The Café Reichsrat in Vienna is notable as the place where Gödel, on August 26, 1930, first announced the incompleteness theorem to Carnap, Feigl, and Weismann. The members of the Vienna Circle had met there to prepare for the trip to the "Zweite Tagung für Erkenntnislehre der Exakten Wissenschaften," a satellite meeting to the congress of the German Society of Mathematicians organized by the Vienna Circle. This was where the famous symposium on the foundations of mathematics took place, with Carnap representing logicism, Heyting intuitionism, and von Neumann speaking for Hilbert's school of formalism -- the contributions are reprinted in Benacerraf's anthology Philosophy of Mathematics. From Carnap's diary: "6-1/2 9 [6pm to 8:30pm] Cafe Reichsrat ... preparations for the trip to Königsberg. Gödel's discovery: incompleteness of the system of Principia Mathematica ... difficulties of the consistency proof."  In February 1930, Gödel and Tarski discussed logic here during the latter's first visit to Vienna.

The Reichsrat no longer exists, and the only picture that's around shows just the top of one of its doors (from Jimmy Schimanovich's photo gallery).

The window atop the door, columns, and stucco match the entrance to the Konditorei Sluka at Rathausplatz 8, and presumably on the basis of this it's long been believed that the Reichsrat used to be located where the Sluka is now. But the Sluka has been around since 1891, which led Paul Raymont to speculate that it expanded into the Reichsrat's space after the latter closed down. In 2010, Karlis Podnieks noticed that on the other side of the main driveway to Rathausplatz 8 there's another door that also looks like the one in the picture, and conjectured that the Reichsrat might have been located there. But Vienna's Kaffeehäuser were cavernous establishments and also almost all located at corners. So I asked Karl Sigmund, co-editor of Kurt Gödel: The Album and creator of the Gödel Exhibition, for help, and he suggested to check the phone book!  And indeed, Adolph Lehmann's allgemeiner Wohnungs-Anzeiger : nebst Handels- u. Gewerbe-Adressbuch für d. k.k. Reichshaupt- u. Residenzstadt Wien u. Umgebung gives the address for the Reichsrat as Stadiongasse 2.

The Café Reichsrat was thus located at the north-west corner of Stadiongasse and Reichsratsstraße/Rathauspark, and the archive picture probably shows the mid-block back entrance facing the Rathauspark identified by Podnieks. A bank now occupies the space:

If you go visit, do have a coffee and cake at the Sluka!  I also made a map for all you Gödel pilgrims.

And here is some background reading:

John W. Dawson, Jr., Karl Sigmund, 2006. Gödel’s Vienna. The Mathematical Intelligencer 28(3), 44-55

For an almost complete list of people and places from the time of the Vienna Circle, consult:

Volker Thurm, 2003. Wien und der Wiener Kreis: Orte einer unvollendeten Moderne: Ein Begleitbuch, Vienna: facultas.wuv / maudric

A group of researchers in philosophy, psychology and mathematics are requesting the assistance of the mathematical community by participating in a survey about mathematicians’ philosophical intuitions. The survey is here: http://goo.gl/Gu5S4E. It would really help them if many mathematicians participated. Thanks.

The Special Session on "The Place of Logic in Computer Science Education" took place at the Logic Colloquium on Tuesday. It was well attended and, I think, overall a successful session.  The newly-formed ACM Special Interest Group on Logic and Computation (SIGLOG) was represented by its chair Prakash Panangaden. He stressed the importance of logicians … Continue reading The Place of Logic in Computer Science Education Followup

So there will be a student party at the Summer of Logic. Help me crowdsource logic/math/CS/AI tracks, preferably danceable. Ideas? Pet Shop Boys - He Dreamed of Machines Turing Machines - Slave to the Algorithm My Robot Friend - Robot High School Super Furry Animals - Fuzzy Logic Daniel Avery - Drone Logic Scooter - … Continue reading Summer of Logic Dance Party

More sad news, via the Studia Logica list: We sadly inform that Professor Joachim Lambek (Jim for friends) passed away on June 23, 2014, at 2:00 p.m. in Montreal. Joachim Lambek was born in Leipzig on December 5, 1922. His parents moved to Leipzig from a small town near Krakow (Poland). In the late 1930-ties … Continue reading Joachim Lambek (1922-2014)

So while everyone is following the World Cup, I'm getting excited about the FLoC Olympic Games to be held at the Vienna Summer of Logic this year.  Still doing my research to pick favourites, but here are some of the disciplines:

• Answer Set Programming (ASP) Model & Solve, divided into single- ("Men's") and multi-processor ("Women's") competitions.
• Automated Theorem Proving, with events in Typed Higher-order Theorems, First-order Theorems (with/without arithmetic, with/without identity), etc.
• Term Rewrite System Confluence, with events in First-order and Conditional Term Rewrite Systems Confluence as well as Certification of Confluence Proofs
• Boolean Satisfiability Solving is the biggest event with two separate competitions, plus a competition in MAXSAT.
• Quantified Boolean Formulas has events in QBF Solving, Preprocessing, and Certification.
• Hardware Model Checkers compete in Single safety, Liveness, and Deep Bound.
• Web Ontology Language (OWL) reasoning competitions will be held in Consistency Checking, Classification, and Realisation

plus a few others.  There will even be live viewing and a medal ceremony!

