The mods at English Usage are intent on undeleting bad answers, even though I've retracted them. In trying to prune, they give suspensions. What are the rules on that? It's literally only a handful of answers, and of course the accepted answers remain untouched.
According to , the only restriction on self-deleting an answer is that you can't delete an answer that's been accepted.  But I've also heard of users getting in trouble for deleting (non-accepted) answers, and there's the CC-SA license to consider, so -- quite aside from what is technically possible -- my question is when it's permitted to delete your own answer.  Some cases to consider:   You now believe the answer is incorrect. Your answer is correct, but another answer covers the same territory better. You aren't satisfied with the quality/rigor of your answer, e.g. it's speculative and you didn't back it up (on a site that expects that). Something in the answer embarrasses you and you'd rather just make it go away. Your answer wasn't well-received by the community (whether that's "meh" or "make the rep bleeding stop please"). (I'm sure there are others; this isn't meant to be an exhaustive list.)   Does voting matter, either in absolute terms or in comparison to other answers?  For example, maybe it's ok to delete a lower-voted one but not the top-voted answer, or one with score > N??  There is a badge, Disciplined, for deleting your own post of score 3 or higher.  This tells me that it's sometimes ok to delete upvoted answers.  But I'm not sure how much policy we can infer from badges.  Could we have some clarification please?
Product of two cyclic groups is cyclic iff their orders are co-prime Say you have two groups $G = \langle g \rangle$ with order $n$ and $H = \langle h \rangle$ with order $m$. Then the product $G \times H$ is a cyclic group if and only if $\gcd(n,m)=1$.  I can't seem to figure out how to start proving this. I have tried with some examples, where I pick $(g,h)$ as a candidate generator of $G \times H$. I see that what we want is for the cycles of $g$ and $h$, as we take powers of $(g,h)$, to interleave such that we do not get $(1,1)$ until the $(mn)$-th power. However, I am having a hard time formalizing this and relating it to the greatest common divisor.  Any hints are much appreciated! is it problematic to cluster across two datacenters w/aag? In general is it problematic to cluster across two datacenters that are up to 15-miles apart?  For this one particular project the approach is the following?   2-Node Failover Cluster across two datacenters, one node per datacenter local SAN disks, no shared disks 'Node and FileShare Majority' at third location on-campus employ AAG, failover will be manual; asynchronous mode   Is anyone implementing something like this with success??!?  Thanks so much for the help!! I was wondering if it's possible to run an Ubuntu virtual machine using VirtualBox in background, I mean, without any window open.  The idea is to connect via SSH to the Linux host, that would be running in background.  Has anyone ever done something like this? Is it possible? How can I prove these are the adjoint operators? can anybody tell me which one of these is the correct one? I have been searching all over the internet but I have still got no answer.  Types of books Types of book How do I evaluate several n-th derivatives of a function at one point? How to distribute proprietary Mathematica code Multiple regression or partial correlation coefficient? And relations between the two I don't even know if this question makes sense, but what is the difference between multiple regression and partial correlation (apart from the obvious differences between correlation and regression, which is not what I am aiming at)?  I want to figure out the following: I have two independent variables ($x_1$, $x_2$) and one dependent variable ($y$). Now individually the independent variables are not correlated with the dependent variable. But for a given $x_1$ $y$ decreases when $x_2$ decreases. So do I analyze that by means of multiple regression or partial correlation?  edit to hopefully improve my question: I am trying to understand the difference between multiple regression and partial correlation. So, when $y$ decreases for a given $x_1$ when $x_2$ decreases, is that due to the combined effect of $x_1$ and $x_2$ on $y$ (multiple regression) or is it due to removing the effect of $x_1$ (partial correlation)? I noticed a peculiar behavior of my Ubuntu 13.04 (although possibly it's also present in previous versions): when my system freezes completely (I do not ask for troubleshooting this) so that even X does not respond to Ctrl+Alt+FX keys, the CapsLock toggle diode on my keyboard blinks (with frequency of ~1Hz), although the system is completely unresponsive.   