What this code mean in VB.NET ?  I don't understand with : operator. Is it same with ternary operator in Java/C#/C ?   If InStr(elementName, "*") > 0 And depth < maxDepth Then isRule = True : isGrRule = True

Here is an interesting piece of code that my fellow team members were just having a slightly heated discussion about...    Dim fred As Integer    If True Then fred = 5 : fred = 3 : fred = 6 Else fred = 4 : fred = 2 : fred = 1   After executing the above code snippet, what is the value of fred?  Try not to cheat and debug the code.  This is a highly contrived code example that started out as an example of using the colon with an If statement, but then someone decided to take it upon themselves to proffer a result for fred.  UPDATE: I would not normally write code like this and this snippet only serves as an example. As it so happens, this question originated from a discussion involving the creation of a coding standards document for our team.


I created a new MediaWiki website, Speedypedia. It's currently in alpha in two languages - English and Hebrew. I also submitted my website to , but this was a mistake - since then my English version is flooded with spambots and I had to protect it with a username & password. I even added a mathematical captcha but it didn't stop the bots. How can I block bots from my website, without making it hard for real humans, including those who are disabled? I prefer an invisible captcha, but since MediaWiki is used by thousands of websites, I'm not sure it's possible (maybe the bots already know how to cheat it).  By the way, there is no spam in my Hebrew version, why? Maybe the spam bots recognize the English language? How can I change my English version not to have spam too? Or maybe the bots only crawled the English list of websites using MediaWiki, I don't know. But I don't want to remove my website from this list, is there any other solution? I don't want users to edit pages anonymously, they have to create an account. Will it help if they will have to validate their email address? Currently email address is optional and they don't have to validate it.  I prefer not to block specific IP addresses, because I consider it .  I'm sorry if this question was already posted before, I found a similar question from 2011 on Stack Overflow, and it's closed, and its answers are not up to date.  Update: I removed my website from the English and Hebrew lists of sites using MediaWiki, and added it to the multilingual list.  I think this question is different than "" because it's a specific question about MediaWiki, which is used in thousands of websites.

This is a general, community wiki question to address all non-specific spam prevention questions.  If your question was closed as a duplicate of this question and you feel that the information provided here does not provide a sufficient answer, please open a discussion on .    For purposes of this question, spam will include:   Any automated post Manually-posted content which includes links to spammers' sites Manually-posted content which includes instructions to visit a spammer's site


My Windows 10 guest OS running in VirtualBox on Mac OS X seems to have . Is there a way to reinstall the OS and wipe any hidden malware, but keep my data files (program customizations, documents not yet backed up to the host, etc.)?

What should I do if my Windows computer seems to be infected with a virus or malware?  What are the symptoms of an infection? What should I do after noticing an infection? What can I do to get rid of it? how to prevent from infection by malware?   This question comes up frequently, and the suggested solutions are usually the same. This community wiki is an attempt to serve as the definitive, most comprehensive answer possible. Feel free to add your contributions via edits.


as above. Simple. Particularly how to use Surface Pro 3 as a 2nd monitor only. not as a surface pro itself. i.e. I have a laptop and use surface pro as a second monitor.

I have tried every solution given on the Internet, as well as some tricks up my own sleeve.  Nothing works to help me "extend" my desktop and not "duplicate" it across 2 monitors.  My question is "What is the appropriate site to ask about this?" I don't think it would be Stack Overflow, but I don't dare try any of them for fear of being downvoted to death if I'm wrong.


I have tried searching stack exchange with a combination of two tags, for example [word] [excel], but the actual search defaults to just the first tag. In this case, only [word].  How do I search with multiple tags?  Edit: From the official FAQ, it sounds like you can search with multiple tags:  I just can't get this to work on desktop (chrome, ie11, windows 7)  Edit 2: this a is a duplicate of the below question. I was searching on a work computer while not logged on:

I just noticed an odd bug.  Steps to recreate:   Do a search for two tags, using the OR operator.   Observe that it properly returns results that contain either tag. Log out. Do a search for two tags, using the OR operator.   Observe that you only get results for the first tag, the OR and second tag are stripped out of the search.   Is this a bug, or on purpose for some reason?


I know that, in the Lord of the Rings and associated works, Eru Ilúvatar is basically the Christian God, with Morgoth being Satan. Since Tolkien famously hated allegory, they should be understood as , not as metaphor for such.  Tolkien occasionally hinted at or stated Christian (specifically Catholic) doctrine, for example in the need for divine intervention to save Frodo from the temptation of the Ring, or the statement that Eru might have to personally redeem humanity at a later date. One might imagine that this extends to the afterlife.   We know a little bit about what happens to creatures that die — Elves are bound to Arda until its end, say — but all I’m aware of for Men is that they “pass out of Arda”.  However, did Tolkien ever state or imply that a literal Christian afterlife existed for those humans who died in Arda? In particular, is there any mention of Heaven, or (even more so) Hell? Conversely, did he imply that a different situation held (at least at that point in time)?

We know in the , :       ... This latter name is somewhat misleading; the land itself, while blessed, did not cause mortals to live forever     In addition Valinor appears to be an actual place        ...Valinor lies in Aman, a continent west of Middle-earth. Ekkaia, the encircling sea surrounds both Aman and Middle-earth     Is there an afterlife where Hobbits, Men and Elves go after death?      There is some indication that Elves are 'immortal', however they can .


I have been given this question from my university to complete and I am having some trouble. The lecturer did not do a very good job of explaining the concept and I could not find any materials online to help so I came here. The question is-  What happens if you apply the method of steepest descent to  $f(x)=(x_1^2)+(x_2^2)+(x_3^2)$  Thank you.

I am totally stumped for what to do here, any help would be appreciated.   1) What happens if you apply the method of steepest descent to $f(x)=x_1^2+x_2^2+x_3^2$?  2)Lagrange multipliers method- Find the dimensions of the rectangular box open at the top of greatest internal volume, given the surface area of the five faces is $108 \, \mathbb{cm}^2$.  Thanks


I am new to ubuntu.  I purchased (donation) a CD from Canonical in March 2015. The first time I inserted disk in drive and turned on laptop I got an error msg something like "no boot ???? found"  I didn't write it down and could not remember msg.  Laptop is Fuji-Siemens Amilo Li 1705 with Intel(R) Celeron(R) M cpu  440 @1.86GHz and 1.75GB RAM. I am running Windows Vista  Now, when I try to boot with the ubuntu cd laptop tries to read it for about 1 minute and then stops and Windows boots.  If I put CD in while Windows is running, laptop seems to be reading disk for about 1 min and then ejects CD and error msg asks me to insert disk.  Can anyone help please, or should I just ask Canonical  for another CD?

I would like to see a full how-to guide on how to install Ubuntu.


I am looking for people interesting in going bicycle touring in S.E.Asia. Having travelled by bike before alone and with a partner, I'm keen this time to find someone likeminded to go through the process of preparing and be up for an adventure. Any websites, forums or otherwise for finding this kind of person?

I like independent trips so I avoid tours packages. But sometimes I need to find a trip companion or to make a small group in order to reduce expenses (i.e. rent a car) or to reduce risks (i.e. big trekking without guide).  The problem is that I can't find a website that join independent travellers. I use Couchsurfing website and ask in forums, so I'd like to know if there is any online resource specific for this topic.  NOTE: I've try to search "trip companion" in Google, but all first page results seems to take me to dating sites except the first one that takes to Lonely Planet forum.


I was searching for a way to disable sudo password promot , then I found a command to remove the user password sudo passwd -d username but after I wrote it and try to make sudo commands it asks for the password, i tried to put the old password and blank password but unfortunately it says  Sorry, try again  What should I type or do ?

I have a realy strange problem in Ubuntu 11.10. I have by accident my password set to empty. If I wan't to install software now the system asks for a password, but I haven't one anymore. If I enter my old password it sais it's wrong and if I leave it empty it also does. Now I wan't to set my password back, but the system asks for the old password before I can change it. That password doesn't exist, so I can't do anything anymore! Can someone help me please?


I'm trying to figure out how to generate 3 different random numbers between 50 and 100 using visual basic. My code only prints out the same number three times. Dim number As Integer number = rndNumber.Next(50, 100)  lblATime.Text = number.ToString lblBTime.Text = number.ToString lblCTime.Text = number.ToString

I need to generate a random integer between 1 and n (where n is a positive whole number) to use for a unit test. I don't need something overly complicated to ensure true randomness - just an old-fashioned random number.  How would I do that?


If a proper noun includes the word "the" and we want to refer to it using the definite article, should "the" appear twice in succession? For example:  "Can you pass me The Who CD?" vs. "can you pass me the The Who CD?"  "The US Government passed The Hague Act" vs. "The US Government passed the The Hague Act?". (this example inspired by a comment to ).  To me the first versions seem incorrect, but the second versions sound very awkward.

The lowest in-game rank of authority is that of the Baron – variations are Timariot, Shaman, Mayor, Bishop, Patrician – of which only Patrician is a playable rank if the player owns the The Republic DLC.  Is "the The" correct in the sentence, or should it just be "The"? DLC stands for downloadable content (in this case, a new place) in a game. It is the same idea as the following.   The New York Times is a good newspaper. We read the The New York Times.


Let $R$ be a ring. What does it mean to be an $R$-algebra?  I missed the definition in my lectures and when I search online, I can only find definitions of what a ring is.

In the following, assume that rings are rings with unity. Here is the definition of $R$-algebra from Wikipedia:  Let $R$ be a commutative ring and $(M,+,\cdot)$ an $R$-module. Assume $\ast$ is a binary operation on $M$, such that:  $x\ast (y+z)= x\ast y + x\ast z$ $\forall x,y,z \in M.(x+y)\ast z = x\ast z + y\ast z$ $\forall r,s \in R,x,y \in M.(rx)\ast (sy)=(rs)(x\ast y) (r,s\in R, x,y\in M)$  then $(M,+,\cdot,\ast)$ is called an $R$-algebra.  This definition has the same form as my definition for "algebra over a field". Note that this definition does not require $\ast$ to be associative. Here is an equivalent definition given in Dummit&Foote (original form is given using a ring homomorphism):  Let $(M,+,\cdot)$ be a ring and $R$ a commutive ring. If $M$ is an $R$-module and the multiplication on $M$ is bilinear, then $M$ is called "an $R$-algebra".  Note that this definition requires $\ast$ to be associative. What is the usual definition for $R$-algebra? References Abstract Algebra, Dummit and Foote, 3rd edition, page 355.


Fails both on chrome and node 8.x  ["4", "5"].map(x => parseInt(x)) // [4, 5] ["4", "5"].map(parseInt) // [4, NaN]   WHAT?

