I got Yosemite via the Apple Beta Program. I installed Yosemite on a separate partition which I had created for the purpose specifically. Now I want to reclaim my 50 GB by deleting the partition. I have already set my startup disk to my original Mavericks partition.   So, if I launch Disk utility in Mavericks and delete the Yosemite partition, will my Mac still boot?   PS: I am not looking to uninstall just yet, but I'm running low on space and might need to get some space back soon enough (before Yosemite gets stable and I get the upgrade).
I have installed the developer preview for Yosemite.  Huge mistake. Everything in my workspace is broken.  I don't have any sort of backup image. I was wondering if I could re-download Mavericks and run the installer - would that effectively downgrade me back to Mavericks?
mv : not found when executed from script that modifies PATH variable I have this in my script. But is returning an error. If I execute the command in the console works fine  ./script.sh[16]: mv: not found [No such file or directory]   I want move some files what starts in T353 from one folder to another. REMOTE_PATH is /tmp/ and PATH is my working directory  cd $REMOTE_PATH mv T353* $PATH #this is the line 16   If I make mv /tmp/T353* . works fine. Draw Lewis structures like a book I want to draw a Lewis structure as in the picture. I tried to do with chemfig but does not perform the separation of the points and a minus in the superscript. Is the product of symmetric positive semidefinite matrices positive definite? I see on Wikipedia that the product of two commuting symmetric positive definite matrices is also positive definite. Does the same result hold for the product of two positive semidefinite matrices?  My proof of the positive definite case falls apart for the semidefinite case because of the possibility of division by zero... How can I prevent my text object from flickering? I have two raster files that are the same cell size but I cannot get them to align properly. (I want the black to line up with the pink)    When creating the black raster file (from using polyline to raster), I imported the pink raster in the Snap Raster section in the Environments setting. I thought that Snap Raster was supposed to make it line up?  Am I doing something wrong or is it a bug in Arc (I remember reading that this was a problem about two years ago), and if it is a bug is there a work around?  I have also read there is a Raster Shift, but I'm not sure what to enter in the X Coordinate and Y Coordinate. Since I only want the black raster to shift down, I know that the X Coor = 0 and the Y Coor should be negative something, but what are the units?  Thanks. Why are RSA key sizes almost always a power of two? I know that other bit sizes are possible, e.g. this HTTPS server seems to have a 9000 bit key , but it's very rare that one sees a key not of size 1024, 2048, 4096, etc. bits in common usage - what is the reason for this? Is it just customary, or is there a cryptographic advantage? Open Safari / Google Chrome developer tools programmatically from JavaScript I want to have a page-filling and -breaking longtable, so I decided to try xltabular. Unfortunately xltabular seems to screw up the booktabs rules in the normal tabular environments, see:  \documentclass{article} \usepackage{booktabs, xltabular} \usepackage[active,tightpage]{preview} \PreviewEnvironment{tabular} \begin{document} \begin{tabular}{ccc}     \toprule     col1 &amp; col2 &amp; col3 \\     \midrule     row 2: &amp; more and moooooooooooore &amp; test \\     \bottomrule \end{tabular} \end{document}     Not loading xltabular resolves the issue.  Did I miss some package option or some incompatibilities? Is there a better package than xltabular which doesn't break booktabs?  (I am using TeXLive 2019 and compile with lualatex)    EDIT (by Skillmon)  I reduced the bug to the following MWE (which doesn't make much sense on its own), it looks like booktabs tries to be smart detecting something, but fails badly.  \documentclass{article} \usepackage{longtable} \let\xltabular\relax \usepackage{booktabs}  \begin{document} \begin{tabular}{ccc}     \toprule     col1 &amp; col2 &amp; col3 \\     \midrule     row 2: &amp; more and moooooooooooore &amp; test \\     \bottomrule \end{tabular} \end{document}   It seems to suffice that longtable is loaded and \xltabular is defined (even if it's just \relax). Listings: text highlighting based on prefix How can I apply different styles to keywords depending on their prefix?  Here is some sample code:  (-2,0,0) (2,1,1) op-registerbox !box1 ;box1 /Blue op-setproperties   I'd like to typeset   words starting with ! and ; in color red, words starting with / in color green, words starting with cp- in bold.   