I recently tried to recompile my thesis that I wrote 5 years ago, but my figures and some biblatex prevent it. Here is an MWE for one of them:  \documentclass{standalone} \usepackage{tikz,ifthen,xcomment,amsmath,amsfonts} \usetikzlibrary{decorations.pathmorphing,decorations.pathreplacing,arrows,automata,patterns,positioning} \newcommand{\NN}{\mathbb{N}} \begin{document}  \begin{align*}      Y &amp;= X\\  X &amp;= \left\{    \tikz[scale=0.3,baseline={([yshift=-3pt]current bounding box.center)}]{     \draw[color=gray!30,fill=green](0,0) rectangle +(1,1);    },  \right\}\cup\bigcup_{n\in\NN}\left\{  \tikz[scale=0.3,baseline={([yshift=1pt]current bounding box.center)}]{   \draw[color=gray!30,fill=green] (0,0) rectangle (1,1);   \draw[decorate,decoration={brace}] (4,0) -- (1,0) node[midway,below=2pt] {$n$};   },  \right\}  \end{align*}  \end{document}   The error I get is the following:  ! Missing \endgroup inserted. &lt;inserted text&gt;                  \endgroup  l.18  \end{align*}   I managed to make a lot of other figures compile by adding [tikz] to the standalone class, but for this one which is sort of a hybrid it does not work.  Lastly, my version of texlive is 2017 and I'm pretty sure things were ok with 2015.
I was surprised to find that standalone package can not compile a document with an equation:  \documentclass{standalone} \begin{document} \begin{equation} % not working! F(V, T) = E(V) + D(T) \end{equation} \end{document}   Is there an option or some workaround that allows this? The current error is something like:   ! Missing $ inserted.   in line 4. (The idea of course is that the including (main) document can just \input the standalone without knowing if is going to be an equation or something else)
Does Stack Exchange use caching and if so, how? Java is the key here. I need to be able to delete files but users expect to be able to "undelete" from the recycle bin.  As far as I can tell this isn't possible.  Anyone know otherwise? I've tried to read and understand this:   As a test, since my layout is "Polish, programmer" in the /usr/share/X11/xkb/symbols/pl file I played with remapping the 'q' character to 'x', and it worked just fine.  But what I want, is to remap LWIN (Left Super) to Left Control.   So I tried this: I started editing /usr/share/X11/xkb/symbols/pc file, assuming this is the 'root' of all the other files. Commented out this line:  //key &lt;LWIN&gt; {  [ Super_L       ]   };   and added this one:  key &lt;LWIN&gt; {    [ Control_L     ]   };   and rebooted PC, with no success. I.e. LWIN + C, doesn't copy selected text in text editors to clipboard, instead it just produces the 'c' letter. In the terminal instead of stopping current programm it also just produces the 'c' letter.  Here is my config file:   When I try the xev command and then press the Left Control Key, I see this:  KeyPress event, serial 40, synthetic NO, window 0x5a00001,     root 0x7e, subw 0x0, time 1053321, (374,-259), root:(374,545),     state 0x0, keycode 133 (keysym 0xffe3, Control_L), same_screen YES,     XKeysymToKeycode returns keycode: 37     XLookupString gives 0 bytes:      XmbLookupString gives 0 bytes:      XFilterEvent returns: False  KeyRelease event, serial 40, synthetic NO, window 0x5a00001,     root 0x7e, subw 0x0, time 1053425, (374,-259), root:(374,545),     state 0x0, keycode 133 (keysym 0xffe3, Control_L), same_screen YES,     XKeysymToKeycode returns keycode: 37     XLookupString gives 0 bytes:      XFilterEvent returns: False   BTW. Ask ubuntu suggests me two links to similar questions, but they are old, and suggest using xmodmap, and afaik it's no longer correct answer on Ubuntu >= 16.04 (Xenial) and this is precisely the version I have.  BTW2. I would really like to avoid using apps like Xbindkeys, considering there is a built in solution, which I guess I almost understand, and already spent some time on trying to understand it. Integral of $\frac{1}{x^4+1}$ Just doing this for revision, seems much harder than it should be, should I use $x=\tan u$ ? Any help appreciated. Schema.org Type for Online Business Effect of space time relativity on the age of the universe? So we all heard about the twins paradox to explain einstein's time space relativity.  