From the :  [1,4,9].map(Math.sqrt)   will yield:  [1,2,3]   Why then does this:  ['1','2','3'].map(parseInt)   yield this:  [1, NaN, NaN]   I have tested in Firefox 3.0.1 and Chrome 0.3 and just as a disclaimer, I know this is not cross-browser functionality (no IE).  I found out that the following will accomplish the desired effect. However, it still doesn’t explain the errant behavior of parseInt.  ['1','2','3'].map(function(i){return +i;}) // returns [1,2,3]


Given 2 matrixes A and B: Assuming that A and B are both nxn and that 𝐴𝐵 ≠ 0 and 𝐵𝐴 ≠ 0. Does rank(𝐴𝐵)=rank(𝐵𝐴)? I’ve tried like 8 different examples and they all turned out to be equal but I’m not sure whether it actually is or not, can someone help me prove/disprove this?

I know that matrix multiplication is not commutative: $ AB \neq BA$.  Still, it may be possible that $\operatorname {rank} (AB) = \operatorname {rank}  (BA)$. But it seems to be not true.  How can it be proved that $ \operatorname {rank} (AB) \neq \operatorname {rank} (BA)$?   (Usually it's not a big deal to prove a negative statement since it only take to find one example when the equality is not satisfied.)


In the case of the following program, I can think simply it has two times probability between One sample t-test(0.002111) and Two sample t-test(0.001053) to the p-value? x1<-c(1,2,3,4,5) x2<-c(6,7,8,9,10) (m1<-mean(x1)) (m2<-mean(x2)) (var1<-var(x1)) (var2<-var(x2))  t.test(x1,mu=8,alternative="two.sided") #        One Sample t-test #data:  x1 #t = -7.0711, df = 4, p-value = 0.002111 #alternative hypothesis: true mean is not equal to 8  t.test(x1,x2,alternative="two.sided") #        Welch Two Sample t-test #data:  x1 and x2 #t = -5, df = 8, p-value = 0.001053 #alternative hypothesis: true difference in means is not equal to 0

I am looking for various ways of explaining to my students (in an elementary statistics course) what is a two tailed test, and how its P value is calculated.  How do you explain to your students the two- vs one- tailed test?


How do I specify the exact position of a float?  I am not talking about the [t],[b],[h!] etc operators, I want to specify the exact position of the float, i.e. 15cm from top and 15cm from left.  Regards

Is there any package or a method to force LaTeX to keep floating environments like table and figure closer to where they are declared?


I looked up the load method to find an alternative to php includes. I got the load to add html dynamically and it works. The one issue though is that function aren't working. I think it's either an order issue, structure issue or plain logic. Any help to get my functions to work in dynamically generated html would be greatly appreciated. Sample structure below.  $(document).ready(function () {     "use strict";      $("header").load("/_includes/header.html");  });  $(window).bind("load", function () {     "use strict";      $('.class').click(function () {         $('#id').slideToggle('fast');     }); });

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


As the question states, I want to find data about a particular project and I am wondering what the right place is to ask people how they go about searching for it. Would Stack Overflow be it?

There seems to be more than a few computer science/programming Stack Exchange networks (is that the correct term?). Stack Overflow, being the first, has by far the most users, questions, and answers.  What is the reasoning for creating the others, and are there clear guidelines for which kinds of questions should be posted? I can see a large amount of potential overflow, many cases of people not getting a good answer to their question, because the person who has the answer isn't browsing that particular network at the moment.  I understand that they were probably created for organizational purposes, but wouldn't it almost make more sense to just have them as categories under Stack Overflow, keep them separated but still connected, instead of making people have to create multiple 'account's, one for each network?  I am sure there was a very good reason to break them up, but as someone that is new to SE, it can be somewhat intimidating to decide which one to post in to ensure you get a good answer. For example, if I am a computer science student, my first instinct might to be to post in the computer science network, until I see that it literally has 1% of the users as the Stack Overflow network, which still seems to be for programming/computer science related questions.  So my second instinct would then to be to post it into the Stack Overflow site on the basis that I have a significantly higher chance of my question being seen and getting a good answer. Then I notice that there is also a 'programmers' network, and I don't even begin to know where that fits in. I, and I am assuming most people, will probably just post on Stack Overflow to be safe.  My question is, other than the short little description blurb of each one, is there a clear cut set of guidelines which what each network is intended for, what kinds of questions should go to each one, and is anything being done to encourage people to post in these newer, smaller (more specialized?) networks as opposed to just posting in big daddy Stack Overflow?  Now again, this is for computer science/programming/"why isn't this code doing what I want?" related questions, I am not saying that if I had a question about Linux or WordPress or something I would have the same confusion.


Please look at my chapp function. I never called it but it runs formatting decorator def formatting(lowerscase=False):     print('called')     def formatting_decorator(func):         def wrapper(text=''):             if lowerscase:                 func(text.lower())             else:                 func(text.upper())         return wrapper     return formatting_decorator  @formatting(lowerscase=False) def chaap(message):     print(message)  How can I solve it?

As an example: def get_booking(f=None):     print "Calling get_booking Decorator"     def wrapper(request, **kwargs):         booking = _get_booking_from_session(request)         if booking == None:             # we don't have a booking in our session.             return HttpRedirect('/')         else:             return f(request=request, booking=booking, **kwargs)     return wrapper  @get_booking def do_stuff(request, booking):     # do stuff here  The problem I am having is, the @get_booking decorator is being called even before I called the function that I am decorating. Output on start: Calling get_booking Decorator Calling get_booking Decorator Calling get_booking Decorator Calling get_booking Decorator Calling get_booking Decorator Calling get_booking Decorator Calling get_booking Decorator Calling get_booking Decorator Calling get_booking Decorator Calling get_booking Decorator [26/Oct/2008 19:54:04] "GET /onlinebooking/?id=1,2 HTTP/1.1" 302 0 [26/Oct/2008 19:54:05] "GET /onlinebooking/ HTTP/1.1" 200 2300 [26/Oct/2008 19:54:05] "GET /site-media/css/style.css HTTP/1.1" 200 800 [26/Oct/2008 19:54:05] "GET /site-media/css/jquery-ui-themeroller.css HTTP/1.1" 200 25492  I haven't even made a call to a function that is decorated at this point. I am just getting started with decorators, so maybe I am missing something.


I bought Mafia II on eBay, the Steam version. Not a Steam Key, but the whole game, all files included, but I was told that I need Steam to play it.  I tried adding the game to my Steam library, but it won't play. I also tried executing the game directly but still no success. It just creates a file called "mafia2.exe.4936.STEAMSTART" (the number is always different) in the same folder but doesn't do anything beyond that.  I have a good computer with all the latest stuff installed, and I'm able to run all my other games no problem.  Is there a certain procedure I need to undergo to add a Steam game, or something I could do to get this game to work?

I personally do not like to purchase games digitally.  There's just something magical about going to the store, picking up a boxed game, staring at the amazing box art, bringing the game home and putting the disc in the drive.  That being said, I know that several game distribution companies are leaning more toward digital distribution, with[Steam holding a large chunk of that market.  Is it possible to buy a retail boxed copy of a game, but still get the benefits of Steam (automatic updates, install on multiple computers, etc.) ?


I generate a the table of contents with latex, but at one position it looks like on this image:    The "point" and the text are overlapping. Can this somehow be avoided?  Thank you

How can i change formatting of the table of contents to avoid section numbering and section title to overlap?  Document:  \documentclass[10pt,oneside,notitlepage]{book}  % Use Heuristica Font \usepackage{heuristica} \usepackage[heuristica,vvarbb,bigdelims]{newtxmath} \renewcommand*\oldstylenums[1]{\textosf{#1}}   \begin{document}  \tableofcontents  \part{Part one}  \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh} \chapter{Chapter Oh}   \section{Chapter Hi} \section{Chapter Hi} \section{Chapter Hi} \section{Chapter Hi} \section{Chapter Hi} \section{Chapter Hi} \section{Chapter Hi} \section{Chapter Hi} \section{Chapter Hi} \section{Chapter Hi}  \end{document}   Example output:


Im' using OSX 10.11 el capitan. I've followed tutorials such as this:  to make renders ore efficient. I don't have a GPU yet. I'm using cycles render... On some videos people are saying "it took only and 1 minute or so to render a whole clip. Why would my set up render so terribly slowly. lasting 3 mins just a render a single frame!!  Many thanks,  Joel

I am currently using Sheep It! to render my blend (built on v2.68c) on multiple computers, and I noticed something rather strange. According to the log on-site, the frames rendered from other people's blends were completing in 3 to 4 minutes. This was on an 4 core i5. My main rig (with an 8 core i7) was completing frames in no less than half an hour. How is this possible?  To clarify, these people's frames are very complex, often with very detailed textures. I have 2 objects in my blend. Below are the options I changed for my blend:   Aspect Ratio: 1000px x 1000px Output: PNG Clamp Indirect: 0.98 Render Sampling: 128 Min Light Bounces: 0 Max Light Bounces: 4 Cycles Render   Is there something in there that I should change to make it go faster? I can't really comprehend how it's going to quickly.  EDIT: To answer what @Duarte asked...   System Specs: i7-920, 3GB DDR3, GT 630, Windows 10 I have two circles, extended to form a sort of coin with a star on it. It is not complex at all. I have Firefox and Steam running in the background, but not actively. I've been away from the computer for 8 hours and noticed this behavior. (I am running Blender from Steam.) I made sure when I began rendering that the blend was set for CPU rendering.          And to answer what @pycoder asked, yes, I am using Cycles Render.


How can I prove that if a linear map $T \ \in \ \text{End}(V)$ with $\dim V < \infty $ has eigenvalues ${\lambda}_{1},{\lambda}_{2}, ..., {\lambda}_{n} $, then $\text{trace}(T)$ $=$  ${\lambda}_{1}+{\lambda}_{2} + ...+{\lambda}_{n} $ and $\det(T)={\lambda}_{1}{\lambda}_{2} ...{\lambda}_{n} $?   The problem that I have is that it says that $T$ is not necessarily diagonalizable. If it is diagonalizable, then it is easy to see that there is a matrix representation with the eigenvalues in the diagonal, so this would be easy to prove. But how can I prove this with a $T$ that is not diagonalizable?  Thank you.

I have looked extensively for a proof on the internet but all of them were too obscure. I would appreciate if someone could lay out a simple proof for this important result. Thank you.


I'm trying to normalize (and or compress) around 100 .ogg files which have audio level really too low.  I know that by hand I can use Audacity ... but that will be too much clicks! Instead I was looking for a tool which can be used in a small script (or with --recursive).  Just tried to look in man oggenc, man ffmpeg, with no success yet...  Thanks!

Are there any simple tools to normalize an .ogg-library of 10'000+ songs so that the volume is the same throughout all songs?  Terminal or GUI doesn't matter, it only need to be simple.  One caveat though, I don't want soft interludes/intermissions and ballads blown out of proportion.  Preferably the process should find the overall gain of the album (I have all my CD's ripped into separate folders) and normalize the level thereafter.


