How do I uninstall XFCE and other GUI in Ubuntu 12.04 server? I'm very new to Linux. I thought having a GUI would be nice, but it is using too much RAM so I'd like to just use the regular terminal for now. I have Ubuntu 12.04 server with XFCE installed.  How can I uninstall all GUI related packages and everything that came with them?
How to remove desktop environments? I installed few environments that I wanted to try out on Ubuntu 12.04, but none of them worked at all. It could be that I installed them all at the same time, meaning the OS didn't get a chance to work everything out, but either way, they didn't work. I would now like to remove them.   The one's that I installed are Xubuntu/Xfce, Lubuntu/LXDE, Kubuntu/KDE, Fluxbox, OpenBox, cinnamon, and MATE. I installed them. Everything seemed to have been working properly until I actually tried to use the shells and nothing loaded at all. Except for Fluxbox, I think that one worked. I want to know of any way to repair or perhaps just remove the packages entirely. I might have already removed them because I did the apt-get remove command on all of them, but they were still in the list on the login screen.
OneDrive for Windows 10 - Remove logged out account Can I have multiple primary keys in a single table? Can I have multiple primary keys in a single table? Can one executable be both a console and GUI application? I want to make a  program that can be run as a CLI or GUI application depending on what flags are passed into it. Can this be done?  I have found these related questions, but they don't exactly cover my situation: Doppler redshift of distant galaxies gave first hint that the universe is expanding. I am curious to know how this redshift is actually measured and interpreted from observation. Suppose I observe some  visible line say red with wavelength \lambda_1.  This is not enough to tell that this line is redshifted, i.e., the  original line emitted from that galaxy had a smaller wavelength. How do I know the value of that particular line when it was emitted from that galaxy? It appears that mere observation of a line is not enough. So how do we proceed? I was trying to look for an answer of mine earlier and did a search like this:  user:me SQLite RunInTransaction   The above found nothing. So I changed it to  user:me SQLite   Which found a bunch of things. I dug through the results and saw this snippet for :     From my experience, wrapping as many database calls as possible into a transaction speeds things up quite a bit: using (var db = new SQLiteConnection(dbPath)) { db.RunInTransaction(() => { …    Notice that the snippet contains both "SQLite" and "RunInTransaction". In looking at the post itself I noticed "SQLite" was in the question title and in my answer as code. I also noticed that "RunInTransaction" is only in my answer in code.  I looked at meta and saw , which says I need to prefix any code with code:, so I tried:  user:me SQLite code:RunInTransaction user:me code:SQLite code:RunInTransaction   None of the above returned any results.  I also found  on meta which says I can search for code like this (without the code: prefix):        So I tried:  SQLite RunInTransaction "SQLite RunInTransaction"   The first did not return my answer. The second did not return any results.  So my question:  How do I properly search for , that has both "SQLite" and "RunInTransaction" in the post? I'm on 10.9, and I had been using internet sharing successfully again for the first time since Lion. Today though, it just decided to stop working again.  Network layout:  Modem -ethernet-&gt; Router -ethernet-&gt; Mac Pro -ethernet-&gt; MacBook Pro Retina   The internet works fine on the Mac Pro, but it is no longer forwarding the proper DHCP settings to the MacBook.  Previously, the MacBook would get the IP address of 192.168.2.12, and was able to surf the web fine. (Though it wasn't able to connect to any AirPlay/AirPrint devices while on the ethernet interface)  Sometime today, a setting got messed up, and I'm not sure how to fix it or what setting it is.  The MacBook now has a "Self-assigned" IP of 169.254.121.24, even though it is set to use DHCP. The ethernet port on the Mac Pro that the MacBook Pro is connected to is showing a "Self-assigned" IP of 169.254.36.53, even though it is set up to use DHCP as well.  The internet sharing options appear to be correct: share connection from Ethernet 1 to Ethernet 2.  But alas, for no apparent reason, I'm not getting internet access. What is the range of the validity of Coulomb's law? How to compute $\lim_{n\rightarrow\infty}e^{-n}\left(1+n+\frac{n^2}{2!}\cdots+\frac{n^n}{n!}\right)$ There is a probabilistic method to solve it. But I am not familiar with probability. I am trying to compute it by analytic method, such as using L Hospital's rule or Stolz formula, but they are not working. How can we distribute Shamir's secret sharing scheme shares without a dealer? Let's say $k$ users have shares to a $(k,n)$ secret sharing scheme, and they want to issue new shares. How can they do this without collecting the shares together?  In particular, no set of $k-1$ users (including the new users) should be able to learn the shared secret during or after the share generating process. There is also no trusted third party.  One way to do this is by doing a secure multiparty computation. Is there a way to accomplish the task without a general multiparty computation scheme? I am designing a hobby project that will run on a battery so I am trying to reduce power consumption. The SoC I am using has the ability to go into a deep sleep mode where it consumes very little power, and then can be interrupted by a falling edge on a pin.  I want to generate a high-low-high pulse when the state of a reed switch changes in either direction. I have been reading a lot and it seems that a one-shot monostable circuit can be built from a couple of transistors and an RC circuit to generate an output pulse when an edge is detected. I understand how that works. However, I can't figure out the best way to also pulse on the opposite edge.  One thought, was to just combine two one-shots that are configured to trigger on rising and falling edges respectively, and use the transistors at the output to pull the common pull-up low (kind of like a NOR gate).  