Fake proof: 2=4 using nested exponents
Seems that I just proved $2=4$.
I am trying to automate these steps so that I don't need to do this on every machines manually. I need to install latest app server software (abc.tar.gz) on all the unix boxes.  I need to do this in around 12 machines - "machine1" ... "machine12". I have a master machine "machine0" which has abc.tar.gz file so I was thinking to run my script from this machine only and install abc.tar.gz software by following below steps in all those 12 machines one by one. My unix account id is david and my process runs as golden user.  This is the steps I follow if I am installing abc.tar.gz in "machine1":  david@machine1:~$ sudo scp david@machine0:/home/david/abc.tar.gz . david@machine1:~$ sudo stop test_server david@machine1:~$ sudo su - golden golden@machine1:~$ cd /opt/process golden@machine1:/opt/process$ rm -rf * golden@machine1:/opt/process$ exit david@machine1:~$ sudo cp abc.tar.gz /opt/process david@machine1:~$ sudo chown -R golden /opt/process david@machine1:~$ sudo su - golden golden@machine1:~$ cd /opt/process golden@machine1:/opt/process$ tar -xvzf abc.tar.gz golden@machine1:/opt/process$ exit david@machine1:~$ sudo start test_server   How can I automate this so that it can do the same steps in all 12 machines one bye one? I mean install abc.tar.gz in machine1 first, then install on machine2 and go on..  I want to run this script from machine0 only.  Is there any way to automate this? Best way to make a shutdown hook? Since Ubuntu relies on upstart for some time now, I would like to use an upstart job to gracefully shutdown certain applications on system shutdown or reboot. It is essential that the system's shutdown or reboot is stalled until these applications are shut down.  The applications will be started manually on occasion, and on system shutdown should automatically be ended by a script (which I already have). Since the applications can't be ended reliably without (nearly all) other services running, ending the applications has to be done before the rest of the shutdown begins.  I think I can solve this by an upstart job which will be triggered on shutdown, but I am unsure which events I should use in which manner. So far, I have read the following (partly contradicting) statements:   There is no general shutdown event in upstart Use a stanza like start on starting shutdown in the job definition Use a stanza like start on runlevel [06S] in the job definition Use a stanza like start on starting runlevel [06S] in the job definition Use a stanza like start on stopping runlevel [!06S] in the job definition   From these recommendations, the following questions arise:   Is there or is there not a general shutdown event in Ubuntu's upstart? What is the recommended way to implement a "shutdown hook"? When are the events runlevel [x] triggered; is this when having entered the runlevel or when entering the runlevel? Can we use something like start on starting runlevel [x] or start on stopping runlevel [x]? What would be the best solution for my problem?   Thank you very much How do I recover the default version of some configuration file? By accident, I messed up a configuration file. How do I recover the default version without reinstalling or affecting other things? jQuery autocomplete tagging plug-in like StackOverflow's input tags? What solutions accomplish the same auto-completion that SO uses for entering tags?  There are plugins that can handle one word but I haven't seen any that handle multiple words. Indicator icons do not appear after upgrade to Ubuntu 17.10 How do I install applications in Ubuntu? How can I install applications like Google Chrome on Ubuntu?  Are there any commands to install an application?    Index of answers: Is there a word to describe a highly desirable cursed treasure? Is there a single word to describe an object or idea that is so desirable that everyone wants to attain it but once they have it they are immediately cursed?  The idea is often used in literature—some examples:   In Lord of the Rings, the 'one ring' is a perfect example of this. In Guy de Maupassant's story , the necklace might be considered to be this. There are many stories of people making deals with the devil (see question: ), or being granted three wishes by a Djinn or fairy, which inevitably turn out bad. In the Twilight Zone episode , Bemis's desire to be left alone with his books would be an example of this word.   