Fees go up tomorrow! http://vsl2014.at/registration/

Very sad news today: Grisha Mints has died.  He was born June 7, 1939 in Leningrad (now St. Petersburg). He received his education in mathematics at Leningrad State University under N. A. Shanin, and held positions there, at the Steklov Institute in Leningrad, and then, from 1980-1991, at the Estonian Academy of Science in Tallinn.  … Continue reading Grigori Mints, 1939-2014

Here's a simple way to pretty-print documentation included as comments in a source file (I'm mainly interested in LaTEX code), with or without the intervening code.  It's useful if you don't want to bother with a more complicated solution such as LaTeX's docstrip + ltxdoc.  It uses the ubiquitous bash tools grep and cut (available … Continue reading Simple Way to Document Code with Markdown, grep, and pandoc

Just came via the proof theory mailing list. I'm wondering why the ASL is not mentioned along with the EATCS, EACSL, and KGS. 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 … Continue reading SIGLOG Launches

The Arthur Prior Centenary Conference will be held at Balliol College, Oxford, on 21–22 August 2014, to celebrate the work of Arthur Norman Prior (1914-1969). Prior was a Fellow of Balliol and famous for his contributions to logic, ethics and metaphysics, but most of all he is known as the founder and principal inventor of … Continue reading Arthur Prior Centenary Conference, August 21-22, 2014

Ergo is a new general philosophy journal, open access, licensed under CC, with an innovative editorial model and triple-blind review.  Their first issue with four papers was published today, the papers are discussed on topic-appropriate blogs. Read the report on submissions, turn-around times, etc., by the editors Jonathan Weisberg and Franz Huber here. First issue: … Continue reading Ergo Publishes First Issue, Report

Within the VIDI project ‘The Roots of Deduction’ led by Catarina Dutilh Novaes, the Faculty of Philosophy of the University of Groningen is advertising a 12-month post-doc position, to commence in January 2015 or shortly thereafter. Given the broad scope of the project, candidates with a number of different backgrounds will be considered, as long … Continue reading Post-doc in Groningen: The Roots of Deduction

Bored by small powers of 2? You can now play 2048, but with large cardinals instead. For the long version, you have to get all the way to 0=1. Fork by Chris Le Sueur, h/t David Schrittesser

The SEP finally has an entry on Jan Łukasiwicz, by Peter Simons: Jan Łukasiewicz (1878–1956) was a Polish logician and philosopher who introduced mathematical logic into Poland, became the earliest founder of the Warsaw school of logic, and one of the principal architects and teachers of that school. His most famous achievement was to give … Continue reading SEP Entry on Łukasiewicz

Helmut Veith and I are organizing a special session at the Logic Colloquium in Vienna.  The panelists will be Byron Cook (Microsoft Research), Alexander Leitsch (University of Technology Vienna), Prakash Panangaden (McGill University), Nicole Schweikardt (Goethe-University Frankfurt am Main). The abstract copied from the ASL Committee on logic Education page: Logic has been called the … Continue reading The Place of Logic in Computer Science Education

Wow. Learn something new every day. a) BASIC just turned 50 years old four days ago. b) You know who invented BASIC? John G. Kemeny, student of Alonzo Church, and the guy who's credited with first defining the now-standard notion of truth in a model! (Kemeny was apparently also a great president at Dartmouth, opening … Continue reading Did You Know Who Invented BASIC!?

Please add your favorite Frege joke in comments (or tweet @RrrichardZach with #fregejokes hashtag). Doesn't have to be good. In fact, just any logic joke is fine.

Check out the funded doctoral program in logic in computer science! http://logic-cs.at/phd/ TU Wien, TU Graz, and JKU Linz are seeking exceptionally talented and motivated students for their joint doctoral program LogiCS. The LogiCS doctoral college focuses on interdisciplinary research topics covering (i) computational logic, and applications of logic to (ii) databases and artificial intelligence … Continue reading Funded PhD Positions in Vienna (Logic in CS)

The LaTeX package bussproofs.sty for typesetting natural deduction/sequent calculus proofs is nifty especially for its nice alignment of sequents.  By contrast to the proof.sty package, it doesn't allow you to typeset missing parts of a proof, though. proofs.sty has the \deduce command for that; it typesets vertical dots instead of a horizontal inference line. I … Continue reading bpextra: entire deductions in bussproofs.sty