Why is there an 'A' in phrase 'Times are a changing'?
The times they are a-changin'
I've often wondered why Stack Exchange has opted to keep the upvote/downvote buttons available for clicking on question/answers posted by the user. For instance:    Even though these buttons have no use for the user, why are they still placed on the post's left hand column? Moreover, the comments have no controls for flagging/+1'ing the user's own comment. What is the reason for this discrepancy? What benefit do the +1/-1 buttons provide to the user, even though they can't be used for anything? Determinant of a rank $1$ update of a scalar matrix, or characteristic polynomial of a rank $1$ matrix Fine-tuning "Open safe files after downloading" Are "if" and "iff" interchangeable in definitions? In some books the word "if" is used in definitions and it is not clear if they actually mean "iff" (i.e "if and only if"). I'd like to know if in mathematical literature in general "if" in definitions means "iff".  For example I am reading "Essential topology" and the following definition is written:     In a topological space $T$, a collection $B$ of open subsets of $T$ is said   to form a basis for the topology on $T$ if every open subset of $T$ can be written as a union of sets in $B$.   Should I assume the converse in such a case? Should I assume that given a basis $B$ for a topological space, every open set can be written as a union of sets in $B$?  This is just an example, I am not asking specifically about this sentence. I try to add an item to my sharepoint list from a custom web part. Is there any mistake in my code?  [WebMethod]         public static string AjouterDemande()         {             SPList ListeDemandeConge = SPContext.Current.Site.RootWeb.Lists["DEMANDE CONGÉ"];             SPListItem ListItem = ListeDemandeConge.Items.Add();             ListItem["CODE"] = code;             ListItem["DEMANDEUR"] = Utilisateur.LoginName;             ListItem["DATE DEMANDE"] = DateTime.Today.Date;             ListItem["DATE FIN"] = EndDateD;             ListItem["DATE DEPART"] = StartDateD;             ListItem["DUREE"] = int.Parse(DayCount);             ListItem["PREMIER RESPONSABLE"] = Employe.FirstSuperior.LoginName;             ListItem["DEUXIEME RESPONSABLE"] = Employe.SecondSuperior.LoginName;             ListItem["PRESENCE PRES"] = Boolean.Parse(FirstRespPresent);             ListItem["SOLDE CONGE"] = Conge.SoldeAnneeConge;             ListItem["MOIS"] = int.Parse(StartDateTab[1]);             ListItem["ANNEE"] = int.Parse(StartDateTab[0]);             ListItem["JOURS APPROUVEES"] = 0;             ListItem.Update();             ListeDemandeConge.Update();             return "true";          }   When I use F10 to process debugging step by step and get to my listitem.update(), it went out without giving any error. If i try to update node revision like this:  $node = node_revision_load(59); $node-&gt;set('publish_on', null); $node-&gt;save();   or simple save:  $node = node_revision_load(59); $node-&gt;save();   I have a PHP memory error, (i have 1gb allocated) Has anyone had any success using twitters typeahead.js within visualforce pages? I am running vsftpd as ftp server on my linux (rasbian), I log in to the machine as a root user.  I would like to be still locked to using only /var/www, how can I configure vsftpd conf to accomplish it? biblatex: change name of author according to language? Usually a name stays the same in whatever language. So, whenever I quote a work by Knuth -- be it in an English article or a German one -- I will quote him as Donald E. Knuth.  This is not always the case with ancient or medieval names. They are spelled differently in different languages. Two examples in English | German | French:   Aristotle | Aristoteles | Aristote Thomas Aquinas | Thomas von Aquin | Thomas d'Aquin   This means that when I write an English article, I need a bib-file that contains the English names, but when I want to write a German article, I need to go through my bib file and change the names accordingly. Depending on how often I in fact publish in English or German this could keep me busy and is prone to error.  So, I though, maybe I could have the different names already included in one single bib-file and let biblatex choose the correct name according to the primary language used in the document. Any ideas?  