, and logic (and their applications in cryptology, computer science, etc.). It is jointly operated by mathematicians from Masaryk University in Brno, Charles University in Prague and Academy of Sciences of the Czech Republic, with offices both in Brno and Prague. The Center invites applications for 6 research positions commencing either from September 1, 2005 or from February 1, 2006, depending on mutual agreement. The positions are initially for one year with a possibility of extension for another year. The candidates must be recent PhD's that obtained their degree not earlier than 2 years before the beginning of their contract with the Eduard C(ech Center. Candidates should submit a letter of application accompanied by a CV, list of publications and an outline of their research project to Professor Jan Slovak slovak(a)muni.cz not later than May 15, 2005. They should also arrange for at least 2 letters of recommendation (one can be from a Czech mathematician) to be mailed directly to slovak(a)muni.cz before May 15, 2005. The successful applicants will be notified as soon as possible but not later than June 15, 2005. Further information about the Eduard C(ech Center can be found at http://ecc.sci.muni.cz <http://ecc.sci.muni.cz> 27-Apr-2005 13:04:19 -0300,1422;000000000000-0000001d

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just for its headline
by Peter Freyd 27 Apr '05

27 Apr '05

The Globe and Mail 27 April 2005 Obituaries Saunders Mac Lane, 95 CHICAGO MATHEMATICIAN INTRODUCED 'FUNCTORS' Associated Press 77 words S7 Chicago -- Saunders MacLane, a leading American mathematician and a professor at the University of Chicago for nearly four decades, died April 14 in San Francisco after a long illness. He was 95. In a landmark paper he co-authored with Samuel Eilenberg in 1945, Prof. Mac Lane developed new ways of thinking about mathematics introducing what are known as "categories," "functors" and "natural transformations." 27-Apr-2005 13:04:19 -0300,3561;000000000000-0000001a

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Call for participation: Quantum Programming Languages Workshop
by Peter Selinger 26 Apr '05

26 Apr '05

CALL FOR PARTICIPATION 3nd International Workshop on Quantum Programming Languages (QPL2005) June 30 - July 1, 2005, Chicago, U.S.A. Affiliated with LICS 2005 http://quasar.mathstat.uottawa.ca/~selinger/qpl2005/ * * * Registration for this workshop is now available, please see below for registration information and a list of talks. Note that the early hotel registration deadline for LICS is May 1. OVERVIEW: The goal of this workshop is to bring together researchers working on mathematical foundations and programming languages for quantum computing. In the last few years, there has been a growing interest in logical tools, languages, and semantical methods for analyzing quantum computation. These foundational approaches complement the more mainstream research in quantum computation which emphasizes algorithms and complexity theory. Possible topics include the design and semantics of quantum programming languages, new paradigms for quantum programming, specification of quantum algorithms, higher-order quantum computation, quantum data types, reversible computation, axiomatic approaches to quantum computation, abstract models for quantum computation, properties of quantum computing resources and primitives, concurrent and distributed quantum computation, compilation of quantum programs, semantical methods in quantum information theory, and categorical models for quantum computation. Previous workshops in this series were held in Ottawa (2003) and Turku (2004). REGISTRATION: Registration and local arrangements will be handled through the LICS 2005 main conference (http://homepages.inf.ed.ac.uk/als/lics/lics05/) There will be a small fee for attending the workshop, which will cover coffee breaks and the informal proceedings. Participants are encouraged to register as early as possible, as this will help us plan how many copies of the proceedings to print. INVITED SPEAKER: * Hans J. Briegel (Innsbruck) CONTRIBUTED TALKS: * P. Adao, P. Mateus: "A process algebra for reasoning about quantum security" * T. Altenkirch, J. Grattage, J. K. Vizzotto, A. Sabry: "An Algebra of Pure Quantum Programming" * B. Coecke: "De-linearizing Linearity" * V. Danos, E. D'Hondt, E. Kashefi, P. Panangaden: "Distributed measurement-based quantum computation" * V. Danos, E. Kashefi: "Pauli measurements are universal" * R. Nagarajan, N. Papanikolaou, D. Williams: "Simulating and Compiling Code for the Sequential Quantum Random Access Machine" * S. Perdrix: "Toward Quantum Data Structures: Types and Subtypes for Entanglement and Separability" * P. Selinger : "Dagger compact closed categories and completely positive maps" * D. Unruh: "Quantum Programs with Classical Output Streams" * P. Zuliani: "Quantum programming with mixed states" PROGRAM COMMITTEE: Bob Coecke (Oxford) Simon Gay (Glasgow) Philippe Jorrand (Grenoble) Peter Selinger (Ottawa) CONTACT INFORMATION: Organizer: Peter Selinger Department of Mathematics and Statistics University of Ottawa, Canada Email: selinger(a)mathstat.uottawa.ca CONFERENCE WEBSITE: http://quasar.mathstat.uottawa.ca/~selinger/qpl2005/ SPONSORS: This workshop is made possible in part by funding from: MagiQ Technologies <http://www.magiqtech.com/> (revised Apr 26, 2005) 27-Apr-2005 13:04:20 -0300,8813;000000000000-00000020

