Timeline for meaning of "the singletons of $\Gamma$ are a basis for $\Gamma$"
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
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| Mar 21 at 15:51 | comment | added | Rupert | I'm afraid I only have a hardback copy of the notes. I appreciate Gro-Tsen's discussion. | |
| Mar 21 at 12:43 | comment | added | Gro-Tsen | I think this is supposed to mean that every nonempty set in class $\Gamma$ contains ($\supseteq$) a singleton in class $\Gamma$. But it could also conceivably mean that every nonempty set in class $\Gamma$ contains ($\ni$) a real in class $\Gamma$. This “basis” terminology is abominable, and totally at odds with the meaning of “basis” in other parts of mathematics; but the general idea is that $B$ being a “basis” for $P$ means $(\exists x.(P(x))) \Rightarrow (\exists x\in B.(P(x)))$. | |
| Mar 21 at 11:55 | comment | added | Alessandro Codenotti | could you link those notes if they are available online? | |
| Mar 21 at 11:14 | history | asked | Rupert | CC BY-SA 4.0 |