Timeline for Which ordinals can be proof-theoretic ordinals of a reasonable theory?
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
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| Jun 23 at 8:21 | history | edited | Martin Sleziak | CC BY-SA 4.0 |
Included the title of the linked paper
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| S Jun 22 at 6:07 | history | suggested | C7X | CC BY-SA 4.0 |
Archived link
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| Jun 21 at 23:24 | review | Suggested edits | |||
| S Jun 22 at 6:07 | |||||
| May 13, 2020 at 16:05 | comment | added | user21820 | Alright thank you! | |
| May 13, 2020 at 13:50 | comment | added | Henry Towsner | @user21820: I'm not aware of any work trying to identify a theory precisely at that ordinal, nor a lot of current work on theories around it, so I doubt the situation has changed. | |
| May 13, 2020 at 6:03 | comment | added | user21820 | This table dated 2018 from an unknown source does not seem to list the large veblen ordinal as a proof-theoretic ordinal of any well-known system. Do you know of one now, since it's been a few years after your answer here? =D | |
| Oct 28, 2014 at 9:54 | comment | added | Wojowu | Thanks for the answer. From what I understand, ACA_0+Kruskal's theorem actually shows small Veblen ordinal well-founded, so its PTO would have to be strictly higher. I haven't read whole paper, so I might be wrong. | |
| Oct 27, 2014 at 22:45 | history | answered | Henry Towsner | CC BY-SA 3.0 |