How to make a USB LaTeX Stick for OS X?
Multi-OS Portable TeX system
This started to happen immediately after I had rebooted the first time after doing a system upgrade. It first starts with a dialogue that says "System program problem detected". Then when I try to hit 'report problem' not much happens. I am led through a dialogue that always ends up the problem cannot be solved.  I am aware this is not a lot of information, however I'm not sure which information I need to publish and how should I obtain it to debug this problem.  Here's a screenshot! Sentence vs proposition The collection of all subsets of $\mathbb{Z}$ is uncountable, due to   But how can I prove that the collection of all finite subsets of $\mathbb{Z}$ is countable? Possible Duplicate:          I am a little bit confused about asking a question:     Can you please tell me my next work?   or     Could you please tell me my next work?   Which is more correct? I'm confused with using single or double brackets. Look at this code:  dir="/home/mazimi/VirtualBox VMs"  if [[ -d ${dir} ]]; then     echo "yep" fi   It works perfectly although the string contains a space. But when I change it to single bracket:  dir="/home/mazimi/VirtualBox VMs"  if [ -d ${dir} ]; then     echo "yep" fi   It says:  ./script.sh: line 5: [: /home/mazimi/VirtualBox: binary operator expected   When I change it to:  dir="/home/mazimi/VirtualBox VMs"  if [ -d "${dir}" ]; then     echo "yep" fi   It works fine. Can someone explain what is happening? When should I assign double quotes around variables like "${var}" to prevent problems caused by spaces? How to prove $|a^k|=n/\gcd(n,k)$ whenever $|a|=n$? Using SUMPRODUCT with ARRAYFORMULA I have the following random data in sheet one  A  orange D  yellow C  yellow B  orange B  orange C  blue A  yellow D  blue C  orange C  blue   In sheet two I use the following query function:  A1=UNIQUE(QUERY(Sheet1!A1:B10,"select A, B order by A asc")) C1=sumproduct(Sheet1!A:A=A1,Sheet1!B:B=B1) C2=sumproduct(Sheet1!A:A=A2,Sheet1!B:B=B2) C3=sumproduct(Sheet1!A:A=A3,Sheet1!B:B=B3) . . .   Which returns the following:  A   orange 1 A   yellow 1 B   orange 2 C   yellow 1 C   blue   2 C   orange 1 D   yellow 1 D   blue   1   Instead of using sum product in each row, I want arrayformula to expand automatically.  When I use E1=ArrayFormula(sumproduct(A1:A10=C1:C,B1:B10=D1:D)) I get     Error: Array arguments to EQ are of different size.   Please help me out. This is a question of the book Linear Algebra of Kenneth Hoffman.  Describe explicitly all inner products on $\mathbb{R}$ and on $\mathbb{C}$.  I think that if $&lt;,&gt;$ is one inner product on $\mathbb{R}$ (or $\mathbb{C}$) then $&lt; ,&gt;=K[,]$, where $[,]$ is the standard inner product. Is that correct? How do I list the default installed packages? I am developing an offline installer for all versions of Ubuntu, and I need Ubuntu's default installed packages list. Is there a way to get this information from any server (web server)? Any script to fetch any Ubuntu version's default installed packages list.  I will give the Ubuntu version, and the script will fetch the packages list.  Note: I need at least a server address. I can write a script for this. Do I cast the result of malloc? In , someone suggested in a  that I should not cast the result of malloc. i.e., I should do this: int *sieve = malloc(sizeof(int) * length);  rather than: int *sieve = (int *) malloc(sizeof(int) * length);  Why would this be the case? This question was triggered by .  Basically, it goes like this: If you have a weapon with a certain magical effect, let's say the minor property unbreakable (can not be broken, requires special means) or temperate (no harm in temperatures between -20 to 120 F), it can bypass the immunity of something like a Werewolf because it is magical instead of mundane. This goes for any minor property because those properties are under the Magic Items portion of the DMG on pg.143.  How does this differ from a pair of gauntlets with the exact same effect being used as an improvised weapon (emphasis added for clarity) from dealing damage in the same manner to the same Werewolf? Or something that's clearly not a weapon like a Shield of Missile Snaring being used to bash an opponent? How old should you be when you begin Jedi training? Anakin Skywalker was about nine years old (see script link, below) during "The Phantom Menace". Yet according to various people, he was too old (or even "far too old") to begin training as a Jedi:   QUI-GON: "I'm afraid not. Had he been born in the Republic, we would have identified him early, and he would have become Jedi, no doubt...he has the way. But it's too late for him now, he's too old." OBI-WAN: "The boy will not pass the Council's tests, Master, and you know it. He is far too old." MACE WINDU: "He is too old. There is already too much anger in him." and even ANAKIN himself: "I'm with Qui-Gon...but...they're not going to let me be a Jedi. I'm too old."   All quotes above from .  However, during "The Empire Strikes Back" Yoda gives Luke's age (18 in chapter IV according to the ) as the reason to deny him training only after first saying that Luke is:   too impatient too angry not ready is unfocused ("Never his mind on where he was") and reckless   All from .  