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Richard Zach

@rrrichardzach@mathstodon.xyz
mastodon 4.7.2
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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

0 Followers
0 Following
10 Posts
Joined October 31, 2022
Website:
https://richardzach.org/
Open Logic Project:
https://openlogicproject.org/
Github:
https://github.com/rzach
Interests:
#Logic #ProofTheory #HistMath #PhilSci #ComputingHistory
Open post
Richard Zach @rrrichardzach@mathstodon.xyz
· 4mo ago

Patti Smith is a fan of Moritz Schlick

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Open post
Richard Zach @rrrichardzach@mathstodon.xyz
· 7mo ago

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

DRAFT: A Formally Verified Constructive Proof of the Consistency of Peano Arithmetic Using Ordinal Assignments
arXiv.org

DRAFT: A Formally Verified Constructive Proof of the Consistency of Peano Arithmetic Using Ordinal Assignments

Gentzen'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

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Open post
Richard Zach @rrrichardzach@mathstodon.xyz
· 7mo ago

So turns out Cantor stole the proof that \(\mathbb{R}\) is uncountable from Dedekind https://www.quantamagazine.org/the-man-who-stole-infinity-20260225/

The Man Who Stole Infinity | Quanta Magazine
Quanta Magazine

The Man Who Stole Infinity | Quanta Magazine

In an 1874 paper, Georg Cantor proved that there are different sizes of infinity and changed math forever. A trove of newly unearthed letters shows that it was also an act of plagiarism.

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Open post
Richard Zach @rrrichardzach@mathstodon.xyz
· 5mo ago

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/

Daily Nous

Philosophers Elected to the American Academy of Arts & Sciences - Daily Nous

The American Academy of Arts & Sciences has announced its latest class of members, and several philosophers are a part of it. They are: Julia […]

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Open post
Richard Zach @rrrichardzach@mathstodon.xyz
· 7mo ago

Places of the Vienna Circle. An online exhibit by the City of Vienna library and the Institute Vienna Circle https://online-ausstellungen.wienbibliothek.at/wiener-kreis/en/overview/

online-ausstellungen.wienbibliothek.at

Wien und die Wissenschaftliche Weltauffassung – Orte des Wiener Kreises – Die beliebte Ausstellung hier zum Nachschauen

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Open post
Richard Zach @rrrichardzach@mathstodon.xyz
· 5mo ago

PhD and Postdoc positions in UnAxiMa: Uncovering the Axioms of Mathematics

The FWF Emerging Fields project UnAxiMa (Uncovering the Axioms of Mathematics) is offering up to 12 postdoc positions and up to 12 PhD positions at TU Wien and the University of Vienna, Austria. The goal of the 5-year project is to explore the axioms of mathematics taking into account aspects of mathematical logic (in particular, set theory, computability theory, and reverse mathematics), complexity theory, automated theorem proving, and philosophy. The project is jointly led by six principal investigators:

Juan P. Aguilera (TU Wien),

Vera Fischer (University of Vienna),

Laura Kovács (TU Wien),

Sandra Müller (TU Wien),

Michael Pinsker (TU Wien), and

Georg Schiemer (University of Vienna).

UnAxiMa is looking for highly motivated and creative candidates, and in particular encourage female researchers to apply. The applicants should have a strong background in at least one of the following fields: mathematical logic, theoretical computer science, universal algebra, or philosophy of mathematics. For the PhD positions the requirements are a Master's degree or equivalent in mathematics, computer science, or philosophy. For the postdoc positions the requirements are a PhD or equivalent in mathematics, computer science, or philosophy. Successful candidates will be based at either TU Wien or University of Vienna, but will collaborate with all of the 18-30 team members intensively.

https://www.unaxima.com/careers

UnAxiMa

Careers — UnAxiMa

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Open post
Richard Zach @rrrichardzach@mathstodon.xyz
· 10mo ago
Replying to
"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!
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Open post
Richard Zach @rrrichardzach@mathstodon.xyz
· 15mo ago

Preparing for Fall 2025

Most of the Open Logic textbooks have seen lots of changes from the versions currently available in hardcopy, so it's time to refresh those to Fall 2025 editions. These will incorporate all the corrections reported by readers since at least 2023 and in many cases going back to 2020 or earlier. Sets, Logic, Computation is seeing the least changes; basically just minor corrections.

https://openlogicproject.org/2025/06/25/preparing-for-fall-2025/

Preparing for Fall 2025
Open Logic Project

Preparing for Fall 2025

Most of the Open Logic textbooks have seen lots of changes from the versions currently available in hardcopy, so it’s time to refresh those to Fall 2025 editions. These will incorporate all t…

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Open post
Richard Zach @rrrichardzach@mathstodon.xyz
· 15mo ago

RIP Robert Woodrow

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

mathmatters.cms.math.ca

Remembering Robert Woodrow – CMS – Math Matters

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