:     1. There was nothing the matter with it when I lent it to him.      2. She had something the matter with her back.   :     3. There's something the matter with my eyes.   It's a strange word order for me.  Is there any rule of using "indefinite pronoun + noun"?  If there's an ellipsis, then what text is omitted?  Thanks!    My question has nothing to do with the question: . In that question a non-inverted word order is "Something is the matter." We see the verb "is" between "something" and "the matter". In my question there isn't any verb between them. I absolutely can't understand how someone could think that this is the same questions.

Is something the matter?  I've read or heard this usage of matter many times. For instance, in The pleasure of finding things out, R.P. Feynman writes:  I could tell that something was the matter.  This usage doesn't seem right to me. It's hard for me to pinpoint what exactly bothers me, but I think it has to do with the use of the definite article "the" when the existence of a problem hasn't even been confirmed/acknowledged yet. I know this usage of matter is accepted by many, but how does it make logical/grammatical sense?  Instead of:  Is something the matter?  I would much prefer  Is there a problem?  Instead of  I could tell that something was the matter.  I would prefer  I could tell that there was a problem/issue.  Note that my issue is with the choice of article, not with that of the noun.


To my understanding, specific geographic regions are always capitalized.  For example, Southern US is proper because it is a specific region.   However, a co-author argues that southern should not be capitalized, because it is an adjective, not a noun.   So which is it? Southern US or southern US?   Per comment: Note that I am speaking of a particular region of the United States, not "a location in a particular sector."  Hence, presumably, the portion of the United States known widely as the (S/s)outhern United States.

So here in America we are in "the West".  Would this become "the Western world" or "the western world? "  I'll assume the same applies to "the East" (Asia).


You can send empty messages in chat! Example . You get this by selecting the text box, hitting tab, then hitting backspace. Please fix it as it's annoying. Also, this does not send spaces, it seems to send empty characters. (Using ubuntu with firefox) I just noticed that this also works with mac. I think it's a FF bug.

I typed . I believe I tab-completed @rumtscho and fully typed @MarthaF (since she doesn't tab complete). However, other people tell me that a Unicode character was inserted into the message; I can't see it:  Originally, I abandoned this bug report for a lack of reproducibility. But on another machine, I can see the character and managed to reproduce it: press tab, then press backspace. It works anywhere in a message, not just in a @-ping. (Actually, it seems that you just need to un-focus the input box; clicking elsewhere then hitting backspace works, too)  First machine is Firefox 12 (Iceweasel) on Debian GNU/Linux AMD64, testing+unstable. No user scripts. Greasemonkey is installed, but disabled in the extension manager Second machine is Firefox 10 (Iceweasel) on Debian GNU/Linux AMD64, testing+unstable. No user scripts, Greasemonkey not even installed Third machine (just tested) is Firefox 11 (Iceweasel) on Debian GNU/Linux AMD64. Greasemonkey installed and enabled, and there is a global userscript. Does not happen on Chromium 18.0.1025.151, running on machine #3.  So far, that's all the machines I've tested on, and it happens on all of them. It only happens in chat. Easiest way to produce it is to click on the page background, somewhere outside the text box, to un-focus the text box. Then press backspace. Note that not all browsers will display the character, even if its there (check  to see if yours does)


Whilst watching the Star Wars movies recently for the first time1 - in order of release - I detected a decrease in the technology between the last of the "new" movies - Revenge of The Sith - and the first of the "old" movies - A New Hope.  I now have two questions:   Is this apparent drop in technology real or perceived?   If it's real, is it ever explained in-universe?2     1 Yes, it has taken me this long and I'm 28!  2 I know that out-of-universe it is because an improvement in the technology, CGI capabilities and imagination and so on between those movies (ANH was release in 1977 and RotS was released in 2005).

In the last 30 years, human technology has developed massively.  Every year a new smartphone is released with a faster processor, more memory, better features.  Why hasn't the same level of progress happened in the Star Wars universe?  In The Phantom Menace, we see a number of droids - R2 units, C-3PO, Pit Droids, etc.  In Return of the Jedi - the droids we see pretty much have the same capabilities.  I would have thought that technology would still be progressing in the Star Wars universe - but it appears to have stopped.  During wars on Earth, our technology capabilities grow - so it can't just be the effect of a massive war which is causing the stagnation of development.  So, what gives?


In the homepage of Data SE, I see that some sites have an extra "SE" in the name, while the rest don't have. Is this an intention or just a kind of bug?      At first I thought that this is a duplicate of , but as you can see not every beta sites have the suffix.

In the  the Stack Exchange site and it's meta site names are displaying.  For the following site and it's meta site's names are ending with Stack Exchange but not the all others.   Software Recommendations Stack Exchange   Mathematics Educators Stack Exchange   Earth Science Stack Exchange   Arduino Stack Exchange   Joomla Stack Exchange   Expatriates Stack Exchange   Beer Stack Exchange     Why these site's names are only ending with Stack Exchange? Initially I thought these sites are recently created by Area 51 proposal. But checking in Area 51, these sites are proposed and launched in different time period.  Is it a bug?     Note: I have Noticed this issue when cross checking this


Is there a way of shuffling the questions (not only the answers) using eqexam?

I happily use the exam document class to create exams and quizzes. I often make at least part of my exams multiple choice, and I'd like to be able to      generate multiple versions of the exam by permuting the answer choices (automatically, rather than by hand as I do now), and   generate an answer key for each version when compiling the exam with answers on.      Do any of you do that or have suggestions about how I might be able to implement that?


Say I set my home /home/john directory as not readable for any other user. But I've forgotten to do so with some files within that directory, say ./.bashrc or ./Downloads/Presentation.ppt. Now, if another user guesses path and name of those files (which is of course easy in case of /home/john/.bashrc) can they read/execute those files by pointing to them directly? Or is it impossible to access any file or directory within a non-accessible directory? Thanks a lot.

Say I have a directory with these permissions:  drwxrwx---   Inside this directory, a file with these permissions:  -rw-rw-rw-   Is the file readable/writable by everyone or not ?  If not, how secure is this access restriction?  What if a random user makes a link to my file inside his home directory? Could he access the file then?  Or could he access the file by guessing its inode number and using some system calls on inodes?


Give an example  of  a  sequence  $(A_n)$  of connected subset   of $\mathbb{R}^2$  such that   $A_{n+1}   \subset A_n$ for  $n \in  \mathbb{N} $  but $\bigcap\limits_n A_n$ is not connected    My attempt : I take  $A_n=(-\frac{1}{n}-1,\frac{1}{n}+1)$ but $\bigcap\limits_{n=1}^{\infty} (-\frac{1}{n}-1,\frac{1}{n}+1) = (-1,1).$ which is  connected  Actually im not able to  find  the  example  that  $\bigcap\limits _n A_n$ is not connected?

How can I find an example of subsets which satisfies;  for every $i \in \mathbb{N}$   $c_1 \supset c_2 \supset c_3 \supset \cdots \supset c_n$ which are closed and connected subsets of $\mathbb{R^k}$ then $\bigcap_{i=1}^\infty c_i$ is not connected.  until now I have     $c_n=\{[n,\infty) , n \in \mathbb{N}\}$ $\Rightarrow$ $\bigcap_{i=1}^\infty c_i=\varnothing$ which is I couldn't decide whether if it is connected or not connected.  $d_n=\{ ( [-\frac{1}{n},\frac{1}{n}] \times \{0\}) \cup (\{0\}\times ([-1,1]\setminus \{0\})), n\in \mathbb{N}\}$ $\Rightarrow$  $\bigcap_{i=1}^\infty d_i= \{0\} \times [-1,1]$  which is connected. (here I want to seperate the vertical one from the point $(0,0)$ for not path connected implies not connected. If i rearrange  the $ [-1,1] \times \{0\}$ element -for not path connecting result-  as $(-1,1) \times \{0\}$ the set will be not closed but intersection is not connected.)   Thanks in advance for your guidances :)


I will be travelling via British Airways from Mumbai, India to Manchester, UK soon with a layover at the Heathrow airport in London.  I am travelling on a short visitors visa to meet family there.   I am guessing I will have to go through immigration in London and not in Manchester. In that case, will I also have to reclaim any checked bags at London and then check them in again for the local flight from London to Manchester ?

I am flying from the US to Edinburgh, UK. My layover is at Heathrow. Will I need to go through customs and check bags again at Heathrow before I take the next flight?


I have a list of three items, and I'd like to say the equivalent of "never the twain shall meet." Is there a word meaning "three" that I could substitute for "twain"? "None of them will ever meet" works, but doesn't have quite the same quaintness. I know that "twain" comes from the Anglo-Saxon "twengen," and was thinking that maybe the word I'm looking for could come from "threo/thrim/thrie" perhaps. Thanks!

I would like to split something into three parts. Is there a phrase I can use with similar overtones to "cleave in twain"?


I am looking for  (or any similar package) available for Ubuntu 19.10. Is anybody aware of anything ?  Thanks in advance

Is there any built-in software or terminal method allowing me to view the hardware profiles on my system? Windows equivalent of such a feature would be Device Manager.


If I give a user full modify access to folder 'foobar' located in path  foo/bar/foobar  Do I also need to manually give the user read access to foo and again to bar?  Or will the client only receive access to foobar when they manually map directly to /foo/bar/foobar?

Quick scenario on a local Windows system.  Drive E: is formatted with NTFS has the following layout and permissions:  E:\                  (JohnDoe) E:\folder            (Administrator) E:\folder\subfolder  (JohnDoe)    JohnDoe has read/write access to the root directory. JohnDoe has read/write access subfolder JohnDoe does NOT have access to folder JohnDoe does NOT have the ability to alter permissions.   Since JohnDoe cannot access folder and thus cannot list the contents, he must type in the path E:\folder\subfolder manually. There is is no "clickable" way to get from E:\ to subfolder.  Here's the question: Is there any way for JohnDoe to discover the existence and path of the accessible subfolder, without being able to list the contents of it's parent folder? Assume that he was not told the subfolder's name and that the permissions do not change from what is stated above.  For the sake of this problem, ignore the possibility of a brute-force attack to guess subfolder's name. Only non-brute-force methods are permitted.


I know how to prove that $^\omega$$\omega$ is uncountable, but how can we prove that it is, in fact, equinumerous to $\Bbb R$? Or at least that $^\omega$$\omega$ is equinumerous to $^\omega$$2$?