NB: I do not want to use in one single document both spellings Aristotle and Aristoteles (as the following MWE might make you think). Of course, if the article's primary language is English, then all the references to Aristotle will use the English spelling of his name. However, I want to be able to write articles in different languages, without (a) having to edit my bib-files each time or (b) generally maintaing not one single bib-file but two different ones, one for each language, or (c) having two distinct entries in one bib-file  MWE  % !TEX TS-program = lualatexmk \documentclass{scrartcl}  \usepackage{fontspec}         \setmainfont[Ligatures=TeX]{Times New Roman}  \usepackage[ngerman, british]{babel} \usepackage[babel]{csquotes} \usepackage[style=verbose,abbreviate=false,backend=biber]{biblatex}  \usepackage{filecontents}  \begin{filecontents}{\jobname.bib} @book{aristotle:ross:1924,     Author = {Aristotle},    % It is here, I think, that something could be done, e.g., ...     Title = {Metaphysics},     % ... british=Aristotle,ngerman=Aristoteles,french=Aristote     Editor = {William David Ross},     Commentator = {William David Ross},     Introduction = {William David Ross},     Hyphenation = {british},     Location = {Oxford},     Publisher = {Clarendon Press},     Volumes = {2},     Year = {1924}} \end{filecontents}  \addbibresource{\jobname.bib}  \begin{document}  \selectlanguage{british} Some English text.\footcite{aristotle:ross:1924}  \selectlanguage{ngerman} Etwas Text auf Deutsch.\footcite{aristotle:ross:1924}  \end{document} How to run a program on a remote pc via command line? How can I run a program on a remote Windows PC in our network without the need of killing an existing remote-desktop-connection? I only need a command line for running the program and getting its results. Thank you! How do I prompt users with a GUI dialog box to choose file/directory path, via the command-line? I got a UK visa for one month (restricted validity). It expires on November 4. Pakistani citizens are eligible to apply for a Turkish e visa if they have a valid UK visa. I want to visit Istanbul for a couple of days - from October 31 to November 2. Would I be eligible to still apply for an e visa?   My visa is for single entry. It's valid from October 4 to November 4. Finding the radius of convergence for $\sum_{n=0}^{\infty} \frac{(n!)^kx^n}{(kn)!}$ I'm reviewing some calculus concepts right now, and this series stumped me. I'm trying to figure out what its radius of convergence is, but it's not falling for any of my old tricks. Using the root-test, I want to compute: $$ L_1=\lim_{n\rightarrow\infty} \left|\sqrt[n]{\frac{(n!)^k}{(kn)!}}\right| $$  where $k$ is some positive integer. Passing the limit through the absolute-value bars and $n$th root symbol, I now want to compute the simpler (?) $$ L_2 = \lim_{n\rightarrow\infty} \sqrt[n]{\frac{(n!)^k}{(kn)!}}$$  Which I can't seem to pin down. Numerical tests indicate it goes to 0, and that jives with an intuitive notion I have that there are always $k$ terms on the numerator, but $kn$ terms in the denominator. But since all of these terms themselves depend on $n$, proving that $L_2 = 0$ escapes me. Once we get this result (if it's correct), then clearly $L_1$ is also 0, and the radius of convergence of the series is $\mathbb{R}$. Thanks for any ideas you may have. How do I view all available HDD's/partitions? I assume that the multimeter should read 2A, why is it only 0.358A? If this is how it is supposed to be, why? If I add a load, how do I measure that this load is being drawn, does the multimeter need to be in series? How do we use drupal_add_library(), drupal_add_css() and drupal_add_js()? How do I use drupal_add_library(), drupal_add_css() and drupal_add_js() in Drupal 8?  I am porting a module that uses those functions. I am following what reported in , which says these functions have been removed in favor of #attached, but I am not able to attach these files to my configuration page.  The error I am getting is the following:     Uncaught PHP Exception LogicException: "You are not allowed to use js in #attached"   How do I attach CSS and JavaScript to a page? How to mesh codeigniter with ajax How to prove that we are living in a 3+1D world? How to clip an Openlayers OSM Background to a Vector Boundary? I'm new to QGIS. In my project i have two layers: one is my vector (city boundaries) and the other is the OSM (obtained with the plugin). How can I cut the OSM along the edges of the vector? I want to obtain only a region of the map, to save it as an image. Systemd is really slow in comparison to upstart I have been using Ubuntu for a long time now, this is what happened when I use:  Systemd: It performs really bad using systemd: it uses 95% of the CPU all the time and the PC gets really hot. Also it takes a really long time to boot (about 1.5 min, and sometimes it does not boot at all as it has a black screen at boot.)  Upstart: When I tried the upstart options at boot, it performs as expected, booted in seconds, and it was awesome as it should be.  Laptop:   AMD A8 Radeon SSD   Questions:   Why does upstart perform better than systemd? How can I debug systemd? Should I switch to upstart? If yes, how do I do it?