I study plain TEX and i need a way to draw a frame around each hbox and vbox in order to undestand how TEX works .. is it possible to do this? thanks !
I'd like to use a sequence of boxes to show how TeX works. I read some time ago that everything (or almost) in TeX are boxes.  So, how to show only the TeX boxes that surround each character, each line, each paragraph?  I'd like something similar to the image below, not fbox which contains blank space around it.
I have two lightning component placed on one page lightning app. First Component have refresh icon and I set onclick action to refresh Component $A.get('e.force:refreshView').fire(); but this event refresh the whole page instead of First component.  how can refresh only one component on page not all the page ? How do I connect to a MSSQL database using Perl's DBI module in Windows? $f$ differentiable except in $1$ point $f'(x) = [f(x)]^{2}$. Prove $f(x) = 0 $ Let $f:\mathbb{R} \rightarrow \mathbb{R}$ be a differentiable function such that $f(0) = 0$ and $f'(x) = [f(x)]^{2}$, $\forall x \in \mathbb{R}$. Show that $f(x) = 0$,  $\forall x \in \mathbb{R} $.  I first (unsuccessfully) tried using the Mean Value Theorem, but this is in the Integrals chapter so the solution probably involves them. Can't really see where integrals come in here though.  What I've got so far:   (i) Since $f$ is differentiable, thus it is continuous and, hence,  integrable. Therefore $f^2$ is also integrable and as $f'=f^2$, $f'$ is too.   (ii) $f' \geq 0$, $\forall x \in \mathbb{R}$ Suppose that $(s_n)$ converges to s. Prove that $(s_n^2)$ converges to $s^2$ I am really struggling with my proofs class, I don't really understand how to prove a statement like this, or what the epsilon is standing for..  Suppose that $(s_n)$ converges to s.  Prove that $(s_n^2)$ converges to $s^2$ directly without using the fact that $lim(s_nt_n)=st$  Suppose that $(s_n)$ converges to s. Then, since $(s_n)$ is convergent, there exists an $M_1$ such that $|S_n|&lt;M_1$, for all $n\in \!\,\mathbb{N} \!\,$. Let $M=M_1+|S|$ (I don't completely understand this step...). Then given $ε&gt;0$, there exists N such that n>N implies that $|s_n-s|&lt;ε/M$. Thus for n>N, we have $|s_n^2-s^2|=|s_n-s|*|s_n+s|&lt;(ε/M)(M)=ε$. Hence, $s_n^2$ converges to $s^2$. I'm one of those exceptions that deviates from the norm: I run CyanogenMod without any Google apps.   Is it possible to download the Stack Exchange Android app .apk directly? I am trying to create a beamer animation using tikz, but I can't even get basic rotating of a tikz image working as desired.  I have a rectangle specified by  \draw[rounded corners,dotted] (-3.5,0) rectangle (-0.5,2);   I would like to rotate this rectangle about the point (-1,.5) (which is near the bottom right corner of the rectangle).  I've tried:  {\rotatebox[origin=c,x=-1,y=.5]{130}{             \draw[rounded corners,dotted] (-3.5,0) rectangle (-0.5,2);}}   But this produces an error.  If I just use the origin=c option, it compiles, but it rotates the rectangle about the point (0,0).  I've also tried it with just the x=-1,y=.5 (without the origin option), and it fails to compile.  I have searched the documentation, which is where I learned about the options x=xdim and y=ydim.  However, I can't find a single example demonstrating how these options should be used.  Any suggestions would be greatly appreciated.    Also, if there is a better command for rotating things that will be more suitable for use in a beamer animation, please let me know.  Thanks! Windows 10 language bar hot keys are reseted to (none) after locking I have 3 different keyboard layouts set up on my laptop and use Ctrl+Shift+[1-3] key combination to switch between them.  Like that:    However, after locking and unlocking Windows (with a password), these hotkeys don't work anymore and key sequence is rolled back to (None):    Signing out from Windows or rebooting the laptop sets everything back to normal, until lock/unlock again.  I think this behaviour is related to the usage of the same hotkeys in File Explorer - to switch view (Extra large icons/Large icons/Medium icons accordingly). After the lock/unlock switch view starts working again.  Seems like File Explorer overrides language bar hotkeys after the unlocking.  How can I disable this functionality? Completely disabling Ctrl+Shift+number functionality in File Explorer will do, however I can't find anywhere on the internet how to do it.  Any ideas or help appreciated! I installed Dev C++ using Wine on Ubuntu 18.04 and the program is compiling but it not showing any output screen. Tall curly brace I would like to put a tall (long) left curly bracket on the left side of the following:  \documentclass[12pt]{article}  \begin{document}  \noindent c: $\{$1, ..., n$\}$ $\rightarrow$ $\{$1, ..., n$\}$, such that  \hspace{20 mm}  \noindent c($a_i$) = $a_{i+1}$ for 1 $\le$ $i$ &lt; $l$  \hspace{20 mm}  \noindent c($a_l$) = $a_1$   \end{document}   Please let me know if you can help. Thanks! Array with labeling columns How to make unit selection circles merge? I would like to know how to make this effect of merged circle selection. Here are images to illustrate:     Basically I'm looking for this effect:    How the merge effect of the circles can be achieved ? I didn't found any explanation concerning this effect. I know that to project those texture I can develop a decal system but I don't know how to create the merging effect.  If possible, I'm looking for purely shaders solution. Fast way to copy a large file on a LAN I am having some trouble with NFS, and I'd like to try using just plain old TCP.  I have no idea where to begin, though.  Hardware-wise, I am using an ethernet crossover cable to network two netbooks.  To network them, I type  $ sudo ifconfig eth0 192.168.1.1 up &amp;&amp; ping -c 10 -s 10 192.168.1.2 &amp;&amp; sudo /etc/init.d/nfs-kernel-server start   on the first netbook and  $ sudo ifconfig eth0 192.168.1.2 up $ ping -c 10 -s 10 192.168.1.1 $ mount /mnt/network1   on the second  where /mnt/network1 is specified in /etc/fstab as  192.168.1.1:/home /mnt/network1 nfs noauto,user,exec,soft,nfsvers=2 0 0  as well as in /etc/exports (using the syntax of that file), on the first netbook.  