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two new preprints and a useful website
by Tim Porter 26 Apr '05

26 Apr '05

Its Tim Porter again, There are two other preprints that would be of interest, perhaps, to a different audience. They are: 05.01 GRATUS, J. & PORTER, T. A geometry of information, I: Nerves, posets and differential forms Abstract: The main theme of this workshop is Spatial Representation: Continuous vs. Discrete. Spatial representation has two contrasting but interacting aspects (i) representation of spaces' and (ii) representation by spaces. In this paper we will examine two aspects that are common to both interpretations of the theme, namely nerve constructions and refinement. Representations change, data changes, spaces change. We will examine the possibility of a differential geometry of spatial representations of both types, and in the sequel give an algebra of differential forms that has the potential to handle the dynamical aspect of such a geometry. We will discuss briefly a conjectured class of spaces, generalising the Cantor set which would seem ideal as a test-bed for the set of tools we are developing. Download: 05_01.pdf <http://www.informatics.bangor.ac.uk/public/mathematics/research/ftp/cathom/…> Presented at: This paper is based on a talk at Schloss Dagstuhl (International Conference and Research Center for Computer Science) as part of the seminar Spatial Representation: Discrete vs. Continuous Computational Models <http://www.dagstuhl.de/04351/Materials/> (August 2004). This paper, and the corresponding part II, evolved from the talks entitled Fractafolds, their geometry and topology: a test bed for spatial representation given at the Seminar, as a result of the insights gleaned by the authors during the excellent sessions of the week. This research forms part of a project : \emph{Fractafolds, their geometry and topology}, partially supported by a grant from the Leverhulme Trust. This help is gratefully acknowledged. ------------------------------------------------------------------------ 05.02 GRATUS, J. & PORTER, T. A geometry of information, II: Sorkin models, and biextensional collapses Abstract: In this second part of our contribution to the workshop, we look in more detail at the Sorkin model, its relationship to constructions in Chu space theory, and then compare it with the Nerve constructions given in the first part. This research forms part of a project: Fractafolds, their geometry and topology, partially supported by a grant from the Leverhulme Trust. This help is gratefully acknowledged. Download: * 05_02.pdf <http://www.informatics.bangor.ac.uk/public/mathematics/research/ftp/cathom/…> ________________________- They, and a lot more by others, can also be found at: http://drops.dagstuhl.de/portals/04351/ Do go and have a look. Best wishes, Tim 27-Apr-2005 13:04:19 -0300,5633;000000000000-0000001b

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New preprint
by Tim Porter 26 Apr '05

