Pictures and videos from the Gödel Centenary Fellowship celebration are online here.

There's a very interesting issue of Erkenntnis just out. It's the proceedings of PhiPMSAP 1. PhiMSAP is the Network on Philosophy of Mathematics: Sociological Aspects and Mathematical Practice of the DFG, run mostly by Benedikt Löwe and Thomas Müller, the third workshop of which I just had the pleasure of attending. Contents of the issue: … Continue reading Towards a New Epistemology of Mathematics

The first issue of the Review of Symbolic Logic will be out soon (Cambridge UP page here). The Review, like the Journal and Bulletin of Symbolic Logic will be mailed to all members of the Association for Symbolic Logic. So if you're not a member (and you probably should be, if you're reading this!), join … Continue reading First Issue of Review of Symbolic Logic Out Soon!

Last week, Brian Leiter posted about possibly re-drawing the dividing lines between the specialty areas ranked in the Philosophical Gourmet ReportIn a comment, Cian asks: Philosophical Logic and Mathematical Logic. While there is a fair amount of divergence between the two rankings, I also see, for example, that NYU gets ranked at 4.5 in mathematical … Continue reading Philosophical Logic and Mathematical Logic in the PGR

What more do we know about a theorem if we have a proof (by restricted means) than merely that it is true? That's an old question of Kreisel's that motivated his "unwinding program": extract additional information from proofs of theorems in constructive theories, such as bounds on y in theorems of the form ∀x∃y A(x, … Continue reading Kohlenbach’s Applied Proof Theory is Out!

From my colleague up north, Rob Wilson: The What Sorts of People blog is now up and running: check it out. This is the blog for the What Sorts of People Should There Be? network, a collaborative blog with regular contributions from around 10 team members. Short, recent posts are available on double-amputee Oscar Pistorius's … Continue reading What Sorts of People Should There Be?

Rob Loftis has a roundup of open access introductory logic textbooks. And Hans von Ditmarsch has a list of logic course software.

It was only a matter of time.

You probably all know the result that Peano Arithmetic is not finitely axiomatizable (a result due to Ryll-Nardzewski), and a similar result for ZFC (due to Richard Montague, I believe). The standard axiom system for PA is not finite since the axiom scheme of induction stands for infinitely many sentences. Ryll-Nardzewski showed that there is … Continue reading Finite Axiomatizability of Theories in the Predicate Calculus Using Additional Predicate Symbols (Classic Logic Papers, Pt. 4)

So the colloquium honoring the recipients of the Gödel Research Fellowships is tomorrow. There should be a live feed. It starts at 9:00 CDT (that's midnight tonight on the West Coast, and 3 am Eastern). I'll try to find out if the lectures will be archived.

Erich Reck's entry on Richard Dedekind in the SEP is now online. I'm particularly happy about this one: It's time Dedekind gets some of the attention for his philosophy of math that Frege's been getting for his, and Erich's entry as well as his other work, I hope, will help bring that about. While many … Continue reading Reck on Dedekind

Two more new entries in the Stanford Encyclopedia of interest to logicians:The Development of Proof Theory by Jan von Plato and Non-wellfounded Set Theory by Larry Moss.From Jan's entry I see that his translation of the interesting third chapter of Genzen's thesis--wherein Gentzen proved normalization of natural deduction derivations--is out in the next issue of … Continue reading More SEP Entries

I am in favor of

There's a very laudable enterprise: Blogging on Pseudoscience (at BPSDB.org) aggregates blog posts debunking or pointing out pseudo-scientific nonsense such as Intelligent Design. Lots of good stuff, PZ Meyers is part of it, etc. But, look at the logo they use:Yes, that's a sequent calculus for linear logic. I know Girard has an idiosyncratic style, … Continue reading Linear Logic is Pseudoscience?

New SEP entry on Definitions by Anil Gupta.

Paolo's Stanford Encyclopedia entry on explanation in mathematics is online.

Ok, that was faster than I expected: The winners of the Kurt Gödel Centenary Research Fellowships have been announced. They are: Pre-doctoral category David Fernández Duque (Stanford): Non-deterministic semantics for dynamic topological logicPavel Hrubeš (Czech Academy of Sciences): On lengths of proofs in non-classical logics Post-doctoral category Andrey Bovykin (Steklov/Liverpool): Independence results in concrete mathematicsPeter … Continue reading Kurt Gödel Centenary Research Fellowship Winners

Hi, I promise to post something logic-related very soon. In the meantime, please enjoy this funny video:[youtube=http://www.youtube.com/watch?v=Ahg6qcgoay4&hl=en]Please look in the mirror before you open your car door!

Shawn at Words and Other Things asks about good books on philosophy of logic. If you have suggestions, comment there, please.

Nice! Andrej Bauer has implemented the Hydra Game in a Java applet. The Hydra Game, like Goodstein sequences, is a way of coding ordinals ≤ ε0 ... hence they provide independence results from Peano Arithmetic. Andrej has all the deets. (A Java applet for Goodstein sequences is here.)