Why do my own edits show up in the suggested edit icon?
Number of suggested edits seems to include own edits
Can we interchange phrases " What's the date today?" and "what day is it today?" Centre of Lie Algebra $sl_2(\mathbb{F})$ For $L=sl_2(\mathbb{F})$ i.e. matrices with trace zero,  what is the centre i.e. $Z(L)$= {$x\in L : [x,y]=[y,x] \ \forall\ y \in L$}.  I will have to find matrices $A \in L$ such that $AB=BA$ for all $B \in L$. But how to appoach this considering trace is zero here. Is 1+1 =2 a theorem? A theorem is defined to be a mathematical statement that is proven to be true. The statement $1+1=2$ has definitely been proven in the history of mankind (Russel and Whitehead had once proven it in the book Principia Mathematica).   So can it be considered as a theorem? What determines something to be a theorem (besides it being proven to be true)? Do I need to apply for a visa to enter South Korea as a tourist on an Australian passport? Do I need to apply for a visa to enter South Korea as a tourist for a few days when travelling on an Australian passport? Or will I be able to get one on arrival? $127$ has an interesting property: It is the $31$st prime number and its rank ($31$) is also a prime. $31$ is the $11$th prime so its rank is also a prime. $11$ is also a prime number with a rank ($5$) that is also a prime. $5$ is the 3rd prime number and and so its rank ($3$) is also a prime. And finally $3$ is the $2$nd prime so its rank is also a prime... Is there a name for primes whose rank (index in the prime series) is also a prime? That is:     If $a_i$ is the $i$th prime number, then $i$ is a also a prime.   How about numbers like $127$ where going down ranks of ranks always produce prime numbers (down to rank $2$ of course)? The first $11$ :-) primes in this (infinite) series would be:  $3, 5, 11, 31, 127, 709, 5381, 52711, 648391, 9737333, 174440041, \dotsc$  Many thanks! What Is Energy? Where did it come from? The simplistic undergrad explanation aside, I've never really understood what energy really is. I've been told that it's something when converted from one kind of something to another kind, or does some "work", as defined by us, but what is that something?  Moreover, if the total amount of energy in the universe is finite and we cannot create energy. Then, where did it come from? I've learned from thermodynamics where it goes, but where does it come from?  I know this sounds like something trivially simple, but there is so much going on in the physical universe and I just can't grasp what it is. Maybe it is because I lack the mathematical understanding that I can't grasp the subtle things the universe is doing. Still, I want to understand what it is doing.  How do I get to the point of understanding what it's doing?  (Note: What prompted me to ask this was . I'm afraid that it just puzzled me further and I sat there staring at the screen for a good 10 minutes.) ASP.NET MVC - Can't bind array to view model How can I add a folder to the launcher for quick access to it. In this particular case I wish to drag it to the launcher. Is there a way to disable the hotkeys? I navigate with Ctrl-n,p,f,b (readline/ keys), so that I don't have to move my hands too much and get  again. Is there a way to disable Ctrl-b being hotkey for bold?  Note that this is not just an Emacs thing. Standard web browsers, like Firefox and Chrome, use things like  Ctrl + K and Ctrl + L to navigate to the Google search bar and address bar respectively. Find the center of the symmetry group $S_n$.   Attempt:  By definition, the center is $Z(S_n) = \{ a \in S_n : ag = ga \forall\  g \in S_n\}$. Then we know the identity $e$ is in $S_n$ since there is always the trivial permutation. Suppose $a$ is in $S_n$, but not equal to identity. Now we can imagine the permutation as bijective function that maps from $\{1,2,\dotsc,n\}$ to $\{1,2,\dotsc,n\}$.  So suppose $p$ is a permutation map. Then $p$ maps from a location $i$ to a location $j$. Take $p(i) = j$ where $i\neq j$. Let $k$ be in $\{1,2,\dotsc,n\}$, where $k$, $i$ and $j$ are all different elements. The cycle $r = (jk)$, then we will see if this commutes.  $rp(i) = rj$    Can someone please help me, I am stuck?  