Variable use during recursion?
UnboundLocalError on local variable when reassigned after first use
What is the meaning of modular fractions? What is the meaning of $$ \\\frac{m}{n}\equiv k\pmod l $$ and $$ \\\frac{m}{n} \mod l $$ $m, n, k, l \in\mathbb N$ and $\gcd(m, n)=1$. Pluralization rule for "five-year-old children", "20 pound note", "10 mile run" How have Superman comics dealt with the Man of Steel, Woman of Kleenex problem? When I was a teen and Superman II came out, when Superman realized he and Lois were in love, he de-supered himself in the Fortress of Solitude so he could be with Lois.  Right after he emerged from the crystal cage that drained his powers, the first thing he does is take Lois' hand and escort her to a conveniently placed bed that we had never seen there before.  This implies it was necessary for him to lose his powers so he could have sex with Lois.  The problems involved in this situation are well covered in the wonderful essay by Larry Niven, .  But I also know that Superman has been in the comics for decades.  A friend of mine once said, "Oh, he tells her who he is a lot, but he always makes her forget it again later."  So how have the comic books (since this is Superman's primary medium) handled this?  Were there different ways it was handled, or was it always handled the same way?  Have they literally kept Superman and Lois from having sex for decades?  Or have there been times when they've ended up in bed together?  How do they deal with the issues of the Man of Steel having sex with, and not killing, a woman of Kleenex? How to provide a file download from a JSF backing bean? Why am I not able to shutdown, log-off and restart after an upgrade to Ubuntu 13.10? After the update neither my desktop (Asus) nor my laptop (HP) respond to the shut-down, log off or restart commands in the right top tool bar.  How do I fix the issue? How can I know what speed card to get for my camera? Cameras rarely specify exactly what speed cards you should be using in them - I just checked the manual for my DSLR, and all it says is to use an SDHD card, and a "high speed" card should be used for recording video.  On the other hand, there are a number of different rating systems for memory card speed (33x! 150x! Class 2! Class 10!) and price seems to increase with speed.  Is there any way to test the maximum write speed the camera is capable of?  Are the read/write speeds documented anywhere? Opening the menu and selecting an item from the "Favorite Sites" menu allows us to see a feed for a specific site. In the top right corner of this page is a drop-down which allows us to select the "sort order" for the posts. The default is "Active" with other options like "Newest", "Hot", etc.  The problem is that when I select "Newest" or any other option. This preference is not remembered when I change between a different "Favorite Site".  So I am requesting that the selection is persisted when changing between site feeds. I have no preference whether this is implemented per site (to allow a different default for each site) or just one single preferred default that works on all sites (last option selected). I just want it to remember that I have selected "Newest" when I am flicking though the sites. R stem and leaf values How to make a stem and leaf plot with the following data in "R":  1717 1719 1645 3739 3024 3664 3830 2991 2430 2730 3469 5086 2119 3021 3292 2844 3426 2067 3215 2767 3124 2573 2840 2449 2584 1505 1390 1645 2497 3466 3228 3192  The only way to get a reasonable amount of stems is to make the stem the first digit in each number and the leaves will all be 3 digit numbers. I am not able to split the data in this way, R represents the stem with 1 digit but round my numbers  so 2584 is shown as 2| 5 (3 decimals to the right) which would be 2500. How do I adjust my stem and leaf numbers? Matching exact string with JavaScript How can I test if a RegEx matches a string exactly?  var r = /a/; r.test("a"); // returns true r.test("ba"); // returns true testExact(r, "ba"); // should return false testExact(r, "a"); // should return true UI annoyances in the suggested edit review on Stack Overflow How to deal with hierarchical / nested data in machine learning I came across a  where a comprehensive example would be very useful. So I wrote an example program showing one way to solve their problem.  