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# All LogBlog Posts

## LogBlog Has Moved!

You are looking at the old blog archive. LogBlog has moved to richardzach.org.
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## Alan Turing gets royal pardon

Submitted by Richard Zach on Mon, 12/23/2013 - 6:05pm

## 20 Year Anniversary: Proof Theory of Finite Valued Logics

Submitted by Richard Zach on Tue, 12/17/2013 - 4:38am

Twenty years ago this month I submitted my Diplomarbeit (MA thesis) on the proof theory of finite valued logics.  Still kinda proud of it.

The main results of this report are: the use of signed formula expressions and partial normal forms to provide a unifying framework in which clause translation calculi, sequent calculi, natural deduction, and also tableaux can be represented; bounds for partial normal forms for general and induced quantifiers; and negative resolution. The cut-elimination theorems extend previous results, and the midsequent theorem, natural deduction systems for many-valued logics as well as results on approximation of axiomatizable propositional logics by many-valued logics are all new.

Here's an old blog post on the whole idea.

## NASSLI 2014 Student Session CfP

Submitted by Richard Zach on Wed, 12/11/2013 - 6:11am

The North American Summer School in Logic, Language and Information wil be held June 23-27, 2014 in College Park, MD.  A call for papers for the student session was just issued; deadline is February 24.

The North American Summer School for Logic, Language and Information (NASSLLI) welcomes paper submissions for presentation at its Student Session. Submissions may be in any of the fields related to the school (logic and language, logic and computation, or language and computation) and should represent original, unpublished work by individuals who will not yet have received their Ph.D. by the time of the conference.
The Student Session will co-occur with NASSLLI and provides students an excellent opportunity to present their work to experts in their field as well as to a broader, well-informed interdisciplinary audience. All submissions will be reviewed by at least three specialists who will provide commentary on the paper regardless of its acceptance status.
Submissions should be prepared for blind review (i.e., should not contain any information identifying the author) and should be uploaded as a .pdf file to the Student Session’s EasyChair site. Submissions should not exceed 10 pages and should be formatted standardly (11 or 12 point font, 1 inch margins).
No more than one-single authored and one co-authored paper should be submitted by an individual. (All co-authors should also be students.) Authors whose submissions have been accepted and who intend to present will be required to register for NASSLLI.
IMPORTANT DATES:
Submissions due: February 28, 2014 (by midnight)
Notifications: April 14, 2014
WEBSITES:
CONTACT
Quinn Harr at qharr@umd.edu

## Summer School at MCMP for Women Formal Philosophy Students

Submitted by Richard Zach on Wed, 12/04/2013 - 9:13am

Wow, awesome. Lecturers include Rachael Briggs, Sonja Smets, and Florian Steinberger.

The Munich Center for Mathematical Philosophy (MCMP) is organizing the first Summer School on Mathematical Philosophy for Female Students, which will be held from July 27 to August 2, 2014 in Munich, Germany. The summer school is open to excellent female students who want to specialize in mathematical philosophy.

Since women are significantly underrepresented in philosophy generally and in formal philosophy in particular, this summer school is aimed at encouraging women to engage with mathematical methods and apply them to philosophical problems. The summer school will provide an infrastructure for developing expertise in some of the main formal approaches used in mathematical philosophy, including theories of individual and collective decision-making, agent-based modeling, and epistemic logic. Furthermore, it offers study in an informal setting, lively debate, and a chance to strengthen mathematical self-confidence and independence for female students. Finally, being located at the MCMP, the summer school will also provide a stimulating and interdisciplinary environment for meeting like-minded philosophers.