26 Apr '05

Dear all, Some of you may be interested in the preprint: 05.03 EHLERS, P.J. & PORTER, T. Ordinal subdivision and special pasting in quasicategories Abstract: Quasicategories are simplicial sets with properties generalising those of the nerve of a category. They model weak infinity-categories. Using a combinatorially defined ordinal subdivision, we examine composition rules for certain special pasting diagrams in quasicategories. The subdivision is of combinatorial interest in its own right and is linked with various combinatorial constructions. Download: 05_03.pdf <http://www.informatics.bangor.ac.uk/public/mathematics/research/ftp/cathom/…> This has been a long time reaching this stage. Phil Ehlers finished his thesis in 1993. Tim 27-Apr-2005 13:04:19 -0300,2879;000000000001-0000001e

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Chicago Sun-Times on Saunders
by Peter Freyd 26 Apr '05

26 Apr '05

Copyright 2005 Chicago Sun-Times, Inc. Chicago Sun-Times April 22, 2005 Friday SECTION: NEWS; Pg. 80 LENGTH: 784 words HEADLINE: Saunders Mac Lane, pioneering mathematician BYLINE: RUMMANA HUSSAIN BODY: Saunders Mac Lane, the prominent University of Chicago mathematician and National Medal of Science recipient, helped create the category theory that deals with mathematical structures and relationships between them. Mr. Mac Lane, who is often hailed as one of the most influential American mathematicians of the 20th century, died April 14 from internal bleeding related to complications with constrictive heart disease at the Mission Villa hospice in Daly City, Calif. He was 95. He began laying down the foundation of the revolutionary theory in a landmark paper he and fellow mathematician Samuel Eilenberg published in 1945. "There are very few mathematicians who ever introduced a completely new theory into the field. That's really rare," said Klaus Peters, a publisher at A K Peters Ltd., which is releasing Mr. Mac Lane's autobiography next month. The category theory, which has influenced most math-related fields including computer science, was first dismissed by more practical minded mathematicians as too abstract to be useful. So when Mr. Mac Lane wrote a book on the theory, he titled it Categories for the Working Mathematician just to poke fun at his detractors. "He had a great sense of humor. He had a very forceful personality. He was very opinionated. He was usually right -- not always -- but he was always subject to persuasion. He listened to people," U of C math professor J. Peter May said. The Norwich, Conn. native, who published 100 research papers and six books, received a bachelor's degree at Yale in 1930 and a master's degree from the University of Chicago in 1931. Mr. Mac Lane received his Ph.D. at the University at Gottingen, Germany in 1934. There, he studied under the renowned mathematicians Hermann Weyl and Paul Bernays. Between the mid-1930s to late 1940s, Mr. Mac Lane taught math at Harvard, Cornell and the University of Chicago before finally choosing the latter as his longtime professional home in 1947 where he lectured on logic, topology and alegebraic theories. He retired in the 1980s, but continued to advise students until the 1990s. While at the U. of C., Mr. Mac Lane served as chairman of the mathematical department between 1952 to 1958 and supervised 39 Ph.D students. During his career, the Fulbright Scholar was honored by numerous fellowships, honorary degrees and awards, including the University of Chicago Alumni Association's Norman Maclean Faculty Award in 2003. In 1989, former President George H.W. Bush bestowed him with the National Medal of Science, the country's highest award for scientific achievement. Mr. Mac Lane always strived to use science to better the country. As a member of the National Science Board, he provided science policy advice to the U.S. government between 1974 and 1980 and in the mid-1940s, he directed Columbia University's Applied Mathematics Group, which was involved in the war effort. "He was an extremely powerful person, who stood up for raising the level of a scientific atmosphere in the whole country," said F. William Lawvere, a retired professor at the State University of New York at Buffalo. Mr. Mac Lane also served as vice president of the National Academy of Sciences and the American Philosophical Society. He also was past president of the Mathematical Association of America and the American Mathematical Society. Mr. Mac Lane, an avid skier who also loved to sail, was described by friends and colleagues as an energetic man who valued hard work. He out-hiked a younger Lawvere in Aspen in his 70s and would insist on walking to his third-floor office at the U. of C. well into his 80s. "When he was 90, I saw him on a Friday night out in the street, and I asked him if he wanted to go to a conference at Northwestern University the next day on the higher category theory. He said, 'yes, please,' and called me the next day at 7 a.m. to make sure I hadn't forgotten him. He sat in the front row and asked questions the whole weekend," May said. Mr. Mac Lane was always dedicated to helping students and would often go out of his way to assist them with their thesis papers, even if they didn't relate to his own research. His textbook written with Garrett Birkhoff, A Survey of Modern Algebra, has been used by college students for years. "I failed physics, so he tutored me. Thanks to him, I was able to understand it," said Gretchen MacLane, Mr. Mac Lane's daughter with his late wife, Dorothy Jones. "He was a wonderful tutor." Her also is survived by his wife, Osa; his other daughter, Cynthia Hay; his stepdaughter, Karen Segal; his stepsons, Andrew and William Segal; his grandson and five stepgrandchildren. Funeral services have been held. 27-Apr-2005 13:04:19 -0300,2053;000000000000-0000001c

