Timeline for Is there a version of inclusion/exclusion for vector spaces?
Current License: CC BY-SA 3.0
19 events
| when toggle format | what | by | license | comment | |
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| Jul 18 at 18:45 | answer | added | Sivakanth Gopi | timeline score: 1 | |
| S Nov 16, 2015 at 23:09 | history | suggested | Tacet | CC BY-SA 3.0 |
Madjax added, removed `
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| Nov 16, 2015 at 22:43 | review | Suggested edits | |||
| S Nov 16, 2015 at 23:09 | |||||
| Feb 6, 2015 at 16:23 | answer | added | Amir Asghari | timeline score: 2 | |
| Feb 6, 2015 at 15:53 | answer | added | Peva Blanchard | timeline score: 8 | |
| Jun 1, 2010 at 17:01 | answer | added | Vladimir Dotsenko | timeline score: 20 | |
| Jun 1, 2010 at 16:28 | answer | added | M T | timeline score: 39 | |
| Jun 1, 2010 at 15:56 | comment | added | Andrea Ferretti | Indeed it is one of the favourite wrong common beliefs on MO mathoverflow.net/questions/23478/… | |
| Jun 1, 2010 at 15:52 | comment | added | Andrea Ferretti | As pointed out in comment 5, the formula expressed in this post is not correct, already for $3$ vector spaces. Indeed the naif extension of the principle of inclusion-exclusion to vector spaces is false! | |
| Jun 1, 2010 at 15:22 | comment | added | user6479 | unapologetic.wordpress.com/2008/07/24/… | |
| Mar 12, 2010 at 23:14 | history | edited | Noah Snyder | CC BY-SA 2.5 |
Changed the title so that it contains the question
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| Mar 12, 2010 at 22:32 | answer | added | Peter Shor | timeline score: 32 | |
| Mar 10, 2010 at 23:11 | comment | added | Kevin Buzzard | The example already kicking around (the spaces generated by v,w,v+w vs the spaces generated by e1,e2,e3) already shows that dim(A1+A2+A3) cannot be computed from the dimensions of sum_{i in I}A_i for I running through all the proper subsets of {1,2,3}, and cap_{i in I}A_i for all I. So what is left of this question? Isn't the answer "if you only allow dim(sum_{i in I}A_i) etc then there's no formula, and if you allow more general things then the answer is that it's dim(A1+A2+A3)". | |
| Mar 10, 2010 at 20:04 | comment | added | Jonas Meyer | To those who haven't seen it, this is a redo of mathoverflow.net/questions/17702. Most of the wording here is copied from Yemon's comment there. | |
| Mar 10, 2010 at 19:07 | comment | added | Theo Johnson-Freyd | For the record, QY's link outlines the inclusion-exclusion principle (IEP), claiming it works for vector spaces, but the comments DS refers to point out that when the subspaces are not in general position, IEP fails. | |
| Mar 10, 2010 at 18:08 | comment | added | Yemon Choi | Nice to see my words get a second airing... ;) | |
| Mar 10, 2010 at 17:42 | comment | added | David E Speyer | See also the comments to the post Qiaochu links; the original post is not correct. | |
| Mar 10, 2010 at 17:38 | comment | added | Qiaochu Yuan | unapologetic.wordpress.com/2008/07/24/… | |
| Mar 10, 2010 at 17:28 | history | asked | mingming | CC BY-SA 2.5 |