Are you an emacs user? If so, have you heard of org mode? It’s a note-taking, project planning, organizational tool for emacs that uses LaTeX, and is GPL’ed. A while ago, I tried writing a small script in emacs lisp to do something like what you describe. Using emacs/org-mode as an interface has lots of advantages for me, including the fact that my emacs is already open all the time, and that all files used by emacs/org-mode are standard ascii text.

Any interest in working on such a thing together?

-Rod

Zotero looks like a very interesting program and certainly answers a lot of my needs: and it already supports MathSciNet, which should be more than sufficient for a mathematician. It is almost (if not more) as suitable as Mendeley. But my main problem with Mendeley is not only that it is closed source, but that it has too many features for me, and is not specific to mathematicians. It is important to me that the program I use has roughly exactly the number of features I want, works without a database, so that I can use grep to search through metadata, and be an independant program (I have a [limited] attraction to minimality). However, I will be glad to recommend Zotero to people in need.

Can we be expecting an AUR package in the near future? 😉

Then I think I misquoted the paper: I updated my post accordingly.

Thanks. But Dehornoy’s article only proves that the function is not provably total in Primitive Recursive Arithmetic, which is significantly weaker than Peano Arithmetic. For example, the Ackermann function is not primitive recursive, but its totality is provable in PA.

I gave a link to an article of P. Dehornoy which gives an idea of why it is so: it roughly says that if you could prove that the period goes to infinity, you would have to manipulate integers so large that no reasoning in terms of elementary arithmetic could possibly generate them, which is a contradiction.

“The annoying fact is that it is not possible to prove using elementary arithmetic techniques (Peano arithmetic) that this period can go over 16. Actually, this non-existence of proof can be rigorously proved.”

Could you give a reference to this unprovability result? Thanks a lot!

Je viens de commencer à étudier le livre de Darboux sur les courbes et surfaces algébriques. N’ayant pas pratiqué la géométrie projective, je surfais donc pour me tuyauter sur les points cycliques et autres créatures étranges du CP2.

Bravo pour ton article, concis, compétent, clair.
Bravo aussi pour ta page.

Si tu peux me recommander des lectures je t’en serai reconnaissant.

Quel est le sujet de ta thèse?

Bon courage.

Claude