In a strange twist of events, I got this error that said that my edits couldn't be submitted because I needed the moderator tag . I'm not a moderator, so I just decided to humor the system.  And now there's this random old FAQ that's featured on SFF meta as a result (). It's even showing up in the sidebar:    Here is a screenshot of , which don't show me adding the tag, but I did:        I'm not sure why this happened, but I will note that it's a community wiki  question and the previous revisions were all done by an ex-moderator whose account is now deleted.  I can't add any red tags here on MSE though.
Look at  edit. I didn't really expect that I would able to suggest adding  tag, but I could!  How is it possible? (seems that usual users can add mod-only tags without moderator help!)  Edit  Oded removed  back :-(
Will tcpdump see packets that are being dropped by iptables? How to solve apt "package cannot be configured because package is in a different version" errors? says that the number of different monomials of degree $M$ in $N$ variables is $$\frac{(M+N-1)!}{M!(N-1)!}\; .$$ Can anyone explain why this is true? Difference Boolean modifier. How do I get it to work with my mesh? I want to make a screw head, but I can't get the cross in the screw head; the Boolean modifier doesn't work.  Link: I made a huge project, wanted to reduce file size from 1.3GB to below 1GB. Compressing did not help. I removed objects from scene. Also textures. I then realized, the file size even was the same when I delete ALL objects. Why?  Download of sample:   Before deleting all: 1.2GB, after: 1.1GB. Setting DIV width and height in JavaScript I remember my English teacher saying that there are only two valid ways to make a one-word sentence:   A question:      Why? Where?  A command:     Go! Stop!    Is this correct? I see stuff like command 1&gt; out or with 2&gt;&amp;1 to redirect stderr, but sometimes I also see &amp;&gt; by itself, etc.  What is the best way to understand &amp; and what it means exactly? Linear transformation of a binomial random variable? Let $X$ be a binomial random variable with parameters $n$ and $p$. Next, let: $$ Y = aX + b $$ I know that: $$ \mathbb{E}[Y] = \mathbb{E}[aX+b] = a\mathbb{E}[X] + b = anp + b \\ \text{Var}(Y) = \text{Var}(aX+b) = a^2 \text{Var}(X) = a^2np(1-p) $$ But how is $Y$ distributed? Is it Possible to Disable Feed and Topics for an Object Completely at Profile Level / Page LayOuts Tall fraction puzzle I was given this problem 30 years ago by a coworker, posted it 15 years ago to rec.puzzles, and got a solution from Barry Wolk, but have never seen it again.  Consider the series:  $$1, \frac{1}{2},\frac{\displaystyle\frac{1}{2}}{\displaystyle\frac{3}{4}},\frac{\displaystyle\frac{\displaystyle\frac{1}{2}}{\displaystyle\frac{3}{4}}}{\displaystyle\frac{\displaystyle\frac{5}{6}}{\displaystyle\frac{7}{8}}},\cdots$$  Each fraction keeps its large bars while being put atop a similar structure. This can also be represented as $$\frac{1\cdot 4 \cdot 6 \cdot 7 \cdot\cdots}{2 \cdot 3 \cdot 5 \cdot 8 \cdot\cdots}$$ terminating at $2^n$ for some $n$, where it is much closer to the limit than elsewhere.  The challenge:   Find the limit, not too hard by experiment In the last expression, find a simple, nonrecursive, expression to say whether $n$ is in the numerator or denominator Prove the limit is correct-this is the hard one. Suppose that $S_0$ and A are positive numbers, let $$S_{n+1} = \frac{1}{2}\left(S_n +\frac{A}{S_n}\right)$$ with $n \geq 0 $.      (a)Show that $S_{n+1} \geq \sqrt{A} $ if $n \geq 0$       (b)Show that $S_{n+1} \leq S_n $ , if $n \geq 1$      (c) Show that $s= \lim\limits_{n \rightarrow \infty} S_n$ exists      (d) find s   (a) Show that $S_{n+1} \geq \sqrt{A} $ if $n \geq 0$  Given $$P_n:  S_{n+1} = \frac{1}{2}\left(S_n +\frac{A}{S_n}\right) \geq \sqrt{A}$$  $$P_0: S_{1} = \frac{1}{2}\left(S_0 +\frac{A}{S_0}\right) \geq \sqrt{A}  $$  We assume that $P_n$ is true  $$P_{n+1}: S_{n+2}= \frac{1}{2}\left(S_{n+1} +\frac{A}{S_{n+1}}\right)$$ by assumption $$S_{n+2}= \frac{1}{2}\left(S_{n+1}\left(1 +\frac{A}{(S_{n+1})^2}\right)\right) \geq \frac{1}{2}\left(\sqrt{A}\left(1 +\frac{A}{(\sqrt{A})^2}\right)\right)$$ $$ S_{n+2}= \frac{1}{2}\left(S_{n+1} +\frac{A}{S_{n+1}}\right) \geq \sqrt{A}  $$  It follows that $S_{n+1} \geq \sqrt{A} $    (b) Show that $S_{n+1} \leq S_n $ , if $n \geq 1$  $$S_{n+1} \leq S_n$$ $$\frac{1}{2}\left(S_n +\frac{A}{S_n}\right) \leq S_n $$ Dividing by $S_n$ $$\frac{1}{2}\left(1 +\frac{A}{S_n^2}\right) \leq 1 $$ $$\frac{A}{2S_n^2} \leq \frac{1}{2}$$ $$A \leq S_n^2$$ $$S_n \geq \sqrt{A}$$ As  $S_{n+1} \leq S_n$ yields a true statement, it follows $S_{n+1} \leq S_n$ is true.    (c) Show that $s= \lim\limits_{n \rightarrow \infty} S_n$ exists  Since $S_{n+1} \leq S_n$, the sequence is non-increasing,   using the non-increasing theorem stating that      if $\{S_n\}$ is non-increasing then $$\lim\limits_{n \rightarrow &gt; \infty} S_n = \inf\{S_n\} $$     (d) find s    Is the argumentation in (a) and (b) appropriate? Also, I have to admit I m getting less confident in my argumentation (c) and (d). How to proceed in (c) and (d)?  Much appreciated for your input or help. Train passport control from London to Paris I'm a non-EU citizen, I will be travelling from London to Paris next month, so I was wondering since most countries track entry and leave dates, if I use the train to switch these countries and they don't control it, my UK visa will seem like entry YES but no leaving. Same for the Schengen, I wouldn't have an entry date but I'll be leaving,  Will it be trouble later? Are they controlling this on trains? If not is there anything I should do before? Network simplex method, leaving and entering variables Solve $x^2$ $mod$ $23 = 7^2$ What is the procedure to solving $x^2$ $mod$ $23 = 7^2$? According to WolframAlpha, there is no integer solution but I am completely confused as to what steps was taken to determine that.  Before asking the question, I did try to solve this using brute force by plugging in some arbitrary numbers to see whether the square of that number mod $23$ gave me a remainder of $49$ but the procedure was quite tedious. Hence the reason I turned to WolframAlpha.   Going back to the question, I want to know how WoflramAlpha determined that there was no integer solution to solving for $x$. Let $G$ be a finite group and $F$ a field with $\mathrm{char}(F)=0$ or coprime to $|G|$. Let $V$ be a $FG$-module in a way that every $ FG$-homomorphism $ f : V \to V $ is given by $f(x)= \lambda x $. Then $V$ is irreducible.   I already managed to proof this by contradiction, using Maschke's Theorem. We can  write $V$ as $U\oplus W$ and get a $FG$-homomorphism $\pi:U\oplus W \to U\oplus W$, $\pi (u+w)=u$, then $\pi(u+w)=\lambda (u+w)=u $ then either $U$ or $W$ are trivial and thus $V$ is irreducible.  My question is if this statements still holds if the characterictic of $F$ divides the order of $G$, since I only used this fact in my proof to use Maschke's theorem. String formatting in Python I want to do something like String.Format("[{0}, {1}, {2}]", 1, 2, 3) which returns:  [1, 2, 3]   How do I do this in Python? Do spellcasters know when a dismissable spell has been broken? Do spell casters know how long their spells are active, and can they tell at a glance?  Specifically lets talk about , as I know its a permanent duration and dismissable. Does the spell caster who put someone under this spell know how long it is active? Could they tell automatically just by seeing the person (without any clues like them walking in a maze without difficulty or reacting to a sound)? So could they tell if someone has broken the spell they cast? How to create a bootable USB with multiple ISO images in it Running Windows 7  I'm trying to boost the startup speed of my computer and I'm going through "msconfig" and "services.msc" to disable some applications from starting up automatically when the computer turns on.  There are some good sites that document the entries found in the "Processes" tab of the task manager.  You can find out if they are safe to kill, who the manufacturer is, and what the process in question is used  for.  Are there any sites that list startup processes &amp;| services that are safe to kill?  For example, there is an entry in msconfig that just says "Computer Browser" - pretty vague, but seems like something to not kill.  On the other hand, there is an entry in msconfig that says "Extensible Authentication Protocol" - pretty specific and seems like it shouldn't be killed, but how can I know for sure?  Does anyone know if there are any websites documenting the "killable" items listed in both msconfig &amp; services.msc?