Encode each $n_1,n_2,n_3,...∈N^N$ by an inﬁnite sequence of 0s and 1s with inﬁnitely many 0s, and hence give a proof that $N^N$ is equinumerous with $R$.  Background: Here the set $N^N=N \times N \times N \times N \times...$ is the set of finite sequences of positive integers. Each inﬁnite sequence $n_1,n_2,n_3,...$ of positive integers gives an irrational number (with a infinite continued fraction) between 0 and 1, because each rational has a ﬁnite continued fraction. Conversely, each irrational number between 0 and 1 has a continued fraction of the above form, and hence gives an inﬁnite sequence of positive integers. Thus, we immediately have a bijection between $N^N$ and the irrational numbers in (0,1). The latter set is equinumerous with (0,1), and hence with $R$.  So far I tried to encode each n in N^N as either ones and zeros, where comas are represented as zeros. For example <3,2,3,0,1> ---> 1110110111001   TIA


I try commands for rain I checked controls it was Button 14 where is Button 14?

Is there a way to change the weather in Minecraft in Creative Mode? All it does is rain all the time. It's rained for three days. Is there a way, mods included, that can change it?


How can I delete photos just from my iPhone and not in my photo library from the Mac?  Every time I delete photos from my iPhone it'll be deleted on my Mac and vice versa...  Thank you

Whenever I got to delete a photo, it says "This photo will be deleted from iCloud Photo Library on all your devices." I don't want it deleted from my iCloud Photo Library, only my iPhone 6s. What I want to do is import photos and videos from my iPhone to my MacBook Pro and then delete them from my iPhone. If I import those photos and videos to my Mac and then delete them from my iPhone (ignoring the warning) will they also be deleted from my Mac?


As discussed , a negative modifier should always be applied to a damage roll. However, it is suggested in the  that the minimum damage should be 1.  I'd like to know if there's an official rule (or a tweet for a game developer) that can back this up?  Specifically, I'm trying to evaluate the consequences of disarming weak creatures. Would a disarmed kobold with a -2 STR modifier do 1 (1-2; minimum 1) or 0 damage (1-2; minimum 0) with an unarmed strike?     On a hit, an unarmed strike deals bludgeoning damage equal to 1 + your Strength modifier. (PHB, p. 195)

In D&D3e, if you successfully hit a target you always did at least 1 point of damage (before applying Damage Resistance), even if you had a Strength penalty.  I can't find any mention of that rule in the 5e PHB.  Does the rule no longer apply, or did I just overlook it?


I have created java project that contains 6 Class file and 1 java file   And I run this project in net beans IDE now my problem is when I clean and build this project am unable to create exe file   How can I make this project as exe (an executable file)?   all 7 files in one single as executable  and found this and tried from here    Can some one help me to solve my problem

If I have a Java source file (*.java) or a class file (*.class), how can I convert it to a .exe file?  I also need an installer for my program.


I'm doing Exercise 14 in textbook Algebra by Saunders MacLane and Garrett Birkhoff.   For $f \in D[x]$, $f` \in D^D$ is the polynomial function induced by $f$. If $f` a=0=f` b$ for $a \neq b$ in $D$, show that $f$ is divisible by $(x-a)(x-b)$.  My proof is very short that I suspect if I made any subtle mistakes. Could you please verify if my understanding is correct? Thank you so much for your help!  Our convention is that $\deg 0 = -\infty$. It follows from $f`a=0$ and division algorithm for commutative ring that $f = (x-a)g$ for some $g \in D[x]$ where $\deg g < \deg f$. Because $D[x] \to D^D, f \to f`$ is a homomorphism of rings, $f` = (x-a)`g`$ and thus $f`b = (b-a)g`b$. Then $f`b = 0 \iff (b-a)g`b= 0$. It follows from $b-a\neq 0$ and $D$ has no zero divisors that $g`b = 0$. Again, we get $g = (x-b)h$ for some $h \in D[x]$ where $\deg h < \deg g$. This completes the proof.

I encountered this proving problem, I can do the proof but my question is why in the condition/premise we need $a$ to be unequal to $b$? My guess is that even $a=b$, the statement is still true, is it correct? If yes, how can we prove it? If false, are there any counter-examples?  The problem: Let $a$ and $b$ be two unequal constants. If $f(x)$ is a polynomial with integer coefficients, and $f(x)$ is divisible by $x-a$ and $x-b$, then $f(x)$ is divisible by $(x-a)(x-b)$.  My proof (just for reference): Let $q(x)$ be the quotient and $px+r$ be the remainder (where p, r are constants that we have to find) when $f(x)$ is divided by $(x-a)(x-b)$. So we have $f(x)=(x-a)(x-b)q(x)+px+r$. We then substitute $a$ and $b$ into $f(x)$ and use factor theorem, we get $pa+r$ and $pb+r$. We solve the simultaneous equations we get $p(a-b)=0$, since $a\neq b$, $p=0$ and $r=0$. So $f(x)$ is divisible by $(x-a)(x-b)$.  Helps are greatly appreciated. Thanks!


Tell me please what does ^ character in the code below:  [AttributeUsage (AttributeTargets::Class)] public ref class ControlDescriptionAttribute : Attribute { public:   ControlDescriptionAttribute (String ^name, String ^description) :     _name (name),     _description (description)   {   }    property String ^Name   {     String ^get () { return _name; }   }    property String ^Description   {     String ^get () { return _description; }   }  private:   String     ^ _name,     ^ _description; };   I have found it looking for something different, but have never met the usage of ^.

I just came across this code and a few Google searches turn up no explanation of this mysterious (to me) syntax.  Hashtable^ tempHash = gcnew Hashtable(iterators_);  IDictionaryEnumerator^ enumerator = tempHash->GetEnumerator();   What the heck does the caret mean? (The gcnew is also new to me, and I asked about that .)


Given a set $M$ and a set $N := \{g | g: M \to \{0, 1\}\}$. Show that N and powerset $P(M)$ are of same cardinality. I can prove the statement in case $M$ is finite with induction, when $|N| = 2^n = |P(M)|$. But how about $M$ is infinite?

Let $A$ be a set and $P(A)$ be the power set of $A$. Define $B(A)$ as   the set of all functions $F:A\rightarrow\{0,1\}$. For example,   $B(\mathbb{N})$ is the set of all binary sequences. Prove that $P(A)$   has the same cardinality as $B(A)$.   When $A$ is finite, this is easy to prove. I am interested in other cases; for instance when $A$ is countably infinite or uncountable. I am also a bit confused with the definition of $B(A)$. Could anyone help me with this one please?


If Alice were to choose n to be a prime, instead of the product of two primes, what exactly would go wrong in the RSA cryptosystem? How would Bob decrypt her message?

I think I roughly understand how the RSA alorithm is working.  However, I don't understand why we need the $N$, which we use as a modulus, to be $pq$ for some large primes $p, q$.  I vaguely know it has something to do with factorization, but I am kind of lost. So, hypothetical questions.   What would happen if the $N$ was not $pq$, but just a big prime? What if $N$ would be some random composite (that's easy to factor)?   The other parts of RSA would stay the same.


I wrote a batch apex to send reports. PFB the main class and test class but not able get the code coverage. Please assist me.  public class BatchReportsAutoSend implements database.Batchable<sobject>,Database.AllowsCallouts {     public transient list<Messaging.EmailFileAttachment> emailAttach;     String reportName1;     Set<String> processingList;      List<String> reportsList;      /*     public BatchReportsAutoSend(set<string> objs ){        processingList = objs;           reportsList = new List<String>(objs);         reportName1 = reportsList[0];     } */     public Database.QueryLocator start(Database.BatchableContext bc) {         list<string> reportListName = new list<string>();         reportListName.add('Testing_Reports1');         reportListName.add('Testing_Reports2');        //String query = 'SELECT Id,name FROM Report where DeveloperName in :reportsList';        //return Database.getQueryLocator(query);         return Database.getQueryLocator('SELECT Id,name FROM Report where DeveloperName IN :reportListName');      }     public void execute(Database.BatchableContext bc, List<Report> scope){         emailAttach = new list<Messaging.EmailFileAttachment>();         for(Report rp : scope){                      system.debug('OBJPAGE ##'+rp.Id);                        ApexPages.PageReference objPage = new ApexPages.PageReference('/'+rp.Id+'?csv=1');             system.debug('OBJPAGE ##'+objPage);             Messaging.EmailFileAttachment objMsgEmailAttach = new Messaging.EmailFileAttachment();             objMsgEmailAttach.setFileName(rp.name+'.csv');             objMsgEmailAttach.setInline(false);             Blob pageContent;             if(!test.isRunningTest()){              pageContent = objPage.getContent();             objMsgEmailAttach.setBody(pageContent);             objMsgEmailAttach.setContentType('text/csv');             }else{             pageContent = blob.valueof('TEST');              }             emailAttach.add(objMsgEmailAttach);         }             system.debug('Attachments'+emailAttach);             Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();             String[] toAddresses = new String[] {'smuti98@gmail.com'};             mail.setUseSignature(false);             mail.setToAddresses(toAddresses);             mail.setSubject('Email from Salesforce');             mail.setPlainTextBody('Hi Team, Please find the reports as you requested');              mail.setFileAttachments(emailAttach);             Messaging.SendEmailResult [] sendMsgResult = Messaging.sendEmail(new Messaging.SingleEmailMessage[] {mail});       }         public void finish(Database.BatchableContext bc){       }   }   Test Class:   @isTest(seealldata=true) public class Test_BatchReportsAutoSend { @isTest static void runReport() {  List<Messaging.SingleEmailMessage> emailList = new List<Messaging.SingleEmailMessage>(); PageReference pdf = Page.Report; //pdf.getParameters().put('id', String.valueOf(testAccount.Id)); Test.setCurrentPage(pdf);  Blob b = blob.valueof('Unit.test'); try {b = pdf.getContentasPdf();  }catch(Exception e) {}  system.debug('The document page  is'+b); Messaging.EmailFileAttachment efa = new Messaging.EmailFileAttachment(); efa.setFileName('FileName'); efa.setBody(b);  Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); String[] toAddresses = new String[] {'smuti98@gmail.com'}; mail.setToAddresses(toAddresses); mail.setSubject('Email from Salesforce'); mail.setPlainTextBody('Hi Team, Please find the reports as you requested');  mail.setFileAttachments(new Messaging.EmailFileAttachment[] { efa }); emailList.add(mail); List<Messaging.SendEmailResult> result = Messaging.sendEmail(emailList); System.assert(result[0].isSuccess(), 'Email not sent');   Test.StartTest();  BatchReportsAutoSend bp = new  BatchReportsAutoSend(); Id jobId = Database.executeBatch(bp); Test.stopTest(); } }

This is a canonical question and answer developed by the community to help address common questions. If you've been directed here, or your question has been closed as a duplicate, please look through the resources here and use them to shape more specific questions. To browse all canonical questions and answers, including more unit test resources, navigate to the  tag.  This canonical question is intended to address several classes of common questions by providing a quick summary and links to comprehensive resources:   How is code coverage obtained and calculated? How do I increase my coverage?  Why can't I cover these lines? Why isn't the body of my loop or conditional statement covered?


