Credit card: did they really cancel it?
How to cancel a credit card and verify it was closed
Open subsets in a manifold as submanifold of the same dimension? An open set in an $n$-manifold is clearly a submanifold of the same dimension as its containing manifold (see open manifolds).   Now, given an $n$-manifold $M$, is it true that a set, to be the underlying set of a submanifold of $M$ with dimension $n$, must be open? Totally disconnected space that is not $T_2$ Uninstalling QGIS that was installed using OSGeo I installed QGIS using OSGEO4W, and would love to know how to uninstall it, because when I go to "Control Panel > Programs > Uninstall" the program does not appear in the list of installed programs.   How can I do this? How disk space is used on Android device? Is there a way to get the (to-be-generated) SQL from a Hibernate Criteria?  Ideally, I would have something like:  Criteria criteria = session.createCriteria(Operator.class);  ... build up the criteria ... ... and then do something like ...  String sql = criteria.toSql()  (But this of course does not exist)   The idea would then be to use the SQL as part of a huge 'MINUS' query (I need to find the differences between 2 identical schemas - identical in structure, not in data - and the MINUS is not supported by Hibernate)  (BTW I know I can check the SQL from the log files) A method for evaluating sums/discrete functions by assuming they can be made continuous and differentiable? Suppose I had a function that satisfied the property $f(x)=f(x-1)+g(x)$.  For any $x\in\mathbb N$, it is easy enough to see that this boils down to the statement  $$f(x)=f(0)+\sum_{k=1}^xg(k)$$  If we return to our functional equation and differentiate it $n$ times, we get  $$f^{(n)}(x)=f^{(n)}(x-1)+g^{(n)}(x)$$  Once again, for any $x\in\mathbb N$, we have  $$f^{(n)}(x)=f^{(n)}(0)+\sum_{k=1}^xg^{(n)}(k)$$  One could then integrate both sides.  For example, this asserts that  $$\sum_{k=1}^xg(k)=xf'(0)+\int_0^x\sum_{k=1}^tg'(k)dt$$  If the sum inside the intagral is generalized to any upper bound.  How would I justify this for discrete functions?    An example of this is letting $f_p(x)=\sum_{k=1}^xk^p$, as it seems to follow the above result.  We can see from the above that  $$f_p(x)=a_px+p\int_0^xf_{p-1}(t)dt$$  $$a_p=1-p\int_0^1f_{p-1}(t)dt$$  which appears to be a true recursive formula.    Under what conditions can I extend discrete functions $f(x)$ and $g(x)$ into continuous differentiable functions and apply this method? How to auto populate with conditions? How do I efficiently get "the most recent corresponding row"? I have a query pattern that must be very common, but I don't know how to write an efficient query for it.  I want to look up the rows of a table that correspond to "the most recent date not after" the rows of another table.  I have a table, inventory say, which represents the inventory I hold on a certain day.  date       | good | quantity ------------------------------ 2013-08-09 | egg  | 5 2013-08-09 | pear | 7 2013-08-02 | egg  | 1 2013-08-02 | pear | 2   and a table, "price" say, which holds the price of a good on a given day  date       | good | price -------------------------- 2013-08-07 | egg  | 120 2013-08-06 | pear | 200 2013-08-01 | egg  | 110 2013-07-30 | pear | 220   How can I efficiently get the "most recent" price for each row of the inventory table, i.e.  date       | pricing date | good | quantity | price ---------------------------------------------------- 2013-08-09 | 2013-08-07   | egg  | 5        | 120 2013-08-09 | 2013-08-06   | pear | 7        | 200 2013-08-02 | 2013-08-01   | egg  | 1        | 110 2013-08-02 | 2013-07-30   | pear | 2        | 220   I know one way of doing this:  select inventory.date, max(price.date) as pricing_date, good from inventory, price where inventory.date &gt;= price.date and inventory.good = price.good group by inventory.date, good   and then join this query again to inventory. For large tables even doing the first query (without joining again to inventory) is very slow.  However, the same problem is quickly solved if I simply use my programming language to issue one max(price.date) ... where price.date &lt;= date_of_interest ... order by price.date desc limit 1 query for each date_of_interest from the inventory table, so I know there is no computational impediment.  I would, however, prefer to solve the whole problem with a single SQL query, because it would allow me to do further SQL processing on the result of the query.  Is there a standard way to do this efficiently? It feels like it must come up often and that there should be a way to write a fast query for it.  I'm using Postgres, but an SQL-generic answer would be appreciated. Is it possible to add images to comments? I was wondering if it is possible to post a comment with an image.  Recently, during a question about data-visualization in Cross Validated, there was a controversy about using one type of chart for another.   I had posted a question about pie-charts, after reading some references I decided to build an example and clarify the point of using waffle-chart vs pie-chart. In a way, my example was not an answer it was more properly a comment on waffle-charts. But it seems to be impossible to post a comment with an image (Maybe, there is a way but I can't figure out how).  I don't know if it is relevant to post images in comments in other SO sites. So, if there is no way to post images in comments... why not making it possible? And if there is a way to post an image with a comment, how I can do it? So this is a question with which I have been stuck for a while and it all revolves around the concept of volt.  I have posted a LOT of questions on physics forums while trying to understand the concept of volt and potential difference. This is hopefully going to be the last one.  What do you exactly mean when you say that a battery is 2.5 V. I know that it says that the potential difference between the 2 terminals of the battery is 2.5 V  but then what is the potential of the 2 ends of the battery? Is there a unit of potential and not just potential difference?  