Timeline for Selection problem in a collection of non-empty sets
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 11, 2016 at 18:56 | vote | accept | Dominic van der Zypen | ||
| Jan 11, 2016 at 16:43 | vote | accept | Dominic van der Zypen | ||
| Jan 11, 2016 at 16:43 | |||||
| Jan 11, 2016 at 16:20 | comment | added | Dominic van der Zypen | Sorry forgot criterion 1 | |
| Jan 11, 2016 at 16:18 | history | edited | Dominic van der Zypen | CC BY-SA 3.0 |
Forgot criterion 1
|
| Jan 11, 2016 at 16:15 | vote | accept | Dominic van der Zypen | ||
| Jan 11, 2016 at 16:19 | |||||
| Jan 11, 2016 at 14:26 | answer | added | David Bevan | timeline score: 3 | |
| Jan 11, 2016 at 14:25 | comment | added | bof | Of course $fa)\ne f(b)$ if $a\cap b=\emptyset$ so you could have just said $f$ is injective. Your selector can't exist if $|\mathcal F|\gt|X|$ so $\mathcal F=\binom X1+\binom X2$ is a counterexample if $|X|\ge2.$ | |
| Jan 11, 2016 at 9:32 | answer | added | Michael Renardy | timeline score: 5 | |
| Jan 11, 2016 at 9:17 | history | asked | Dominic van der Zypen | CC BY-SA 3.0 |