Richard Zach

Richard Zach

@richardzach.org

Logician, historian and philosopher of logic, mathematics, and computability Copied to @richardzach.org on Bluesky. Follow @ap.brid.gy so I can follow you back [bridged from https://mathstodon.xyz/@rrrichardzach on the fediverse by https://fed.brid.gy/ ]

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Richard Zach reposted

Richard Zach
@richardzach.org

New (interactive) HTML edition of forall x: Calgary Hexuan "Ricky" Huang (University of Cambridge) has created an interactive online edition of forall x: Calgary. Like our own HTML version, it should help make forall x more accessible. While our version is designed for use in courses as merely […]

mathstodon.xyzOriginal post on mathstodon.xyz

Richard Zach reposted

Richard Zach
@richardzach.org

New forallx Fitch proof editor & checker Daniyal Akif, a math undergrad student at UT Austin, has updated Kevin Klement's old Fitch proof editor and checker. If you're learning or teaching natural deduction from forall x: Calgary, it may be useful to you. New features include: Support for […]

mathstodon.xyzOriginal post on mathstodon.xyz
Richard Zach
@richardzach.org

New (interactive) HTML edition of forall x: Calgary Hexuan "Ricky" Huang (University of Cambridge) has created an interactive online edition of forall x: Calgary. Like our own HTML version, it should help make forall x more accessible. While our version is designed for use in courses as merely […]

mathstodon.xyzOriginal post on mathstodon.xyz
Richard Zach
@richardzach.org

Philosopher of mathematics (and my Doktorvater) Paolo Mancosu elected to the American Academy of Arts & Sciences! https://dailynous.com/2026/04/23/philosophers-elected-to-the-american-academy-of-arts-sciences/

dailynous.comPhilosophers Elected to the American Academy of Arts & SciencesThe American Academy of Arts & Sciences has announced its latest class of members, and several philosophers are a part of it. They are: Julia Driver, University of Texas at Austin Melissa S. Lane, Princeton University Jane Maienschein, Arizona State University Paolo Mancosu, University of California, Berkeley James Owen Weatherall, University of California, Irvine David B. Wong, Duke University Gideon Yaffe, Yale University Lea Ypi, London School of Economics The full list of new members is here. The American Academy of Arts & Sciences is a learned society founded in 1780 by John Adams, John Hancock, and other Founding Fathers of the United States. You can learn more about it here. Induction ceremonies for new members will take place in Cambridge, Massachusetts, in October 2026. The post Philosophers Elected to the American Academy of Arts & Sciences first appeared on Daily Nous.
Richard Zach
@richardzach.org

Aaron Bryce and Rajeev Goré have formalized Gentzen's consistency proof for PA in Coq/Roqc https://arxiv.org/abs/2603.00487 This finishes an attempt by Morgan Sinclaire https://scholarworks.boisestate.edu/cgi/viewcontent.cgi?article=2662&context=td

arxiv.orgDRAFT: A Formally Verified Constructive Proof of the Consistency of Peano Arithmetic Using Ordinal AssignmentsGentzen's 1936 proof of the consistency of Peano Arithmetic was a significant result in the foundations of mathematics. We provide here a modified version of the proof, based on Gödel's reformulation, and including additional details and minor corrections which are necessary to definitively prove the well-foundedness of the cut-elimination argument in a constructive environment. All results have been verified using the Coq theorem prover. NOTE TO READERS 26 February 2026: this is a draft which we had intended to submit to the Journal of Automated Reasoning with no particular time-line in our minds as the work was completed as part of Aaron's honours project at ANU in 2023. For that reason, we have used the Springer style files. We are putting it on arxiv as there appears to be some interest in this work as indicated by a post to https://proofassistants.stackexchange.com/questions/6462/how-far-is-gentzens-consistency-proof-of-peano-arithmetic-from-being-formalized in early February 2026. The Coq code is available here: https://github.com/aarondroidbryce/Gentzen/tree/master
Richard Zach
@richardzach.org

"Again" because this happened already once in 2008, when all editors resigned and founded the Review of Symbolic Logic. But that's not diamond open access while the new Philosophical Logic is!