## Maria Reichenbach (1909-2013)

Submitted by Richard Zach on Mon, 12/02/2013 - 9:07pm

Alan Richardson writes on HOPOS-L:

Professor Maria Reichenbach passed away on 28 November at the age of 104. She survived her husband, Hans Reichenbach, by over 60 years. Within the HOPOS community, Maria Reichenbach is best known for her efforts to keep alive the work of Hans, including her translations of several of his early books and her editorship (jointly with Robert S. Cohen) of his selected writings. Less well known is the fact that she donated funds from a German compensation scheme for academics who lost their jobs due to Nazism to fund a variety of activities at UCLA's Department of Philosophy, including the annual Hans Reichenbach Lecture and the Hans Reichenbach Chair of Scientific Philosophy, held from its inception by David Kaplan.

## Help sought for a biography of Richard Montague

Submitted by Richard Zach on Fri, 11/29/2013 - 5:06pm

Ivano Caponigro at UCSD writes:

I'm working on a biography of Richard Montague (1930-1971) that aims to reconstruct his intellectual and personal life, his contributions, and his legacy.  Please contact me if you knew him personally (or just met him a few times) or have any material from him or about him (letters, manuscripts, pictures, audio recordings, etc.) or if you know anybody who knew him or may have material about it.

Thanks!

ivano@ucsd.edu

## Mancosu on Pasternak (!)

Submitted by Richard Zach on Fri, 11/15/2013 - 2:12pm

My Doktorvater Paolo Mancosu has a new book: Inside the Zhivago Storm, on the publication history of Pasternak's Doctor Zhivago.

That's the kind of scholar Paolo is: write a 400-page literary thriller because his duties as department chair at Berkeley keep him from doing his "real" work as a logician and philosopher of mathematics.

UPDATE: He now has a website/blog on the book as well.

From the publisher:

In Inside the Zhivago Storm. The Editorial Adventures of Pasternak’s Masterpiece, Paolo Mancosu, Professor of Philosophy at the University of California at Berkeley, provides a riveting account of the story of the first publication of Doctor Zhivago and of the subsequent Russian editions in the West. Exploiting with scholarly and philological rigor the untapped resources of the Feltrinelli archives in Milan as well as several other private and public archives in Europe, Russia, and the USA, Mancosu reconstructs the relationship between Pasternak and Feltrinelli, the story of the Italian publication, and the pressure exercised on Feltrinelli by the Soviets and the Italian Communist Party to stop publication of the novel in Italy and in other countries.

Doctor Zhivago, the masterpiece that won Boris Pasternak the Nobel Prize in 1958, had its first worldwide edition in 1957 in Italian. The events surrounding its publication, whose protagonists were Boris Pasternak and the publisher Giangiacomo Feltrinelli, undoubtedly count as one of the most fascinating stories of the twentieth century. It is a story that saw the involvement of governments, political parties, secret services, and publishers. In Inside the Zhivago Storm. The Editorial Adventures of Pasternak’s Masterpiece, Paolo Mancosu, Professor of Philosophy at the University of California at Berkeley, provides a riveting account of the story of the first publication of Doctor Zhivago and of the subsequent Russian editions in the West. Exploiting with scholarly and philological rigor the untapped resources of the Feltrinelli archives in Milan as well as several other private and public archives in Europe, Russia, and the USA, Mancosu reconstructs the relationship between Pasternak and Feltrinelli, the story of the Italian publication, and the pressure exercised on Feltrinelli by the Soviets and the Italian Communist Party to stop publication of the novel in Italy and in other countries. Situating the story in the historical context of the Cold War, Mancosu describes the hidden roles of the KGB and the CIA in the vicissitudes of the publication of the novel both in Italian and in the original Russian language. The full correspondence between Boris Pasternak and Giangiacomo Feltrinelli (spanning from 1956 to 1960) is also published here for the first time in the original and in English translation. Doctor Zhivago is a classic of world literature and the story of its publication, as it is recounted in this book, is the story of the courage and of the intellectual freedom of a great writer and of a great publisher.