So far, this is what I've got:  \lstdefinelanguage{XX} { basicstyle=\small\sffamily\fontseries{c}, emphstyle=\underbar, keywordsprefix=[2]{/}, alsoletter={/}, keywordstyle=\textbf, keywordstyle=[2]\color{green}, morekeywords={op,registerbox, ...}, morestring=[b][\color{green}]", columns=flexible, escapechar=\%, numbersep=6pt, numberstyle=\scriptsize }   I'm aware that only one keywordsprefix can be defined at the moment: specifying more than one class of prefix (keywordsprefix=[2]{/}) is currently not supported. I'd like to avoid having to list all the words that match my description into morekeywords. Is that possible? How? What happens if I use RAM of a faster speed than the CPU supports? Probability of asymmetric random walk returning to the origin Consider the random walk $S_n$ given by $ S_{n+1} =  \left\{   \begin{array}{l}     S_n+2 &amp; \text{with probability $p$}\\     S_n - 1 &amp; \text{with probability $1-p$}   \end{array} \right. \ $  Assume that $S_0 = n &gt;0 $. What is the probability of eventually reaching the the point $0$?  Seems that the probability for this must be less than one; since it is not symmetric, it is not guaranteed to reach the origin if $p&gt;0.5$. It also seems like the positive starting value not being at the origin matters too, but I'm not sure how to compute the probability of eventually reaching the origin. It is well known that compactness implies pseudocompactness; this follows from . I know that the converse does not hold, but what is a counterexample?  (A  is a topological space $S = \langle X,{\mathfrak I}\rangle$ such that every continuous function $f:S\to\Bbb R$ has bounded range.) Why does lightning emit light? What exactly is causing the electric discharge coming from the clouds to emit light while traveling through the air. I've read and thought about it a little but with my current knowledge I cant really figure what is happening at a subatomic level. In other words, what causes the emission of photons during lightning. What I want to know is, is there some sort of collisions taking place that produces the photons we see, or is it some other interaction that is causing it?. I don't know too much about particle physics, I've only read a couple of pages in the Introduction to Elementary Particles by Griffihts. So if you could keep the answer simple then that would be great. Changing an element's ID with jQuery I need to change an element's ID using jQuery.    Apparently these don't work:  jQuery(this).prev("li").attr("id")="newid" jQuery(this).prev("li")="newid"   I found out that I can make it happen with the following code:  jQuery(this).prev("li")show(function() {     this.id="newid"; });   But that doesn't seem right to me. There must be a better way, no? Also, in case there isn't, what other method can I use instead of show/hide or other effects? Obviously I don't want to show/hide or affect the element every time, just to change its ID.  (Yep, I'm a jQuery newbie.)  Edit I can't use classes in this case, I must use IDs. Is it possible to load a TikZ library locally? Importing an .obj file and nothing is showing I've been looking all over for a proper explanation of how to delete photos from the device (nexus 5) to reclaim some space, while being sure that the pictures are still in the Google+ backup. Unfortunatley i have not found one, other than "wild claims" it works somehow, while other say it does not. Plus deleting photos via the Pictures app actually warns you (now?) that it will delete the backed up copies too. Do i have to delete them in the Gallery app?  I did delete some photos recently, and i was quite sure they ware still backed up (still showed up on the Google+ website) but looking now i see they are in the trash in the device.  Is there really no way to be able to know for sure if the pictures are backed up savely while i can delete them from the device?  Alternatively i'm also open for alternative solutions to this problem, or i just go back to the "good old copy and paste when plugging the phone". Is there a way to use the formatter that comes with eclipse, outside of eclipse?  I would like to format some java files using my formatter.xml file that I have configured using eclipse.  Does anyone have any code examples that would allow me to do this?  I would also like to use this standalone, so the specific jars that are used would be nice. I want to open a file for reading, the C++ way. I need to be able to do it for:   text files, which would involve some sort of read line function. binary files, which would provide a way to read raw data into a char* buffer. This might seem a stupid question but why do Ethernet cables have 8 wires? Cat5 cables were just using 4 of the 8 wires, so only 4 are actualy 'needed'. Why not 12 or 16 wires?