Timeline for A doubt about the Gödel condensation lemma
Current License: CC BY-SA 4.0
20 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| S Jun 30, 2023 at 22:19 | history | suggested | C7X | CC BY-SA 4.0 |
Common terminology, typos
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| Jun 30, 2023 at 20:13 | review | Suggested edits | |||
| S Jun 30, 2023 at 22:19 | |||||
| Mar 4, 2022 at 12:49 | vote | accept | Ândson josé | ||
| Mar 4, 2022 at 12:37 | history | edited | Ândson josé | CC BY-SA 4.0 |
added 214 characters in body
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| Mar 4, 2022 at 12:31 | comment | added | Ândson josé | @FarmerS you are right, i think about sentences (formulas without free variables), but we need to considere all formulas, Thanks | |
| Mar 4, 2022 at 12:28 | comment | added | Farmer S | ...I'm not sure what your point is. We have a $\Sigma_1(x)$ assertion, about some $x\in V_{\omega_1}$, which is false over $V_{\omega_1}$ but true over $L_\alpha$. So $V_{\omega_1}\not\preccurlyeq_1 L_\alpha$. | |
| Mar 4, 2022 at 12:23 | comment | added | Ândson josé | " $x$ is not constructible" is a $\Pi_{1}$ sentence, so is not upward absolute like the $\Sigma_{1}$ formulas | |
| Mar 4, 2022 at 12:16 | comment | added | Farmer S | @NoahSchweber already showed where the mistake is. But regarding the edit, the relation $V_{\omega_1}\preccurlyeq_1 L_\alpha$ is not true (for any $\alpha$). For it requires that $V_{\omega_1}\subseteq L_\alpha$, hence $\alpha\geq\aleph_{\omega_1}$. But then for each $x\in V_{\omega_1}$, $L_\alpha\models$"$x$ is constructible" (a $\Sigma_1$ assertion about $x$), but there are $x\in V_{\omega+2}$ such that $V_{\omega_1}\models$"$x$ is not constructible". | |
| Mar 4, 2022 at 12:01 | history | edited | Ândson josé | CC BY-SA 4.0 |
added 389 characters in body
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| Mar 4, 2022 at 7:26 | history | became hot network question | |||
| Mar 4, 2022 at 1:26 | comment | added | Nik Weaver | @LSpice respectfully disagree. He isn't asking us to check his argument, he knows it's wrong. It seems like a reasonable mathematical question, and more importantly, may stimulate an answer from an expert that will be educational for us. | |
| Mar 4, 2022 at 1:25 | answer | added | Noah Schweber | timeline score: 13 | |
| Mar 4, 2022 at 0:21 | review | Close votes | |||
| Mar 8, 2022 at 3:03 | |||||
| Mar 4, 2022 at 0:20 | comment | added | Ândson josé | it's a problem my own | |
| Mar 4, 2022 at 0:04 | comment | added | LSpice | Is this an argument you found somewhere, or your own argument? Generally speaking, MO is not the appropriate space for checking your arguments. | |
| Mar 4, 2022 at 0:04 | history | edited | LSpice | CC BY-SA 4.0 |
Capitalise title, and other minor proofreading
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| Mar 3, 2022 at 23:36 | history | edited | Ândson josé | CC BY-SA 4.0 |
added 31 characters in body
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| Mar 3, 2022 at 23:34 | comment | added | Ândson josé | no, but we can take his transitive collapse and we have $M\in H(\aleph_{1})$ | |
| Mar 3, 2022 at 23:33 | comment | added | Wojowu | I don't think LS theorem guarantees $M$ is transitive. | |
| Mar 3, 2022 at 23:22 | history | asked | Ândson josé | CC BY-SA 4.0 |