Wikipedia Quote :" In physics, the twin paradox is a thought experiment in special relativity involving identical twins, one of whom makes a journey into space in a high-speed rocket and returns home to find that the twin who remained on Earth has aged more. This result appears puzzling because each twin sees the other twin as traveling, and so, according to a naive application of time dilation, each should paradoxically find the other to have aged more slowly. "  So what if the universe has been travelling at varying speeds (increasing or descreasing), wouldn't this effect our measurements on age of the universe? using gb4e keeping interlinear glosses together on the same page I am using gb4e for several hundred interlinear glosses in my dissertation. Several of the examples span more than one page, that is, the vernacular and gloss will be on one page, while the free translation appears at the top of the next page.   How can I keep all three elements together on the same page? I often have subexamples (a, b, c) that don't need to stay together. That is, 1a can be on one page, and 1b on the next, as long as vernacular-gloss-free translation for each subpart stay together.  In the MWE below, the free translation is at the top of page 2, while the vernacular and gloss are at the bottom of page 1.  \documentclass[11pt,letterpaper]{article} \usepackage{lipsum} \usepackage{gb4e} \noautomath \begin{document} \lipsum[1-4] \begin{exe}     \ex \gll wuz x̃ũch it-ak xohish-em\\              1\textsc{sg.prn} bread eat-\textsc{inf} want.\textsc{prs}-1\textsc{sg}\\         \glt `I want to eat bread.'  \end{exe} \end{document}   A solution was proposed to a similar question (), but it requires me to manually look for what could be dozens of orphans throughout my dissertation (and doesn't work when applied to my example, since it still strands the FT). I would prefer a more elegant solution that takes care of the problem automatically. case insensitive find in mongodb for usernames in php Format timedelta to string How to work with Dried Mushrooms? I was recently given a bag of dried mushrooms and am unsure how to work with them.  What's the best way to use them? How do I create a D&D character correctly as a total newbie? I am Haitian, and traveling with a Haitian passport. I have to go to London with a work permit (tier 2 visa) on the 29th of July but I have 2 hour transit in Dublin.  Do I need a transit visa? Can I get it at the airport?  I also have a valid US visa. How do I set a featured image (thumbnail) by image URL when using wp_insert_post()? While looking through the , I noticed that there's no parameter in the array it requires which will allow me to set the 'Featured Image' for a post, displayed as the  in my theme.   I have looked into functions like , as suggested by Mr. Bennett, but this seems to be a relatively new addition to WordPress itself and the WordPress codex. As such, there aren't any sources that I can find which explain how the $thumbnail_id parameter should be acquired and supplied. If this really is the function to use, in what way could I provide it with a valid $thumbnail_id parameter when all I have is an image URL?  Thanks in advance! Everybody who is using Lightroom probably has seen this. After importing RAW files, Lightroom shows a preview, but contrast and color of the preview change after a few short seconds to a slightly different view.  For some users the change is small, for others the change is huge. Colors are different (read: wrong), contrast is off.  Rumor says this is happening only (more?) for Nikon users.  What is Lightroom doing here?  I'd guess that for the first preview, LR is showing the JPG preview file, which is embedded in the RAW file. Then after a moment, LR renders the RAW file itself to show it's own interpretation.  But why is this interpretation so different from the embedded JPG? How to search for email of a particular date from years ago in Gmail There are similar questions and several answers. I tried to follow the methods provided in the answers.  They did not work. So I am going to ask it again with more specifics.  I only knew the date of the email in the in-box in 2012 and the content of it but did not know the exact wording of the subject. Is it possible to find this email? Why does the volume of the unit sphere go to zero? The volume of a $d$ dimensional hypersphere of radius $r$ is given by:  $$V(r,d)=\frac{(\pi r^2)^{d/2}}{\Gamma\left(\frac{d}{2}+1\right)}$$  What intrigues me about this, is that $V\to 0$ as $d\to\infty$ for any fixed $r$.  How can this be?  