'Bane' covers the cursed part, but no one desires it.  Is there a single word to describe a most highly desired treasure that (knowingly or unknowingly) comes with a curse? How to prove that $\sum_{r=0}^n\binom{n}{r}2^r=3^n$ Firefox running with rare arguments I got this output from ps aux|grep firefox command:  $ ps aux|grep firefox auraham   5443 17.3 11.0 2600628 426484 ?      Sl   18:10   0:54 /usr/lib/firefox/firefox auraham   5496 24.0 17.9 2558108 691700 ?      Sl   18:10   1:15 /usr/lib/firefox/firefox -contentproc -childID 1 -isForBrowser -intPrefs 5:50|6:-1|18:0|28:1000|33:20|34:10|43:128|44:10000|49:0|51:400|52:1|53:0|54:0|59:0|60:120|61:120|91:2|92:1|106:5000|117:0|119:0|130:10000|155:24|156:32768|158:0|159:0|167:5|171:1048576|172:100|173:5000|175:600|176:4|177:1|186:2|200:60000| -boolPrefs 1:0|2:0|4:0|26:1|27:1|30:0|35:1|36:0|37:0|38:0|41:1|42:1|45:0|46:0|47:0|48:0|50:0|55:1|56:1|57:0|58:1|62:1|63:1|64:0|65:1|66:1|67:0|68:1|71:0|72:0|75:1|76:1|80:1|81:1|82:1|83:0|85:0|86:0|87:1|88:0|93:1|94:0|100:0|105:0|108:1|109:0|111:1|112:1|114:1|118:0|120:0|122:0|124:1|125:1|131:0|132:0|133:1|135:0|146:0|153:0|154:0|157:1|160:0|162:1|164:1|165:0|170:0|174:1|179:0|180:0|181:0|182:1|183:0|184:0|185:1|188:1|192:0|193:0|194:1|195:1|196:0|197:1|198:1|199:1|201:0|202:0|204:0|212:1|213:1|214:0|215:0|216:0| -stringPrefs 3:7;release|134:3;1.0|151:332;  ¼½¾ǃː??։֊׃״؉؊٪۔܁܂܃܄ᅟᅠ᜵           ???‐’․‧??????? ‹›⁁⁄⁒ ⅓⅔⅕⅖⅗⅘⅙⅚?⅜⅝⅞⅟∕∶⎮╱⧶⧸⫻⫽⿰⿱⿲⿳⿴⿵⿶⿷⿸⿹⿺⿻　。〔〕〳゠ㅤ㈝㈞㎮㎯㏆㏟꞉︔︕︿﹝﹞?．／｡ﾠ???￼�|152:8;moderate| -greomni /usr/lib/firefox/omni.ja -appomni /usr/lib/firefox/browser/omni.ja -appdir /usr/lib/firefox/browser 5443 true tab auraham   5694  0.0  0.0  15444  1092 pts/2    S+   18:15   0:00 grep --color=auto firefox   According to , this error occurs after firefox crashes. However, every time I run Firefox again, that large line of arguments appears too.  I already try these things:   Run Firefox with addons disabled Reinstall Firefox (sudo apt-get purge firefox; sudo apt-get install firefox)   However, it did not work.  Is it possible to remove such a line of arguments? I have seen some very weird for loops when reading other people's code. I have been trying to search for a full syntax explanation for the for loop in C but it is very hard because the word "for" appears in unrelated sentences making the search almost impossible to Google effectively.  This question came to my mind after reading  which made me curious again.  The for here:   for(p=0;p+=(a&amp;1)*b,a!=1;a&gt;&gt;=1,b&lt;&lt;=1);   In the middle condition there is a comma separating the two pieces of code, what does this comma do? The comma on the right side I understand as it makes both a&gt;&gt;=1 and b&lt;&lt;=1.   But within a loop exit condition, what happens? Does it exit when p==0, when a==1 or when both happen?  It would be great if anyone could help me understand this and maybe point me in the direction of a full for loop syntax description. Some people (me) would prefer the straight GNOME experience as opposed to the Unity style desktop offered in Ubuntu 17.10.  How can I get the standard GNOME desktop and interface? PHB says 'once per turn,' so, it would seem that a Rogue with Sentinel, for example, could "consistently" deal Sneak attack twice per round (whether the enemy triggers an OA or the melee weapon attack provided by the Feat).  So, can rogues deal sneak attack damage with any weapon attack outside their turn? (obv. one that meets the standard requirements--finesse, adv or adj ally) I am happy to always not understand how does a transformer works ... One answer give me 10 questions ... (So I suggest you to not answer to this question, if you do not want to have more questions :D)  Here is the circuit :     So I put the "coupling" factor to 1, in order to have no leakage inductance and I set the value of the inductors very high in order to have a very low magnetizing current. So the primary current is approximately equal to the secondary current. My question is the following : How the primary current can reach an equilibrium to be equal to the secondary load current ? I will not accept answer which tells Pout is equal to ... So Pin is equal to Pout... There is something happenning into the transformer ...   