Macro returning the number of arguments it is given in C?
C++ preprocessor __VA_ARGS__ number of arguments
override at runtime __setattr__ I struggled with this over the weekend, and need to remap my mouse buttons. Finding all homomorphisms between $\mathbb{Z}/m\mathbb{Z}$ and $\mathbb{Z}/n\mathbb{Z}$ I want to find all group homomorphisms $\varphi: \mathbb{Z}/ m \mathbb{Z} \to \mathbb{Z}/n\mathbb{Z}$, with $m$ and $n$ natural numbers.  Clearly $\varphi(0)=0$ since the identity in $\mathbb{Z}/m\mathbb{Z}$ must map to the identity in $\mathbb{Z}/n\mathbb{Z}$, and it follows that $m \varphi(1)=0$, so is $mx \equiv 0 \bmod n$?  This as far as I get. How can I find all the homomorphisms? Two icons on Unity Launcher on non-standard application launch I have an application which doesn't come from any Ubuntu repo (neither official, nor PPA) but available as tgz and supposed to be unpacked and ready to use. To be precise it is .   The problem is the  application when launched shows its own icon in Unity Launcher. After making a custom .desktop file and placing shortcut onto Unity Launcher (by dragging from the dash) and launching it I see two icons - one placed by me and another one with real application.  This is the .desktop contents:  [Desktop Entry] Version=1.0 Type=Application Terminal=false Exec=/opt/LightTable/LightTable Name=Light Table Icon=/opt/LightTable/core/img/lticon.png   One more thing. The /opt/LightTable/LightTable is bash script file and eventually /opt/LightTable/ltbin is being launched. I think this is the problem but have no idea how to fix the problem. How can I remove whitespace when declaring an XSL variable? Process substitution and pipe I was wondering how to understand the following:     Piping the stdout of a command into the stdin of another is a powerful   technique. But, what if you need to pipe the stdout of multiple   commands? This is where process substitution comes in.   In other words, can process substitution  do whatever pipe can do?   What can process substitution do, but pipe cannot? What do you call a person who is always online on the Internet? Is there any specific word for a person who is always online on the Internet?  I am just curious to know because staying online is like a profession nowadays. Infinite sum of ideals I've been trying to prove that given a ring $R$ and a collection of ideals $\{I_{\beta}\}_{\beta \in B}$ in $R$, the set $$\sum_{\beta \in B} I_{\beta}=\{f_1+\cdots+f_r:f_j \in I_{\beta_j}, \mbox{ for some } I_{\beta_j}\}$$ is an ideal and is the smallest ideal containing $\cup_{\beta \in B} I_{\beta}$.  I've already proved when I only have two ideals, and so, using induction, I've seen it for finite sums. But I don't see how to generalise that to an arbitrary family of indexes (maybe infinite) $\beta$.   Could someone please give me a hand? Thank you. What is EV, when used as an absolute measurement? How do you know when to wean? What signs can a baby show to indicate he/she is ready for weaning?  What does a parent look for to determine the right timing for this for baby, mom and family? How to list files installed by a snap package? After a snap has been installed with sudo snap install [package] how can I list the files which have been installed by the snap? From  by Richard Brualdi  We have a chess master. He has 11 weeks to prepare for a competition so he decides that he will practice everyday by playing at least 1 game a day. To make sure that he's able to take a couple of breaks, he also decides that he wont play more than 12 games per week.  My question is, how do you prove/dis-prove that there will be a succession of (consecutive) days in which he will play k games, $k \geq  22$?  Specifically, I don't quite understand the use of the pigeonhole principle here.  Thanks in advance! :D  EDIT  I'll try to clarify what I'm asking:  The goal is to prove that for every possible practice schedule that the chess master makes, there will always be a consecutive sequence of days such that he plays exactly k games.  So for example, if k = 22, how do you prove that no matter what his schedule is like, he will always play exactly k games in r days, $1 \leq r\leq  77$.  My main question is: what is the general method for proving different values of k? Are there values of k (from 1 to 132 inclusive) that are impossible to obtain?  Note that he does not necessarily have to play 132 games within 77 days! Also, keep in mind the bounds of k. How Can I prove (a+b) mod m = (a mod m) + (b mod m)) mod m? modular arithmetic  How Can I prove (a+b) mod m = (a mod m) + (b mod m)) mod m ? Java reflection: how to get field value from an object, not knowing its class Problem recreating BCD on Windows 7 64bit - The requested system device cannot be found JSonNet boolean serialization Which is better to do client side or server side validation?  In our situation we are using    jQuery and MVC.   JSON data to pass between our View and Controller.     A lot of the validation I do is validating data as users enter it. For example I use the the keypress event to prevent letters in a text box, set a max number of characters and that a number is with in a range.   I guess the better question would be, Are there any benefits to doing server side validation over client side?    Awesome answers everyone. The website that we have is password protected and for a small user base(&lt;50). If they are not running JavaScript we will send ninjas. But if we were designing a site for everyone one I'd agree to do validation on both sides. How to import Illustrator swatch libraries into InDesign - Adobe Indesign Mac? I have a very reach swatch library in adobe-illustrator like food colors and.... But in adobe-indesign I don't have many colors. Why? Can I import them to indesign? Do characters provoke opportunity attack when they leave another character's reach who is not facing them? "You can make an opportunity attack when a hostile creature that YOU CAN SEE moves out of your reach."   In 5E do you have to specify which way your character is facing at all times?  If an enemy who is behind him leaves melee range but his back is to him does that enemy provoke an opportunity attack?    Are enemies within five feet and 360 degrees of a character considered to be within reach?  For example... Kruska and Atone are attacking Dip.  Dip is facing or only attacking Kruska.    Then Atone moves out of Dip's reach (melee range 5 feet) to engage a silly looking wizard.    Does Atone's move provoke an opportunity attack from Dip even though he's not facing him?  Is he assumed to be able to see him? While explaining to my nephew about the physics of light, I told him we cannot see infrared color, and he kicked back with a very simple question: why can't we see it? I could not tell him. Is the human eye unable to sense such light or can it indeed but the brain can't understand the signal? any other reason?