What is the cause of this phenomena? Is it caused by some internal kernel mechanisms? Is this specific to Ubuntu (is it caused some custom Ubuntu additional software)? Does it has anything to do with HAL? What is the purpose of it? Can I customize this behavior on Ubuntu? problem with using loop inside the tabular environment What's the incentive to flag duplicates? I only say duplicates but I think this could be extended to several other flagging reasons. Since accepted answers/upvotes don't get reverted on questions I see people sometimes cut and paste the answer from a duplicate question without flagging as duplicate. In the end they can usually score a few upvotes and even an accepted answer.  Found this related question:   Seems to have a lot of popularity but nothing ever happened  Jeff on Dupes     Those arguing for “remove reputation from dupes” have no idea of the   Frankenstein monster you’d be creating.      That would be an awesome rep-denial tool for griefing others, first of   all.      Second, it creates a MASSIVE disincentive to participation — even if   you had no idea there were duplicates, you could be bushwhacked at any   time even if you contributed a fantastic answer. Oops sorry dupe!   Zero rep, buddy! Bzzzzt! Go away! Take your awesome answer elsewhere!      Incentives are fine, but penalties are an incredibly bad idea and   would actively hurt users and the network.   I guess this answers my question, even if I disagree with jeff. Prove that $\frac d {dx} x^n=nx^{n-1}$ for all $n \in \mathbb R$.   I saw some proof of $\frac d {dx} x^n=nx^{n-1}$ using binomial theorem, which is only available for $n \in\mathbb N$. Do anyone have the proof of $\frac d {dx} x^n=nx^{n-1}$ for all real $n$? Thank you. Is there a conventional wisdom to what gear a bike should be left in, when used infrequently? US doctor working in Tripoli wants me to open online account Which is faster/best? SELECT * or SELECT column1, colum2, column3, etc I've heard that SELECT * is generally bad practice to use when writing SQL commands because it is more efficient to SELECT columns you specifically need.  If I need to SELECT every column in a table, should I use   SELECT * FROM TABLE   or   SELECT column1, colum2, column3, etc. FROM TABLE   Does the efficiency really matter in this case? I'd think SELECT * would be more optimal internally if you really need all of the data, but I'm saying this with no real understanding of database.  I'm curious to know what the best practice is in this case.  UPDATE: I probably should specify that the only situation where I would really want to do a SELECT * is when I'm selecting data from one table where I know all columns will always need to be retrieved, even when new columns are added.   Given the responses I've seen however, this still seems like a bad idea and SELECT * should never be used for a lot more technical reasons that I ever though about. Is there a VB.NET-Like operator in C#? When does a .com domain become available after it expires? (With status clientTransferProhibited) This problem is from Romanian G.M. and although it is very short, it is also (I think) very hard. Let $x, y, z$ real non-negative numbers such that $x+y+z=3$. Prove that   $$27 \leq (x^2+2)(y^2+2)(z^2+2) \leq 44 $$  I didn't succeed in any of the inequalities, I only managed to find the equality cases ($x=y=z=1$ for the first one and one of them $3$ and the others $0$). Any hint/idea/solution is welcome. Adding related resources or hyperlinks in edits So, I've been rejecting the addition of resources/hyperlinks to posts simply because I had no idea that this was an acceptable practice.  Today, I was browsing through the edits page and saw:     Some common reasons to edit are:         to fix grammatical or spelling mistakes   to clarify the meaning of a post without changing it   to correct minor mistakes or add addendums / updates as the post ages   to add related resources or hyperlinks      Why is this an acceptable practice?  I can see adding links to official documentation, but the quality of outside resources is (potentially) subjective.  I see the merit in adding resources, but it seems to me that these additional resources should be placed in comments, not inserted into the post via an edit.  Anyone have thoughts on this? Lowering the throttling temperature in Windows 8 for a laptop