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Peter on Saunders (The Independent)
by Peter Freyd 26 Apr '05

26 Apr '05

[The three bracketed passages below were in Peter's original manuscript, and are here restored.] Copyright 2005 Independent Newspapers (UK) Limited The Independent April 26, 2005 LENGTH: 1113 words HEADLINE: OBITUARY: SAUNDERS MAC LANE BYLINE: Peter Johnstone BODY: Saunders Mac Lane was the joint creator " with Samuel Eilenberg " of the subject of category theory, which permanently changed the way in which mathematicians view the foundations of their subject. But he will also be remembered by many generations of mathematics students as the co-author, with Garrett Birkhoff, of A Survey of Modern Algebra (1941), which for at least 30 years remained the definitive English-language treatment of abstract algebra. And the more select company of those who had the good fortune to encounter him as a teacher will remember one of the most forceful and inspiring lecturers imaginable. Mac Lane was born in Taftville, Connecticut, in 1909. His father and grandfather were both Congregationalist ministers, and his nonconformist ancestry could be detected in his strong sense of duty and service (allied to a sense of humour, not to mention a dress sense, that was decidedly un-Puritan). His father died when he was 15, and an uncle made it possible for Mac Lane to go to Yale, where he excelled in mathematics. After a year of postgraduate work in Chicago, he went to Gttingen to study for a PhD in mathematical logic under the supervision of Paul Bernays. On returning to the United States, he spent the next five years in fixed- term appointments at Yale, Harvard, Cornell and Chicago, before becoming an assistant professor at Harvard in 1938. Although his PhD thesis had been in logic, Mac Lane's early published papers were in algebra (particularly valuation theory), a subject which he had imbibed deeply at Gttingen from Emmy Noether, the 'mother of modern algebra', and her students. It was at Harvard that he met Birkhoff, who like him had travelled to Europe (in his case Cambridge) to do research, and they agreed to collaborate on writing an English-language account of the new developments in algebra which they had both encountered there. At that time the only available textbook on 'modern algebra' was Bartel van der Waerden's Moderne Algebra (1931), which was fairly tough going, even for those who could read German (an English translation eventually appeared in 1949). Birkhoff and Mac Lane, in contrast, produced a classic which remained a standard reference for undergraduate algebra courses for more than three decades, and is still in print today. It was in 1941, the year the Survey was published, that the Eilenberg- Mac Lane collaboration began. Eilenberg, a Polish Jew trained in the formidable Polish school of topologists, had arrived in the United States two years earlier and was then at the University of Michigan. Mac Lane visited Michigan to lecture on his current research in group extensions; Eilenberg recognised the similarity of Mac Lane's calculations to ones he was encountering in algebraic topology, and suggested to Mac Lane that they collaborate. The partnership lasted 14 years, and produced 15 major papers which changed the direction of 20th-century mathematics. The common calculations gave rise to the subject of homological algebra, a subject which was created independently (thanks to wartime communication difficulties) by researchers in Europe. But Mac Lane and Eilenberg went further. In seeking to provide a sound conceptual framework for the subject, they invented the notions of category and functor. These notions were slow to gain acceptance (the first Eilenberg-Mac Lane paper on categories was nearly rejected by the Transactions of the American Mathematical Society) on account of their seeming lack of content: for a decade or so, category theory was derided by other mathematicians as 'abstract nonsense'. But in time the substantial new advances made possible by the categorical way of thinking about mathematics won it acceptance: