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Oct 6, 2010 at 11:54 answer added David E Speyer timeline score: 10
Oct 6, 2010 at 8:57 history edited Bjørn Kjos-Hanssen
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Sep 6, 2010 at 14:52 vote accept C.S.
Aug 5, 2010 at 9:39 answer added Primoz timeline score: 2
Aug 5, 2010 at 8:30 answer added coudy timeline score: 2
Jul 31, 2010 at 19:58 history edited Charles Matthews CC BY-SA 2.5
downcase
Jul 31, 2010 at 19:58 answer added Tony Scholl timeline score: 8
Jul 31, 2010 at 19:08 history edited S. Carnahan CC BY-SA 2.5
Minor corrections.
Jul 31, 2010 at 18:24 comment added Robin Chapman If $G$ is a finite group then all its subgroups have finite index. What the statement should say is that if $H$ is a proper finite index subset of $G$ then $G\ne\bigcup_{g\in G}gHg^{-1}$ (the case of infinite $G$ readily reduces to the case of finite $G$). As Keith shows, this is not always true for subgroups of infinite index.
Jul 31, 2010 at 18:20 comment added Jim Humphreys Yes, the statement is out of focus: $gHg^{−1}$ is intended (and "infinite index case"). The natural starting point is to ask whether the proof for finite index breaks down. –
Jul 31, 2010 at 18:16 answer added KConrad timeline score: 23
Jul 31, 2010 at 18:15 comment added José Figueroa-O'Farrill There's something I don't understand here: do you perhaps mean $gHg^{-1}$ instead of $ghg^{-1}$?
Jul 31, 2010 at 18:05 history asked C.S. CC BY-SA 2.5