Since I am a hobbyist, I am mostly using passive components. What is the "real" way of doing this in a low-power configuration using logic devices?  Edit: I figure I should mention something about the timing requirements. Normally the reed switch will be either open or closed for many seconds at minimum before changing states.  Edit: Here is an example of the circuit I was using for detecting only the falling edge:    And here is the ~20ms pulse it was producing for ~200ms button press simulating the reed switch (Channel 1 is Vbe for T1 and Channel 2 is measured at RST): Q. Find all pairs $(p,n)$ of positive integers where $p$ is prime and $p^3-p=n^7-n^3$.   Rewriting the given equation as $p(p+1)(p-1)=n^3(n^2+1)(n+1)(n-1)$, we see that $p$ must divide one of the factors $n,n+1,n-1,n^2+1$ on the $\text{r.h.s}$.   Now, the $\text{l.h.s}$ is an increasing function of $p$ for $p\ge1$. This implies that for any given $n\ge1$, there is exactly one real $p$ for which $\text{l.h.s}=\text{r.h.s}$. For $p=n^2$, we get $\text{l.h.s}=n^6-n^2&lt;n^7-n^3=\text{r.h.s}.$ This means that either $p&gt;n^2$ or $p&lt;n^2$ must hold.  Assuming $p&gt;n^2$, it follows that the prime $p$ cannot divide any of $n,n+1,n-1$. So $p$ must divide $n^2+1$ and hence $p=n^2+1\quad (\because p&gt;n^2)$.  Substituting the value of $p$ in the given equation we get, $n^2+2=n^3-n\implies n^3-n^2-n=2$. As the factor $n$ on the $\text{l.h.s}$ must divide $2$, the above equation has a unique integer solution $n=2$.  Finally, we get $(5,2)$ as the solution to the given equation.      But how do I conclude this is the only solution possible? Also, why does'nt $p&lt;n^2$ (the case which I ignored) hold? As a bonus question, I would like to ask for any alternative/elegant solution (possibly using congruence relations) to the problem. Extra blue line appearing in the top bar (Firefox only) Whenever we click on the Inbox or the Achievements in the top bar, an extra blue line appears near by them. This is reproducible on Stack Overflow and Anime &amp; Manga(as I use only those) but not on Meta Stack Overflow. Here is a snapshot of that.    I'm using Firefox 25.0.1 on Win7 Pro.  Edit: Just to be double sure, I restarted the FF and still I'm able to see it. Here is another snapshot, with the 2 distinct sites. $(document) vs. $("document") Problem:  Start page numbers from chapter one and also reflect this in the TOC.  Currently the code for TOC is:  \renewcommand{\contentsname}{Table of contents}  \setcounter{secnumdepth}{2} \setcounter{tocdepth}{2} \tableofcontents   I would appreciate if I can be pointed in the right direction. So far I have understood that you can use \chapter* in order not to include a chapter in the TOC.  Questions:  1) How would you force Latex to start numbering from chapter 1 and forward?  2) How can you start page numbering from the first chapter? Why does a Ball bounce back if Forces are Equal and Opposite? When a ball is thrown onto a wall, the ball exerts a force onto the wall. According to Newton's Third Law, the wall will exert an equal and opposite force to the ball. Thus, how would the ball be able to bounce back? Shouldn't it just slide down the wall? Geometric series for two-point function In deriving the expression for the exact propagator  $$G_c^{(2)}(x_1,x_2)=[p^2-m^2+\Pi(p)]^{-1}$$   for $\phi^4$ theory all books that i know use the following argument:  $$G_c^{(2)}(x_1,x_2)=G_0^{(2)}+G_0^{(2)}\Pi G_0^{(2)}+G_0^{(2)}\Pi G_0^{(2)}\Pi G_0^{(2)}+...$$  wich is a geometric series so the formula for the exact propagator.Here  $$G_0^{(2)}$$   is the free propagator and   $$\Pi=X+Y+Z+...+W$$  is the sum of all irreducible diagrams.Here the irreducible diagrams is represented by $X,Y,Z,...,W$.  Using the path integral i can see, that  connected diagrams $D$ can be written in the form  $$D=G_0^{(2)}XG_0^{(2)}Z...G_0^{(2)}W$$  Question: But how to prove that there is no constant $C$ so that instead we have  $$D=G_0^{(2)}XG_0^{(2)}Z...G_0^{(2)}W$$  we would have  $$D=CG_0^{(2)}XG_0^{(2)}Z...G_0^{(2)}W~?$$  In the last case we would not have a geometrical serie. Can someone explain me i t please  or give me another way to derive it. What does the phrase "begging the question" really mean? And does it even matter if I use it correctly? Almost everyone just uses it as a synonym for "posing the question" these days. Quantum Entanglement - What's the big deal? Bearing in mind I am a layman - with no background in physics - please could someone explain what the "big deal" is with quantum entanglement?  I used to think I understood it - that 2 particles, say a light-year apart spatially, could affect each other physically, instantly.  Here I would understand the "big deal".  On further reading I've come to understand (maybe incorrectly) that the spatially separated particles may not affect each other, but in knowing one's properties you can infer the other's.  If that it the case, I don't see what the big deal is... 2 things have some properties set in correlation to each other at the point of entanglement, they are separated, measured, and found to have these properties...?  What am I missing? Is it that the particles properties are in an "un-set" state, and only when measured do they get set?  (i.e. the wave-function collapses).  If this is true - why do we think this instead of the more intuitive thought that the properties were set at an earlier time? Do neutrinos not couple to the Higgs field? I was reading the CernCourier, my favorite source of message on Higgs and friends. I was rather shocked, when I saw this:     "The mechanism by which neutrino mass is generated is not known."   What? Not known?  says: In Higgs-based theories, the property of 'mass' is a manifestation of potential energy transferred to particles when they interact ("couple") with the Higgs field, which had contained that mass in the form of energy.  Does this mean that neutrinos don't couple to the Higgs field? If I have a string with a valid math expression such as:  String s = "1 + 2 * 7";   Is there a built in library/function in .NET that will parse and evaluate that expression for me and return the result? In this case 15.