## Post Doc in History of Geometry/Epistemology of Math at MPI Berlin

Submitted by Richard Zach on Tue, 11/12/2013 - 11:06am

A postdoc in history of geometry is being advertised at Vincenzo de Risi's group at the MPI for History of Science,Berlin!

https://www.h-net.org/jobs/job_display.php?id=47973

Research projects should concern the history of geometry, the history of mathematical epistemology or the history of the concept of space from the Ancient to the Early Modern Age. Possible topics include: The history of elementary geometry and Euclid’s Elements in Antiquity and the Renaissance. The philosophy of mathematics from Antiquity to the 18th century. The conception of space from Descartes to Kant. The beginnings of projective geometry. Optics and the theory of vision.

## Philosophy in the SSHRC Insight Grant Competition

Submitted by Richard Zach on Mon, 11/11/2013 - 5:22pm

The Insight Grant Adjudication Committee (Committee 1C) for the 2013 Insight Grant competition of SSHRC, on which I served, prepared the following statement when the results of the competition were announced in April. We sent it to the CPA to distribute, but somehow it fell throught the cracks.  They did post an excerpt of an earlier letter which was sent to all Canadian philosophy departments inApril on their forum a month ago though.  I'm posting it here and now for the record.

(La version française suit)

The Social Sciences and Humanities Research Council of Canada (SSHRC) funds research projects by Canadian philosophers through its Insight Grant program. This program replaced the Standard Research Grant program in 2011. In the 2012 competition, the results of which were just announced, 13 applications were funded.  This represents a success rate of 21%, down from last year’s 18 applications funded (success rate: 26.5%).

This is bad news. But Canadian philosophers should understand some hidden factors driving the trend. Under SSHRC's old system, each disciplinary committee was allocated a separate pot of money, where the size of the pot was determined by a formula involving the number of applicants to that committee and the total budget requested in each application. After ranking applications on their merits, committees were at liberty to trim the budgets of successful applicants in order to fund more applications (but to a lesser degree), and Philosophy was quite aggressive about doing so (resulting in a higher success rate for our committee than for some others).