In the book The Linux Programming Interface, it says      The kernel imposes limits on the number of dereferences to   handle the possibility of circular chains of symbolic links.   Where can I find this limit?

In a python script, I am creating a bunch of symbolic links chained together.  example: link1->link2->link3->.......->somefile.txt  I was wondering how you can change the max number of symlinks to be greater than 20?


I use the following code to produce this figure:    \documentclass{article}  \usepackage{forest}  \forestset{ sn edges/.style={for tree={parent anchor=south, child anchor=north,base=top},              where n children=0{tier=word}{}              }}  % auxiliary nodes without node label \forestset{   empty nodes/.style={     delay={where content={}{shape=coordinate,for parent={for children={anchor=north}}}{}}} }   \begin{document}  \begin{forest} sn edges, empty nodes [{}   [{} [{} [Mummy]]      [{} [must]]      [{} [leave]]]  [{} [now]]] \end{forest}  \end{document}   This works nicely for forest 1.0 (e.g. texlive 2013) but I cannot get it to work for forest 2.0.   This is what I tried:  \documentclass{article}  \usepackage{forest}  \useforestlibrary{linguistics} \forestapplylibrarydefaults{linguistics}  \forestset{ sn edges/.style={for tree={parent anchor=south, child anchor=north,base=top},              where n children=0{tier=word}{}              }}   \begin{document}  \begin{forest} sn edges [{}, nice empty nodes   [{} [{} [Mummy]]      [{} [must]]      [{} [leave]]]  [{} [now]]] \end{forest}  \end{document}

I've been using the "nice empty nodes" style from the forest manual for trees for quite a while now. Today I updated the package, and now it throws an error (though the output still seems to work). Minimal example:  \documentclass{article} \usepackage{forest} \forestset{ nice empty nodes/.style={     for tree={calign=fixed edge angles},     delay={where content={}{shape=coordinate,for parent={                 for children={anchor=north}}}{}} }, } \begin{document} \begin{forest}     [{},nice empty nodes     [b][     [c]     [     [b] [a]     ]     ]     ] \end{forest} \end{document}      Error: "Package forest Error: nodewalk stepped to the invalid node;   stack: ",tree,tree,parent". \end{forest}"   Anyone got an idea how to fix this?


My phone is broken so I have switched between 2 other phones, and when im logging in I always have to start at the beginning, so I never get to a high level! Can someone help me?

So I had 20+ Pokemon on my account and today when I tapped on the app, it brought me back to the original screen when you first start playing. My friend who signed up tested using my username when she first started and my username was unavailable, meaning the account still exists. I don't have the password for the account, but I do have the email. So I wanted to know if it was possible to log back into an account?


This is a followup question to .  Fix $n \in \mathbb{N}$. What is the easiest way to see that the set of unordered $n$-tuples of points of $\mathbb{CP}^1$ can be identified with $\mathbb{CP}^n$?

For each $m \ge 1$, how do I construct a homeomorphism $(\mathbb{CP}^1)^m/S_m \overset{\sim}{\to} \mathbb{CP}^m$?  My thoughts so far: I probably want to identify $\mathbb{C}^{m+1}$ with the vector space $\mathbb{C}^m[z, w]$ of degree $m$ homogeneous polynomials in two variables and use that a polynomial in one variable is determined by its roots up to a nonzero constant factor somehow... but from here, I'm kinda of stuck. Could someone help?  EDIT: Progress so far. After reading Eric Wofsey's response, I have the following. Since a projective variety is determined by its homogeneous coordinate ring, it suffices to determine the homogeneous coordinate ring of $(\mathbb{CP}^1)^m/S_m$.  For $(\mathbb{CP}^1)^m$, the coordinate ring is the graded ring $\mathcal{S}$ whose $d$th degree part is the $m$-fold tensor product (over $\mathbb{C}$) of $\mathbb{C}[s, t]_{d}$. That is, $S_d$ consists of polynomials in $s^1, t^1, s^2, t^2, \dots, s^m, t^m$ of multidegree ($d, d, \dots, d$). And $S_m$ acts in the obvious way, i.e. if $\sigma(i) = j$, then $\sigma$ sends $s^i$ to $s^j$ and $t^i$ to $t^j$. The homogeneous coordinate ring of $(\mathbb{CP}^1)^m/S_m$ is just the ring of invariants of the $S_m$ action on $\mathcal{S}$. But I still have two questions.   Which polynomials are invariant under this action? I still don't see how to conclude that Eric Wofsey's map is a homeomorphism. How do I see that Eric Wofsey's map is a homeomorphism?


I am posting this as my last step before giving up completely on making my Ubuntu 16.04 on my laptop recognize my bluetooth headset.   I have followed all the other questions and answers regarding this with no luck, the Bluetooth adapter in my laptop is obviously capable of finding this headset as it works perfectly from windows.  both blueman and the regular bluetooth manager show a lot of unnamed devices (only by address) all of them are of type "all types" and they are all unpairable (pairing fails after a few seconds, doesn't look like anything is really happening there).   On my Android device, the address of the bluetooth headset is listed as "00:11:67:B4:A4:DF". none of the recognized devices have this address.  Output from sudo service bluetooth status :  bluetoothd[1274]: Not enough free handles to register service bluetoothd[1274]: Sap driver initialization failed. bluetoothd[1274]: sap-server: Operation not permitted (1) bluetoothd[1274]: Endpoint registered: sender=:1.48 path=/MediaEndpoint/A2DPSource bluetoothd[1274]: Endpoint registered: sender=:1.48 path=/MediaEndpoint/A2DPSink bluetoothd[1274]: Endpoint registered: sender=:1.84 path=/MediaEndpoint/A2DPSource bluetoothd[1274]: Endpoint registered: sender=:1.84 path=/MediaEndpoint/A2DPSink bluetoothd[1274]: RFCOMM server failed for Headset Voice gateway: rfcomm_bind: Address already in use (98) bluetoothd[1274]: Endpoint unregistered: sender=:1.48 path=/MediaEndpoint/A2DPSource bluetoothd[1274]: Endpoint unregistered: sender=:1.48 path=/MediaEndpoint/A2DPSink   Output from bluetoothctl :  [NEW] Controller 48:E2:44:F5:E9:6E yaniv-XPS [default] [bluetooth]# scan on Discovery started [CHG] Controller 48:E2:44:F5:E9:6E Discovering: yes [NEW] Device 54:79:7A:A9:F1:58 54-79-7A-A9-F1-58 [NEW] Device 62:D2:69:E6:51:4C 62-D2-69-E6-51-4C [NEW] Device 76:53:BC:C4:D9:9E 76-53-BC-C4-D9-9E [NEW] Device 5E:8D:79:7D:91:28 5E-8D-79-7D-91-28 [NEW] Device 79:E3:D4:8C:18:E1 79-E3-D4-8C-18-E1 [NEW] Device 98:01:A7:9B:19:5A 98-01-A7-9B-19-5A [CHG] Device 79:E3:D4:8C:18:E1 RSSI: -97 [CHG] Device 76:53:BC:C4:D9:9E RSSI: -97 [CHG] Device 79:E3:D4:8C:18:E1 RSSI: -82 [CHG] Device 62:D2:69:E6:51:4C RSSI: -69 [NEW] Device F8:77:B8:1D:16:74 F8-77-B8-1D-16-74 [CHG] Device 98:01:A7:9B:19:5A RSSI: -80 [CHG] Device 62:D2:69:E6:51:4C RSSI: -93 [CHG] Device 79:E3:D4:8C:18:E1 RSSI: -93 [CHG] Device 98:01:A7:9B:19:5A RSSI: -92   Output from dmesg | grep -i blue  Bluetooth: Core ver 2.21 Bluetooth: HCI device and connection manager initialized Bluetooth: HCI socket layer initialized Bluetooth: L2CAP socket layer initialized Bluetooth: SCO socket layer initialized Bluetooth: HCI UART driver ver 2.3 Bluetooth: HCI UART protocol H4 registered Bluetooth: HCI UART protocol BCSP registered Bluetooth: HCI UART protocol LL registered Bluetooth: HCI UART protocol ATH3K registered Bluetooth: HCI UART protocol Three-wire (H5) registered Bluetooth: HCI UART protocol Intel registered Bluetooth: HCI UART protocol BCM registered Bluetooth: HCI UART protocol QCA registered Bluetooth: hci0: BCM: chip id 102 Bluetooth: hci0: BCM20703A1 Bluetooth: hci0: BCM (001.001.005) build 0000 bluetooth hci0: Direct firmware load for brcm/BCM-0a5c-6410.hcd failed with error -2 Bluetooth: hci0: BCM: Patch brcm/BCM-0a5c-6410.hcd not found Bluetooth: BNEP (Ethernet Emulation) ver 1.3 Bluetooth: BNEP filters: protocol multicast Bluetooth: BNEP socket layer initialized Bluetooth: RFCOMM TTY layer initialized Bluetooth: RFCOMM socket layer initialized Bluetooth: RFCOMM ver 1.11   Any help on this matter would be highly appreciated! Thanks ahead.

Bluetooth is on but can't find or be found by any other devices.  Output of sudo service bluetooth status:  ● bluetooth.service - Bluetooth service    Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)    Active: active (running) since ხუთ 2015-06-04 22:33:18 GET; 13min ago  Main PID: 26678 (bluetoothd)    CGroup: /system.slice/bluetooth.service            └─26678 /usr/sbin/bluetoothd -n  ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPAG ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPHS ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSource ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSink ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPAG ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPHS ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSource ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSink ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Adapter /org/bluez/26678/hci0 has been enabled ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Adapter /org/bluez/26678/hci0 has been enabled   Output of lsusb:  Bus 003 Device 005: ID 0a5c:21d7 Broadcom Corp. BCM43142 Bluetooth 4.0   How can I fix it?


Presburger  Arithmetic is a decidable theory but if multiplication is added to it would that theory remain decidable?  UPDATE: I began to write out the axioms that would distinguish Presburger Arithmetic from Peano Arithmetic and realized that adding the Peano axioms which give semantics for multiplication (E.g., commutativity of multiplication, the distributive law -- essentially, all of the peano axioms which include the multiplication symbol -- etc) to Presburger Arithmetic result in Peano Arithmetic. And the decidability of Peano Arithmetic is already widely known due to Gödel. So I've decided to change my question: why does a definition of multiplication in Presburger Arithmetic result in an undecidable theory? In other words, why would the addition of the multiplication symbol and axioms for multiplication result in an undecidable theory?

