Is there a keyboard shortcut for "to the power of" signs?  Example: ²
The title pretty much says it all: how can I type Unicode characters - specifically the em-dash —?
Is GNOME Terminal a type of non-login shell? Counting binary operations on a set with $n$ elements I am trying to solve following problem but not able to find any way to proceed.  Let $S$ be a set having $n$ elements. Can we count about number of binary operations that can be defined on a set? Can we also count number of commutative binary operations defined on  $S$?  Thanks for the help and suggestions Common binaries with support for command execution, like `awk` and `vim`, not respecting setuid bit? Proof that the irrational numbers are uncountable Can someone point me to a proof that the set of irrational numbers is uncountable? I know how to show that the set $\mathbb{Q}$ of rational numbers is countable, but how would you show that the irrationals are uncountable? If column matches another file, print every line with match (awk/grep) Copy file geodatabase using Python? I am trying to copy fgdb from one path to another using Python.  copy(base.gdb,dest)   And got the message:  Error Info:  [Errno 13] Permission denied:   How to fix it? Just switched from 10.04 to 11.10. I'm wondering about the limited options in the GUI for managing users and groups. Where is the old GUI to change groups, id's, etc. I know that I can do this from cli, that's no problem. But I want this comfortable GUI back. I have learnt that the cardinality of the power set of the natural numbers is equal to the cardinality of the real numbers. What is the function that gives the one-to-one correspondence between these two sets?  I have also learnt that there exists no set whose cardinality is strictly between the natural numbers and the real numbers. Is there a proof of this or at least some intuitiveness behind it? How would I be able to create a grill of sorts found on the front of some computer cases such as this one I have created this with cycles:  But the edge between the glowing and non glowing materials is very sharp. The material was manually applied to faces in edit mode. Is there any way I can smooth the edge between them in cycles? Can one construct a non-measurable set without Axiom of choice? Is axiom of choice required to show the existence of non-measurable sets? Is there a Lebesgue non-measurable set that can be constructed without axiom of choice?  Related question on MO says it is consistent: I'm always on the hunt for free stock images to use while I design, what are some good resources for images that are under a a royalty free or creative commons licence? Why are some of my screen-recording/capturing/sharing applications (or app features) not working in Ubuntu 17.10 (and later releases)? After upgrading to Ubuntu 17.10 I noticed some of my screencasting applications are not working, for example screencasting tools like SimpleScreenRecorder and vokoscreen. ()  Also I noticed features like screenshot from GIMP is not working properly, producing blank screenshots (). Shutter too is producing glitchy screenshots ().  Screen-sharing option on Skype is also not working ().  The issue occurs sometimes on later Ubuntu releases too.  Why is this happening and how do I fix this? How is the recommended next badge determined exactly? According to , the     "Progress to next badge" bar automatically selects the badge you're closest to earning (or that's most logical to go for next)   While "the badge you're closest to earning" is pretty easy to determine: it's the bar with the most progress, I'm wondering what "most logical to go for next" means. Because right now on Meta Stack Exchange, I can track two badges: Illuminator and Legendary. My progress for Illuminator is 66.40% and for Legendary it's 66.67%, yet Illuminator is shown as the recommended next badge:    On some child metas where I barely have any activity, Student is shown as recommended next badge with a progress of 0/1, but I do have cast some votes so I have a small progress towards e.g. Civic Duty. So obviously there is some other logic at work, but what? Prove that for any square matrix, an invertible matrix B exists, so that BA is triangular I'm given a matrix A, its dimensions are n x n.  I am required to prove that an invertible matrix B exists, such that the product of the matrices BA is triangular.  Any help? Sex worker student offering her (lawful) services One of my students is an escort/stripper and she has offered me (and other faculty in my department) her "services". I am pretty sure my initial reaction of "thanks for letting me know, now can you answer the question about how to calculate the standard deviation", may not have been the best reaction. The offers have continued. My head of school is aware of the issue, and has asked if I want him to do anything.  Is the student doing anything wrong by offering her services to me? For what it is worth, prostitution is legal in the UK. Is this any different then a student telling me she works in a restaurant?  What is the correct response in a situation like this? How to solve "Extra junk at end of file" when using apt? I'm trying to configure some proxies for a guest virtual machine and now I'm getting:  sudo apt-get update E: Syntax error /etc/apt/apt.conf.d/95proxy:4: Extra junk at end of file   The content of the file is:  cat /etc/apt/apt.conf.d/95proxy   Acquire::http::proxy  "http://10.0.0.60:3128/" Acquire::ftp::proxy "http://10.0.0.60:3128/" Acquire::https::proxy "http://10.0.0.60:3128/" Examples and further results about the order of the product of two elements in a group Automate Fixed Width Page, length > some minimum length, but only as long as needed I am trying to automate the solution proposed by egreg to  by hooking into \begin{document} and \end{document}.  So, egreg's solution works fine:  \documentclass{article} \def\MinimumPaperHeight{12cm} \usepackage{geometry} \geometry{paperwidth=\MinimumPaperHeight,paperheight=\maxdimen,margin=1cm} \usepackage{lipsum}  \begin{document} \setbox0=\vbox{ \lipsum[1-6] } \dimen0=\dp0 \pdfpageheight=\dimexpr\ht0+2cm\relax \ifdim\pdfpageheight&lt;\MinimumPaperHeight \pdfpageheight=\MinimumPaperHeight \fi \unvbox0\kern-\dimen0 \end{document}   But can't seem to get this to work:  \documentclass{article} \def\MinimumPaperHeight{12cm} \usepackage{geometry} \geometry{paperwidth=\MinimumPaperHeight,paperheight=\maxdimen,margin=1cm} \usepackage{lipsum} \usepackage{environ}  \NewEnviron{MyBox}{     \setbox0=\vbox{\BODY}% }{%     \dimen0=\dp0%     \pdfpageheight=\dimexpr\ht0+2cm\relax%     \ifdim\pdfpageheight&lt;\MinimumPaperHeight \pdfpageheight=\MinimumPaperHeight \fi%     \unvbox0\kern-\dimen0% }  \AtBeginDocument{\begin{MyBox}} \AtEndDocument{\end{MyBox}}  \begin{document} \lipsum[1-6] \end{document}   Hooking into \AtBeginDocument is per this solution on . In Ubuntu 18.04 I'm not able to assign Ctrl+Alt+← or Ctrl+Alt+→ to anything. To be precise I may bind it to something, but it doesn't work when using the keyboard combination, up/down arrows do however work.   .  The strange thing is that the system detects the keyboard combinations when assigning a key, but not when trying to use them. As a result the keyboard combinations don't work in any other programs either.