Under the new Insight Grant system, the application success rate is standardized to be the same across all committees.  For the 2012 competition, committees in all disciplines (Economics, Linguistics, etc.) had the same 21% application success rate.  Instead of tinkering with individual budgets, the appropriateness of an applicant's budget was factored into the "feasibility" score, so applicants whose budgets were sharply out of line with the norms (median request: $23k per year) tended to suffer numerically. It remained possible for the committee to make a rough budget cut on an excellent proposal (say, funding just 50% or 75% of what someone asked), but it was hard to do this while still allocating that proposal the near-perfect score on feasibility needed to make the top-of-the-list position that was necessary for funding. Some large projects were certainly funded, but they needed excellent justifications for their large budget requests. It is important to understand that the drop in the national success rate was driven not primarily by increased stringency on SSHRC’s part, or a decrease in overall funding, or any bias against Philosophy, but by an increase in the number of applications across all committees: the Insight Grant went from 1,821 applications in 2011 to 2,220 applications in 2012, an increase of 399 applications (21.9%). Meanwhile, Philosophy marked an exception to this general trend: we went from 68 applications in 2011 to 62 applications in 2012, a decrease of 8.8%. If Philosophy had increased on a par with other disciplines, we would have had 83 applications, and with this year’s standardized success rate of 21% we would have been able to fund 17 of them, very close to last year's 18 applications funded. One factor for the decrease in Philosophy applications may have been that last year’s success rate was lower for Philosophy than it has been in the past, and applicants may have been discouraged from even trying. This is exactly the wrong thing to do, especially in a climate in which disciplines other than Philosophy are responding to the fixed success rate by sharply increasing their number of applications. In many departments, SSHRC grants are vital both to the support and to the training of graduate students. It is in the interest of Canadian Philosophy and our graduate programs that as many eligible faculty members as possible apply. It may be a pain, and discouraging not to be funded. But it can be useful to prepare a research plan, and it’s not much work to do some small revisions to research plans that were unsuccessful in the past. The very same proposal can pass from an insufficient ranking in one year to being funded in the next, for a number of reasons (budget appropriateness, different letters of assessment, different adjudication committee, different fields of applications). There were many excellent proposals this year that very narrowly missed being funded. Le Conseil de recherches en sciences humaines du Canada (CRSH) subventionne les projets de recherche des philosophes canadiens par son programme des subventions Savoir. Ce programme a remplacé en 2011 le programme des subventions ordinaires de recherche. Au concours de 2012, dont les résultats viennent tout juste d’être annoncés, 13 subventions ont été approuvées. Cela représente un taux de succès de 21%, alors que l’année dernière, 18 projets avaient été financés pour un taux de succès de 26,5%. Ce résultat est une mauvaise nouvelle. Les philosophes canadiens doivent comprendre que certains facteurs peu apparents ont joué. Sous l'ancien régime, chaque comité disciplinaire disposait d'une somme donnée, déterminée par une formule qui tenait compte du nombre de demandes reçues par le comité, ainsi que du total des budgets demandés. Après avoir classé les demandes au mérite, les comités pouvaient à leur gré réduire la somme accordée aux candidats retenus pour subvention afin de financer plus de projets (de façon un peu moins généreuse). Le comité de philosophie usait assez largement de cette possibilité, ce qui assurait à ce comité un taux de succès plus élevé qu’à d’autres comités. Dans le nouveau système des subventions Savoir, le taux de succès est normalisé de façon à être identique pour tous les comités. Donc, en 2012, toutes les disciplines ont eu le même taux de succès de 21%. Il n’est plus question d’ajuster les budgets de façon détaillée, mais seulement de vérifier s’ils sont globalement adéquats, en notant la « faisabilité » du projet : ainsi toute demande dont le budget s’écarte significativement de ce qui apparaît raisonnable (compte tenu d’un budget moyen demandé de quelque 23K$) tend à être numériquement défavorisé dans l’évaluation. Quoiqu'il demeure possible de réduire (par exemple de 25% ou même 50%) un budget jugé excessif pour un excellent projet de recherche, le fait d'avoir à le faire fait perdre des points au chapitre de la faisabilité, alors qu’une note quasi maximale est requise pour figurer en tête de liste et être financé. Certains projets au budget élevé ont été certes approuvés, mais seulement moyennant d’excellents justifications.

Il est important de comprendre que la baisse constatée du taux de succès général n'a été due ni à un resserrement des critères de la part du CRSH, ni à une baisse du financement disponible, ni à un quelconque préjugé contre la philosophie. Elle résulte uniquement de l'augmentation du nombre total des demandes pour l’ensemble des comités, nombre qui est passé de 1821 en 2011 à 2200 en 2012, soit 399 demandes ou 21,9% de plus. La philosophie a fait exception à cette tendance générale, avec 62 demandes en 2012, 8,8% de moins qu’en 2011 où il y en avait eu 68. Si les philosophes avaient fait comme les chercheurs des autres disciplines, nous aurions eu 83 demandes, ce qui, compte tenu du taux de succès normalisé de 21% aurait vraisemblablement donné 17 subventions octroyées, soit presque le même nombre que les 18 de l'an passé.

Le nombre décroissant des demandes en philosophie pourrait s’expliquer du moins en partie par le fait que le taux de succès, l’année dernière, avait été plus faible qu’antérieurement, ce qui pourrait avoir dissuadé certains philosophes de tenter leur chance. Or il faudrait réagir de manière exactement contraire, surtout dans un contexte où les autres disciplines s’ajustent au taux de succès fixe en augmentant nettement le nombre de leurs demandes.

Les subventions du CRSH jouent un rôle essentiel dans le financement et la formation de nos étudiants gradués. Il est de l’intérêt de la philosophie au Canada et de nos programmes d’études supérieures que le plus grand nombre de professeurs et chercheurs éligibles se portent candidats. Il peut être pénible, voire décourageant de ne pas être financé. Mais il peut être profitable d’élaborer un programme de recherche et le modeste effort requis pour réviser un projet, précédemment refusé, peut valoir amplement la peine : il semble bien établi, en effet, qu’un programme similaire de recherche peut recevoir une note insuffisante une année et se voir financer l'année suivante, pour diverses raisons (ajustement du budget, lettres d’évaluation différentes, changement dans la composition du comité, autres champs d’application). Cette année, plusieurs excellentes demandes ont manqué de très peu d'être financées.

