I'm currently using a Ubuntu 20.04 machine with a small root volume. The default snap setup occupies ~1G space, though with only a few packages. And when I tried to remove core from snap I got the following error. # snap remove core18 error: cannot remove &quot;core18&quot;: snap &quot;core18&quot; is not removable: snap is being used by snaps gnome-3-34-1804, gtk-common-themes and snap-store.  I understand I can work around the issue by manually remove the dependants first, but is there a one-liner solution that manages the dependencies automatically so that all snaps and snapd can be removed in one go?
How do I remove snap? apt pretends it's not there but I can still call commands with it.  Trying to rm it says "read only file system"  root@tunnel:/# apt remove snap Reading package lists... Done Building dependency tree Reading state information... Done Package 'snap' is not installed, so not removed 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. root@tunnel:/# snap whoami email: -
I'm trying to create a command, which calls on an environment, which defines a custom column definition with one argument using \newcolumntype, and defines a second command, containing parameters for a table column.  Then, still within the first command, I begin the tabular environment and call the custom column, with the second command as its argument. I always get an undefined control sequence error, though. Any thoughts on why that might be?  I'm sure that was clear as mud, but I've cut it down to a minimal example, which follows:  \documentclass{article} \usepackage{array} \usepackage[table,dvipsnames]{xcolor} \usepackage{colortbl}  \newenvironment{tablecolor}{     \newcommand{\tlight}{\columncolor{SkyBlue!30}\color{black}}     \newcolumntype{C}[1]{&gt;{##1}c} }{}  \newcommand{\tablegoals}{ \begin{tablecolor} \begin{tabular}{l|C{\tlight}} Goal 7  &amp; \\ \end{tabular} \end{tablecolor} }  \begin{document}     \tablegoals \end{document}     Here's my second attempt. Different approach, same undefined control sequence error with \columncolor.  \documentclass{article} \usepackage{array} \usepackage[table,dvipsnames]{xcolor} \usepackage{colortbl} \usepackage{ifthen}  \newenvironment{tablecolor}{     \newcolumntype{C}[1]{&gt;{         \ifthenelse{\equal{dark}{##1}}{             \columncolor{Cyan}\color{white}             }{             \columncolor{SkyBlue!30}\color{black}         }     }c} }{ }  \newcommand{\tablegoals}[1]{     \begin{tablecolor}         \begin{tabular}{l|C{dark}}             Goal 7  &amp;   #1         \end{tabular}     \end{tablecolor} }  \begin{document}     \tablegoals{Check mark} \end{document} What is the distribution of the sum of non i.i.d. gaussian variates? If $X$ is distributed $N(\mu_X, \sigma^2_X)$, $Y$ is distributed $N(\mu_Y, \sigma^2_Y)$ and $Z = X + Y$, I know that $Z$ is distributed $N(\mu_X + \mu_Y, \sigma^2_X + \sigma^2_Y)$ if X and Y are independent.  But what would happen if X and Y were not independent, i.e. $(X, Y) \approx N\big( (\begin{smallmatrix} \mu_X\\\mu_Y \end{smallmatrix}) , (\begin{smallmatrix} \sigma^2_X &amp;&amp; \sigma_{X,Y}\\ \sigma_{X,Y} &amp;&amp; \sigma^2_Y \end{smallmatrix}) \big) $  Would this affect how the sum $Z$ is distributed? Why doesn't using the approximation $\sin x\approx x$ near $0$ work for computing this limit? The limit is $$\lim_{x\to0}\left(\frac{1}{\sin^2x}-\frac{1}{x^2}\right)$$ which I'm aware can be rearranged to obtain the indeterminate $\dfrac{0}{0}$, but in an attempt to avoid L'Hopital's rule (just for fun) I tried using the fact that $\sin x\approx x$ near $x=0$. However, the actual limit is $\dfrac{1}{3}$, not $0$.  In this , the approximation reasoning works out. The ^^ notation in various engines Basically, how does the ^^^... notation work in LuaTeX and XeTeX, exactly?  In 8-bit TeX engines (recent TeX, eTeX, pdfTeX, at least), two consecutive identical catcode 7 characters (typically ^), followed by two lowercase hexadecimal digits, are converted before the tokenization step to the corresponding byte.  Namely, ^^6f is exactly equivalent to o: for instance, \sh^^6fw ^^6f will cause TeX to show the letter o.  There is also the notation with two ^ (identical catcode 7 characters), followed by any ascii character (but not two lowercase hexadecimal digits), which is replaced by the character obtained by either subtracting or adding 64 to the character code, remaining among ASCII characters (range 0 to 128).  