Goedel's incompleteness tells us that any system containing Robinson arithmetic is incomplete.  OTOH, Presburger Arithmetic, which contains only the successor and addition, is complete.  I'm pretty sure that I have read that it possible to define a complete arithmetic with only sucessor and multiplication axioms.  So, this raises the question about what is special about the combination of addition and multiplication.  In reviewing the proof of Goedel's theorem, I thought I had located the key point: the $\beta$-function involves both addition and mutliplication.  Without that, we cannot get to the primitive recursive functions, which means we cannot arithmetize syntax, so you cannot form the Goedel sentence, and there is nothing that says it cannot be proved.  This isn't a 100% satisfying, but it makes a certain amount of sense.  But then I learned that there are  which can arithmetize syntax despite being much weaker than Robinson arithmetic.  So that cannot be right.  Is there, then a simple explanation of why the combination of addition and multiplication is necessary for incompleteness to kick in?


Is  $(A\cup B)\times(C\cap D)=(A\times C)\cup (B \times D)$ true for all sets $A$,$B$,$C$ and $D$?  I have no idea what to do here. How could I possibly go about trying to prove this?  Or disprove it? It's not exactly the same question with the previous one First I tried to prove that both sides are equal if $(A\cup B)\times(C\cap D)\subseteq(A×C)∪(B×D)$ and $(A×C)∪(B×D)\subseteq(A\cup B)\times(C\cap D)$ .  Thank you!

Is $(A \cup B)\times (C ∩ D)=(A∪C)×(B∪D)$ true for all sets A,B,C and D?  I have no idea what to do here. How could I possibly go about trying to prove this?  Or disprove it?


Noob questions.  I have static IPs on many of my Windows computers in our Windows 2008 domain. In the network settings at each, I have an a static IP and subnet. The default Gateway is set to our Sonicwall.  Question: Under DNS servers, do I just list the Server IP? I've found this works fine on XP through Win7, but Win8 needs an alternate DNS to get to the Internet. (using 8.8.8.8). Do I need to list the Server IP at all?

We have a Windows 2008 server that is connected to a managed switch with about 15 Cat5e connections and three fiber branches that go to different parts of campus. At each of these parts there is another managed switch that branches out to the LAN. Our cable Internet comes into one of these locations, goes through the supplied modem and into a Sonicwall.  Question: Under DNS settings on all the switches, should I list the LAN Server IP and/or just the Gateway IP (Sonicwall)?


My hard drive appears to be filling itself up by itself. Every time I delete files, it immediately fills up. I do not have back up enabled either. I don't even download much. I mostly stream. The only thing that autodownloads is variety.

I recently wiped my computer to have 14.10 as my only OS. It has 160 GB of storage. That was a month ago. Now, I keep getting prompts that the storage is almost full. And when I look it says I only have 543 MB free. How is this possible? I haven't torrented any large files. I do have Variety to autodownload wallpapers and not erase though.  Filesystem Size Used Avail Use% Mounted on  /dev/sda1  146G  138G  554M  100%  /  none 4.0K 0 4.0K 0% /sys/fs/cgroup  udev 742M 4.0K 742M 1% /dev  tmpfs 151M 1.1M 150M 1% /run  none 5.0M 4.0K 5.0M 1% /run/lock  none 752M 540K 751M 1% /run/shm  none 100M 80K 100M 1% /run/user –  er –


Is there any method available using which we can change the position of side bar laucher from left to right. I have installed the unity tweak tool but it only allows to auto hide the launcher. There are many tutorials which teaches about how to move launcher to the bottom but i am unable to find any links pertaining the position change to the right   P.S. not to confuse with any other launcher i am uploading this picture

I can’t get used to the new Unity system. I’d like to move the left Unity panel to the bottom of screen (like Windows 7 – more similar is better).  But I can't find a way. Is it possible?


I have lot of files that contains urdu and english. I have to search for those words that are in urdu only. For english, I know its not a problem by using regular expression. r'[a-zA-Z]' But How I can use regular expression for urdu language.  Suppose this is the string  test="working جنگ test  بندی کروانا not good"   Please guide.

I have a script that parses the filenames of TV episodes (show.name.s01e02.avi for example), grabs the episode name (from the www.thetvdb.com API) and automatically renames them into something nicer (Show Name - [01x02].avi)  The script works fine, that is until you try and use it on files that have Unicode show-names (something I never really thought about, since all the files I have are English, so mostly pretty-much all fall within [a-zA-Z0-9'\-])  How can I allow the regular expressions to match accented characters and the likes? Currently the regex's config section looks like..  config['valid_filename_chars'] = """0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!@£$%^&*()_+=-[]{}"'.,<>`~? """ config['valid_filename_chars_regex'] = re.escape(config['valid_filename_chars'])  config['name_parse'] = [     # foo_[s01]_[e01]     re.compile('''^([%s]+?)[ \._\-]\[[Ss]([0-9]+?)\]_\[[Ee]([0-9]+?)\]?[^\\/]*$'''% (config['valid_filename_chars_regex'])),     # foo.1x09*     re.compile('''^([%s]+?)[ \._\-]\[?([0-9]+)x([0-9]+)[^\\/]*$''' % (config['valid_filename_chars_regex'])),     # foo.s01.e01, foo.s01_e01     re.compile('''^([%s]+?)[ \._\-][Ss]([0-9]+)[\.\- ]?[Ee]([0-9]+)[^\\/]*$''' % (config['valid_filename_chars_regex'])),     # foo.103*     re.compile('''^([%s]+)[ \._\-]([0-9]{1})([0-9]{2})[\._ -][^\\/]*$''' % (config['valid_filename_chars_regex'])),     # foo.0103*     re.compile('''^([%s]+)[ \._\-]([0-9]{2})([0-9]{2,3})[\._ -][^\\/]*$''' % (config['valid_filename_chars_regex'])), ]


Is it possible to pass some linux capabilities using sudo. Like this: sudo -u web-server --capabilities CAP_NET_BIND_SERVICE -H ./server  Without setting the capabilities on the file. Using setcap

I am experimenting with capabilities, on Debian Gnu/Linux. I have copied /bin/ping to my current working directory. As expected it does not work, it was originally setuid root. I then give my ping the minimal capabilities (not root) by doing sudo /sbin/setcap cap_net_raw=ep ./ping, and my ping works, as expected. Then sudo /sbin/setcap -r ./ping to revoke that capability. It is now not working as expected. I now try to get ping working using capsh. capsh has no privileges, so I need to run it as root, but then drop root and thus all other privileges. I think I also need secure-keep-caps, this is not documented in capsh, but is in the capability manual. I got the bit numbers from /usr/include/linux/securebits.h. They seem correct, as the output of --print shows these bits to be correct. I have been fiddling for hours, so far I have this. sudo /sbin/capsh  --keep=1 --secbits=0x10  --caps="cap_net_raw+epi" == --secbits=0x10 --user=${USER} --print -- -c "./ping localhost" However ping errors with ping: icmp open socket: Operation not permitted, this is what happens when it does not have the capability. Also the --print shows Current: =p cap_net_raw+i, this is not enough we need e. sudo /sbin/capsh    --caps="cap_net_raw+epi" --print -- -c "./ping localhost" will set the capability to Current: = cap_net_raw+eip this is correct, but leaves us as root. Edit-1 I have now tried sudo /sbin/capsh --keep=1 --secbits=0x11  --caps=cap_net_raw+epi  --print -- -c "touch zz; ./ping -c1 localhost;" This produces: touch: cannot touch `zz': Permission denied ping: icmp open socket: Operation not permitted  The first error is expected as secure-noroot: yes But the second is not Current: = cap_net_raw+eip Edit-2 If I put == before the --print, it now shows Current: = cap_net_raw+i, so that explains the previous error, but not why we are loosing capability when switching out of root, I though that secure-keep-caps should fix that. Edit-3 From what I can see, I am loosing Effective (e), and Permitted (p), when exec is called. This is expected, but I thought that secure-keep-caps, should stop them being lost. Am I missing something. Edit-4 I have been doing more research, and reading the manual again. It seems that normally e and p capabilities are lost when: you switch from user root ( or apply secure-noroot, thus making root a normal user), this can be overridden with secure-keep-caps; when you call exec, as far as I can tell this is an invariant. As far as I can tell, it is working according to the manual. As far as I can tell there is no way to do anything useful with capsh. As far as I can tell, to use capabilities you need to: use file capabilities or have a capabilities aware program, that does not use exec. Therefore no privileged wrapper. So now my question is what am I missing, what is capsh for. Edit-5 I have added an answer re ambient capabilities. Maybe capsh can also be used with inherited capabilities, but to be useful these would need to be set on the executable file. I can not see how capsh can do anything useful without ambient capabilities, or to allow inherited capabilities.  Versions:  capsh from package libcap2-bin version 1:2.22-1.2 before edit-3 I grabbed the latest capsh from git://git.debian.org/collab-maint/libcap2.git and started using it. uname -a Linux richard-laptop 3.2.0-4-amd64 #1 SMP Debian 3.2.65-1+deb7u2 x86_64 GNU/Linux User-land is 32bit.


I have a wireless adapter that used to work in ubuntu 13.10 (dwa 171) after installing drivers for it. Now it won't work the same way anymore since I upgraded to ubuntu 14.04.  I've found the only way to make it work properly is to run the command sudo service network-manager restart I already tried putting this command in rc.local, rc2.local and rc3.local with no real luck. I want this command to run automatically right after login in with startup application program. Please tell me how to.

I had a script that automatically enables my wifi without using networkmanager, but I don't know how to run the script as root while the system is booting. How do I make the script run automatically during boot?


Is there any standard or popular symbol to indicate that two set A and B are disjoint?  Of course, it can be described by:     But it is still way too long. Is there any popular symbol for the disjointness relation R such that we can write as below?

Consider I have two sets that neither one is a subset of the other (for example, the set of prime numbers and the set of odd integers). Is there a specific notation that combines the meanings of both ⊄ and ⊅ ?  Also, is there a notation to mean that two sets are completely distinct and share no elements in common (for example, the sets of odd and even integers)?  ≠ seems very inappropriate, and I'd like to avoid it.  Context: My area is actually Computer Science. I'm using this refine my vocabulary in order to teach my students about  (which is basically about sets and subsets of IP addresses), and to write some exercises for them. I'll probably use the words incomparable and disjoint as suggested.


Somebody could help me to clarify how its possible that different choices of the observable to measure can lead to different outcomes of the observed system state?

When an observer causes the wave function of a particle to collapse, how can we know that the wave function was not collapsed already before the measurement?  Suppose we measure the z-component of the spin of an electron. After the measurement, it is entirely aligned along the measured direction, e.g. the +z-direction. Before the measurement we need to assume that a probability distribution proportional to $|\Psi|^2$ of the two allowed directions is present.  If we repeat the measurement with many identically prepared electrons, we should see such a distribution finally. For example, we could measure 40% spin-down and 60% spin-up.  However, it seems we could also assume that all of these particles have a defined spin-direction before we measure them.  What is an intuitive (being aware that quantum phenomena as such are rarely intuitive) explanation for why we cannot simply assume that the spin was already aligned completely in that measured direction?    With regards to the suggestion that this two-year old question is a duplicate , I would like to point out that my question isn't limited to entanglement, but asks about a very fundamental principle in quantum mechanics, and as such is not a duplicate.


I have the piece of code:  \begin{lstlisting} <?xml version="1.0"?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"                  xmlns:ex="http://www.example.org/" >   <rdf:Description rdf:about="http://www.example.org/Heitor_Villa-Lobos">       <ex:origem rdf:resource="http://www.example.org/Rio_de_Janeiro"/>    </rdf:Description> </rdf:RDF> \end{lstlisting}   and I want to show it in the footnote. I've tried to use   \footnote{ \begin{lstlisting} <?xml version="1.0"?> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"                  xmlns:ex="http://www.example.org/" >   <rdf:Description rdf:about="http://www.example.org/Heitor_Villa-Lobos">       <ex:origem rdf:resource="http://www.example.org/Rio_de_Janeiro"/>    </rdf:Description> </rdf:RDF> \end{lstlisting}   }  I've added an extra bracket "{}" to protect the content, but it doesn't work, too. When I run this I get the following error: "Argument of \lst@next has an extra }. }".  Does anyone could help me?  TIA

This code won't compile:  \documentclass{article} \usepackage{listings} \lstset{     language=C,     basicstyle=\small }  \begin{document} lorem ipsum\footnote{% \begin{lstlisting} // some C code or whatever... printf("Blah blah\n"); \end{lstlisting}} \end{document}   It says Illegal parameter number in definition of \lst@insertargs. I know listings is really picky about where it goes, but there must be a way to cram a listing into a footnote, right?  (This is a MWE and my tex files are a bit more complex; my actual error is Paragraph ended before \lst@next was complete. but they are hopefully related; I couldn't get this error with the MWE.)


Especially in light of recent changes to comment flagging so that now we distinguish between comments that are chatty, flagged for general reasons, or are rude/offensive, could we have some sort of heuristic that bans people from leaving comments if they have too many comments correctly flagged as rude/offensive?  Restoring the user's ability to comment could be done via having them contribute more answers. Answers are not the same as comments of course, but that's a pretty decent way to track someone's positive contribution to the site.  Alternatively, the ban could be time-based and just put the user in an automatic timeout for a few days with an appropriate message that'd let them know that too many of their comments have been deemed rude or offensive by the community.  Note: I'm thinking just about rude and offensive comments here. Comments flagged as "chatty" or "general" would be not count.

There's been problems with abusive comments since the site started.   We still haven't managed to conquer the issue.   Users can be issued chat bans and post bans. The API automatically bans IP addresses with validated spam flags. (Would it be difficult to implement comment bans? Would mods have the power to impose comment restrictions?).   Although comments have been classically referred to as second class citizens, rude comments on the site are the one place that is driving people away.   Can we implement temporary automatic comment ban on 'x' number of validated rude comment flags? It would probably be better if the exact heuristics were not disclosed publicly, much like the serial voting scripts  This question  was asked 7 years ago. Can we revisit it?  This question is related, but is asking for a more complex approach:


I have 40 images, and I would like to group them into 1 picture (sprite sheet). 4 lines by 10 column with a transparent font.

I have a shell scripting request. I haven’t spent much time figuring it out myself yet, but I want to try and convert animated gifs into sprite sheets for use in SDL game development. I know how to break an animated gif into a series of images: convert animation.gif target.png, but not how to string them together end to end, in a single image file.   Is there a shell command that can help me create a single sprite sheet out of multiple images?


My instinct feels the second one is more polite but I'm not sure if it is grammatically correct. Can someone answer this and explain which is the correct and polite way to frame this question?

Please can you help me with this question?   Can you please help me with this question?   Can you help me with this question please?      Is there a correct place for please in this question or is it just a matter of choice?


I am a college freshman who is looking to research in a experimental physics lab this year. I am an engineering student and have taken basic Physics classes, but I lack the background knowledge to fully understand what is going on with the topics this lab is researching (Rydberg atoms, Rydberg atom collisions, heavy-Rydberg-ion-states, etc.) I've tried looking for review papers but have mostly found things from the 80s, (some of which were written by the professor I hope to research with). What resources are good for a relative novice to learn about these things? Sorry if this question is too broad!

Every once in a while, we get a question asking for a book or other educational reference on a particular topic at a particular level. This is a meta-question that collects all those links together. If you're looking for book recommendations, this is probably the place to start.  All the questions linked below, as well as others which deal with more specialized books, can be found under the tag  (formerly ).  If you have a question to add, please edit it in. However, make sure of a few things first:   The question should be tagged  It should be of the form "What are good books to learn/study [subject] at [level]?" It shouldn't duplicate a topic and level that's already on the list   Related Meta:


I need to get the number of seconds since the last reboot, using ksh.  What is the command or function to achieve this?

Under Linux I can get a process's uptime in seconds with:   echo $(($(cut -d "." -f1 /proc/uptime) - $(($(cut -d " " -f22 /proc/$PID/stat)/100))))   But how can I get it under different OS? ex.: SunOS, HP-UX, AIX?


I am making a program that will allow the user to enter a name, which will then be added and displayed to a list in the jframe window, but cannot figure out how to add to the lsit using code.  I have tried several things, like:  lstNames.append(name); lstNames.Add(name); lstNames.add(name, this);   (name is a string)  Currently my code looks like this:  DefaultListModel model = new DefaultListModel(); JList list = new JList(model); ArrayList<String> names;  private void btnAddActionPerformed(java.awt.event.ActionEvent evt) {                                             String name = txtFirst.getText() + " " + txtLast.getText(); // works             names.add(name); // works      for (int i = 0; i < names.size(); i++) {         model.add(i, names.get(i));     }     lstNames.setModel(model);  }                                         I just want to add a name to a list, but all I get is errors, any help would be great.  Here are my errors:  Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException     at javaapplication2.NewJFrame.btnAddActionPerformed(NewJFrame.java:99)     at javaapplication2.NewJFrame.access$000(NewJFrame.java:12)     at javaapplication2.NewJFrame$2.actionPerformed(NewJFrame.java:45)     at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)     at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)     at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)     at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)     at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)     at java.awt.Component.processMouseEvent(Component.java:6533)     at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)     at java.awt.Component.processEvent(Component.java:6298)     at java.awt.Container.processEvent(Container.java:2236)     at java.awt.Component.dispatchEventImpl(Component.java:4889)     at java.awt.Container.dispatchEventImpl(Container.java:2294)     at java.awt.Component.dispatchEvent(Component.java:4711)     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)     at java.awt.Container.dispatchEventImpl(Container.java:2280)     at java.awt.Window.dispatchEventImpl(Window.java:2746)     at java.awt.Component.dispatchEvent(Component.java:4711)     at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)     at java.awt.EventQueue.access$500(EventQueue.java:97)     at java.awt.EventQueue$3.run(EventQueue.java:709)     at java.awt.EventQueue$3.run(EventQueue.java:703)     at java.security.AccessController.doPrivileged(Native Method)     at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)     at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)     at java.awt.EventQueue$4.run(EventQueue.java:731)     at java.awt.EventQueue$4.run(EventQueue.java:729)     at java.security.AccessController.doPrivileged(Native Method)     at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)     at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)     at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)     at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)     at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)   No errors appear until, the button to run the code is pressed. Very basically, I want to add the user input to the jlist

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I found drivers in the official site of Konica Minnolta.They are rpm files. But don't know how to install

I have a Canon Pixma P200 and I have downloaded the Linux drivers from their site. I extracted them and I found 4 .rpm files. I decided to open terminal and type in  /home/rsbayani/Desktop/cnijfilter-p200series-4.00-1-rpm/packages/cnijfilter-p200series-4.00-1.x86_64.rpm -i   but it doesn't work, it just gives me permission denied. I also tried the code below  /home/rsbayani/Desktop/cnijfilter-p200series-4.00-1-rpm/packages/cnijfilter-p200series-4.00-1.x86_64.rpm --install   But like the one above it, it ssill gives me a permission denied. I am using Ubuntu 14.04 LTS. Any help would be gladly appreciated.


What are the differences and  advantages of Gauss's Integral and Differential Equations? Thank you so very much!

I would like to understand what has to be differential and integral form of the same function, for example the famous  of James Clerk Maxwell:    How to know where to apply each way? Excuse the ignorance, but always confused me the head.  Edit  Remembering that, I know that the concept of integration and derivation, is something like:


How to get a list of all disks, like this?  /dev/sda /dev/sdb

I need to know what hard disks are available, including ones that aren't mounted and possibly aren't formatted. I can't find them in dmesg or /var/log/messages (too much to scroll through). I'm hoping there's a way to use /dev or /proc to find out this information, but I don't know how. I am using Linux.


Given this sample code:  var s = "abc\r\ndef"; foreach (var c in s) {     Console.WriteLine($"Current char: {c}"); }   Of course, the '\r' and '\n' characters, are written as whitespace and an actual newline, respectively. What I want to achieve is to write '\r', '\n' instead.  What's the easiest way to convert a character to it's (C#) 'escaped representation'? Should I look at Roslyn for this, or is there a simple conversion function available?

In C#, can I convert a string value to a string literal, the way I would see it in code? I would like to replace tabs, newlines, etc. with their escape sequences. If this code: Console.WriteLine(someString);  produces: Hello World!  I want this code: Console.WriteLine(ToLiteral(someString));  to produce: \tHello\r\n\tWorld!\r\n


Gollum tries to have Frodo and Sam killed by Shelob, so he could get the One Ring back from Frodo's corpse after Shelob would kill and "drink" him. And Gollum is no stupid, so I guess he knows that Shelob is not interested in the One Ring (yeah, ok, spider means no hand, no fingers, so no place to "properly" put the ring on, but can't believe the meaning/effect/power of the One Ring has such a material restriction as being wearable only by a human-like finger). Why has she no desire to possess the One Ring? Even Gandalf, Galadriel and anybody else in the books seems to be tempted (or at least assumed temptable) by the One Ring, with the main exception being Tom Bombadil. What makes Shelob different? In the already existing questions the answers refer to Shelob just wanting to kill and eat everything (but not vegetables), so I can imagine another creature, other than Shelob, that only wants to kill pigs and eat pigs, probably a very insatiable hobbit. Or a troll. Are they also immune to the power of the ring? The last paragraph is mostly a joke to say that I'm not really satisfied with Shelob only want to kill and eat, so she's not interested in the One Ring.

Did Shelob know about the Ring? Considering she doesn't really have fingers, could she have used it if she had known about it?


I have the following question:  Let $P$ and $Q$ be polynomials with $\deg(Q) \geq \deg(P) + 2$. Show that there is an $r > 0$ such that for any closed curve $\gamma$ outside the disc of radius $r$ centered at the origin that  $$\int_\gamma \frac{P(z)}{Q(z)} dz = 0$$ I can prove the claim in the special case that $Q(z)$ is a power of $z$. This can be done by separating the fraction and noting that each term has a primitive (because each integrand will be of the form $1/z^k$ where $k \geq 2$). However, I do not know what to do for the general case. I have tried factoring out the highest power of $z$ in $Q(z)$ and try to reduce to the previous case. However, when I do this I am unable to find an antiderivative.

