Timeline for Definability in pure-second order logic
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 13 at 6:30 | vote | accept | Lavinia Picollo | ||
| May 12 at 18:19 | comment | added | Joel David Hamkins | I don't view the ordinary SOL notion as "naive", as you say, but natural. | |
| May 12 at 17:45 | comment | added | Noah Schweber | That said, there is a nontrivial notion of "SOL without equality" - see here. | |
| May 12 at 14:42 | history | edited | Joel David Hamkins | CC BY-SA 4.0 |
added 72 characters in body
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| May 12 at 14:21 | comment | added | Joel David Hamkins | Note that $=$ is definable in second-order logic without $=$, since $a=b\iff\forall U\ (Ua\leftrightarrow Ub)$. | |
| May 12 at 13:06 | history | answered | Joel David Hamkins | CC BY-SA 4.0 |