Unicode-aware engines (I'm thinking of LuaTeX and XeTeX, there are perhaps other less known ones around) also provide ^^^^xxxx and ^^^^^xxxxx for characters whose hexadecimal representation has 4, or 5 digits.  But this does not seem to be done in the same way across engines.  For instance, both LuaTeX and XeTeX appear to accept the notation with 4, 5, or 6 carets followed by the same number of hexadecimal digits, but XeTeX also accepts it for 3, while LuaTeX doesn't. Compiling the following with pdfTeX, LuaTeX, and XeTeX gives different results.  \catcode0=12 \newlinechar=10 \def\loopshow#1{\message{\meaning #1^^J}\loopshow} \loopshow \/   ^^56   ^^^056   ^^^^0056   ^^^^^00056   ^^^^^^000056   ^^^^^^^0000056 {\end\iffalse} \fi} \bye   One weird fact about XeTeX (a bug?) is that  \show ^^^^^^010101   shows the character displaywidth.  My goal (there may be a better way to do this) is to provide a way to test whether passing a given list of tokens through \scantokens is safe.  For that, my plan is to go through the \detokenized token list one character at a time, applying TeX's rule for tokenizing (but no need to fully tokenize), and detecting begin-group and end-group tokens, as well as invalid characters. Live notification shown for own edits When editing an answer, the &quot;new revision&quot; message is shown for a short moment. This makes no sense because the revision you just created is automatically displayed anyway. I am trying to solve the following question which is Ex3 from Arthur Engel, Problem Solving strategies. Here is the question: $\sum_{k=1}^n k^3 {n \choose k}$ and asks to find the sum. I am sincerely having a hard time trying to figure out how to solve it and get $n^2 (n+3)(2)^{n-3}$. I would really appreciate if someone could show the step-by-step process. Thank you! Determinant of a specially structured matrix ($a$'s on the diagonal, all other entries equal to $b$) I have the following $n\times n$ matrix:  $$A=\begin{bmatrix} a &amp; b &amp; \ldots &amp; b\\ b &amp; a &amp; \ldots &amp; b\\ \vdots &amp; \vdots &amp; \ddots &amp; \vdots\\ b &amp; b &amp; \ldots &amp; a\end{bmatrix}$$  where $0 &lt; b &lt; a$.  I am interested in the expression for the determinant $\det[A]$ in terms of $a$, $b$ and $n$.  This seems like a trivial problem, as the matrix $A$ has such a nice structure, but my linear algebra skills are pretty rusty and I can't figure it out.  Any help would be appreciated. Direct way leads to nowhere.  $$\lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{\sqrt {n^2 +i} } = \lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{n \sqrt {1 +\frac{i}{n^2}} } = $$  $$ = \lim_{n\rightarrow \infty} \frac{1}{n} \cdot \lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{\sqrt {1 +\frac{i}{n^2}} } = 0 \cdot \sum^{n}_{i=1} 1 = 0 \cdot n $$  So, I tried to apply squeeze theorem:  $$\lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{\sqrt {n^2 +i} } \leq \lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{n}  = 1$$  Could you help me to figure out the lower bound? How do i renable connecting a network drive using SMB1 since Windows 1709 I find today that I can no longer mount my Netgear ReadyNas drive because apparently it is using SMB1 and Windows 10 have disabled since release 1709. This is very problemaic because I need to access these files and because I have lost the admin password for the ReadyNas itself so I cannot login in order to update/reconfigure it to use SMB2 instead.  Microsoft refers me  to  which in turn refers me to  if I really want re-enable SMB1  And I successfully did re-enable SMB1 by running  Enable-WindowsOptionalFeature -Online -FeatureName smb1protocol   from Powershell as Adminstrator.  However even after reboot I still cannot re-establish connection to my Netgear from Windows Explorer, it gives the same error  What else do I need to do ?  PS C:\WINDOWS\system32&gt; Get-WindowsOptionalFeature –Online –FeatureName SMB1Protocol   FeatureName      : SMB1Protocol DisplayName      : SMB 1.0/CIFS File Sharing Support Description      : Support for the SMB 1.0/CIFS file sharing protocol and the Computer Browser protocol. RestartRequired  : Possible State            : Enabled CustomProperties :                    ServerComponent\Description : Support for the SMB 1.0/CIFS file sharing protocol and the Computer                    Browser protocol.                    