Richard Zach
@richardzach.org

RIP Robert Woodrow https://mathmatters.cms.math.ca/en/article/remembering-robert-woodrow/

mathmatters.cms.math.camathmatters.cms.math.ca# Remembering Robert Woodrow Feature June 20, 2025 Issue Feature June 2025 (Vol. 2, No. 24) Issue Contents June 20, 2025 Issue : Vol. 2, No. 24 Feature Remembering Robert Woodrow CMS Meetings 2025 CMS Winter Meeting, Dec 5-8 | Save the Date! 2025 CMS Winter Meeting | Call for Education Sessions 2025 CMS Winter Meeting | Call for Scientific Sessions Announcements International Congress of Mathematicians | July 23 - 30 , 2026 — ICM Call for Proposals: BIRS-MATRIX Tandem Workshop (November 22-27, 2026) Proceedings A: Mathematical theory and applications of multiple wave scattering 2025 CMS Summer Ottawa Math Camp | Registration Now Open Calls for Nominations Call for Nominations: 2026 David Borwein Award | Deadline November 15, 2025 Call from the International Prize Committee — Javad Mashreghi Call for Nominations: 2026 Research Prizes | Deadline September 30, 2025 Call for Nominations: Editor-in-Chief (EIC), Crux Mathematicorum | Deadline July 15, 2025 CMS Student Committee Connect with us on Discord! — Student Committee of the CMS The Canadian Mathematical Society (CMS) is deeply saddened to announce the unexpected passing of Dr. Robert Woodrow on June 10, 2025, shortly after returning to Calgary from the CMS Summer Meeting. He was deeply engaged in every facet of the academic community throughout both his career and retirement. Dr. Woodrow was involved with the CMS for over 45 years, serving in many capacities and most recently, and for over ten years, as the Chair of the Canadian Open Mathematics Challenge (COMC). He was a pillar whose dedication, insight, and kindness left an enduring and profound impact on all of us. Members of our community have shared their heartfelt memories of him: “ _Robert Woodrow was a true asset to the CMS and a dedicated member since 1981. His commitment was further demonstrated through his invaluable contributions to the Board of Directors and numerous committees._ _Robert dedicated the last decade of his efforts specifically to competitions and the student committee, particularly as a pivotal chair of the COMC committee. He generously invested countless hours in this competition, through proctoring and rigorously vetting exams, leading the COMC committee, and providing exceptional leadership for our largest math competition._ _Robert will be truly missed and remembered fondly by all staff and everyone who had the privilege of working with him. We will miss his dedication and unwavering enthusiasm for math competitions. We’ll also deeply miss his presence at CMS Meetings; he was a truly dedicated champion of the CMS_.” – Dr. Termeh Kousha, Executive Director, Canadian Mathematical Society “ _Dr. Robert Woodrow was a very special colleague and a tremendous friend of the Canadian Mathematical Society. As a former Executive Director of the CMS, I was fortunate to work with Robert in many different ways. He was a member of the CMS for more than 45 years and he was always ready to help whenever asked. His tireless efforts, infectious personality, generosity and commitment to the work of the CMS was an inspiration to all. Of particular note was his service as Chair of the Canadian Open Mathematics Challenge Committee, the Faculty Advisor to the CMS Student Committee, a member of the CMS Advancement of Mathematics Committee and as the Olympiad Editor of Crux Mathematicorum. Robert was awarded the Society’s Distinguished Service Award in 2010 and appointed a CMS Fellow 2018. His dedication and unwavering commitment to the Society continued until only a few days before his untimely passing on June 10, 2025. The Society has lost one of its most respected and valued members and I have lost a remarkable friend. It is hard to imagine the CMS without Dr. Robert Woodrow. He will be greatly missed by all who knew him_.” – Dr. Graham Wright, Former Executive Director of the Canadian Mathematical Society “ _Robert was truly an extraordinary, kind and caring person, who spent his life to his last hours serving the mathematical community, in particular its younger members. His actions clearly came from his heart. I am extremely grateful to have had the honour to work with him and benefit from his wisdom and experience in administering the COMC and other competitions. He was very generous with his time and always willing to help ensuring each student was treated fairly. He clearly enjoyed what he did and it was a joy to work with him_.” – Dr. Dorette Pronk (Dalhousie), Chair, Math Competitions Committee “ _A gregarious host, a lively and generous table companion, a stimulating research collaborator, and a colleague with a decades-long dedication to math contests and other math enrichment activities: Robert was each of these, and in each case no-one could have asked for more._ ” – Dr. Bill Sands (University of Calgary) The CMS sends its heartfelt condolences to Dr. Woodrow’s family and friends. His absence leaves a void that will be deeply felt across our community, and his legacy of generosity, leadership, and unwavering dedication to mathematics will continue to inspire us for many years to come. **An extended tribute to Dr. Woodrow will be featured in the September issue of the _CMS Notes_. If you have photographs or personal memories you would like to contribute, please email them to ****communications@cms.math.ca****.** **For more information, please contact:** Dr. Claude Laflamme Professor Emeritus University of Calgary laflamme@ucalgary.ca| Dr. Bill Sands Professor Emeritus University of Calgary sands@ucalgary.ca| CMS Executive Office cms@cms.math.ca ---|---|--- Share on Facebook Share on email Post this on X/Twitter Instagram Send to printer

