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A module $M_{R}$ is called semi-artinian if every nonzero image of $M$ contains a simple submodule. Given $m\in M$ and $a_1,a_2,...$ in J(R). Why $ma_1a_2...a_{n-1}a_n=0$ for some $n\geq 1$.


(Edit by KennyTM: The above is OP's original question. The latest, completely changed question follows:)

if $R$ is regular what is the relation between:

1) J(R)

2) a left $R$-module has a projective cover?

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    Are you assuming R is noetherian? Not every semiartinian ring is T-nilpotent, that is, not every semiartinian ring is perfect.2010-12-14
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    Jack Schmidt@: We don't have extra condition.2010-12-14
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    Dear Arash, Where did this question come from? The argument that Mariano links to below is quite subtle, and so I'm curious at what level this question was assigned as an exercise (if indeed it was so assigned). Regards,2010-12-14
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    This question *completely* changed with the edit 3 mins ago. All the above comments and the answer below apply to the previous version, which can be read in the edit history.2010-12-14
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    @Arash: Why are you changing your questions in this manner? Something strange is happening to Arash's questions. I've flagged it for moderator attention (this is not the only question to which this has happened, and some of the previous edits were to silly questions)2010-12-14
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    I've started a meta discussion about these perplexing edits. http://meta.math.stackexchange.com/questions/1343/what-to-do-with-a-user-who-is-editing-existing-questions-and-replacing-with-entir2010-12-15
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    @Arash: Please visit the meta thread quoted above and explain why you made the radical edits to the questions. Current consensus is to roll-back your edits if you log in and don't address the problem, or don't log in by the end of today.2010-12-15

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