it has by now become an indispensable part of the vocabulary of the great majority of pure mathematicians (and, increasingly, of researchers in theoretical physics and computer science). Apart from a period at Columbia University in 1944-45, when he worked on problems in aerial gunnery as part of the US war effort, Mac Lane remained at Harvard until 1947, when he was recruited by Marshall Stone to join the faculty of the University of Chicago. He spent the rest of his career at Chicago, becoming Max Mason Distinguished Service Professor in 1963 and Professor Emeritus in 1982. His distinction was recognised by honorary degrees from several universities, and by the award of the National Medal of Science in 1989. Mac Lane's sense of duty, and his real concern for the health of the academic profession, led him to take on onerous administrative responsibilities. [In succession to Stone, he served as Chairman of the Chicago Mathematics Department from 1952 to 1958. On a national level, he served as President of both the Mathematical Association of America and the American Mathematical Society, as a Vice-President of the National Academy of Sciences and the American Philosophical Society, and as a member of the National Science Board.] But he found administration uncongenial in comparison with actually doing mathematics. He was a born teacher: both as a forceful and challenging lecturer, and also as an adviser of research students. His list of PhD students is both long and distinguished: significantly, it includes a good many mathematicians who went on to eminence in fields quite different from his own. His last student received his degree when Mac Lane was 87. He greatly enjoyed the company of younger colleagues, and remained an active participant in international conferences right up to his 90th year. [In later years, he would often lecture on topics in the history of 20th-century mathematics, and the numerous papers he wrote on this subject form a unique body of material for future historians, written by someone who was there at the time and who knew what it was like to be working at the cutting edge of mathematical research.] His physical energy astonished his younger colleagues: on the 'conference hike', he would always be among the leaders, dressed in tartan trousers (the MacLean tartan, of course) and wielding a heavy stick. In addition to the best-selling A Survey of Modern Algebra, Mac Lane was author or co-author of five books. His accounts of homological algebra (Homology, 1963) and category theory (Categories for the Working Mathematician, 1971) both carry the authority of having been written by a founder of the subject; a second algebra textbook with Birkhoff (Algebra, 1967) was a pioneering attempt to let the new ideas of category theory 'trickle down' into the undergraduate curriculum; a book on philosophy of mathematics (Mathematics: form and function, 1985) was unconventional but widely admired; and his last book (Sheaves in Geometry and Logic, 1992), written jointly with Ieke Moerdijk, was a textbook on topos theory, one of the major new developments in mathematics that category theory made possible. Sadly, he did not live to see the publication of A Mathematical Autobiography, which is due to appear in a few weeks' time. [In addition to a long life, Mac Lane was blessed with two very happy marriages. His first marriage to Dorothy Jones lasted more than 50 years; after her death in 1985, he married Osa Skotting, former wife of the mathematician Irving Segal, who subsequently cared for him during his long final illness as he had earlier cared for Dorothy. She survives him, as do the two daughters of his first marriage.] Saunders Mac Lane, mathematician: born Taftville, Connecticut 4 August 1909; staff, Mathematics Department, University of Chicago 1947-63, Max Mason Distinguished Service Professor 1963-82 (Emeritus); married 1933 Dorothy Jones (died 1985; two daughters), 1986 Osa Segal (nZe Skotting); died San Francisco 14 April 2005. 29-Apr-2005 08:37:42 -0300,10929;000000000000-00000021

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