Timeline for $M \oplus N$ is of finite type if $M,N$ are of finite type?
Current License: CC BY-SA 2.5
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 16, 2010 at 12:31 | vote | accept | Martin Brandenburg | ||
| Nov 15, 2010 at 21:41 | history | edited | Torsten Ekedahl | CC BY-SA 2.5 |
Added complete proof; deleted 2 characters in body
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| Nov 15, 2010 at 20:28 | comment | added | Kevin Buzzard | Aah---I see what I'm missing---the word "directed" :-) Very nice! | |
| Nov 15, 2010 at 20:23 | comment | added | Kevin Buzzard | I am totally confused. Let $V$ be a 2-dimensional vector space. Let $M$ and $P1$ and $P2$ be distinct one-dimensional subspaces. Then $V=P1+P2$ but $M$ is not $(M\cap P1)+(M\cap P2)$. What am I missing? | |
| Nov 15, 2010 at 20:19 | comment | added | Torsten Ekedahl | That's exactly the Ab5 axiom. | |
| Nov 15, 2010 at 20:17 | comment | added | Kevin Buzzard | Stupid question: how did you interchange the sum and the intersection with $M'$? | |
| Nov 15, 2010 at 20:15 | history | answered | Torsten Ekedahl | CC BY-SA 2.5 |