See . PHP syntax highlight is clueless about namespaces:    First letter of a class name in a root namespace should not be black. Could this be updated? I know namespaces aren't most popular feature of PHP, but they are quite important one.
I noticed that sometimes my code gets highlighted in different colors when rendered.   What is syntax highlighting? How does it work? Why isn't my code being highlighted correctly? How do I report a bug or request a new language? How do I use syntax highlighting? What languages are currently available on Stack Exchange?
Get the cartesian product of a series of lists? Find and replace text within multiple files In C#, I want to initialize a string value with an empty string.  How should I do this?  What is the right way, and why?  string willi = string.Empty;   or  string willi = String.Empty;   or  string willi = "";   or what? Prove that there exists disjoint open subsets $U,V$ of $X$ such that $x \in U$ and $B \subseteq V$. Let $B$ be a compact subset of a metric space $X$. Let $x \in X \setminus B$. Prove that there exists disjoint open subsets $U,V$ of $X$ such that $x \in U$ and $B \subseteq V$.   Is this an existence proof? If yes, do I get to define $U,V$? Travelling from India to canada via Dubai and London. Do I need a transit visa I am travelling to Calgary from Delhi. I have an Air India flight from Delhi to Dubai then British Airways flight from Dubai to London and Air Canada flight from London to Calgary. My query is "Do I require a transit visa." Plz help as I am travelling in four days Let $\displaystyle f$ be differentiable, $\displaystyle f(x)=0$ for $|x| \geq 10 $ and $g(x)=\sum_{k \in \mathbb Z}f(x+k).$ Add custom command in the open with dialog? In earlier versions of Ubuntu (10.10-) there was an option in the "open with" tab in the properties window, to add a custom command to open a file. However, this is no longer the case in Ubuntu 11.10. Is there any way that I can add these file type associations with a command of my choice rather than the applications detected by the system. App version: 1.0.35 Device: Nexus 7 Problem: Users with weird/unusual name won't display on the Android app, there will just be a blank space where the username should be. For example,  user is showing as:   On a question:   On their profile: Does the selection of sRGB or Adobe RGB in camera when shooting RAW ever matter? I shoot RAW essentially 100% of the time, and have the in-camera color space setting at AdobeRGB (sRGB is also offered). The raw converter in turn is set to produce sRGB output files. As I understand the process, the general flow is for raw shooting: raw sensor data readout (including A/D conversion), compression, write to a raw file, then in post-processing rather than in-camera apply color space/color temperature/etc; for JPEG shooting: raw sensor data readout, apply color space/color temperature/etc, JPEG compression, write to memory card (in camera).  Hence, when a colleague said that I should leave the camera set to sRGB for best/consistent results despite using the camera's raw format, it didn't really make much sense to me. I have mulled it over for a while now and it still doesn't really make any sense.   seems to support my view of the differences in the data recorded in RAW and JPEG modes, respectively.  I did find , but the answers there seem to focus more on the difference between AdobeRGB and sRGB. My question is, when shooting RAW, does it ever matter (except for the image preview) whether the camera is set to sRGB or AdobeRGB? If it does, then why, and in what situations? Is my understanding of the "raw" format processing chain flawed?  In case it matters, I have a Canon EOS 50D. Does a photon exert a gravitational pull? This question exists as it fills a specific criterion.  While you are encouraged to help maintain its answers, please understand that "big list" questions are not generally allowed on Ask Ubuntu and will likely be closed per the . More information on the .   What kind of desktop environments or shells are there for Ubuntu users to install?  Please list a desktop environment or shell for each:   a description on why you like or suggest it (features, performance, etc.). a good screenshot, preferably of it running on Ubuntu and showing off some of its features. the minimal requirement for it to be usable, If there's any setting to lower it's requirement (Like kde's low-fat profile); how to enable the said setting some instructions on how to set it up if in the repositories, please provide a software centre link proof that on a compact manifold a vector field is complete I would like to know if my proof of the following statement is correct     If $M$ is a compact manifold, then every vector field $X$ over $M$ is complete.   Proof:  I take $p\in M$ and $(\gamma_p,I_p)$ a maximal integral curve through $p$. $I_p$ is open and non empty so if $I_p$ is closed, it is equal to $\mathbb{R}$.  So take $s\in \text{Adh}(I_p)$. There exists $t_i\rightarrow s, t_i\in I_p$. Define $q$ as $\text{lim}(\gamma_p(t_i))$ and take a maximal integral curve passing by $q$ as $(\gamma_q,I_q)$. Then since the vector fields are $C^\infty$, $\gamma_q(I_q)\cap\gamma_p(I_p)$ is nonempty (intuitively, this is clear but don't really know how to show it).  