I would have thought that, if at 9 Anakin was too old, Yoda would have seen Luke at 18+ and started off by saying, "No chance, he has".  So, what is the age to begin Jedi training? How can I write the name show in axis of 3D array using TiKz I am drawing a 3D array like the attached picture, which actually describes a multidimensional array. However, I can not put the name of the axis and take the value from the matrix like the attached picture.  This is the code that I have:  \documentclass[margin=5mm]{standalone} \usepackage{tikz} \usetikzlibrary{matrix,calc}  \begin{document} \begin{tikzpicture}[every node/.style={anchor=north east,fill=white,minimum width=1.4cm,minimum height=7mm}] \matrix (mA) [draw,matrix of math nodes] { (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ };  \matrix (mB) [draw,matrix of math nodes] at ($(mA.south west)+(1.5,0.7)$) { (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ };  \matrix (mC) [draw,matrix of math nodes] at ($(mB.south west)+(1.5,0.7)$) { (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ (1,1,3) &amp; (1,1,3) &amp; (1,1,3) &amp; (1,1,3) \\ };  \draw[dashed](mA.north east)--(mC.north east); \draw[dashed](mA.north west)--(mC.north west); \draw[dashed](mA.south east)--(mC.south east); \end{tikzpicture}   \end{document} I have a scrbook document with an openright option, i.e. every once in a while a blank left page appears in the document. Not that I really want to do this, but how could I include the infamous "This page has been intentionally left blank" in those blank pages cleanly, i.e. without too many hacks?  Bonus points for including a different famous quote on each blank page instead of the dull default ;) network manager says "device not managed" I used to be able to share my network connection by editing the Auto Eth0 to share with other computers in the Ipv4 section and now I upgraded my laptop to 11.10 .  Now are there no wired connections in the network manager. When I click my connections applet at the top of the tray it also says wired device not managed!  when I type ifconfig -a  daniella@daniella-1001HA:~$ ifconfig -a eth0      Link encap:Ethernet  HWaddr 90:e6:ba:83:d6:fc             UP BROADCAST MULTICAST  MTU:1500  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)           Interrupt:45   eth0:avahi Link encap:Ethernet  HWaddr 90:e6:ba:83:d6:fc             inet addr:169.254.13.40  Bcast:169.254.255.255  Mask:255.255.0.0           UP BROADCAST MULTICAST  MTU:1500  Metric:1           Interrupt:45   lo        Link encap:Local Loopback             inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:16436  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0            RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)  wlan0     Link encap:Ethernet  HWaddr 00:25:d3:90:43:41             inet addr:192.168.0.6  Bcast:192.168.0.255  Mask:255.255.255.0           inet6 addr: fe80::225:d3ff:fe90:4341/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:12881 errors:0 dropped:0 overruns:0 frame:0           TX packets:12867 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000            RX bytes:8851081 (8.8 MB)  TX bytes:2343199 (2.3 MB) Is it possible to install Windows 7 alongside Ubuntu and windows 10 dualboot? I installed windows 10 on my laptop in UEFI mode with HDD GPT disk format, then I installed Ubuntu 16.04LTS on another partition. So I have Ubuntu dualboot with Windows 10 now.  I also installed rEFInd (it's like GUI for you to choose between different OSs) because I don't wanna use Grub2 as the default bootloader. Now I want to have Windows 7 too, but when I boot from the USB stick, an error screen showed up saying something like  the windows boot manager is having problems due to a recent hardware change   My system is still working fine so I don't know if the problem came from my system or if the setup I want is impossible. I have to prove that:     $$\sum_{k=0}^{n} {{m+k} \choose{m}} = { m+n+1 \choose m+1 }$$   I tried to open up the right side with Pascal's definition that: $$ { n \choose k} = {n-1 \choose {k}} + {n-1 \choose {k-1}}$$  Here is what I came up with, and I am sure it is wrong because it does not equal the left side:  $$ {m+n+1 \choose m+1} = {m+n \choose m+1} + {m+n \choose m} = ... ={m+n \choose m+1} + {m+n-1 \choose m} + {m+n-2 \choose m-1} + ... + {m \choose m+1} = \sum_{k=0}^{n} {m+k \choose m+k-n+1 }  $$  Which, again, probably is wrong because it is not equal $\sum_{k=0}^{n} { m+k \choose m}$. Any help is appreciated R's lmer cheat sheet There's a lot of discussion going on on this forum about the proper way to specify various hierarchical models using lmer.  I thought it would be great to have all the information in one place. A couple of questions to start:   How to specify multiple levels, where one group is nested within the other: is it (1|group1:group2) or (1+group1|group2)? What's the difference between (~1 + ....) and (1 | ...) and (0 | ...) etc.? How to specify group-level interactions? Show that if the Riesz map is surjective on $H$, then $H$ is a Hilbert space Let $H$ be a vector space equipped with an inner product $(\cdot, \cdot)$ and $f:H\to H',\ f(x)=(\cdot,x)$ surjective. Now, why $H$  is a Hilbert space? The other direction is clear by Riesz' representation theorem but what about this? Escaping ampersand in URL