Timeline for About the rank of sets
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 25, 2013 at 7:51 | vote | accept | Gérard Lang | ||
| Nov 25, 2013 at 3:05 | comment | added | Rachid Atmai | Another ranking function which will accomplish what Joel's describes is Quine's pairing function: en.wikipedia.org/wiki/Ordered_pair#Quine-Rosser_definition | |
| Nov 24, 2013 at 19:01 | comment | added | Asaf Karagila♦ | True, Joel. Thank you for pointing that out. It's one of the places where the choice of encoding the pairs matters. | |
| Nov 24, 2013 at 17:56 | comment | added | Joel David Hamkins | If you use a flat pairing function (and your sets have infinite rank), you can reduce the $+3$ to $+1$, since in that case pairs do not increase rank. The $+3$ arises from the Kuratowski pairing function, which increases rank by $2$, but there are other pairing function that do not do this. | |
| Nov 24, 2013 at 16:37 | history | answered | Asaf Karagila♦ | CC BY-SA 3.0 |