From The Twelf Project
- January 17, 2015
- After a year of issues stemming from the age of our old server, twelf.org has been moved to a new machine. Some features, like Twelf Live and syntax highlighting, still only exist on the old site. Let Rob know about any other deficiencies in the new site.
- June 10, 2013
- Taus Brock-Nannestad, Chris Martens, and Carsten Schürmann to hold a Twelf Tutorial at CADE.
- October 26, 2012
- John Boyland's Twelf library is available on Github.
- September 2, 2011
- We've finally moved from twelf.plparty.org to twelf.org! All old links will continue to work through at least August 2013 (and they should actually continue to work indefinitely).
- March 19, 2011
- After many years of new features being added only to the subversion branch, Twelf now has a new official point release! Twelf 1.7.1 contains many fixes and new features that are documented on this site, and using any version of Twelf prior to 1.7 is highly discouraged. The "development" version of Twelf in the subversion repository remains quite stable and is also recommended. Go to the download page to get Twelf.
- September 1, 2010
- The Twelf Wiki has undergone an upgrade, and in the process code underlying the syntax-highlighing TwelfTag system has been substantially rewritten and simplified. However, this meant several deprecated-but-still-used options to the <twelf> tags now don't work and print error messages. Leave a note on Rob's talk page if you see any weird error messages around Twelf code.
- February 22, 2009
- Rob has a case study on lax logic that uses the admissibility of cut and identity show a sound and complete correspondence between two sequent calculus presentations of lax logic.
- October 1, 2008
- Carsten says: As a result of the work of some overly active system administrators at the ITU, the twelf mailing list was accidentally erased a few weeks ago. Since then I have tried to reconstruct the subscriber list with more or less success, but there are still some that I have missed. Therefore, if you haven't received any mail from the list lately, but you expect to be on it, please resubscribe under [http://mail.itu.dk/mailman/listinfo/twelf-list].
- September 19, 2008
- We are running a Twelf Tutorial co-located with POPL 2009.
- July 19, 2008
- January 28, 2008
- John took Rob's example to the next step and directly provided a bijection between a HOAS encoding of lambdas and natural numbers.
- October 4, 2007
- Rob posted a page on concrete representation based on a question by John about demonstrating a correspondence between HOAS and concrete term representations.
- April 25, 2007
- April 11, 2007
- If you think up some exercises while you're learning Twelf, add them to the intro tutorial.
- March 21, 2007
- Official launch day! Thanks to everyone who has contributed so far, and welcome to new visitors.
- March 16, 2007
- Dan has revised and expanded several of the tutorials, and written new ones on catch-all cases, numeric termination metrics, and hereditary substitution.
- March 14, 2007
- February 28, 2007
- The Twelf Project wiki now supports uploading SVG images! Check out the article on tabled logic programming for an example of the unnecessarily beautiful illustrations this allows.
February 24, 2007
January 25, 2007
- Rob has developed a beta build system that has source, Linux binary, and Windows installer versions of "CVS Twelf."
December 1, 2006
October 30, 2006
October 20, 2006
October 19, 2006
October 18, 2006
October 16, 2006
October 14, 2006
- An alpha version of "AJALF"-powered Twelf Live is online
- Dan has started the Ask Twelf Elf project providing Twelf help over email
October 13, 2006
October 9, 2006
- The TwelfTag system now allows for direct checking of code in the wiki.
- Carsten has added code proving various properties of Lily to the case studies.
October 5, 2006
September 30, 2006
- The wiki has been moved to its real home on the Moog server, and given a permanent domain name, twelf.plparty.org.
- A first draft of the non-technical quick introduction has been introduced for consideration.
September 28, 2006
- Substitution lemma — Dan Lee's thorough explanation of the different ways substitution lemmas are dealt with by Twelf.
- Twelf CVS — We have instructions from the Software page on downloading the development version of Twelf from the CVS repository. The CVS version of Twelf has undocumented features which are being described on the wiki, such as its capacity for working with holes in metatheorems.