For fixed $r$, I would have thought adding a dimension would make the volume bigger, but apparently it does not.  Anyone got a good explanation? How do I remove code duplication between similar const and non-const member functions? Let's say I have the following class X where I want to return access to an internal member:  class Z {     // details };  class X {     std::vector&lt;Z&gt; vecZ;  public:     Z&amp; Z(size_t index)     {         // massive amounts of code for validating index          Z&amp; ret = vecZ[index];          // even more code for determining that the Z instance         // at index is *exactly* the right sort of Z (a process         // which involves calculating leap years in which         // religious holidays fall on Tuesdays for         // the next thousand years or so)          return ret;     }     const Z&amp; Z(size_t index) const     {         // identical to non-const X::Z(), except printed in         // a lighter shade of gray since         // we're running low on toner by this point     } };   The two member functions X::Z() and X::Z() const have identical code inside the braces.  This is duplicate code and can cause maintenance problems for long functions with complex logic.    Is there a way to avoid this code duplication? I would like to show that the function $\frac{1}{x}$ is not uniformly continuous on $(0,1)$ using two approaches.   First Approach:   We have the fact that if a function $f$ is uniformly continuous on an open interval $(a,b)$, then the function $f$ is bounded on $(a,b)$. By using its contrapositive, since $\frac{1}{x}$ is not bounded on $(0,1)$, it is not uniformly continuous.  Second Approach:  Proof by definition. Note that the definition of non-uniform continuity is:  There exists an $\epsilon_0&gt;0$ such that for all $\delta&gt;0$, there exists $x,y \in (0,1)$ such that $|x-y|&lt;\delta$ but $|\frac{1}{x} - \frac{1}{y}| \geq \epsilon_0$.  Assume that $\delta &lt; 1$. Let $x = y + \frac{\delta}{2} \in (0,1), y &lt; \frac{\delta}{2} \in (0,1), \epsilon_0 = 1$. Then we have   $$|\frac{1}{x} - \frac{1}{y}| = |\frac{1}{y + \frac{\delta}{2}} - \frac{1}{y}| = \frac{\frac{\delta}{2}}{|y(y + \frac{\delta}{2})|} &gt; \frac{\frac{\delta}{2}}{(\frac{\delta}{2})(\delta)} = \frac{1}{\delta} &gt; 1 = \epsilon_0 $$  If $\delta \geq 1$, then let $\delta^{\prime} = \frac{1}{\delta}$ so that $\delta^{\prime} \leq 1$. The rest proceeds the same as above.   Question: Are my two approaches correct? I once saw watch a sci-fi movie or an episode of a tv series (not sure) in which:   Every police officer was a judge, and hence could act by themselves on the streets. Each "judge" had a gun, which appended their DNA to the bullet. This was used later in investigations about a crime scene, and I think was confidential before the trial was held. Only a judge could use the gun, try to use it and you've been electrified. Also the guns had a self-destruction feature. The main villain was an ex-judge who purchased and activated a very old "killer robot" which was a residue of a long-ended war. When a judge was exiled, they were given a copy of the book of law, and sent outside the city to enlighten the people outside cities.   Can you help me find it?  PS: It was difficult to select a title I'm trying to "add" an 3D object onto a photo. I have added the photo to the scene in three ways so far, but none of them render (eevee):   Camera > Background Images Empty a. Add > Empty > Image (Empty gets added to current Collection) b. Add > Image > Backround (Empty gets added to Scene Collection)   These all show up in the 3D View and I was able to align the camera and the object so its perspective matches the scene in the photograph. But when I Render the scene, I only see the object, not the background image.  For the latter, it's simple: Empties are not rendered at all. There are few questions about this, since 2.8 has changed how it handles background images. The most popular seems this one (it includes references to others):      But I seem not to be able to find a method to have the background image render.  Another method might be to use the Compositor (Nodes) to Mix or Alpha Over an Image with the Render Layers. But this does not give the same alignment as achieved with the background image (also this requires that the World background does not get rendered (Alpha channel); for Eevee, this can be achieved by checking Film>Transparent).  What other options are there?  Docs: