How does &= work in Javascript?
What is this operator: &=
Do my animals need fences? I have a barn and a coop. Each has several animals in. Because fences keep deteriorating and get in the way, I didn't build any. The animals can roam freely around my farm.  Is there a downside to this? Will the animals eat my crops or escape if I don't enclose them? How do I change file permissions on a FAT32 drive? I am using TeXworks 0.4.5 r1280 with MikTeX 2.9 on Windows 7 64-bit. When I add  \usepackage{datetime}   and try to typeset the document, I get a dialog window like this:    I select "Install", confirm UAC request and then get the following error on the console:  ! LaTeX Error: File `datetime.sty' not found.   If I try to typeset the document again - the dialog and the error appear again.  Same thing happens when I've tried installing wrapfig and a few other packages at random: cases, comma, dowith, microtype.  Other packages have installed fine before. What is wrong with my setup? Please let me know if you need more info about my setup in comments.  I've tried this solution: . Didn't work. If $0 &lt; \alpha &lt; 1$, then       $$ (x + y)^{\alpha} &lt; x^{\alpha} + y^{\alpha} $$      for $x$, $y$ positive.   Is this inequality true in general?  I tried using Young's Inequality: For $z,t &gt; 0$, and for $n$, $m$ such that $n+m=1$, then   $$ z^n + t^m \leq nz + mt $$  So, using this we have   $$ (x+y)^{\alpha} \cdot 1^{1 - \alpha} \leq \alpha(x+y) + (1-\alpha) = \alpha x + \alpha y + (1-\alpha)$$  which is not as tight as I want. The current process for self-deletion of a user account has several problematic aspects, both in the process itself and in the end result. Some of these issues are:   The process requires manual intervention of a mod or SE employee, leading to delays and sometimes mistakes. It is more complicated than it has to be, which can lead to the impression that SE is imposing some rather arbitrary-looking restrictions and steps one has to take. This can give the impression that the user isn't really in control of his private data at SE. It is irreversible once the account is deleted, although an account can be partially reconstructed with a lot of manual effort from an SE developer. There is no real protection against mod/SE employee errors, if an account is deleted in error, there is no easy way to undo the damage. Because it is manual, it consumes the time of SE employees that have to deal with it  (unless  is used), removing useful voting information and annoying users that lose reputation that way.   I'm proposing an alternative way of handling self-deletion that would be automated, and also reversible to some extent, while still being pretty much a hard-delete (and not a soft-delete that would be problematic with respect to user privacy). The process would work roughly like this:   The user clicks a "delete profile" button in his profile. There should be a way to indicate if you want to delete all profiles on all SE sites, only on this site and a way to select multiple sites from a list where the profile should be deleted. It is verified that the user has true access to the account in some way (confirmation mail?) and not just someone that found the unlocked computer of the user. A countdown until deletion is started (I'd go with 48h, but that could be different). The timer shouldn't be too long, but long enough to correct mistakes and leave users a bit of time to reconsider. Alternative options would be to enable users to override the countdown if they really want to nuke their account immediately. Another option would be to soft-delete the account immediately, and make the countdown only for hard-deletion of the user data. Upon deletion, the posts of the user and his votes are transferred to a newly created blank account, the original account itself is hard-deleted with all the remaining data it contains. The dummy account that holds the user's data should be flagged in some way as deleted, so that the profile links will be disabled, the profile won't be accessible and it won't appear in any user lists.  The user receives a private code that can be used to claim ownership of the account. Other ways are not possible as all private information is removed about the account. This allows for an automatic way of reclaiming most of the important parts of a deleted account. The ability to restore a deleted account might have to be somewhat restricted to avoid misusing it to get rid of the account history. It is more meant as an additional safeguard so that account reconstruction is more easily possible in rare cases. Such additional safeguards might be necessary as the deletion itself would be automatic and without oversight from SE or moderators.   I personally think that the information which posts and votes were connected to a (now anonymized) account is not sensitive enough that it would have to be removed on account deletion. My idea is that this would be close enough to a hard-delete that it satisfies any privacy concerns, but still allow reassociation of posts with a recovered account. The partial reversibility would alleviate concerns about removing the manual oversight by mods and SE employees over the account deletion process. Computer unstable at lower temperatures My computer is playing some strange joke at me, and I'm at a loss.  Everybody knows that hot temperatures causes many components to become unstable and even cause damage. When I built this machine, I was careful to do a bunch of experiments with different airflow configurations, with CPU-and-GPU intensive benchmarks running, and measuring the temperature at different points to find the best configuration.  Generally, the internal temperature of this machine is very close to ambient temperature (with 2 exceptions: the GPU always runs ~10°C above ambient, and the CPU goes to at most ~12°C above ambient when running CPU-intensive applications).  Now comes the problem: at really cold mornings. At cold mornings (~10°C (50°F) or below), the system shows really strange general instability. Beeps from the BIOS, the operating system displays strange messages about memory corruption and PCI devices that failed to initialize, and then, everything hangs. The computer hangs to the point that all USB devices turn of. Hitting the Reset button blanks the screen but the mainboard fails to proceed to the boot.  I never thought that low temperatures could cause computer instability. And 10°C is not that cold, it is still within operating temperatures of all components as far as I checked.  I'm quite sure it is related with the temperature. There were too many cold and warm mornings that demonstrated that the problem only showed in the cold ones. I'm working around this problem by letting the computer sit at the GRUB menu for some 5-10 minutes before letting the OS start, or blowing hot air inside the case if I'm in a hurry.  I don't know what should I approach next to find the source of this problem. Since it is difficult to reproduce (I need a cold morning, and the computer must be cooled down (powered off for many hours)), I need to plan ahead the experiment, since it stabilizes after a few minutes on.  Machine is an ASUS P5VDC-X equipped with Intel P4 64-bit 3GHz, 2GB of DDR2 RAM, a 500W PSU and an nVidia GeForce 9600GT. Everything else was already disconnected/removed before and the problem persisted, so the problem should be in one of these remaining parts.  Any help is appreciated! Implicit newline at the end of each paragraph? In certain styles of text I define \parindent 0pt in the preamble and write the text in this manner:  paragraph 1\\  paragraph 2\\   and so forth. I wonder if there is anything I can include in the preamble for instance to modify how the end of paragraphs are interpreted so I don't have to include the \\ at the end of each? Line of Bones to Travel and Conform to Curve (Train or snake following path) I want to sort in-text citations by year, but bibliography by name. It sound exactly like .  However, suggested solution (using \usepackage[sorting=ynt]{biblatex} and \printbibliography[sorting=nty]) does not work for me (see MWEB below). Indeed, the list of references remains year-sorted instead of name sorted.  Question: How to force sorting=nty in \printbibliography?      \documentclass{article}     \usepackage[%         backend=biber,%         style=authoryear-comp,%         natbib=true,%         sorting=ynt%     ]{biblatex}     \addbibresource{\jobname.bib}     \usepackage{filecontents}  \begin{filecontents}{\jobname.bib}     @book{key2000,       author = {Author, A.},       year = {2000},       title = {Alphabetical fist \&amp; Year last},       publisher = {Publisher},     }     @book{key1900,         author = {Boathor, B.},         year = {1900},         title = {Alphabetical last \&amp; Year first},         publisher = {Publisher}, } \end{filecontents}  \begin{document}     Citation should be year-sorted, even if \verb+\citep+ is random \citep{key2000, key1900}.% citation NOT year-sorted      \printbibliography[sorting=nyt] \end{document}   P.S.: At the opposite, using  \begingroup     \newrefcontext[sorting=nyt]     \printbibliography \endgroup    overrides the \usepackage[sorting=ynt]{biblatex} option (i.e. LoR is name-sorted, but in-line citations as well). Can this intuition give a proof that an isometry $f:X \to X$ is surjective for compact metric space $X$? A prelim problem asked to prove that if $X$ is a compact metric space, and $f:X \to X$ is an isometry (distance-preserving map) then $f$ is surjective. The official proof given used sequences/convergent subsequences and didn't appeal to my intuition. When I saw the problem, my immediate instinct was that an isometry should be "volume-preserving" as well, so the volume of $f(X)$ should be equal to the volume of $X$, which should mean surjectivity if $X$ is compact. The notion of "volume" I came up with was the minimum number of $\epsilon$-balls needed to cover $X$ for given $\epsilon &gt; 0$. If $f$ were not surjective, then because $f$ is continuous this means there must be a point $y \in X$ and $\delta &gt; 0$ so that the ball $B_\delta(y)$ is disjoint from $f(X)$. I wanted to choose $\epsilon$ in terms of $\delta$ and use the fact that an isometry carries $\epsilon$-balls to $\epsilon$-balls, and show that given a minimum-size cover of $X$ with $\epsilon$ balls, that a cover of $X$ with $\epsilon$-balls could be found with one fewer ball if $f(X) \cap B_\delta(y) = \emptyset$, giving a contradiction. Can someone see a way to make this intuition work? test fails because of TestMethod do not support getContent call My below test fails because of Run Failures: TestRangehoodObjectionSheet.RangehoodObjectionSheetTest Methods defined as TestMethod do not support getContent call. I added the Blob thinking it might resolve but it doesn't work. What could be the problem here? Have I used the Blob correctly?  @isTest public with sharing class TestRangehoodObjectionSheet {      static testMethod void RangehoodObjectionSheetTest() {             String Build                = NBATRecords.getIdFromDeveloperName('Plan_Reviews__c','Building_Plan_Review');             Account a = new Account(Name = 'Test1' ,Type = 'Lead Acct',BillingState = 'CA',Industry = 'Business Services');             insert a;              Establishment_Record__c er = new Establishment_Record__c(Account__c=a.Id ,Project_Name__c = 'TestPreet',PremiseStreet__c='Manhattan ave',PremiseBorough__c='Manhattan',PremiseState__c='NY',PremisePostalCode__c='11102',Referral_Source__c='311',Data_Source__c='CAMIS',Phase__c='Initiate',Business_Status__c='Open' );             insert er;              Application__c ap = new Application__c(Establishment_Record__c=er.Id,Job_Number__c='222222222');             insert ap;              Plan_Reviews__c pr = new Plan_Reviews__c(Application__c =ap.Id ,DOB_Job_Number__c='222222222',RecordTypeId =Build,Objections__c='Pipe size not indicated');             insert pr;             PageReference pageRef = Page.RangehoodObjectionSheet;              Test.setCurrentPage(pageRef);               Blob content = Test.isRunningTest() ? Blob.valueOf('UNIT.TEST') : pageRef.getContent();              Plan_Reviews__c              p   = new Plan_Reviews__c(id=pr.Id);                ApexPages.StandardController sc  = new ApexPages.standardController(p);             System.assertNotEquals(sc,null);             RangehoodObjectionExtention    ext = new RangehoodObjectionExtention(sc);              ext.Savecopy();       } }   Actual class for the test:  public with sharing class RangehoodObjectionExtention { private final ApexPages.StandardController controller; private final Id                           planreviewID; public String imageURL{get;set;} public List&lt;String&gt; objlist {get;set;}  public string currentdate {get; set;}    public RangehoodObjectionExtention (ApexPages.StandardController stdController) {         controller   = stdController;         planreviewID = (Id)controller.getRecord().get('Id');         Date dt = Date.today();         currentdate = dt.format();         list&lt;Plan_Reviews__c&gt; prlist = [select FDNY_Objections__c from Plan_Reviews__c where id = :planreviewID limit 1];         string obj;         for(Plan_Reviews__c pr: prlist){            obj = pr.FDNY_Objections__c;             }         if(obj!=null){            list&lt;string&gt; objections = obj.split(';');             integer i =1;            objlist = new list&lt;string&gt;();            for(string o : objections){               objlist.add(i++ +'. '+o);            }         }         imageURL='/servlet/servlet.FileDownload?file=';         List&lt; document &gt; documentList=[select name from document where Name='RangehoodObjectionLogo'];         if(documentList.size()&gt;0)         {            imageURL=imageURL+documentList[0].id;         }       }          public PageReference Savecopy(){       PageReference p = Page.RangehoodObjectionSheet;       blob b = ApexPages.currentPage().getContentAsPDF ();       Attachment a = new Attachment();       a.body = b;       a.name = 'Rangehood Objection sheet Issued '+currentdate+'.pdf';       a.parentid = planreviewID;        insert a;        PageReference pref = new PageReference('/'+planreviewID);       return pref;    } } Finding $\lim\limits_{n \rightarrow \infty}\left(\int_0^1(f(x))^n\,\mathrm dx\right)^\frac{1}{n}$ for continuous $f:[0,1]\to[0,\infty)$ Find $$\lim_{n \rightarrow \infty}\left(\int_0^1(f(x))^n\,\mathrm dx\right)^\frac{1}{n}$$if $f:[0,1]\rightarrow(0,\infty)$ is a continuous function.   