The purpose of this repository is to formally prove the Hoffman-Singleton theorem.
Warning
The proof still has some sorry
s. PRs are welcome!
If the question is "why formalize?", refer to this 1. If the question is "why formalize the Hoffman-Singleton theorem?", then the reasons are:
- It is often used as an example in books related to combinatorics 2 3.
- An unsolved problem is related 4.
- I'm interested in formalizing a proof that uses multiple areas of math.
- It is a beautiful result!
Footnotes
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Patrick Massot, Why formalize mathematics? ↩
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Laszlo Babai and Peter Frankl, Linear Algebra Methods in Combinatorics, ver. 2.2, pp. 26-29. ↩
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Donald Knuth, The Art of Computer Programming, Vol. 4A, pp. 7. ↩
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Vance Faber, Jonathan Keegan, Existence of a Moore graph of degree 57 is still open. ↩