Which is standard usage in British English?
British placement of punctuation relative to inverted commas
In C# check that filename is *possibly* valid (not that it exists) Is there a method in the System.IO namespace that checks the validity of a filename?  For example, C:\foo\bar would validate and :"~-* would not  Or a little trickier, X:\foo\bar would validate is there is an X: drive on the system, but wouldn't otherwise.  I suppose I could write such a method myself, but I'm more interested in a built-in one. I would change the font of section and subsection of my document. I have created it using book class. I would use this font:    According to Adobe pdf propriety, this font is AvantGarde-Demi. How can I use it in Latex. what command I should use to recreate this in latex. I think I should use titlesec package right? Unexpected output of xargs There are often situations where buying two separate one-way tickets from A to C via B is cheaper than buying a normal multi-leg ticket. This can be especially useful with airlines such as Ryanair, which specifically avoids selling multi-leg tickets.  Is there a search engine which allows one to search for such flights? Looking for a science fiction story collection about nanotechnology — included a story about anti-graffiti paint I remember reading it while in middle school in English in the United States, so the latest it would have come out was 1998. I don't remember if it was all one author, or even the same universe. These are the stories I remember:   A man finds a way to create a medicine that prevents radiation poisoning (or possibly makes someone fireproof... it's a little confused in my head) and learns that part of the problem is finding a market for it. I vividly remember the inventor telling someone to not "let the doorknob ream you" as it slams shut. A bout of graffiti artists leads to the city buying anti-graffiti paint that dissolves any other paint put on top of it. After learning the futility of trying to paint over it, the protagonist consults with a friend and learns that the anti-graffiti paint will eat away at the paint above it at a steady rate, and will even eat successive layers of the anti-graffiti paint. he uses this property to engineer an animation involving a harlequin thumbing this nose at the officials even as they try to wash it away. Some guys (I want to say a gang) go to a clinic for an illegal nanotech transformation. The viewpoint character gets turned into a woman while a friend gets turned into a dog. After roaming about in their new forms, they return to find the clinic being raided, meaning there's no one to turn them back. I think I remember something bad happening to the one transformed into a dog where the transformation continued, erasing his human thought patterns. There was also a scene where the viewpoint character submitted to being sexually assaulted by his former friends as if it was simply to be expected given his form.   I don't remember if the first or the second story was the actual first story of the collection... I want to say that those are the order that they showed up as in the book. When a user has the  privilege, they can click on the post score to see the individual counts for upvotes and downvotes.  When a user doesn't have this privilege this functionality isn't present, except after loading newly added answers without refreshing the page. After clicking the "new answers to this question" link the click functionality to view vote counts is added to all posts, though actually clicking on it results in a dialog stating that an error occurred (I'd assume due to not having the required reputation).  May be related to the fix for this previous bug report: In JavaScript:  encodeURIComponent("©√") == "%C2%A9%E2%88%9A"   Is there an equivalent for C# applications? For escaping HTML characters I used:  txtOut.Text = Regex.Replace(txtIn.Text, @"[\u0080-\uFFFF]",     m =&gt; @"&amp;#" + ((int)m.Value[0]).ToString() + ";");   But I'm not sure how to convert the match to the correct hexadecimal format that JS uses. For example this code:  txtOut.Text = Regex.Replace(txtIn.Text, @"[\u0080-\uFFFF]",     m =&gt; @"%" + String.Format("{0:x}", ((int)m.Value[0])));   Returns "%a9%221a" for "©√" instead of "%C2%A9%E2%88%9A". It looks like I need to split the string up into bytes or something.  Edit: This is for a windows app, the only items available in System.Web are: AspNetHostingPermission, AspNetHostingPermissionAttribute, and AspNetHostingPermissionLevel. I have this function:  $$ f(x,y) = \frac {xy}{|x|+|y|} $$  And I want to evaluate it's limit when $$ (x,y) \to (0,0)$$ My guess is that it tends to zero. So, by definition, if:  $$ \forall \varepsilon \gt 0, \exists \delta \gt 0 \diagup \\ 0\lt||(x,y)||\lt \delta , \left|\frac{xy}{|x|+|y|}\right| \lt \varepsilon $$ Then $$ \lim_{(x,y)\to(0,0)}\frac {xy}{|x|+|y|} = 0 $$ So:  $$ \left|\frac{xy}{|x|+|y|}\right| = \frac{|xy|}{|x|+|y|} = \frac{|x||y|}{|x|+|y|} \le 1 |y| \lt \delta $$  So for any $$\delta \lt \varepsilon$$ the inequality is true. Hence, the limit exists and is equal to zero.  . Am I wrong or is Wolfram|Alpha wrong? "They're using a cell phone" vs. "They're using cell phones" The usage of singular and plural has always been confusing for me.   I often see sentences like these         People are using cell phones.   People are using a cell phone.      Does the first sentence mean everyone has a phone and they are all using their own?  Does the second sentence mean they are sharing one cell phone?   If I see a group of people holding a cell phone in their hand(s), &lt;- even this is confusing for me, should I use the first sentence then?   Another example: you see two men, and both of them are carrying a bag. Which sentence should I say/use?        They are carrying backpacks          They are carrying a backpack      Could you please make it clear for me? MySQL strip non-numeric characters to compare Why are American-style options worth more than European-style options? Why are American-style options worth more than European-style options?   