principia

Rewriting Principia Mathematica in Lean

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Rewriting Principia Mathematica in Lean

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Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 5:04:57 PM UTC.

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Observed mentions: 2025-04-25 18:49:30 UTC to 2025-04-25 21:09:53 UTC.

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Period	Start (UTC)	End (exclusive, UTC)	Mentions	Submissions	Comments
Apr 25, 18:00	2025-04-25 18:00:00 UTC	2025-04-25 19:00:00 UTC	1	1	0
Apr 25, 19:00	2025-04-25 19:00:00 UTC	2025-04-25 20:00:00 UTC	0	0	0
Apr 25, 20:00	2025-04-25 20:00:00 UTC	2025-04-25 21:00:00 UTC	0	0	0
Apr 25, 21:00	2025-04-25 21:00:00 UTC	2025-04-25 22:00:00 UTC	1	0	1

What Hacker News says

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hackandthink·Apr 25, 2025

I only see these very initial propositional theorems. Am I missing something, or has the project only just begun? https://github.com/ndrwnaguib/principia/blob/main/Principia/...

In Show HN: Formalizing Principia Mathematica using Lean

ndrwnaguib·Apr 25, 2025Submission

Show HN: Formalizing Principia Mathematica using Lean

This project aims to formalize the first volume of Prof. Bertrand Russell’s Principia Mathematica using the Lean theorem prover. Throughout the formalization, I tried to rigorously follow Prof. Russell’s proof, with no or little added statements from my side, which were only necessary for the formalization but not the logical argument. Should you notice any inaccuracy (even if it does not necessarily falsify the proof), please let me know as I would like to proceed with the same spirit of rigour. Before starting this project, I had already found Prof. Elkind’s formalization of the Principia using Rocq (formerly Coq), which is much mature work than this one. However, I still thought it would be fun to do it using Lean4. https://ndrwnaguib.com/principia/ https://github.com/ndrwnaguib/principia

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