Timeline for What non-standard model of arithmetic does Hofstadter reference in GEB?
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
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| Dec 23, 2023 at 2:54 | vote | accept | Dave Pritchard | ||
| Sep 18, 2018 at 11:03 | comment | added | Bjørn Kjos-Hanssen | @ EmilJeřábek maybe he figured it was close enough to true | |
| Sep 18, 2018 at 8:09 | comment | added | Emil Jeřábek | I guess you may well be right, but then the quote does not make sense. (The additive reduct of a nonstandard model of arithmetic cannot be isomorphic to a recursive nonstandard model of $\mathrm{Th}(\mathbb N,+)$, and likewise for multiplication. This is true not just for PA, but also for very weak subtheories of arithmetic–essentially for all that are known not to have nonstandard recursive models in the first place.) Perhaps Hofstadter is just confused. | |
| Sep 18, 2018 at 7:33 | history | answered | Bjørn Kjos-Hanssen | CC BY-SA 4.0 |