My problem is that when I was done creating it, and testing to make sure it worked, it was over 400 lines in 18 files. My example included source code, header files, and scripts for building the example in a variety of circumstances.   It's a working and tested, so it's of huge value to illustrate the tricky solution, but because it's all there, my response was huge! Is there a better way of posting my code dump?  Edit:  I guess there isn't a current "best way" to include a large chunk of code, so I made this a feature request and tried to add some ideas.  Perhaps code entries that are longer then a certain number of lines, or ones that have been specifically marked could initially be displayed as "collapsed", and someone could expand them if they want to see them?  Or maybe, like attaching images, users with enough reputation could attach an archive of files. They could be displayed as "attached code" (initially collapsed also).  Some problems have simple answers that unfortunately touch disproportionately large parts of the program, or can be solved in slightly different ways depending on the environment. I feel that stackoverflow needs a way of capturing these large solutions. Sometimes, they're large chunks of code. In my case, the code was small, but there were many files.  Using github or a similar code repository is great, but we risk linkrot (even for big guys like github) and loose the community editing, commenting, and voting abilities.  I understand the problems that could come from with people dumping whole "I can't get this to work" packages, but surely we already have a solution for that in moderation.  Edit again:  I'm starting to see that this may have been already addressed in posts like    , and    If you feel this a dupe, I'm open to having it "closed as already addressed" How to zero out a drive? Do Chinese citizens require a visa to go to Hong Kong for less than 7 days? Expected value of x in a normal distribution, GIVEN that it is below a certain value I'd like to implement a big int class in C++ as a programming exercise&mdash;a class that can handle numbers bigger than a long int.  I know that there are several open source implementations out there already, but I'd like to write my own.  I'm trying to get a feel for what the right approach is.  I understand that the general strategy is get the number as a string, and then break it up into smaller numbers (single digits for example), and place them in an array.  At this point it should be relatively simple to implement the various comparison operators.  My main concern is how I would implement things like addition and multiplication.  I'm looking for a general approach and advice as opposed to actual working code. Decision boundaries and Gaussian density functions The ending I got is :      the genocide   When I reset my file, my past choices still take effect. I want to start a clean run.  I don't want to buy the game again, what do I do? What is the width of the standard paragraph indent in LaTeX's article class? If no changes has been made to the settings of indentation of an article class LaTeX document, what is the width of the paragraph indent?  texdoc article in the terminal opens the Standard Document Classes for LaTeX version 2e manual. In section 6.2 Paragraphing I find the following line:  ⟨10pt⟩ \setlength\parindent{15\p@}   The  means 1pt ... so I guess this would mean that the standard indent is 15 pt at a 10 pt text size? Is this correct? If $\sum_{n=1}^{\infty} a_n^{2}$ converges, then so does $\sum_{n=1}^{\infty} \frac {a_n}{n}$ Let $a_1,a_2,a_3,\ldots$ be reals. Prove that if $\sum_{n=1}^{\infty} a_n^{2}$ converges, then so does $\sum_{n=1}^{\infty} \frac {a_n}{n}$.   For this I have shown the case for when $ a_n^{2} \le\frac {|a_n|}{n}$ $\Rightarrow$ $ |a_n|\le\frac {1}{n}$ $\Rightarrow$ $\frac {|a_n|}{n} \le \frac{1}{n^{2}}$ and we know that $\sum_{n=1}^{\infty} \frac {1}{n^{2}}$ converges and hence $\sum_{n=1}^{\infty}\frac {a_n}{n}$ converges by the comparison test. Now considering $ a_n^{2} \ge\frac {|a_n|}{n}$ $\Rightarrow$ $\frac {|a_n|}{n} \le a_n^{2}$ $\rightarrow$ combining the two cases for any n we have: $\frac {|a_n|}{n}\le\frac{1}{n^{2}}+a_n^{2}$ Hence using the comparion test again we know that $\sum_{n=1}^{\infty} a_n^{2}$ converges and $\sum_{n=1}^{\infty} \frac {1}{n^{2}}$ converges hence the sum converges so we can conclude that $\sum_{n=1}^{\infty} \frac {a_n}{n}$ is absoluetly convergent $\Rightarrow$ convergent.  Not to sure if this is correct, any help would be much appreciated, many thanks.