Unwanted space after \NewDocumentCommand vs. \newcommand
What is the use of percent signs (%) at the end of lines? (Why is my macro creating extra space?)
Why's &quot;what's up&quot; used as greeting among young people? It sounds like asking &quot;what is up there&quot;?  A: What's up? B: The sky. Inequality between $\ell^p$-norms What is the best way to dump entire objects to a log in C#? It seems that I'm missing something about this.  First of all, the series is convergent: $\lim_{n\rightarrow\infty}\frac{2^{-n-1} (n+1)^2}{2^{-n} n^2}=\frac{1}{2}$ (ratio test)  What I tried to do is to find a limit of a partial sum $\lim_{n\rightarrow\infty}S_n$ as follows: $S_n=\frac{\frac{1}{6} n (n+1) (2 n+1)}{\frac{1-\left(\frac{1}{2}\right)^n}{2 \left(1-\frac{1}{2}\right)}}$. Still, the limit is $\infty$ and I'm clearly doing something wrong. Is the "the ... the ..." construction governed by some grammatical rule? How to install software provided in software-center via terminal? Story about a sentient star system, in a 50s or early 60s anthology Story about a sentient star system, possibly in f&amp;sf anthology from 50s or early 60s. I know this is a long shot, but I hope someone will know of this story.  I believe it was called "Darkness or into the darkness". End of the story had it spinning off a galaxy, (possibly ours?). Query for list of attribute instead of tuples in SQLAlchemy Combining multiple textures with a white background I'd like to sort of "overlay" these shaders, but the only options are mix and add. Allow me to explain.  I made two images, both white background, one with red scribbles and one with blue scribbles, both 1920x1080. Image textures plugged into diffuse was my node setup. I want both scribbles to be added to the plane while the background stays the same color.  If I mix them I get the following:  The red and blue scribbles are now 50% dimmer than they would be on their own, and the white color hasn't changed in intensity.  If I add them I get the following:  The red and blue scribbles are still 50% dimmer than they normally would be (since the white background is being added over each). But the white background is now 2x brighter than normal.  Can I get a result where the white background is normal brightness and both the blue and red scribbles are at normal brightness? My WordPress website currently uses this custom permalink structure: %author%/%year%/%monthnum%/%day%/%postname%  In this case, %monthnum% instantiates numbered dates with a leading zero -- e.g., "09" for September. So, a sample URL might look like this: mywebsite.com/username/2012/09/12/post-name  Is there a function I can add or .htaccess change that I can make which will remove the leading zeros from my permalink stucture? So, using the example above, my URLs would ideally look like this: mywebsite.com/username/2012/9/12/post-name  Thank you! I've read up on WordPress' structure tags documentation (http://codex.wordpress.org/Using_Permalinks), but I can't find any solutions or plugins for the above-mentioned problem. XML attribute vs XML element At work we are being asked to create XML files to pass data to another offline application that will then create a second XML file to pass back in order to update some of our data. During the process we have been discussing with the team of the other application about the structure of the XML file.   The sample I came up with is essentially something like:  &lt;INVENTORY&gt;    &lt;ITEM serialNumber="something" location="something" barcode="something"&gt;       &lt;TYPE modelNumber="something" vendor="something"/&gt;     &lt;/ITEM&gt; &lt;/INVENTORY&gt;   The other team said that this was not industry standard and that attributes should only be used for meta data. They suggested:  &lt;INVENTORY&gt;    &lt;ITEM&gt;       &lt;SERIALNUMBER&gt;something&lt;/SERIALNUMBER&gt;       &lt;LOCATION&gt;something&lt;/LOCATION&gt;       &lt;BARCODE&gt;something&lt;/BARCODE&gt;       &lt;TYPE&gt;          &lt;MODELNUMBER&gt;something&lt;/MODELNUMBER&gt;          &lt;VENDOR&gt;something&lt;/VENDOR&gt;       &lt;/TYPE&gt;    &lt;/ITEM&gt; &lt;/INVENTORY&gt;   The reason I suggested the first is that the size of the file created is much smaller. There will be roughly 80000 items that will be in the file during transfer. Their suggestion in reality turns out to be three times larger than the one I suggested. I searched for the mysterious "Industry Standard" that was mentioned, but the closest I could find was that XML attributes should only be used for meta data, but said the debate was about what was actually meta data.  After the long winded explanation (sorry) how do you determine what is meta data, and when designing the structure of an XML document how should you decide when to use an attribute or an element? How to prevent a background process from being stopped after closing SSH client in Linux I'm working on a Linux machine through SSH (Putty). I need to leave a process running during the night, so I thought I could do that by starting the process in background (with an ampersand at the end of the command) and redirecting stdout to a file.  To my surprise, that doesn't work. As soon as I close the Putty window, the process is stopped.  How can I prevent that from happening?? I'm struggling to understand the difference between the standard error and the standard deviation. How are they different and why do you need to measure the standard error? Deriving Schrodinger equation from Klein-Gordon QFT with the definition $\psi(\textbf{x},t)\equiv \langle 0|\phi_0(\textbf{x},t)|\psi\rangle$ In the book "Quantum Field theory and the Standard Model" by Matthew Schwartz, , the position space wavefunction is defined as   $$\psi(x)=\langle 0|\phi(x)|\psi\rangle, \tag{2.82+2.83}$$  where $|\psi\rangle$ is any state in the Fock space. Then he uses the equations (i) $\partial_t^2\phi_0=(\nabla^2-m^2)\phi_0$ (i.e., the Klein-Gordon equation for the free massive scalar field $\phi_0(\textbf{x},t)$) and (ii) $[H,\phi_0]=-i\partial_t\phi_0$ to derive Eq. 2.85, in following 3 steps:  $$i\langle 0|\partial_t\phi_0(\textbf{x},t)|\psi\rangle=\langle 0|\int \frac{d^3\textbf{p}}{(2\pi)^3}\frac{\sqrt{\textbf{p}^2+m^2}}{\sqrt{2\omega_\textbf{p}}}(a_p e^{-ip\cdot x}-a^\dagger_p e^{ip\cdot x})|\psi\rangle\\ =\langle 0|\sqrt{m^2-\nabla^2}\phi_0(\textbf{x},t)|\psi\rangle.\tag{2.85}$$  This equation is used to successfully derive the Schrodinger equation in quantum mechanics for the state $\psi(\textbf{x},t)\equiv \langle 0|\phi_0(\textbf{x},t)|\psi\rangle$.   The first equality follows from differentiation of $\phi_0(x)$ w.r.t $t$. How does the second equality follow from the first? How are the inputs (i) and (ii) are utilized to derive the second equality from the first? Is it true that the operator $$i\partial_t\sim\sqrt{m^2-\nabla^2}~?$$ If yes, what is the use of doing the middle step? What are PPAs and how do I use them? I keep reading about  ('PPAs') and people answer questions with a link to a PPA. What's the best way to use these?     There are multiple valid answers for this question spanning over several versions of Ubuntu. For your convenience, an index of each is below. grep a file, but show several surrounding lines? My Applications are not showing after upgrading from Ubuntu 18.04 to 20.04 There are many red and black spots in my photos,what are those? Should we `enable` the User Systemd service `pulseaudio.service`? Interpret geometrically the equation The function $f$ is convex when:  $$f(tx+ (1-t)x', ty + (1-t)y') ≤  tf(x,y) + (1-t)f(x', y')$$  for all numbers $0≤t≤1$ and all pairs of points $(x,y)$ and $(x',y')$ in the domain of $f$ (the whole of $R^2$)  How would I interpret this geometrically? Also what is an example of a convex function whose graph is not a plane?