Suppose I ask a question which for one reason or another might have multiple valid answers. Maybe it's subjective, maybe it's a problem that could have multiple solutions, maybe there are just different ways to explain the same idea. I get some answers, and one is definitely the most helpful or useful to me, among other good answers. Should I accept it? Or is that bad, because I'd be declaring it to be the one true correct answer?  Note that I'm asking this in the context of StackExchange as a whole, where this is a more common occurrence than on SO. For example, on cooking, a lot of questions can have multiple good answers. Also, I know this is a historically contentious topic, but I'm looking for fresher answers, not pointers to questions from years ago, when we didn't know what to do with subjective questions and didn't have so many diverse sites.
I asked  that turned out to have multiple correct answers. How do I pick between them to determine which to accept?  All of the answers were different. They were not the same answer given multiple times.
Hyphen or no hyphen when modifying an adjective with a quantity? If $E[X|Y]=Y$ almost surely and $E[Y|X]=X$ almost surely then $X=Y$ almost surely Assume that $X$ and $Y$ are two random variables such that $Y=E[X|Y]$ almost surely and $X= E[Y|X]$ almost surely. Prove that $X=Y$ almost surely.   The hint I was given is to evaluate: $$E[X-Y;X&gt;a,Y\leq a] + E[X-Y;X\leq a,Y\leq a]$$  which I can write as: $$\int_A(X-Y)dP +\int_B(X-Y)dP$$ where $A=\{X&gt;a, Y\leq a\}$ and $B=\{X\leq a,Y\leq a\}$.  But I need some more hints. Punctuation with units I remember reading somewhere that if a unit is abbreviated as one character, there must not be a space between the number and the unit (e.g., 5m, 26K). If the unit is abbreviated as two or more Characters, there must be a space between the number and the unit (e.g., "10 km", "USD 5").   Can you please help me find the source again? Is this recommendation correct? How can I retrieve \thepage (or detect a page change) from Lua in LuaTeX? I am writing (contributing to) a LuaLaTeX package where a Lua function is used to generate images that are inserted in the LaTeX document.   One piece of information we need is the current page number to determine if we're on an odd or even page (I know that this is not that trivial, and I know about some strategies beyond \thepage). We set a Lua variable when we're still in the LaTeX part, and so far this works pretty well.  However, now it turns out that the sequence of images we create may be distributed on several pages, and we would really like to reflect that because our images may behave differently on odd and even pages.  Basically what we have is a series of  tex.print('\\includegraphics{something}\\par')   statements, executed in a loop within one Lua function.  Now the question: is there any way to either directly detect a page change between two such graphics or repeatedly retrieve the current page within such a loop?  All the solutions I have found for determining current odd or even state are in LaTeX itself. I know how to use \directlua to retrieve a value for use in LaTeX, but is there a way to do the opposite - retrieve a LaTeX value from within LUa?  Edit: to respond to TeXnician's comment and answer: When I modify the example code so it produces repetitions of paragraphs it seems that the page counter won't get updated within one Lua chunk:  \documentclass{article}  \newcommand\printluapage{%     \directlua{for i = 1, 60 do tex.print(tex.count['c@page'])          tex.print([[\par]]) end} }  \begin{document} \printluapage  New command  \printluapage  New command  \printluapage \end{document}   The page number is only updated with each new call of \printluapage. What harm can be done with a copy of one's passport? In one of the questions on this site, it was suggested the use of  to save a backup copy of your passport, in case you need to proof who you are if your original document is lost.   I like the idea, but what if someone gets access to your Dropbox folders and is able to acquire the copy of your passport.  The same goes for when you leave a copy of your passport at a hotel receptions desk. Once someone has the info printed on that copy, would that make it easier to steal your identity? I just came across this glowy ore, and my 'Sharp Silver Pickaxe' won't mine it. I'm playing on the PC version of Terraria, if that helps.  How do I mine the glowy ore block? What server control panels are available for Ubuntu Server? As a dedicated Ubuntu server or as a VPS, I am looking for a web control panel, something like cPanel which is something like a web administrator for a server.  I have not used any on Linux since I do everything through the terminal, but still want to know what I can use in the case I have to recommend Ubuntu Server with such an application installed. A question occurred to me when browsing SE this evening, just curious.  