My attempt:  Say $f(x)$ has a max. value $M$. Then $$\left(\int_0^1(f(x))^ndx\right)^\frac{1}{n}\leq\left(\int_0^1M^ndx\right)^\frac{1}{n} =M$$  I cannot figure out what to do next. Can we really not tell if we are moving? It has been a while since I've thought about physics, however, I remember something about how if you are on a train with no windows that is going perfectly straight and is perfectly smooth, there is no experiment that you could perform to prove that you are in motion or at rest. So I have a couple of questions related to this.   Is this still held to be true? I was just wondering if anything in physics has come to light since I learned about this (about 10 years ago) that would allow an observer on the train to tell if they are moving. If this is true, why couldn't you accelerate a particle in different directions to a certain mass and measure how much energy it took to get it up to that mass. If you were moving in any direction, wouldn't you measure less energy in your direction of travel? Would having an outside observer affect the aforementioned experiment in any way? In the book on Brownian Motion by Yuval Peres, he makes the following claim:     Suppose that $\{ B(t); \ t \geq 0 \}$ is a Brownian Motion and $U$ is an independent random variable, uniformly distributed on $[0, 1]$. Then the process $\{ \tilde{B} (t); \ t \geq 0 \}$ defined as,   $$\tilde{B}(t) = \begin{cases} B(t)  &amp; \mbox{ if $t \neq U$} \\ 0  &amp; \mbox{ if $t = U$} \end{cases}$$      has the same finite-dimensional distributions as a Brownian motion, but is discontinuous if $B(U) \neq 0$, i.e. with probability one, and hence this process is not a Brownian motion.   I'm having difficulty in proving that the finite dimensional joint distribution ( basically the joint distribution of $( \ \tilde{B}(t_1), \ \tilde{B}(t_2), \tilde{B}(t_3), \dots \tilde{B}(t_n) \ )$ ) is the same as the finite dimensional distribution of $B(t)$. Can you please give me some clues. Finding a formula to sum natural numbers up to $n$ Possible Duplicate:          I got this question in homework:  Find an expression for the sum ‫‪     $\sum k = 1 +\cdots + n‬‬$.    and prove it using an induction.   I'm not even near finding the expression. What I did notice is that if $n$ is (for example) 5 then the sum would be   $5^2 - 4^2 + 3^2 - 2^2 + 1^2$  So the first number is always positive and from there on the sign changes.  Any tips on how do I contintue from this point on, assuming I'm in the right direction?  Thanks! GNOME 3.26 - Clicking one window brings another in the foreground (Ubuntu 17.10) I'm on Ubuntu 17.10 with GNOME 3.26.  Often I have windows tiled on the left and right side of the screen. A typical setup is to have a browser and text editor on the left, a PDF reader and terminal on the right.  Something I've seen happen very often: I'm reading the PDF on the right, having the window in focus. The text editor on the left. When I click on the text editor to write something, it brings forward another window on the right (say the file browser), covering the PDF reader.  This seems to have something to do with the Alt-Tab view history.  My question is: Is it possible to remove the automatic bring-to-front of windows? I don't understand why unrelated windows are brought to the front when I click on another application. I'm searching a way to append a group in Python.  It should behave exactly like the Append function (ShiftF1) works, all objects should be local and editable. The idea is to append a character (with rig etc.) via Python and not Link it (to be able to modify it without making everything local one by one).  Thanks How to find a program which is preventing sleeping? I am noticing that recently my laptop does not go to sleep/lockout after its configured X minutes of inactivity like it did in the past. I suspect some program (like media player does) is preventing it from going to sleep. I do not have any media player running, so how can I find which program is preventing it from sleeping?  It does go to sleep if I close the lid. But I would also like for it to go to sleep after X minutes of inactivity.  Update: Upgraded to Ubuntu 18.04 with default Gnome and Wayland enabled. While looking at online code samples, I have sometimes come across an assignment of a String constant to a String object via the use of the new operator.  For example:  String s; ... s = new String("Hello World");   This, of course, compared to  s = "Hello World";   I'm not familiar with this syntax and have no idea what the purpose or effect would be.  Since String constants typically get stored in the constant pool and then in whatever representation the JVM has for dealing with String constants, would anything even be allocated on the heap? How to create a Wi-Fi Hotspot (in Access Point mode)?