## SEP Entry on Gödel's Incompleteness Theorem

Submitted by Richard Zach on Mon, 11/11/2013 - 4:59pm

The Stanford Encyclopedia now has a separate entry on Gödel's incompleteness theorem (by Panu Raatikainen).

http://plato.stanford.edu/entries/goedel-incompleteness/

(Juliette Kennedy's entry on Gödel also covers incompleteness.)

## LaTeX for Philosophers

Submitted by Richard Zach on Sat, 11/09/2013 - 11:49am

This last Thursday I held a little workshop to tell our graduate students about LaTeX.  Since LaTeX is fairly commonly used by philosophers, I thought they should at least know what it's all about.  I made a presentation (the handout version contains additional info).  I didn't have time to provide a list of documents/sites to check out or detailed instructions (and wouldn't really know how to do that, as e.g., I haven't installed TeX on a Windows machine in at least a decade, and never on a Mac).  We did play around with a few packages and experiment with BibTeX as a group.  Nice that WriteLaTeX lets you do that without even signing up for a free account!

PDFs of the presentation are attached to this post if you want to have a look, and the source code is on my GitHub.  I unlicense'd it, so feel free to use it for your own workshops on LaTeX for Philosophers (or other non-techy acedemics).  Suggestions for additions, requests for changes, typos, etc.: comment and/or file an issue on GitHub.

## Gillian Russell Interviewed on 3:AM

Submitted by Richard Zach on Fri, 09/27/2013 - 9:12am

Read this.

## Awodey Explains Significance of Homotopy Type Theory to Philosophy of Mathematics

Submitted by Richard Zach on Thu, 07/25/2013 - 12:12pm

Steve Awodey (CMU) explains the relevance of the foundational program of homotopy type theory and the univalence axiom to the philosophy of mathematics in a new preprint, "Structuralism, Invariance, and Univalence."

Recent advances in foundations of mathematics have led to some developments that are signicant for the philosophy of mathematics, particularly structuralism. Specically, the discovery of an interpretation of Martin-Löf's constructive type theory into abstract homotopy theory  suggests a new approach to the foundations of mathematics, with both intrinsic geometric content and a computational implementation. Leading homotopy theorist Vladimir Voevodsky has proposed an ambitious new program of foundations on this basis, including a new axiom with both geometric and logical signicance: the Univalence Axiom. It captures the familiar aspect of informal mathematical practice according to which one can identify isomorphic objects. While it is incompatible with conventional foundations, it is a powerful addition to the framework of homotopical type theory.

## Gödel's Incompleteness Theorems Formally Verified

Submitted by Richard Zach on Fri, 07/12/2013 - 6:24am

Going through old emails, I found the following announcement by Larry Paulson, posted to the FOM list by Jeremy Avigad.  Good stuff, including the link to Stanis?aw ?wierczkowski's monograph in Dissertationes Mathematicae where he carries out the proof of the incompleteness theorems in HF, the theory of hereditarily finite sets. This should be of independent interest even if you don't care about proof formalization -- I hear of it, I think, but haven't read it. You can buy it here.

I've completed a formalisation of Gödel's two incompleteness theorems, including what may be the first-ever formalisation of the second incompleteness theorem. The proof was done in Isabelle/HOL and uses Christian Urban's Nominal2 package for dealing with bound variables. The formalisation follows an unpublished paper by S. ?wierczkowski, who presents proofs of both incompleteness theorems using the hereditarily finite sets rather than Peano Arithmetic:

http://journals.impan.gov.pl/dm/Inf/422-0-1.html

Proving the second incompleteness theorem requires some quite intricate operations on alphabets, as well as lengthy derivations in an internal calculus. Apart from those derivations, the proof script is structured and quite legible. The full development is concise, at under 17,000 lines, plus a further 3000 lines to develop HF set theory. (A recent Coq proof of the first incompleteness theorem alone is over 52,000 lines.)

