All LogBlog Posts

Two months ago, Blogger turned off FTP publishing on blogs, which meant I couldn't update LogBlog anymore.  It's taken a while, but the blog has now moved.  Well, I managed to import all the old posts into Drupal, the CMS we use at the University of Calgary and which generates the rest of my site.  I still need to fix the URLs, add archive pages, get the blogroll to display, etc., but at least I can post again.  Your feed reader should be automatically redirected to the new feed, but if it isn't, here's the URL:

http://www.ucalgary.ca/rzach/rss.xml

If you find any broken links, disappeared images, commenting weirdness, etc., do let me know!

If you see this, I probably don't have to tell you the new URL for the mainpag, but in any case, here it is:

http://www.ucalgary.ca/rzach/blog/

Here are my slides from my PM@100 talk.

Just up on the SEP, by Yaroslav Shramko and Heinrich Wansing, an entry on truth values.

Happy Ada Lovelace Day!

Rózsa Péter (1905-1977) was a Hungarian mathematician and early contributor to the theory of (primitive) recursive functions. She received her PhD in 1935 from (what is now) Eötvös Loránd University in Budapest. Her fellow student Laszlo Kálmár had introduced her a few years earlier to the then brand-new work of Gödel, and she proceeded to study the class of (primitive) recursive functions first clearly defined by Gödel in his 1931 incompleteness paper. In a number of articles in the 1930s, she laid the groundwork for the study of hierarchies of sub-recursive functions and clarified the notion of primitive recursive function. I'll just mention four of her contributions on the subject: In her paper, "Über den Zusammenhang der verschiedenen Begriffe der rekursiven Funktion" (Math. Ann., 1935) she showed that course-of-values recursion and nested recursion can be reduced to ordinary primitive recursion. In "Konstruktion nichtrekursiver Funktionen" (Math. Ann., 1935), Pétér simplified and expanded on Ackermann's work, and proved that there are multiply recursive but not-primitive recursive functions. In "Über die mehrfache Rekursion" (Math. Ann., 1937), she studied multiple recursion in more detail and showed that the hierarchy of k-recursive functions is proper. In "Zusammenhang der mehrfachen und transfiniten Rekursionen" (JSL, 1950), she proved the equivalence of k-fold recursion and transfinite recursion along ω^k. Her early work on primitive recursive function theory is set out in her monograph, Rekursive Funktionen (1951), translated into English as Recursive Functions (1967). She also wrote a popular book on mathematics, Playing with Infinity, which was translated into 14 languages.

Pétér was barred from teaching in 1939 due to her Jewish heritage, but obtained positions at the Budapest Teacher's College in 1945 and at her alma mater in 1955. She was the first female mathematician to be elected to the Hungarian Academy of Sciences. She retired in 1976.

Women in Science (San Diego Supercomputer Center)
Biographies of Women Mathematicians (Agnes Scott College)
MacTutor History of Mathematics Archive

If you have access to Oxford Scholarship Online, you can now read Mancosu's excellent collection The Philosophy of Mathematical Practice via the internets.

Robin Milner died on March 20. He was a leading theoretical computer scientist who developed the LCF theorem prover, the ML programming language, and introduced the π-calculus. He was founding director of the Laboratory for Foundations of Computer Science at the University of Edinburgh and then Professor of Computer Science at Cambridge. Milner was a Fellow of the Royal Society, a Fellow of the ACM, and winner of the Turing Award.

From today's mini-AIR:

The Oscillating Humans Project, announced here, is searching for a living specimen - an exemplar - of an oscillating human.

DEFINITION: For purposes of the project, an Oscillating Human is someone who consistently, repeatedly, over many years, expresses opinions directly opposite to opinions he or she expressed earlier, always ignoring and/or denying the existence of copious, easily found clear documentation of the earlier opinions.

From Abstruse Goose:

Sorry for the long silence...

You may have heard by now, but in case you haven't: The Group in Logic, Language, and Information at King's College is threatened by "budget cuts": looks like the administration is just willfully destroying it by firing several faculty.

Information and links to protest sites etc. given here.

Leila Haapaaranta's collection The Development of Modern Logic came out earlier this year. It's a handy one-volume compendium to the history of logic in the modern era (full disclosure: I have an article in it). The price tag might still be a bit steep: $150, although that buys you over 1,000 pages of scholarship in an attractive hardback volume!