Android app doesn't render LaTeX content in comments
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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? Solve $[2^{(2^{403})}] = [a]$ in $\mathbb Z_{23}$ where $0 \le a < 23$. Solve $[2^{(2^{403})}] = [a]$ in $\mathbb Z_{23}$ where $0 \le a &lt; 23$.  I've tried to combine corollaries of Fermat's little theorem and various other methods to solve this, but have always been stuck. Are keywords in URLs good SEO or needlessly redundant? A coworker and I are locked in a debate over the value of SEO keywords in the URL of a page. She wants to change all the filenames of the HTML pages of a fencing company so they look like residential-home-chicago.html, contact-chicago-contractor.html, and so on. She is convinced that because Google highlights keywords in URLs in search results, that means that putting keywords here is more valuable.  My position is that these do not improve SEO, since Google doesn't seem to give keywords in the URL any more weight than keywords in the body of the page, and . In the meantime, they make it harder for me to find the pages I want when its time to edit them, and the site as a whole looks cheap and spammy.   suggests to me that yes, keywords in URLs are useful, but not superior, and that they are more useful for human readability than search engine rankings.  I'm looking for authoritative sources that support either position, not blog articles from SEO optimization companies trying to promote themselves. Story [novel, novella?] that featured faster-than-light or hyperdrive gained from observing distant drive use, also had a sentient star I have little recollection when I read this, but it started with people observing indications of some special engine use many lightyears away, and it led them to 'reverse-engineer' the traces to create their own drive.  Had the usual tropes of international crew-selection for first-voyage.  Somewhere in the travel, they encounter a sentient star or quasar.  When they get back hundreds/thousands of years later, they arrive to an uncaring Earth that no longer pursues space-travel. Java ReentrantReadWriteLocks - how to safely acquire write lock? I am using in my code at the moment a  to synchronize access over a tree-like structure.  This structure is large, and read by many threads at once with occasional modifications to small parts of it - so it seems to fit the read-write idiom well.  I understand that with this particular class, one cannot elevate a read lock to a write lock, so as per the Javadocs one must release the read lock before obtaining the write lock.  I've used this pattern successfully in non-reentrant contexts before.  What I'm finding however is that I cannot reliably acquire the write lock without blocking forever.  Since the read lock is reentrant and I am actually using it as such, the simple code  lock.getReadLock().unlock(); lock.getWriteLock().lock()  can block if I have acquired the readlock reentrantly.  Each call to unlock just reduces the hold count, and the lock is only actually released when the hold count hits zero.    EDIT to clarify this, as I don't think I explained it too well initially - I am aware that there is no built-in lock escalation in this class, and that I have to simply release the read lock and obtain the write lock.  My problem is/was that regardless of what other threads are doing, calling getReadLock().unlock() may not actually release this thread's hold on the lock if it acquired it reentrantly, in which case the call to getWriteLock().lock() will block forever as this thread still has a hold on the read lock and thus blocks itself.  For example, this code snippet will never reach the println statement, even when run singlethreaded with no other threads accessing the lock:  final ReadWriteLock lock = new ReentrantReadWriteLock(); lock.getReadLock().lock();  // In real code we would go call other methods that end up calling back and // thus locking again lock.getReadLock().lock();  // Now we do some stuff and realise we need to write so try to escalate the // lock as per the Javadocs and the above description lock.getReadLock().unlock(); // Does not actually release the lock lock.getWriteLock().lock();  // Blocks as some thread (this one!) holds read lock  System.out.println("Will never get here");   So I ask, is there a nice idiom to handle this situation?  Specifically, when a thread that holds a read lock (possibly reentrantly) discovers that it needs to do some writing, and thus wants to "suspend" its own read lock in order to pick up the write lock (blocking as required on other threads to release their holds on the read lock), and then "pick up" its hold on the read lock in the same state afterwards?  Since this ReadWriteLock implementation was specifically designed to be reentrant, surely there is some sensible way to elevate a read lock to a write lock when the locks may be acquired reentrantly?  This is the critical part that means the naive approach does not work. How can I integrate $\ln \left( x+\sqrt{1+x^2} \right) $? May I use a question mark in the middle of a sentence? Examples:  Would you like the drapes to be white? or perhaps something off-white? Would you like the logo to be centered? at the bottom? left off entirely? What does the Web.Config file do in the views folder of a MVC project Why is quantum entanglement considered to be an active link between particles? How can I require an optional Perl module if installed? I have Perl code which relies on Term::ReadKey to get the terminal width. My installation is missing this module, so I want to provide a default if the module isn't present rather than throw an exception. How can I conditionally use an optional module, without knowing ahead of time whether it is available. # but only if the module is installed and exists use Term::ReadKey; ...  How can I accomplish this? Calculating $\lim_{x\to0} \left\lfloor\frac{x^2}{\sin x \tan x}\right\rfloor$ Find $$\lim_{x\to0}  \left\lfloor\frac{x^2}{\sin x \tan x}\right\rfloor$$ where $\lfloor\cdot\rfloor$ is greatest integer function   I am a high school teacher. One of my students came up to ask this limit.  For $\lfloor\frac{\sin x}{x}\rfloor$, I have used $\sin x &gt; x$ using increasing decreasing functions.  I tried to prove $x^2 &gt; \sin x \tan x$ using increasing /decreasing  function but I am not getting it. Find the limit: $\lim_\limits{x\to 0}{\frac{\left(1+x\right)^{1/x}-e}{x}}$ Find the limit: $$\lim_\limits{x\to 0}{\frac{\left(1+x\right)^{1/x}-e}{x}}$$   I have no idea what to do, but I thought that this is the limit of the derivative of $f(x)=\left(1+x\right)^{1/x}$, as $x$ tends to 0. Any help? problems installing mathtools What are the uses of "using" in C#? User  answered the wonderful  question by mentioning the using keyword. Can you elaborate on that? What are the uses of using? How can I distribute a native executable for a Python program? Ubuntu 19.10 change desktop environment Precision of Coulomb's law Up to which precision has the coulomb law proven to be true? I.e.  if you have two electrons in a vacuum chamber, 5 meters appart, have the third order terms been ruled out? Are there any theoretical limits to measure the precision ( Planck's constant?). Obviously there are practical limitations ( imperfect vacuum, cosmic rays, vacuum fluctuation). Still, does anyone know what was the smallest amount ever correctly predicted by that law?    Edit : Summary  On the high end of the energy spectrum a precision of 10^-16 has been shown ( 42 years ago )  For electron point charges at large distances the law might brake down due to practical reasons.  For moving particles QED gives a correction to the law: Determining functions from specifications... my high school teacher asked this question today, and I am struggling to find an answer that will work. The question is outlined below:  Give an example of a cubic polynomial, defined on the open interval (-3,3), which reaches both its maximum and minimum values. View a man page in a specific section I wanted to access man pages for command chmod.  Command whatis chmod gave this output:  chmod (2)            - change permissions of a file  chmod (1)            - change file mode bits  But I was actually looking for chmod(2).  When I type man chmod, man pages for chmod(1) appears.   Both man chmod(2) and man 'chmod(2)' commands show error.   I tried running info coreutils 'chmod invocation', but output is some kind of documentation which doesn't look like a typical man page. More numbers between $[0,1]$ or $[1,\infty)$?