ServerComponent\DisplayName : SMB 1.0/CIFS File Sharing Support                    ServerComponent\Id : 487                    ServerComponent\Type : Feature                    ServerComponent\UniqueName : FS-SMB1                    ServerComponent\Deploys\Update\Name : SMB1Protocol   Solution  Thanks Bob, SMB 1.0/CIFS File Sharing Support was enabled but within it SMB 1.0 Client was not enabled, checking that box and rebooting fixed the issue. Measuring accuracy of latitude and longitude? Proficiency with specific weapons vs 'simple and martial'? In the PHB on pg. 146 it states that there are two weapon categories in which the players can be proficient: simple and martial.  As per  answer to another question, being proficient in either category makes the players character proficient in using all weapons of the respective category.   However in the race descriptions the players are given proficiency for specific weapons. Dwarfs, for example, have the trait Dwarven Combat Training giving proficiency with battleaxes, handaxes, throwing hammers and warhammers.   How do the two types of proficiencies interact with each other? Successfully connected to a bluetooth speaker, but how do i direct sound there? Word to describe the way cattle and buffalo consume fodder? Restrict node list in entity reference field based on node field My "Article" nodes have a "domain" field that links to a taxonomy term. My "Article" nodes also have a repeatable "entity reference" field "more like this" that links to other "article" nodes.  How can i restrict the list in the "more like this" field to show only the nodes that have the same "taxonomy term" that the node i am currently editing ?  Thanks a lot ! Creating Users on secondary server in log shipping I have a production Server say ServerA I have setup log shipping to ServerB which is left in read-only mode. The purpose of this log shipping is to lower the load on production server for some expensive queries (painful reports).   Now if I have to create some logins using our domain accounts. I cannot do this because the secondary database is in standby mode.   I thought if I create these logins on Primary server it will be copied over to secondary server then the logs are restored there but this isnt the case.   I have done a lot of research online finding a way around to this. I found the following resources for this. I tried every method suggested in this articles but none of them seems to work.   1)   2)   3)   Has someone experienced the same issue? what did you do? Is there any way around for this issue? Any suggestions any pointer please. how to extract multiple zipped and rar files recursively? I have a folder ExampleFolder which contains many zipped folders. These zipped folders also contains multiple zipped folders. How to go through ExampleFolder and extract all of its zipped folders recursively?   Note that ExampleFolder itself, is not zipped, it's just a normal folder  Okay now I know what's happening Rinzwind and nux answers are both correct (except that I have to keep pressing Y or A forever)  But it's seems that some of the zipped files, contained zipped files and rar files as well, the rar files will not be extracted by   while [ "`find . -type f -name '*.zip' | wc -l`" -gt 0 ]; do find -type f -name "*.zip" -exec unzip -- '{}' \; -exec rm -- '{}' \;; done    or whatever  Edit 2 Some files are named .r00 and r01, .r02 up to r14, they are rar files, but not .rar Locally bounded additive function is linear Let $T:\mathbb{R}^k\to\mathbb{R}^m$ is additive, i.e. $T(X_1+X_2)=T(X_1)+T(X_2)$. $T$ is locally bounded. Prove that $T$ is a linear transformation.  I know there is a relation between boundedness, convexity and scalar multiplicity. But not sure where to start or how to tie things together. Binary search (bisection) in Python I need a way to determine the type of an HTML element in JavaScript. It has the ID, but the element itself could be a &lt;div&gt;, a &lt;form&gt; field, a &lt;fieldset&gt;, etc. How can I achieve this? Can I make a script always execute as root?