Thank you very much and have a nice day ! Fractions with large elements What is best practice for typesetting fractions with large objects in the numerator and denominator?  For example, fractions with limits, integrals, summations, etc... cause the expressions to look contracted and somewhat odd.  I understand that it is probably best to leave this as is when writing mathematics inline, but as a stand-alone fraction I feel it would be much less distracting if the symbols were typeset at normal size and the fraction was given more height in which to place itself.  Are there standards (for pure mathematics) regarding this problem? And what are the options - if it's generally permitted - for expanding the fraction size to incorporate large objects?    Example  \frac{\sum_{i=0}^{n} i^2}{\iint_{D}\frac{\partial (x,y)}{\partial (u,v)}\,\mathrm{d}u\,\mathrm{d}v}   Both the summation and the integral look somewhat cramped. I think sometimes there is a need to post question as anonymous, reason being to avoid linking content of a question with the identity of the questioner. This may not be so evident or required on technical sites like stackoverflow.com but sometimes is a necessity on sites like  or maybe in future depression.stackexchange.com  On such sites user may not want to link his identity to some questions where he may detail about his being over-weight or skinny or maybe some other attribute which he may like to keep private and avoid making his concerns public, but still want to ask a question with valid data.  I am not suggesting that user asking question should not be registered or not responsible for content. I think all down-votes or up-votes should still be attributed to user, but this way most users would not suffer , and reputation could even be used for a bounty. The only change should be that while asking question a valid registered user can hide his identity (the whole user signature block/user card and the reputation should be replaced by "identity-hidden") and that question should not be listed in his public profile.  Anyway identity of questioner doesn't add much value to question. If we think such anonymous question may reduce social nature of Stack Exchange sites, and maybe majority of questions will become anonymous we can curb that by putting a daily or monthly limit per user or put a price of say 50 reputation per anonymous question.  PS: I don't think this is duplicate of        because motive for question and reason for feature request are different, and I propose a different solution too, because creating another account for asking such questions has many problems which having a single account doesn't have    I don't have to manage other account If I keep single account I still may want to keep my details to be linked to my non-anonymous questions I may want to use reputations I earned as bounty for anonymous questions    also allows anonymous questions and may be we can take some hint from there. Is there an idiom for someone who gets what he deserved? Like someone receiving punishment for his evil deeds or someone getting awarded for his good deeds? What was the galaxy formation Rust saw before confronting Erol Childress in  S01E08?  It was weird like out of the series. I guess it was some sort of hallucination, a product of Rust's madness or addiction. Let $\{a_n\}$ be an unbounded, strictly increasing sequence of positive real numbers and let $x_k=\frac{a_{k+1}-a_{k}}{a_{k+1}}$. Which of the following statements is/are correct? (CSIR NET December 2014)         For all $n\geq m, \sum\limits^{n}_{k=m}x_k&gt;1-\bf{\frac{a_m}{a_n}}$   There exist $n\geq m, \sum\limits^{n}_{k=m}x_k&gt;\frac{1}{2}$      My attempt:  Analysing question in light of $a_k=k\implies x_k=\frac{k+1-k}{k+1}=\frac1{k+1}$, I feel both are correct, I doubt if  I can generalise the result in light of this one example.   Any way to prove that this true for general case?    Note: Please do not confuse  with my question. The first two options are different, I've marked the difference in bold. What is causing disabled options when adding a mesh/curve object to the scene? Why is LaTeX3 taking so long to come out? I feel as though I have been hearing about the LaTeX3 project for a very long time.   Why is it taking so long for it to come into fruition? Are there major technical difficulties, or is it purely a lack of developers that is causing a bottleneck?