Timeline for "incidental" intersections of a complete graph in the plane
Current License: CC BY-SA 2.5
4 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Oct 22, 2010 at 11:27 | vote | accept | Brendan Foreman | ||
| Oct 21, 2010 at 12:35 | comment | added | Gerry Myerson | @Qiaochu, you are right, to get $n$-choose-4 you must arrange that no three lines meet at a non-vertex point. Of course, that's easily done; if three meet, just move one vertex a tiny bit. | |
| Oct 21, 2010 at 11:30 | comment | added | Qiaochu Yuan | This isn't enough; for example, if the vertices lie at the nth roots of unity then lots of edges will intersect at the origin. You need some kind of general position requirement. | |
| Oct 21, 2010 at 10:48 | history | answered | Gerry Myerson | CC BY-SA 2.5 |