On the intersection, $\gamma_p$ and $\gamma_q$ coincide. So we can extend the maximal curve $\gamma_p$ to include $\gamma_q$. This implies that $q\in\gamma_p(I_p)$ and is actually equal to $\gamma_p(s)$  I think the main idea is there even though it probably lacks a bit of rigour. My Android device screen got broken and I can't see what I'm doing. That's the only wrong thing with my device, the rest is apparently working OK. Is there any way to send my device screen to my computer? I don't want to work blindly anymore! Doesn't Matlab work on ubuntu 16.04? This issue happens only on UEFI systems with enabled Secure Boot.  When I try to install DKMS modules like VirtualBox, Nvidia, or Broadcom drivers, they do not install and I get Required key not available when I try to modprobe them.  VirtualBox complains that vboxdrv is not loaded.  Broadcom wl driver is shown in lspci -k as a kernel module but is not in use. sudo modprobe wl throws Required key not available.  Also this issue may happen when I install some kernel modules from git sources.  This issue may appear after a kernel update as disabled wireless adapter, black screen after a reboot, etc.   How can I fix it? Is there a way to see who voted on your posts? Help with completing the proof: Any unbounded sequence is either infinitely large or has a convergent subsequential limit Given $\{x_n\}$ is an unbounded sequence, prove:   $$ \lim_{n\to\infty}x_n = \infty\ \  \text{or}\ \ \lim_{n_k \to \infty} = A $$   In other words any unbounded sequence either infinitely large or has a convergent subsequence.     Everything before udpate section is wrong.  Part 1. Proving $|x_n| &gt; M \implies \lim_{n\to\infty} x_n = \infty$  $\Box$ Start with the definition of an unbounded sequence: $$ \forall M &gt; 0 \in \Bbb R \ \exists N \in \Bbb N: \forall n &gt; N\implies |x_n| &gt; M $$  Suppose that: $$ \lim_{n\to\infty}x_n \ne \infty $$ That means: $$ \forall n\in\Bbb N\ \exists C &gt;0 \in\Bbb R : |x_n| &lt; C $$  Now taking $M^\prime = \max\{M, C\}$ we have that: $$ \begin{cases} \begin{align} \exists N \in \Bbb N : &amp;\forall n&gt;N \implies &amp;|x_n| &gt; M^\prime \\ &amp;\forall n \in \Bbb N: &amp;|x_n| &lt; M^\prime \end{align} \end{cases} $$  So we have arrived to a contradiction which means the assumption is wrong and: $$ \lim_{n\to\infty}x_n = \infty $$ $\Box$     Part 2. It's not clear to me how to prove that if unboundedness does not imply infinity limit then it must imply the existence of a convergent subsequence.   Two questions is my mind:   Is part 1 correct?  How do I proceed with the second part?     I'm using the following definition. $$ \lim_{n\to\infty}x_n = +\infty \stackrel{\text{def}}{\iff} \forall \epsilon &gt; 0 \exists N \in \Bbb N :\forall n &gt; N \implies x_n &gt; \epsilon \\ \lim_{n\to\infty}x_n = -\infty \stackrel{\text{def}}{\iff} \forall \epsilon &gt; 0 \exists N \in \Bbb N :\forall n &gt; N \implies x_n &lt; -\epsilon \\ $$ A sequence is considered infinitely large when: $$ \lim_{n\to\infty}x_n = \infty\ \ \text{when}\ \ \lim_{n\to\infty}x_n = + \infty \ \ \text{or} \ \ \lim_{n\to\infty}x_n = - \infty $$    Update.   Looks like i've messed up a lot of things. I will try once again. As shown in comments and answers the statement holds only in case: $$ \lim_{n\to\infty} |x_n| = \infty \iff \forall \epsilon &gt; 0 \exists N \in \Bbb N: \forall n &gt; N \implies |x_n| &gt; \epsilon $$  Consider the following: $$ \lnot P = \lnot\left(\lim_{n\to\infty}|x_n| = \infty \right) \iff \exists \epsilon &gt; 0\ \forall N_1 \in \Bbb N : \exists n &gt; N_1 \land |x_n| &lt; \epsilon $$  But on the other hand it is given that $x_n$ is unbounded: $$ Q = \forall M &gt; 0\ \exists N_2 \in \Bbb N : |x_{N_2}| &gt; M $$  Construct a negative expression for boundedness: $$ \lnot P = \exists M &gt; 0\ \forall N_2 \in \Bbb N : |x_{N_2}| &lt; M $$  If $S = \lnot P \implies \lnot Q$ then $S = P \lor \lnot Q$  Let $\epsilon = M$, choose $N = \max\{N_1, N_2\}$ then both statements are true and: $$ \exists \epsilon &gt; 0\ \forall N = \max\{N_1, N_2\}: \exists n &gt; N \land |x_n| &lt; \epsilon $$  Now either $P$ is true, which would mean $\lim |x_n| = \infty$, or $\lnot Q$ is true which would mean the sequence is bounded and hence contains a convergent subsequence. "There is/are more than one". What's the difference? While adding to an Answer to  question, I needed to use the above phrase, and I suddenly realised I was unsure whether to write "is" or "are".   There is more than one way to skin a cat. If there are more than one species of cat, we will flay each species differently.   I don't think that second example above sounds quite right to me (disregarding the meaning - sorry!), but in my original Answer I felt "is" would have been even worse.  Is "are" always wrong here? If so, what exactly is the rationale? If not, is there a case where it's unquestionably preferred – and why is that?    Note that in both the problematic Answer and my example attempting to mimic the same context more briefly, the writer doesn't know how many there are. There may be one, more, or even none.  Getting even more specific, the writer might have an opinion on how many there might be, and wish to convey his leanings by choice of verb form if language allows this to be done succinctly. Sending a value to JavaScript I have set theme handler for a form in Drupal and this handler has a template file. What is the easiest way to send a value from PHP to JavaScript in that include file? Sending email in .NET through Gmail