#define with :: (double colon) in identifier for namespaces
What are the valid characters for macro names?
Can't boot Windows 7 after installing Ubuntu I installed Ubuntu yesterday alongside Windows 7 and whenever I start my computer I don't have the option to boot Windows. When the computer starts it goes straight to Ubuntu without giving me an OS selection menu. When it goes to Ubuntu it gives me Ubuntu repair options and Ubuntu normal start option. I still have all of the Windows 7 files on my hard drive, but Windows 7 has no way to boot. Smoke Generator does not work When I try to run the smoke simulator in Blender 2.62 I get no smoke at all. When I attempt to render, the only output is a black screen. What am I doing wrong here that is making the smoke simulation not render?  Is it a mistake I made, or a problem with Blender version 2.62? What determines which frames are inertial frames? I understand that you can (in principle) measure whether "free particles" (no forces) experience accelerations in order to tell whether a frame is inertial. But fundamentally, what determines which frames are inertial (i.e. what principle selects in which frames free particles will not appear to accelerate)? I've been told that the cosmic microwaves determine the ultimate rest frame of the universe, but that doesn't make sense to me, since one can still ask why that frame is an inertial frame.  Also, I understand that there are no real inertial frames in general relativity, but it seems like there certainly exists approximate inertial frames and we can ask why those frames are approximately inertial and not others. For example, in the frame of a person riding a merry go round, free particles appear to greatly accelerate; while in the frame of someone standing next to the merry go round there are no such great accelerations. Why does the guy (or gal) on the merry go round see free particles accelerating while the other guy doesn't.   And if you're gonna tell me that it's "the rest of the stuff in the universe" that determines whether the person on the merry go round sees free particles accelerate, I'll ask how you know that all that stuff is not spinning.  I hope this question sort of makes sense, it's been bothering me for a while and my study of relativity (most of special relativity and just the outline of general relativity) hasn't really clarified it for me much. From , I have tried the using \hspace{0pt} and   \makeatletter \renewcommand{\dddot}[1]{%   {\mathop{\kern\z@#1}\limits^{\vbox to-1.4\ex@{\kern-\tw@\ex@    \hbox{\normalfont ...}\vss}}}} \renewcommand{\ddddot}[1]{%   {\mathop{\kern\z@#1}\limits^{\vbox to-1.4\ex@{\kern-\tw@\ex@    \hbox{\normalfont....}\vss}}}} \makeatother   after loading mathtools but the problem still persists.    \documentclass{article} \usepackage{mathtools} \begin{document} \[ \dot{\mathbf{r}}\times\ddot{\mathbf{r}}\times\dddot{\mathbf{r}} \] \end{document}   In the case the font scheme I am using has any affect as well, the fonts are:  \usepackage[utf8]{inputenx} \renewcommand{\rmdefault}{ppl}                  \linespread{1.05}                   \usepackage[scaled]{helvet} \usepackage{courier}               \usepackage{eulervm} \normalfont       \usepackage[T1]{fontenc}            \usepackage{textcomp} What is a 'Closure'? I asked a question about Currying and closures were mentioned. What is a closure? How does it relate to currying? How to change boot splash screen in 18.04 I have done this in the past in 16.04 and 17.10 but in 18.04 I can not get plymouth manager to work.  Downloaded it from the software center but it doesn't work.  Is there a guide available that will let me do it in terminal? Why is a Hyperplane called a "Hyper"plane? I just had this curious question. In other fields, the word "hyper" is actually used to refer to something which is "over; beyond; above" as defined by Google. An example of such terms would be Hyperglycaemia, defined by Wikipedia as:     a condition in which an excessive amount of glucose circulates in the blood plasma.   Or Hypersonic, defined by Google as:     relating to speeds of more than five times the speed of sound.   So, my question is, what would be the motive to give a Hyperplane such a name when it is defined as :     a subspace of one dimension less than its ambient space I'm very new to presentations in LaTeX (I've been using PowerPoint for years but have finally converted). I am wondering how to get a GIF into a section. If need be, I can convert a GIF into lots of pictures and have them overlay to give the impression of movement. property not working with getter AND setter I am making the check for update script for my theme  I have 2 text files. First one is called "current.txt" and contains the current version. There is 4.1.1 string in that text file.  Second one is called "latest.txt" and contains the latest version. There is 4.2 string in this text file.  So here is the code  echo "Checking update"; x=$(cat ./current.txt) y=$(cat ./latest.txt) if [ "$x" -eq "$y" ] then        echo There is version $y update else        echo Version $x is the latest version fi   What it mean is if current.txt is NOT the same with latest.txt then it will say "there is version 4.2 update". If not, it will say "version 4.1.1 is the latest version"  But when I try to run it. I get this error  Checking update ./test.sh: line 4: [: 4.1.1: integer expression expected Version 4.1.1 is the latest version   So what am I doing wrong with this? Suppose every subsequence of X converges to 0. Show that lim(X)=0 Question: Suppose that every subsequences of $X = (x_n)$ has a subsequence that converges to $0$. Show that $\lim(X) = 0$   My attempt:   Suppose that $\lim(X) =L \neq 0$  Let $\epsilon &gt; 0$, and let $K(\epsilon)$ be s.t. $n \ge K(\epsilon)$   then $|x_n-L| &lt; \epsilon$  let $n_k \ge k$, and then $k \ge K(\epsilon)$ and $n_k \ge k \ge K(\epsilon)$ s.t. $|x_{n_{k}}-L| &lt; \epsilon$, which is a contradiction. therefore $\lim(x) =0$ Laplace transform of $1/t$ AppFabric / WF 4.0 instances stuck despite no bookmark and pending timer Play YouTube videos with MPMoviePlayerController instead of UIWebView Stack Overflow is not getting refreshed automatically Stack&nbsp;Overflow is not getting refreshed automatically. I have to press F5 explicitly to refresh the website. What might be the issue? Would it better the community if we got compensated for posts? Even with minuscule alt coins? If we are effectively generating more traffic to Stack Exchange sites, would it become a better community if users were compensated somehow besides rep points? Even with minuscule alt coins? Could cancer be in itself a evolutionary process? Could cancer be in itself a evolutionary process? Maybe in some way could it be a process of variation? Or would this idea be completely without support, if so, why?   I don't mean that each case would lead to evolution, but that within an entire group of organisms, it could lead to case of of individuals developing ways to resist what caused the cancer, maybe in cases of individuals beating the cancer or in cases of successive generations of off spring from individuals with cancer?   Could it be possible that in rare cases it could lead to the development of new organs or specialized cells? Should 'drive by' downvoting be more effectively caught? I have an answer that I'm certain is technically correct. However, it continues to be downvoted. The answer has already been noted in comments on other answers to be better. It goes more in-depth than the others, yet it continues to be downvoted.  The already upvoted answers were nowhere close initially, and I had already commented on them to say why it is wrong...  Isn't there a limit for that? Shouldn't something be catching this? How did they post process before Photoshop? What is the use of percent signs (%) at the end of lines? (Why is my macro creating extra space?)