Checking a number with calculator package
Checking for valid floating point number
Faithful group actions for singleton group or for empty set Let $G$ be a group, possibly a singleton. Let $M$ be a set, possibly empty. Let $\mu: M \times G \to M$ be a right group action. Let $1_G$ be the identity of $G$.  I understand 's second definition of faithful as follows:     $\mu$ is faithful if for each $g \in G$ such that $g \ne 1_G$, there exists $x \in M$ such that $\mu(x,g) \ne x$. $\tag{1}$   Later  says if $\mu$ is free and $M$ is a non-empty set, then $\mu$ is faithful.  Question: Given the idea that we can have $M$ as an empty set, I would like to clarify: Are these correct?   If $G$ is a singleton, then every action $\mu$ is faithful, whether or not $M$ is empty. If $G$ is not a singleton, but $M$ is empty, then every action $\mu$ is not faithful. Currently selected indicator's colour in flag summary and help pages, can be the same as the site's colour code How do regular expressions differ from wildcards used to filter files I am looking for an example such that in a pre-Hilbert space $H$ we have for a subspace $U$ that  (i) $\bar{U} \oplus U^\perp \neq H$  (ii) $ \bar{U} \neq U^{\perp \perp}$  Since finite and closed subspaces will probably not do it, I am not good at inventing nice examples. Does anybody here have a few at hand? The ground was ice-cold, no hint of anyone having lay/laid/lain there   at all.   Which one is the correct option? Test for convergence  $$\sum_{n=1}^{\infty} \frac{1}{n^n}$$  I'm at a loss on what to do, is this a geometric series $\frac{1^n}{n^n}$? What influences findability on a post?   Upvotes Views Asked date Last active time   How is this done in the Stack Exchange internal search engine? And how does Google do it?  Why is it that when searching on Google for 'iPhone development stackoverflow' the fourth result is ? Script Tag Error - Aura Lightning Component Are PHP variables passed by value or by reference? Why does $(x \to a) ≠ (x = a)$ , But $f(x \to a) = f(x = a)$ What are the most important things I need to do to encourage Google Sitelinks? What is the setting in bash for globbing, to control whether * matches dot files I was surprised recently when I did something like mv ./* ../somedirectory and found that files like .gitignore were not moved.  I do most of my work in zsh on OS X, and this surprise bit me in bash on CentOS.  I tried bash on OS X and found the same behavior: * does not match dot files.  This seems very undesirable to me, but apparently it's the bash default.  (It may be the zsh default too for all I remember, but I may have changed it years ago in my .zshrc and forgotten it ever worked differently.)  How can I configure bash to behave as I expected: for * to match all files, and not ignore dot files.  In case this is at all unclear, here's how to reproduce it    cd /tmp mkdir {t,d}est touch test/{.,}{1,2,3,4,5,6,7} ls -hal test mv test/* dest ls -hal test     # notice dot files are still there ls -hal dest     # notice only some files were mv'ed I can't understand how the "cryptographic functions" are to be selected RSA + OAEP which are used in OAEP. How to choose these "cryptographic functions"(G and H)? I upgraded my Nexus 4 to Lollipop a few days ago but I don't like it. I'll leave out my reasons because they're not relevant here. I wiped my phone and installed a clean stock 4.2.2 version instead. I'm happy with this.  Not long after, Android automatically downloaded the 4.3 upgrade and notifies me with the choices "Later" and "Install". I don't want to do this upgrade.  How do I:   get rid of the notification, and  remove the downloaded update (to free up precious storage space).     I have already tried choosing "Later" but the same notification immediately reappears.    Based on Google search results, I also tried going to Settings &gt; Apps &gt; All &gt; Google Services Framework and unticked "show notifications" but it still appears. Force stop or disable also doesn't seem to help, so I've re-enabled the service including notifications. I didn't see any other apps in this list that sounded relevant - did I just not see it? How to expand the ext4 primary partition size in a VMware Player virtual disk? I have a VMware Player virtual machine setup, running Ubuntu 10.04 as the a guest OS.  The VM was created on a 20GB virtual drive, with a single partition for working space. Finally I got to the point where I need to expand the size of the virtual drive. Resizing the drive itself, adding some 10GB, was easy via the VMware Player menus. I now need to resize the main partition itself (I prefer this over creating a separate partition and mounting it).  According to GParted, I now have the following partitions:    My question is, how can I increase the size of the Filesystem partition to include the free 10GB?  From information I found online, it looks like one limitation is the fact that he swap partition is immediately adjacent to the filesystem, so my understanding is that first thing would be to move that partition to the end of the volume. How can this be done?  Also, some sources suggest that the system should be booted from a LiveCD, so the filesystem is not the boot partition, and thus make it easier to resize. As mentioned above, I run a VM, so I am not sure how to boot it from a LiveCD. Any ideas? Troubleshooting "program does not contain a static 'Main' method" when it clearly does...? Whitespace Problems With Script and Variables Pluralizing Noun Phrase? How to disable pagebreak on \hline in longtable? How to disable pagebreak on \hline in longtable?  This is an example illustrating my problem:  \documentclass[12pt,a4paper,oneside]{letter}  \usepackage{longtable}  \begin{document}  \begin{longtable}{ | p{5cm} | } \hline Table header\\* \hline Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris pharetra porttitor turpis, id egestas neque congue in. Nam sed lorem lorem, ac tristique tellus. Nunc ornare feugiat orci, a blandit turpis facilisis ut. Aenean pharetra ornare ante. Sed tempus leo in dolor eleifend placerat. Integer at enim augue. Ut nisl tortor, interdum ac porttitor ac, sagittis quis libero. Vivamus nibh metus, ornare vel pulvinar nec, fringilla nec orci. Maecenas mollis nulla a nibh fringilla nec convallis augue varius. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere   cubilia Curae. \\ Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris pharetra porttitor turpis, id egestas neque congue in. Nam sed lorem lorem, ac tristique tellus. Nunc ornare feugiat orci, a blandit turpis facilisis ut. Aenean pharetra ornare ante. Sed tempus leo in dolor eleifend placerat.  Integer at enim augue. Ut nisl tortor, interdum ac porttitor ac, sagittis quis libero. Vivamus nibh metus, ornare vel pulvinar nec, fringilla nec    orci. Maecenas mollis nulla a nibh fringilla nec convallis augue varius.   Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere   cubilia Curae. \\ \hline Table header\\* \hline Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris pharetra porttitor turpis, id egestas neque congue in. Nam sed lorem lorem, ac    tristique tellus. Nunc ornare feugiat orci, a blandit turpis facilisis ut. Aenean pharetra ornare ante. Sed tempus leo in dolor eleifend placerat.    Integer at enim augue. Ut nisl tortor, interdum ac porttitor ac, sagittis  quis libero. Vivamus nibh metus, ornare vel pulvinar nec, fringilla nec    orci. Maecenas mollis nulla a nibh fringilla nec convallis augue varius.   Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere  cubilia Curae. \\ \hline \end{longtable}  \end{document}   I'd like to have second header on page 3. I do not control table contents, so I can not do page breaks manually. The error I am having when trying to update my package list.  W: GPG error: http://download.opensuse.org ./ Release: The following signatures were invalid: KEYEXPIRED 1436387333  W: Failed to fetch http://ppa.launchpad.net/samrog131/ppa/ubuntu/dists/trusty/main/binary-amd64/Packages  404  Not Found  E: Some index files failed to download. They have been ignored, or old ones used instead.