How to change terminal prefix to $
How can I shorten my command line (bash) prompt?
A story about a male protagonist with special eyes that tells him if things are safe or not; green = safe. Can’t remember if it’s a manga or webtoon. It starts with a male protagonist who was dying on a battlefield, the goddess took pity on him, sent his emotions back into his younger self, (not memories). He had eyes that told him what is safe/good and what is dangerous/bad by using colors: green, orange, red. He used this to gamble, his eyes stopped working, borrowed money from his ex-girlfriend (who works in a cafe). Money got stolen while he took a nap by a river, the evil lady who stole his money tried to get him to enter a contract. From his future emotions, he knew he wanted an invitation instead. This leads to a gathering of people in a school gym, their tasks are given. Invited people are given bags with tools. An oni busted out under the floor. People get killed. Stairways with gates, etc. This is considered the tutorial. Points are given after, those points are needed to buy daily necessities. The protagonist had the highest points, given VIP room. Etc. $a^2b^2+a^2c^2+b^2c^2\leq 3$ Let $a, b, c\geq 0$ s.t.$$(a^2-a+1)(b^2-b+1)(c^2-c+1)=1$$  Show that $ a^2b^2+a^2c^2+b^2c^2\leq 3$.  My idea:  I denote $a+b+c=x$, $ab+bc+ac=y$ and $abc=z$.  Then I have $$x^2+y^2+z^2-xy-xz-yz+2z-y-x=0$$ I have to show that $$y^2-2xz\leq 3$$ I tried to prove it with the sign of trinom, but it doesn't work. Is there any example of a non-measurable set whose proof of existence doesn't appeal to the Axiom of choice? Is there any example of a non-measurable set whose proof of existence doesn't appeal to the Axiom of choice?  What would it imply if there was such an example?  EDIT: For instance, maybe this will help understand the kind of example I had in mind, it is known that an important feature to determine that the AC is needed in the Banach-Tarski case is the non-transitivity of rotations on Euclidean space, one might find an example of a transitive group for some given space keeping the rest equal and make the AC unnecessary?  I guess then it might be said that this transitivity will be in this particular case equivalent to the AC or some amount of it, but I guess that it would be important to show this if it hadn't been realized before. Extreme cursor delay with Acer Aspire E15 on Ubuntu 16.04 Occasionally my laptop will enter a state where the cursor starts lagging so bad that it's unusable.  Oddly during this state, everything other than the cursor is still completely responsive.  I.e. anything that only involves the keyboard (opening a terminal, typing, etc) is unaffected.  Once it enters this state, on successive reboots and shutdowns it re-enters this state within seconds.  However, if I shutdown and leave it alone for a few minutes, it does not immediately re-enter this state.  Based on search results for "acer aspire ubuntu freeze" I have tried setting the intel_idle_max_cstate field in grub to 0, 1, and 2, but this did not seem to help.  To be clear - I am not experiencing any crashes, the system is completely responsive except for the cursor is delayed to the point where it would take several seconds to go from one edge of the screen to the other. Easier way to debug a Windows service I'm trying to prove that if $A\neq 0$ is a commutative ring and there is an injective $A$-module homomorphism $A^m\hookrightarrow A^n$ then $m\leq n$ must necessarily hold.    This is exercise 2.11 from Atiyah and MacDonald's Introduction to Commutative Algebra, but unfortunately all the solutions available online are either very sparse with regard to this question or seem to use (to my surprise) a generalized version of Cramer's rule. Is there perhaps some other "cleaner" approach to solving this problem? Is it possible to detect, on the client side, whether the user is using an encrypted page or not?  Put another way -- I want to know if the URL of the current page starts with http or https. How can I access shared folders on an Ubuntu host and a Windows XP guest? Variance of product of multiple independent random variables Is there an SE for Cell-phones? Where would I ask a question pertaining to an ordinary phone? Or just cell phones in general? I saw Windows Phone while browsing the SE database, nothing else really popped out at me. Google didn't bring up anything either. Is that just too small a community to cover with SE? The full question: suppose N is normal in G and $[G:N]=p$ is a prime. Prove that for any $K \leq G$, either (1) $K \leq N$ or (2)$KN=G$ and $[K:K \cap N]=p$.  Since $N,K \leq G$, it is of course possible that $K \leq N$ could happen.  but for (2), we can show $KN \subseteq G$  but how can we show $KN=G$?  And what information does "$[G:N]=p$" give us? Site specific magic comment links Natbib -- change author conjunction in citation call-out from 'and' to '&' I'm using natbib, german babel and natbib creates output of the form   Foo and Bar (1337)   I would like to get   Foo &amp; Bar (1337) for citet and (Foo &amp; Bar 1337) respectively for citep. My little brother is just getting into programming, and for his Science Fair project, he's doing a simulation of a flock of birds in the sky. He's gotten most of his code written, and it works nicely, but the birds need to move every moment.  Tkinter, however, hogs the time for its own event loop, and so his code won't run. Doing root.mainloop() runs, runs, and keeps running, and the only thing it runs is the event handlers.  Is there a way to have his code run alongside the mainloop (without multithreading, it's confusing and this should be kept simple), and if so, what is it?  Right now, he came up with an ugly hack, tying his move() function to &lt;b1-motion&gt;, so that as long as he holds the button down and wiggles the mouse, it works. But there's got to be a better way. The title of  of  is, "Is it posible [sic]?"  This doesn't provide any information at all. It should be mandatory for everyone asking questions on the Internet to read , which says:     Help your community learn from the question. When you field a good question, ask yourself "How would the relevant documentation or FAQ have to change so that nobody has to answer this again?" Ephemeral error message: "cryptsetup: unknown fstype, bad password or options?" I activated disk encryption for my Ubuntu 15.10 64bit installation and get every time after entering the (correct) password the error message:  cryptsetup: unknown fstype, bad password or options?  But after few seconds (without any further interaction) this error message is replaced by the expected message:  cryptsetup: sda5_crypt set up successfully  That's it and the system is started.  Any suggestions what could be the problem? Is it merely cosmetic or serious? Adjusting font size with TikZ picture Taking from the PGF manual,  \begin{tikzpicture}   \draw [help lines] (0,0) grid (3,3);   \coordinate (a) at (rnd,rnd);   \coordinate (b) at (3-rnd,3-rnd);   \draw (a) -- (b);   \node (c) at (1,2) {x};   \draw let \p1 = ($ (a)!(c)!(b) - (c) $),             \n1 = {veclen(\x1,\y1)}         in circle [at=(c), radius=\n1]; \end{tikzpicture}   I'd like to increase the size of x. The problem is that I have multiple circles in the same diagram. Some of them require a larger sized font, while others are okay at default. How do I do this? Flag abusive users I think the community does a great job policing questions/answers, etc. and the community has some good tools available to do this.  Between flagging questions with some reasons behind it and editing posts, closing them, and deleting them, the only thing that seems to be missing to me is the ability to flag a user.  Reasons to flag a user as abusive:   Duplicate User Abusive Behavior Offensive user name or profile User profile consists of spam Others? A hard problem on exponential integration Suppose $a : [0 , 1] \to \Bbb R$ is an infinitely smooth function. For $\lambda\ge1$, define $$F(\lambda) := \lambda \int_0^1 e^{\lambda t} a(t) \, dt.$$ If $\sup_{\lambda\ge1}|F(\lambda)|\lt\infty$, then $a$ is the identically zero function. Below are the some results I have derived:   Derivatives of any order of $a$ vanishes at $t = 1.$ For any $\delta\lt1$, $a(t)$ has a zero in the open interval $(\delta , 1).$  The same is true for all the derivatives of $a(t)$. This tells us that the $n^\text{th}$ derivative of $a$ has infinitely many distinct zeros for all natural $n$. If $a$ is analytic, then I can show that $a(t)\equiv 0.$ If $a(t)\ge0$ on $[0 , 1]$, then it is obvious that $a\equiv 0.$   I would appreciate any hint.  Actually $(1)$ and $(3)$ follows from $(2)$. For $(2)$, suppose that $a(1)\gt0$ (the case that $a(1)\lt0$ can be argued in the same way as the following), then there exists $\delta\lt1$ such that $a(t)$ is strictly positive on $I = [1-\delta , 1]$. Then write $F(\lambda) = \lambda\int_0^{1-\delta}e^{\lambda t}a(t)dt + \lambda\int_{1-\delta}^1e^{\lambda t}a(t)dt$. Now there exists $c\gt0$ such that $a(t)&gt;c$ on $I$ since $I$ is compact, so that the second term is bounded below by $c (e^{\lambda}-e^{\lambda(1-\delta)})$. But the first term is only $O(e^{\lambda(1-\delta)})$, so this contradicts the fact that $F(\lambda)$ is bounded. Morever, using the same idea and integration by parts, one can see that $n^{th}$ derivative of $a$ must vanish at $1$. How does long to int cast work in Java?