Also volt = work/charge but how can work/charge express the difference of potentials across the 2 terminals? Is using "fruits" as the plural of "fruit" acceptable? What to do if I can't get a visa to attend a conference that accepted my paper? My work got accepted into a very good category in a very good conference in my field. Due to complicated visa issues it will be very hard for me to attend that conference.   If I don't attend the conference they are certainly going to remove my work from the proceedings.  I am worried I won't be able to claim any sort of achievement if I don't attend this conference.  Can I still add it to my CV and specify that my work got accepted in this conference in a very good category? What do I need to know before upgrading the CPU of a laptop? I have an AMD laptop, which has AMD APU (e1-2500). I don't really like the speed of it and would love to upgrade to faster APU. There are some AMD APUs available in ebay. So the question is:   What do I need to check to be sure that a new APU will work without problems? Why do we need virtual functions in C++? How do I make an HTML text box show a hint when empty? I want the search box on my web page to display the word "Search" in gray italics. When the box receives focus, it should look just like an empty text box. If there is already text in it, it should display the text normally (black, non-italics). This will help me avoid clutter by removing the label.  BTW, this is an on-page  search, so it has no button. What's the best blog post/video/tweet/whatever to explain how the Stack Exchange system works to regular people? I am trying to gauge interest for a new Stack Exchange site, but I want to explain it to people as best (and preferably) as visually as I can. Any YouTube clips breaking it down?  anyone?  Note: I am fully aware of , but mine is about Stack Exchange, not Stack Overflow.  Most people think I'm describing traditional forum software, which they know sucks. Is there some way to describe the magic of how the design of the Stack Exchange system actually produces useful results very quickly? I can describe generally that it is a Q&amp;A site that users vote on the answers, but Stack Overflow feels like so much more. Am I perhaps thinking too big about this? How to remove the "3D Objects" entry from Windows 10 Explorer? The 2017 Fall Creators Update to Windows 10 added a "3D Objects" folder to the "This PC" view of Windows Explorer:    How can this be removed? How to connect a Nokia Lumia 730 to Ubuntu 14.04? I know I'm asking for the close-to-impossible -- as a real full-backup certainly requires root permissions. But still there are many folks around not wanting to root their devices -- afraid of voiding their warranties or bricking their devices, or just not having their devices supported by any rooting method.  I also know there were a lot of questions asked already on this topic, and I checked all of them having the backup tag -- none covers the entire topic, all just have pieces, and especially people new to Android (but other non-power-users as well) would have a hard time figuring out the best way.  So I want a detailed canonical answer to the question:  Not involving root-solutions, how to achieve a backup as close as possible to a full backup?  Please do not give simple one-liner answers like "Use app xyz [full-stop]." If mentioning an app (and I doubt a single app would be the answer here), include what parts are covered by it -- as well as ideas on how to fill the gaps it leaves. (And to make it absolutely clear: I know the first thing coming to mind is Titanium Backup -- I use it myself, but this does not apply here: This question is strictly about methods for non-rooted devices!) Moreover, the answer should be as generic as possible in terms of applying to a wide range of devices (i.e. it should not be restricted to one device or manufacturer).  I already mentioned having investigated all questions here tagged backup. These will certainly be helpful providing details for answers here, so I will list up the topmost ones concerning my question:            All these provide some details for my question (so feel free to get inspired by them) -- but I feel there are still details missing. Also it would be helpful to have a summary -- say, an answer including the full description of "the maximum possible".  A last criterium: While I'd consider cloud-based solutions legit, I'd favour local solutions. If you can provide both: all the better. But some people value privacy quite high (I'm one of them), and thus would not trust their data to some cloud service.    Thanks to Ryan, we now have a solution for a really complete backup of all apps and their data -- which I didn't dare to hope for! The only disadvantage: His solution only works for less than 10% of all Android users; namely those whose devices are running at least with Android 4.x.  So again, I ask the close-to-impossible: Any solutions applicable at least on Gingerbread (2.3.x) or, better, even Froyo (2.2.x) -- so they cover the majority of current devices? These solutions may involve multiple tools (try to keep it as simple as possible though; think of your mother to follow your instructions ;)  And keep in mind: NO ROOT!    To further motivate high-quality answers (and hopefully avoid low-quality ones), I will be a harsh one here: As I rarely do, I will down-vote answers not fitting the mentioned criteria on one end -- but on the other end, I will setup a bounty for the best answer (which cannot be done immediately, but earliest after 2 days). What is the historic present tense? I learned that the historical present may be used to create an effect of immediacy in narratives. I have a question about the historic present tense. Why don't we use the progressive tense instead of the simple present tense?   ※My English skill is poor, so my question might sound rude. But I don't mean to offend anyone. I'd be glad if someone could reply to my question.