What specifies the inside of a 3D construct? If I have a hollow sphere, what's to say that the world isn't the inside, and the center of the sphere isn't the outside. Picture the Asylum in the Hitchhiker's Guide to the Galaxy series, if you have read that.  Additionally, if the inside of a 3D object is defined as what is smaller than the outside, what happens when there is a a sphere with a volume equivalent to 51% of the universe? Why is Cat5/Cat5e Ethernet cable rated 100MHz? As the questions says, is there any specific reason why Ethernet cable is rated 100MHz?  For a 100Mbps Ethernet the data rate is 100Mbps, and the baud rate is 125Mbaud, because of the specific line coding that it uses. What is the relationship between 125Mbaud rating of data transfer and 100MHz rating of cable?  Thank you. I tried to create a script by echo'ing the contents into a file, instead of opening it with a editor  echo -e "#!/bin/bash \n /usr/bin/command args"  &gt; .scripts/command   The output:     bash: !/bin/bash: event not found   I've isolated this strange behavior to the .  $ echo ! !    $ echo "!" bash: !: event not found  $ echo \#! #!  $ echo \#!/bin/bash bash: !/bin/bash: event not found    Why is bang causing this?   What are these "events" that bash refers to?     How do I get past this problem and print "#!/bin/bash" to the screen or my file? I think we need a button that says Edit and Close added to the Review Close button options.  Many of these closed posts will be around forever (and should be, closed should not just be a path to deletion), so they need editing.  If I edit it now it goes away, with the only option being a back click to get back to the review, and then click into the post and edit it.  We have an Edit and Reopen button, so this would fit in just fine. In natural language parsing, what is the feature function? I'm working in the area of natural language processing, to be specific I'm reviewing the parsers that take advantage of data-mining techniques.   I've read an introduction to natural language processing, specifically the  by Della Pietra and others. In that paper, the authors explain that features are indicator functions that take into account certain aspects of the text. The problem is that this aspects affect the maximum entropy function.  In the case of parsing, I have problems understanding the concept of features. For parsing one must have:   Two sets, $X$ for the sentences and $Y$ for the parses For each sentence $x \in X$, one must have the N-best list of candidate parses; denoted $GEN(x) \subset Y$. Training samples $(x_j,y_j)$. The $x_j$ are sentences and the $y_j$ are parses. And a feature mapping $\Phi(X,Y)$ that maps each pair (x,y) to a vector of feature values.   The problem of parsing will consist of finding the weight vector such that the following expression is minimized  $$ -\sum log P(y_j|x_j,w) + \lambda ||w||_1 $$  where   $$ P(y_j|x_j,w) = \frac{exp \{w^T \Phi(x_j,y_j)\}   }{ \sum_{u \in GEN(x)} exp\{ w^T\Phi(x_j,u) \}  } $$  My question is, what are the features in this case? Some codified version of the parsing tree? Are the features a statistical concept?  I will also appreciate any bibliography that can be useful in tackling this issue.  UPDATE: I've talked to a professor and he had just told me that the features are obtained after doing a classification algorithm based on the parse-tree. Do you know what kind of classification is done with the parse tree? IBM Slack links broken Does anyone know where I can find working Slack invite links to any of IBM's Slack pages? The Slack links on  are all broken. Thank you. how I can draw an skew cylinder (rotate around x axis) and fill it (in 3D tikz)? I want to create a scratch-card-like effect in new Unity UI's new Image tag.  I know it's possible with setPixels, but that's prohibitively expensive on mobile devices.  Something like this:    I'd like the user to be able to drag on any part of the image to "scratch off" the top layer and reveal the content underneath it.  How can I do this? Finding files by only knowing extension? How do I run an executable using Lua? Create a tar archive split into blocks of a maximum size I need to backup a fairly large directory, but I am limited by the size of individual files. I'd like to essentially create a tar.(gz|bz2) archive which is split into 200MB maximum archives. Clonezilla does something similar to this by splitting image backups named like so:  sda1.backup.tar.gz.aa sda1.backup.tar.gz.ab sda1.backup.tar.gz.ac   Is there a way I can do this in one command? I understand how to use the split command, but I'd like to not have to create one giant archive, then split it into smaller archives, as this would double the disk space I'd need in order to initially create the archive. Why isn't Google Chrome available in the Software Centre? About the localization of a UFD I was wondering, is the localization of a UFD also a UFD?    How would one go about proving this? It seems like it would be kind of messy to prove if it is true.  If it is not true, what about localizing at a prime? Or what if the UFD is Noetherian?