Timeline for Does Taranovsky's system of ordinal notations make sense?
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
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| Feb 16, 2018 at 9:09 | answer | added | Boris Dimitrov | timeline score: 8 | |
| Feb 22, 2017 at 21:07 | comment | added | Wojowu | Taranovsky's page has been updated some time ago with some proofs (not to mention the overall revisions which have happened over the years). I would love to see this question revisited, but I'm afraid the notation has still not received enough attention to have been independently analysed... | |
| Mar 12, 2013 at 0:52 | comment | added | Deedlit | I've analyzed one of Taranovsky's notations (the one currently under "Degrees of Recursive Inaccessibility") and I believe that most of his evaluations of his ordinals are correct; in particular, the notation C(C(2, 0, 0), 0) does seem to be the ordinal for Pi-1-1 transfinite recursion, or psi(Omega_Omega_Omega...). So even this early notation is quite strong. However, it does seem that his notation for second-order arithmetic is simpler than purportedly much weaker notations from Rathjen. So I don't know. My first doubts start to creep in when he talks about Pi-n reflection for n > 3. | |
| Jan 14, 2013 at 15:41 | answer | added | Timothy Chow | timeline score: 14 | |
| Jan 14, 2013 at 1:26 | history | asked | Gro-Tsen | CC BY-SA 3.0 |