Timeline for Formal proof of Con(ZFC) => Con(ZFC + not CH) in ZFC
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
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| Sep 9, 2019 at 12:34 | comment | added | andrey bovykin | @EmilJeřábek I have so little experience with theories with limited coding techniques that I didn't dare to claim anything lower than ISigma_1. (But, at least for arithmetized completeness you need ISigma_1 to build the branch). You, people in Czechoslovakia, are masters of weak arithmetic proofs, so I'll trust you here. | |
| Sep 8, 2019 at 7:34 | comment | added | Emil Jeřábek | If you just chow syntactically that “$\mathrm{ZFC+\neg CH}\vdash\phi\implies\mathrm{ZFC}\vdash\|\phi\|=1$”, this argument can be formalized in weak fragments of arithmetic such as the theory $PV_1$ of polynomial-time functions. | |
| Sep 7, 2019 at 21:24 | comment | added | andrey bovykin | I agree with Yang RuiZhi. | |
| Jun 23, 2016 at 3:41 | comment | added | Ruizhi Yang | I wonder if these relative consistency results can be proved in $I\Sigma_1^0$ or PRA. The latter is presumed to be accepted by most finitists. | |
| Feb 11, 2012 at 2:28 | history | edited | Joel David Hamkins | CC BY-SA 3.0 |
Improved exposition; added 4 characters in body
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| Feb 11, 2012 at 0:46 | history | edited | Joel David Hamkins | CC BY-SA 3.0 |
added 87 characters in body
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| Feb 11, 2012 at 0:38 | history | answered | Joel David Hamkins | CC BY-SA 3.0 |