Thank you. Background reflected in glossy glass, but I didn't set it I've made a roughness 0 glass pane, when I'm in lookdev mode it's reflecting a background that I didn't put there. I know I could just ignore it, but I'd rather be able to see what it'll mostly look like when I'm in the later stages. I also just want to know how on Earth I managed to set this background without realising it  Reflection completely ignores any objects I put in front of it. If I placed this glass inside my house, it would still just reflect trees (This is the point where I felt I couldn't ignore it - reflections are going to play a big part in my project and I don't want to be in render mode all the time)  The nodes are the default glass BSDF, except I set roughness to 0  The glass is set to 20mm thick, if that makes a difference  The background moves with my perspective and moves when I relocate the glass  I have a few HDRI's on my PC, but none look remotely like this   Also, I'm using cycles as I find Evee buggy as hell I have two files in a directory. One has correct permissions and the other has not. Is there a way I can "copy" the set of permissions from one file to another? What is the difference between old style and new style classes in Python?  When should I use one or the other? Derivative of an even function is odd and vice versa Where can I safely store my stuff? I'd like to find a place to store stuff while I'm out adventuring, without spending 5000 on a house (at least, until I can afford that...). Where can I safely store items without worrying about them disappearing?   There are two possible places that come to mind,  (to which I have the key and was told I could stay), and the small bedroom given to me at the  (which I was told was mine, despite seeing J'zaro sitting in it later). Can I store items safely in either of these places? Is it acceptable to change colors on a logo to make it fit a website's theme? I have a few payment brand images that need to go in the footer of a website, the footer is very dark grey, to the point where making the logos grey-scale wouldn't be much of a good idea, especially as we still need the logos to stand out.  For example I took the following logo:   And changed it to fit with our very dominant red theme:    Is this good in terms of the user's perspective? Is this legal or misrepresenting the brand? If so is completely changing a logo to white acceptable for dark backgrounds? Asymptotic behavior of a trigonometric series Consider the following series $$S_N = \sum_{k=1}^N \frac{\sin[k\pi/(N+1)]}{k}.$$ What is the asymptotic behavior of this series for $N \to \infty$?  If we replace the sine function with the factor $1$, we get the standard harmonic series which diverges $\sim \ln N$. However, if we replace the sine function with $(-1)^k$, we get a convergent series with the result $\ln 2$. Therefore, I think that $S_N$, defined above, should diverge, but more slowly than the logarithm. Am I correct? What is the dot product and why do we need it? I understand how to calculate the dot product of the vectors. But I don't actually understand what a dot product is, and why it's needed.  Could you answer these questions? Let $a$ and $b$ be two integers such that $\left(a,b\right) = 1$. Prove that $\left(a+b, ab\right) = 1$.   $(a,b)=1$ means $a$ and $b$ have no prime factors in common  $ab$ is simply the product of factors of $a$ and factors of $b$.  Let's say $k\mid a+b$ where $k$ is some factor of $a$.  Then $ka=a+b$ and $ka-a=b$ and $a(k-l)=b$.  So $a(k-l)=b, \  a\mid a(k-1)$ [$a$ divides the left hand side] therefore $a\mid b$ [the right hand side].  But $(a,b)=1$ so $a$ cannot divide $b$.  We have a similar argument for $b$.  So $a+b$ is not divisible by any factors of $ab$.  Therefore, $(a+b, ab)=1$.  Would this be correct? Am I missing anything? Wrong kernel version returned by uname Ubuntu 16.04.1 LT uname -a returns:    Linux decebal-mobile 4.2.0-35-generic #40-Ubuntu SMP Tue Mar 15 22:15:45 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux   but E: Package 'linux-headers-4.2.0-35-generic' has no installation candidate  and my machine says linux headers version is at linux-headers-4.4.0-21-generic.   I have seen a similar problem described in a .  How can I update that?