Richard Zach reposted

DougMerritt (log😅 = 💧log😄)
@dougmerritt.mathstodon.xyz.ap.brid.gy

@AmenZwa Logisim port to browser "using a version of OpenJDK that runs in WebAssembly" https://drs.software/blog/announcing-logisim/ https://logisim.app/ via https://mathstodon.xyz/@regehr@mastodon.social/114385140845729553

mathstodon.xyzamen zwa, esq. (@AmenZwa@mathstodon.xyz)4.58K Posts, 330 Following, 346 Followers · I am an ordinary man. So, I am unique up to isomorphism. 🇺🇸 JD ⊥ MSCS Ω BSEE 🇺🇦 Washington, DC

Richard Zach reposted

Ehud
@duhe.bsky.social

Truly remarkable stuff in this thread.

Dr Keith 🎃 Wilson@keithwilson.eu

Here’s a fun game: what actor, living or dead, would play your favourite or other philosopher in a popular biopic? I’ll go first: Anthony Hopkins as Socrates. #PhilosophyBiopics

Richard Zach reposted

philosophyblogs
@philosophyblogs.zirk.us.ap.brid.gy

Blog of the APA || Philosophy of Language, Landon D. C.Elkind https://blog.apaonline.org/2025/02/12/philosophy-of-language-landon-d-c-elkind/

blog.apaonline.orgPhilosophy of Language, Landon D. C.ElkindThis syllabus is designed for a course that introduces students to some issues in the philosophy of language. There are seven-ish units to the course: Free speech (Mill, Hornsby, Brison) Speech Acts (MacDonald, Austin, Strawson, Millikan) Implicature (Grice and Saul) Names for Fictional Characters (Thomasson and Sainsbury) Names Part 1 (Frege, Russell, Jones) Names Part…

Richard Zach reposted

Kevin Zollman
@kevinzollman.com

People often ask me what I think about the philosophical gourmet report (the most well-known ranking of philosophy departments). So, I thought it might be worthwhile to put together some thoughts on it. tldr: They are on the whole negative, but I think some positives get overlooked.

Richard Zach reposted

Kevin Zollman
@kevinzollman.com

In principle, I like the idea of having someone else write the abstract. I often think that other people summarize my views better than I do. This case reveals that LLMs are definitely not capable of that. (Maybe they will be one day?) And I can't fathom why they wouldn't run it by the author!

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