Let the degree of the polynomials $P(z)=a_0+a_1z+a_2z^2+\cdots+a_nz^n$   $a_n\neq0$ and $Q(z)=b_0+b_1z+b_2z^2+\cdots+b_mz^m$ $b_m\neq 0$ be such that $m\geq n+2$. Show that   if all the zeros of $Q(z)$ are interior to a simple closed contour C,   then $$\int_C\frac{P(z)}{Q(z)} \, dz=0$$   I am lost on how to show it $P(z)$ and $Q(z)$ are polynomials, then the ratio is analytic in all the points except where $Q(z)=0$. If $\frac{P(z)}{Q(z)}$ be analytical in all the points on the contour or inside, so I could tell straight that the integral is zero, but that is not the case.


As electricity is transferred in earth by earthing and lightning, why it does not become negatively charged?

This question arose in a seminar today about the solar wind... This is my vagueish understanding of the problem - please correct if you see errors! The 'classical' picture of atmospheric electricity is that the Earth as a whole is neutral, but that thunderstorms maintain a voltage of around +300kV at the electrosphere with respect to the Earth's surface, with a current of around 1 kA slowly discharging around 500 kC of total charge separation. The solar wind is supposed to neutralise any net charge that might be there between the Earth as a whole and the solar wind. However, positive and negative charges in the solar wind are differently trapped in the van Allen belts, from which they can then descend to the Earth's atmosphere, which implies that a net charge can be developed due to this differential leakage. This begs the question of whether there are any estimates of the total net charge. I've hunted in the literature but have found little useful material other than Dolezalek's 1988 paper:  Can anyone offer an explanation, or point me to some more relevant papers?


The number of real roots of  $$ \frac{3}{x-3}+\frac{5}{x-5}+\frac{17}{x-17}+\frac{19}{x-19} = x^2 -11x -4 $$ How to solve without actually finding the roots or is it the only way? I know that if the equation changes it's sign between two no.s it will have at least one root contained in them.

Let $m$ be the largest real root of the equation $$\frac3{x-3} + \frac5{x-5}+\frac{17}{x-17}+\frac{19}{x-19} =x^2 - 11x -4.$$ Find $m$.   do we literally add all the fractions or do we do something else  I have no clue how to solve this


I have tried to use Pokébank to transfer xerneas from Moon back to X. Is there a way to do this? I need to transfer back.

Title says it all, I don't see confirmation in  and a cursory google search seemed to say assume no and speculate about the pokemon bank.


Let $C$ be an $n\times n$ Hermitian matrix. Show that $$\text{Tr}(C)=0  \iff \exists P,Q \text{ Hermitian s.t.} \,\, PQ-QP=iC.$$   Ideas: The right-to-left direction I have no problem with. For the left-to-right direction, I'm going to start with the fact that $$\text{Tr}(C)=0 \implies \exists A,B \in M_n \text{ s.t. } C = AB-BA.$$  I'm having trouble showing we can choose $A,B$ Hermitian. One method would be to try to show $A,B$ must be Hermitian, but that seems too strong. Along this road...  $\text{Tr}(iC)=0$, so we can write $iC=AB-BA$. $iC$ is diagonalizable with all imaginary eigenvalues, so it is skew-Hermitian. Thus $$BA-AB=-(AB-BA)=(AB-BA)^*\\=(AB)^* - (BA)^* = B^*A^*-A^*B^*.$$  But this hasn't gotten me anywhere.

I'm looking to solve some matrix equations. One of the equations involves a commutator, so my question is as follows: let $A$ be a skew-self-adjoint, traceless matrix, does the equation $[X,Y] = A$ always have a self-adjoint solution? For every size of matrices.  I hope that this is a well-known fact. Perhaps it is related to the fact that the traceless skew-adjoint matrices are $\mathfrak{s}\mathfrak{u}_n$.


I've just discovered an old Stack Exchange account of mine that seems to be in use by someone unknown to me (who has knowledge that doesn't fit anyone I know).  How do I delete that account?

About an hour ago, from my account, an inappropriate message was posted as a reply to a Stack Overflow question.  I have noticed it, because I started getting downvotes. To my understanding my Gmail account wasn't compromised (I reviewed my account security settings and login history). I am from a secure WPA2 connection. I cannot find enough information on how to investigate this. Although I changed my passwords everywhere, I still seem confused and I would like to ask how to investigate this issue myself.


I freshly installed ubuntu , didnt expected this. and it has never happened before atleast for ubuntu 20.04.1 LTS . I did ran sudo apt update then I tried to install. $ sudo apt install openssh-server -y Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies.  openssh-server : Depends: openssh-client (= 1:8.2p1-4)                   Depends: openssh-sftp-server                   Recommends: ssh-import-id but it is not going to be installed E: Unable to correct problems, you have held broken packages.  I installed ssh-import-id and then tried to installed openss-sftp-server but I still get thsi depends error.

How do I fix broken packages when it is not working? When I try to fix broken packages, it tells me to "fix broken packages."


I have just installed Windows 7 (for the 10th time), installed all my required software,  made all the little tweaks that I want in Windows.  I want to be able to save this condition of my computer so that in the future when things go kaput, and I reformat, I can get back to this state without having to install and tweak everything again..  Possible?

I want to create an image of a already setup windows7 machine which has lots of software installed like VS,Sql server and even IIS has lots of websites and lots more. I have another new machine and i just want to install all the software with the system image i have created.   I am not sure if it is feasible or how it is done? But it will surely save lot of time for new hires in my company to avoid lengthy installation steps and becoming productive asap.  Thanks in advance!


Let $f(z)$ be entire such that $ \text{Im} (f(z)) \geq 0.$ Show that $\text{Im}(f(z))$ is constant.  So far what I have done is this:  Consider $|e^{if(z)}| = |e^{v(x,y)}| \geq 1.$   Then this implies $|e^{-v(x,y)}| \leq 1.$  I have shown that $e^{-v(x,y)}$ is bounded.  Since f is entire, does it follow that its real and imaginary parts are also entire?

How do you show that if $f$ is entire and if $\text{Im} f\ge0$, then $\text{Im} f$ is constant? Is this even true in the first place?


How would he do that?   And     How will he do that?

What is the difference in meaning between the following sentences?     Why don't you do the exam?      I'm sure you will pass it.    or     I'm sure you would pass it.


I have watched a few David videos and have noticed he has this pet rabbit. It follows him around and hops when he hops. I was wondering if it's possible to tame a rabbit.

I've been playing a custom map and I wanted to tame and breed a few rabbits in the custom map pet store. But then I realized I wasn't able to tame or breed rabbits. I'm not sure whether I really can tame and breed rabbits but I'm not doing it right, or if I was just being dumb and not realizing taming and breeding rabbits is not possible.


(Arithmetic–Geometric Mean).   (a) Explain why $\sqrt{xy}≤ (x+y)/2$ for any two positive real numbers x and y. (The geometric mean is always less than the arithmetic mean.)   (b) Now let $0≤x_1 ≤y_1$ and define $x_{n+1} = \sqrt{x_{n}y_{n}}$ and $y_{n+1} = (x_{n} + y_{n})/2$ . Show $\lim x_n$ and $\lim y_n$ both exist and are equal.  My attempt:  (a) I know that I can show this by using $(\sqrt{x} -\sqrt{y})^2 \geq0$ but I dont know how to illustrate, let alone explain it.  (b) I know that $x_{n+1} \leq y_{n+1}$ for all $n \in \mathbb{N}$. But now I need to know how to show that they are equal.

I am given this problem: let $a\ge0$,$b\ge0$, and the sequences $a_n$ and $b_n$ are defined in this way: $a_0:=a$, $b_0:=b$ and $a_{n+1}:= \sqrt{a_nb_n}$ and $b_{n+1}:=\frac{1}{2}(a_n+b_n)$ for all $n\in\Bbb{N}$    To prove is that both sequences converge and that they have the same limit. I don't know how to show this. I have spent 2 hours on this, no sign of success


I have already created a database design with a set schema. The database schema is for a web quotation form. PS it is not a simple quotation form and hence need to customise the form, form builders like Gravity Form have been tried and suitable in this case.  I have about 15 tables (mostly in 2NF and 3NF) with set attributes and datatype.  But the question is should I stick with the traditional normalized schema design or use EAV design instead for some tables? It seems Gravity Form uses EAV DB design but that is due to the dynamic nature of a form builder.  This question has come up due to the fact that later on a attribute may need to be added, removed or updated from one or set of tables. The fields in the quotation form are reasonably standard with research done and I don't imagine modifying the fields and hence the attributes in the DB often.  I have read there are concerning pitfalls of EAV design. So if the fields are not going to changed often then is a set schema design with relationships useable?  Also in the event of modifying the schema is ALTER table going to cause any issues? If one adds a attribute to a table with ALTER table what would the previous data sets in the table have the value of the new attribute? What are the alternative of ALTER table?

I am working on an application which records data from different forms. New forms can (and will be) constructed dynamically by an admin. I am wondering what would be the correct way to save this data in a database? My first guess would be to use EVA, but considering all the bad publicity I am a bit hesitant.  Let's say I have two forms:  #form 1 description = TextField() score = IntegerField()  #form 2 feedback = TextField() NOR_score = IntegerField()   There is no way of predicting the number of possible attributes. I am playing around with two ideas, but maybe you'll be able to suggest a much better approach.  Idea I:  unique_id | entity | attribute   | value 1         | form 1 | description | test123 2         | form 1 | score       | 90 3         | form 2 | feedback    | blabla 4         | form 2 | NOR_score   | 5   Idea II:  unique_id | entity | value 1         | form 1 | {"description": "test123", "score":"90"} 2         | form 2 | {"feedback": "blabla", "NOR_score":"5"}   Thanks in advance for any suggestions.


I just used taig to jailbreak an 8.3 pad.  All went well for a while and I was investigating and enjoying the freedom.  An app then crashed and now I have a black screen with what appears to be no way of restarting.  I should mention that my home button is not functional.    I could wait for the battery to run out but I'd rather not :)  I've tried the hold power for x seconds, tried it with the home but that doesn't do anything, there doesn't seem to be an option within iTunes and I'd rather not restore.  Is there an option for sending a reset signal without restore / home button?  thanks for any help.

I have an iPhone 3Gs and recently noticed that the home button doesn't work anymore. I used AssistiveTouch.  Now I want to jailbreak my iPhone, but it's gone wrong: the device is stuck on a black screen after jailbreaking, iTunes doesn't recognise my iPhone and my home button doesn't work.  What can I do?