I realize I can exercise American-style options anytime before the  expire, but I can only exercise European-style options during their  "exercise period" (usually right when they expire, but no earlier).   So it makes sense that an American option is worth at least as much as  a European option.   But why is it worth more? If I exercise my American option early, I  may make more money than waiting until expiration, but I also may make  less. Mathematically, there's no advantage, since I'm equally likely  to make as much money by waiting for expiration.   Mathematically speaking, is there ever a good reason to exercise an  American option early?   I realize people don't always behave logically, but even the formulas  that valuate options show that American options are worth more.   EDIT (answering comments):    Many of the comments people made would apply to lookback options  (), but not to American  options.  American options can do everything European options can and more. I  understand that, and that means American options can't be worth any  LESS than European options, but I'm still not clear on how you would  mathematically calculate this extra value.  @Aaronaught: "The difference between an American and European  option is the difference between getting N chances to get it right (N  being the number of days 'til expiration) and getting just one  chance. It should be easy to see why you're more likely to profit  with the former, even if you can't accurately predict price  movement."    REPLY: I don't think you really get N chances. Once you exercise the  option, that's it, no more chances. And, if you decide not to exercise  the option today, and the underlying's price falls, you can't go back  in time and exercise it yesterday.    @jdsweet: Think of it this way, if you traveled back through time  one month - with perfect knowledge of AAPL's stock price over that  period - which happens to peak viciously then return to its old price  at the end of the period - wouldn't you pay more for an American  option?    REPLY: Well, no. I'd simply buy a cheaper European option that expires  right at the spike. Or, I'd buy a European option that expires later,  and sell it when the spike occurs. American options don't give you  precognition, so you're still guessing as to when to sell/exercise.    @jdsweet: "one of the more common reasons people exercise (as  opposed to sell) an American option before expiration is if an  unexpected dividend (larger than remaining time value of the option)  was just announced that's going to be paid before the option contract  expires"    REPLY: This makes sense. I'm actually trading FOREX options, so there  is no dividend. In that scenario, are European and American options  worth the same? Does GTA V Online Network Merge Xbox 360 and PS3 players? How rare are magic items and how many should I be handing out? How to find the 'sizeof' (a pointer pointing to an array)? First off, here is some code:  int main()  {     int days[] = {1,2,3,4,5};     int *ptr = days;     printf("%u\n", sizeof(days));     printf("%u\n", sizeof(ptr));      return 0; }   Is there a way to find out the size of the array that ptr is pointing to (instead of just giving its size, which is four bytes on a 32-bit system)? How align 2 adjacent divs horizontally WITHOUT float? "debconf: DbDriver "config": config.dat is locked by another process: Resource temporarily unavailable" while installing packages I'm trying to install the flashybrid but when I enter the apt-get install flashybrid command, I get this error:  root@user-desktop:/home/user# apt-get install flashybrid Reading package lists... Done Building dependency tree Reading state information... Done flashybrid is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 0B of additional disk space will be used. debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable Setting up flashybrid (0.15+nmu2) ... debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable dpkg: error processing flashybrid (--configure): subprocess post-installation script returned error exit status 1 Errors were encountered while processing: flashybrid E: Sub-process /usr/bin/dpkg returned an error code (1)   I also tried this one to find what is already using that file:  root@user-desktop:/home/user# lsof | grep /var/cache/debconf/config.dat lsof: WARNING: can't stat() fuse.gvfs-fuse-daemon file system /home/user/.gvfs Output information may be incomplete. dpkg-prec 4672 root 4rW REG 8,6 39658 1697827 /var/cache/debconf/config.dat   But I don't know how to fix this. Short story about a robot who wants to become a writer Sorting an Array of Objects in PHP In a Specific Order I have two arrays in PHP. The first array ($author_array) is comprised of user_ids in a particular order, like so: (8, 1, 6)  The second array ($user_results) is comprised of an array of objects like so:  Array (     [0] =&gt; stdClass Object         (             [ID] =&gt; 1             [user_login] =&gt; user1         )     [1] =&gt; stdClass Object         (             [ID] =&gt; 6             [user_login] =&gt; user6         )     [2] =&gt; stdClass Object         (             [ID] =&gt; 8             [user_login] =&gt; user8         ) )   I'd like to "sort" the second array so it's in this order, which matches the order of the values in the first array of (8, 1, 6). So it'd look like this:  Array (     [0] =&gt; stdClass Object         (             [ID] =&gt; 8             [user_login] =&gt; user8         )     [1] =&gt; stdClass Object         (             [ID] =&gt; 1             [user_login] =&gt; user1         )     [2] =&gt; stdClass Object         (             [ID] =&gt; 6             [user_login] =&gt; user6         ) )   I'm weak on data structures. How could I do this? :-)  Thanks in advance for your help!  -Bob How to hide notification center button in Mountain Lion? I am using Mountain Lion.  The only advantage (for me) over the gesture is that Option + clicking the button enables/disables showing alerts and banners (toggles the switch in the notifications center).  Is there a way to hide the button in the status bar that opens notification center? Python Implementation of Track-to/aim constraint