The development is instructive. While first-order logic is formalised here using "nominal" binding primitives, the coding uses de Bruijn indexes. A precise correspondence is proved between the two representations of formulas. A series of correspondence proofs provides confidence in the correctness of the complicated syntactic definitions. The second incompleteness theorem follows from the Hilbert-Bernays derivability conditions. Proving the crucial theorem |- A => Prov["A"] requires transforming a coded formula. During this process, the coded variables (which are constant terms) need to be replaced by terms consisting of a special function applied to the same variable (not coded). But this calculus has no functions, and this step needs to be expressed by introducing new variables that satisfy a certain relation with the original variables. The proof is by induction on the formula A, but relies on properties proved by a mutual induction within the encoded first-order calculus itself.

## Ergo, An Open Access Journal of Philosophy

Submitted by Richard Zach on Thu, 07/11/2013 - 6:30am

http://quod.lib.umich.edu/e/ergo

Ergo is a general, open access philosophy journal accepting submissions on all philosophical topics and from all philosophical traditions. This includes, among other things: history of philosophy, work in both the analytic and continental traditions, as well as formal and empirically informed philosophy.

Ergo uses a triple-anonymous peer review process and aims to return decisions within two months on average.

Ergo is published by MPublishing at the University of Michigan and sponsord by the Department of Philosophy at the University of Toronto. Papers are published as they are accepted; there is no regular publication schedule.

To submit a paper, please register and login to Ergo's editorial management system at:

Submitted manuscripts should be prepared for anonymous review, containing no identifying information. Submissions need not conform to the journal style unless and until accepted for publication.

Submission and publication is free, but the journal essentially depends on the support of reliable reviewers returning informative reports in a timely manner. We hope that you will consider acting as referee for Ergo if asked by one of its editors. We also hope that you will consider submitting your work to Ergo.

Please share this call for papers with your colleagues!

Managing Editors
Franz Huber (University of Toronto)
Jonathan Weisberg (University of Toronto)
ergo.editors@gmail.com

Section Editors
Rachael Briggs (Australian National University & Griffith University)
Eleonora Cresto (University of Buenos Aires)
Vincenzo Crupi (University of Turin)
Imogen Dickie (University of Toronto)
Catarina Dutilh-Novaes (University of Groningen)
Kenny Easwaran (University of Southern California)
Matt Evans (University of Michigan)
Laura Franklin-Hall (New York University)
Ole Hjortland (LMU Munich)
Michelle Kosch (Cornell University)
Antonia LoLordo (University of Virginia)
Christy Mag Uidhir (University of Houston)
Julia Markovits (Massachusetts Institute of Technology)
Lionel McPherson (Tufts University)
Jennifer Nagel (University of Toronto)
Jill North (Cornell University)
Brian O'Connor (University College Dublin)
Laurie A. Paul (University of North Carolina at Chapel Hill)
Richard Pettigrew (Bristol University)
Martin Pickavé (University of Toronto)
Adam Sennet (University of California at Davis)
Nishi Shah (Amherst College)
Quayshawn Spencer (University of San Francisco)
Ásta Sveinsdóttir (San Francisco State University)
Robbie Williams (University of Leeds)
Wayne Wu (Carnegie Mellon University)
Jiji Zhang (Lingnan University)

## PBS: Math Might Not Actually Exist

Submitted by Richard Zach on Thu, 06/06/2013 - 2:31am

The online Youtube channel PBS Ideas is doing a segment on the realism/antirealism debate in the philosophy of mathematics as one of "10 Unanswered Questions of Science". The format doesn't lend itselft to much nuance, the views mentioned are naive, and it's a bit frustrating that the only philosopher referred to is Alain Badiou, but it's funny and might make a good promo video for your next philosophy of math course.