The above works fine, but the files and directories are huge. The files average about half a gigabyte a piece, and the directories are all between 15 and 50 gigabytes.   I'm using rsync to transfer them, and the command (on 192.168.1.2) is  $ rsync -avxS /mnt/network1 ~/somedir   I'm not sure if there's a way to tweak my NFS settings to handle huge files better, but I'd like to see if running an rsync daemon over plain old TCP works better than rsync over NFS.  So, to reiterate, how do I set up a similar network with TCP?  UPDATE:  So, after a good at few hours of attempting to pull myself out of the morass of my own ignorance (or, as I like to think of it, to pull myself up by my own bootstraps) I came up with some useful facts.  But first of all, what led me on this rabbit trail instead of simply accepting the current best answer was this: nc is an unbelievably cool program that resolutely fails to work for me. I've tried the netcat-openbsd and netcat-traditional packages with no luck whatsoever.  The error I get on the receiving machine (192.168.1.2) is:  me@netbook:~$ nc -q 1 -l -p 32934 | tar xv Can't grab 0.0.0.0:32934 with bind tar: This does not look like a tar archive tar: Exiting with failure status due to previous errors   route gives:  me@netbook:~$ route Kernel IP routing table Destination     Gateway         Genmask         Flags Metric Ref    Use Iface default         dir-615         0.0.0.0         UG    0      0        0 wlan0 link-local      *               255.255.0.0     U     1000   0        0 eth0 192.168.0.0     *               255.255.255.0   U     2      0        0 wlan0 192.168.1.0     *               255.255.255.0   U     0      0        0 eth0   But, here's the good news: having the static IP addresses set in /etc/network/interfaces, which I started doing while trying to get nc working, fixed all my NFS problems and rekindled my love for NFS.  The exact configuration I used (with 192.168.1.1 for the first netbook, of course) was:  auto eth0 iface eth0 inet static address 192.168.1.2 netmask 255.255.255.0   With those settings, the two netbooks will be able to ping each other directly after being booted up, without even an ifup.  Anyway, I'd still really like to see nc in action, so I'm hoping someone help me debug this process. How can I limit ssh *remote* port forwarding? I need to limit which ports can be remotely 'ssh -R' forwarded by an user.  I know about permitopen option on authorized_keys, but as it says on man page it only limits local 'ssh -L' port forwarding  As discussed  a user would get the same with netcat or similar, but in this case user has no shell access  I also found  that talks about using selinux or LD_PRELOAD, but I never configured selinux before and can't find info on how to do that with LD_PRELOAD.  maybe someone have made a patch for openssh to implement that?  EDIT: I've found  so I guess it's not yet implemented Sometimes when you're downloading an image and the connection breaks mid stream, you are left with a half downloaded image. If you try to view it you get the upper part of the image and the bottom part is usually coloured grey or green or some other color.  In other words, it is corrupted.  Is there a way to check whether the image is damaged in that way or otherwise corrupted? Changing ChildOf constraint influence to 0, but keeping the position it had as a child I had a sword object rigged with a single bone, with a ChildOf constraint making it a child of a sheath (with an influence of 1). Throughout an animation i move the sheath, and the sword bone follows as expected.  However, i cant seem to lower the influence of the sheath to zero and still have the sword retain the position it was just at, and I am wondering how i should go about making this happen.  Thanks for your time. How do I read an entire file into a std::string in C++? How do I read a file into a std::string, i.e., read the whole file at once?  Text or binary mode should be specified by the caller. The solution should be standard-compliant, portable and efficient. It should not needlessly copy the string's data, and it should avoid reallocations of memory while reading the string.  One way to do this would be to stat the filesize, resize the std::string and fread() into the std::string's const_cast&lt;char*&gt;()'ed data(). This requires the std::string's data to be contiguous which is not required by the standard, but it appears to be the case for all known implementations. What is worse, if the file is read in text mode, the std::string's size may not equal the file's size.  A fully correct, standard-compliant and portable solutions could be constructed using std::ifstream's rdbuf() into a std::ostringstream and from there into a std::string. However, this could copy the string data and/or needlessly reallocate memory.    Are all relevant standard library implementations smart enough to avoid all unnecessary overhead?  Is there another way to do it?  Did I miss some hidden Boost function that already provides the desired functionality?     void slurp(std::string&amp; data, bool is_binary) I want to unwrap a label which has a transparent area Use of "to lunch" vs."for lunch" Which is right?      I went to the (mall) to meet my parents for lunch / to lunch   This for a paper I am submitting for a writing assignment. I have heard "to lunch" is right, but is it right in this sentence please? Is it possible to only allow specific packages updates from a PPA Let us say I have added a PPA that has X package that I want but it also has Y package that I do not want to use or receive updates from. How can I, from the same PPA, receive updates for a specific package but deny updates from the same PPA for other packages.  A step by step example would be good since this has happened to me in several PPAs that have a particular package I want but also add a whole bunch of others that I do not yet want to update.