## LaTeX Package for Typesetting Fitch Proofs LPL-Style

Submitted by Richard Zach on Thu, 05/16/2013 - 11:07am

You probably already know about the two packages that you can use to typeset Fitch-style natural deducation proofs in LaTeX.  Here's another, which you may be interested in if you use Barker-Plummer, Barwise, and Etchemendy's popular logic text Language, Proof, and Logic. It makes proofs like this:

I've taken Etch's original style file and Dave's documentation, put it together in standard docstrip format, cleaned up the code a bit and added a few features.  You can download the beta from

https://github.com/rzach/lplfitch

I've also attached the documentation here.

Please file any problem reports on github, if you could, or email me directly. (The comment system here is unreliable.)  I'm hoping to put it on CTAN in a month.

UPDATE: CTAN upload done.

## Formal Epistemology and the Legacy of Logical Empiricism

Submitted by Richard Zach on Wed, 04/24/2013 - 11:54pm

If you're in Austin, you probably know this already. If you're not, it's probably too late. But this is what I'll be doing this weekend:

Friday, 26 April 2012
Thomas Uebel, University of Manchester, “The Logic of Science and the Pragmatics of Science: The Challenge of Complementarity.”
Christopher French, University of British Columbia, “Carnap, Jeffrey and Explication of Radical Probabilism.”
Sebastian Lutz, Ludwig-Maximilians-Universität München, “The Criteria for the Empirical Significance of Terms.”
Saturday, 27 April 2012
Sahotra Sarkar, University of Texas, “Nagel on Reduction.”
Michael Stoeltzner, University of South Carolina, “Could Mathematical Physics serve as a Model for Formal Epistemology?”
Flavia Padovani, Drexel University, “Reichenbach On Causality in 1923: One Word, Many Concepts”
Richard Zach, University of Calgary, “Carnap on Logic.”

Thanks to Sahotra Sarkar for putting this together!

## Running Beamer Presentations from Your Phone

Submitted by Richard Zach on Wed, 04/17/2013 - 1:27pm

Have you ever given a presentation at a conference using your laptop, and then were annoyed that you had to carry aroudn the thing for the entire rest of the evening?  It happens to me all the time. By which I mean, once in a great while, but I nevertheless though it would be cool if I could give my presentation just from my phone (a Samsung Nexus).  Just in case I can help other mathematicians/philosophers/scientists with either a bad back or a tendency to leave bags in restaurants, here's how I did it:

• Get the phone to talk to the projector. For that you need a microUSB-to-VGA adaper, or, for versatility, a microUSB-to-HDMI plus a HDM-to-VGA adapter. In the latter case you can plug into the HDMI port on the projector if you have it. I got this and this but I'm sure there are other options.
• Get a longer power cord or simply a longer USB-to-microUSB cable.  The microUSB-to-HDMI adapter is powered and you don't want the phone to be suspeded between the power outlet and the projector. Don't forget your power adapter.
• Get a Bluetooth mouse/clicker thing, since swiping from slide to slide on the phone is a drag. I got this one.
• My presentations are produced with the beamer package for LaTeX, which produces PDF. So I need a PDF viewer app which displays the PDF properly (centered, full screen, no controls), transitions from slide to slide without delay or silly page flip effects, and reacts to the clicker.  This was actually the hardest part, but the OfficeSuite PDF Viewer works fine.  If you use PowerPoint or something like it, you'll have to look for something that does that.
• When you actually give the presentation, you don't want to be interrupted by text messages or phone calls.  So turn airplane mode on. But you need the clicker, so turn Bluetooth back on. Luckily, this is possible.

## Gillian Russell on Logical Pluralism

Submitted by Richard Zach on Wed, 04/17/2013 - 10:11am

New entry in the Stanford Encyclopedia:
Logical Pluralism