How can I get this:    MWE:  $i^{'}$
Why does the following code does'nt work when i am using PDFLaTeX or just LaTeX ? I tried it in different editors as well.  This is the code   $\{f^'_n\}$   Surprisingly it works on Math.SE site
Confusing [...] List in Python: What is it? So I was writing up a simple binary tree in Python and came across [...]  I don't believe this to be related to the Ellipsis object, more it seems to have something to do with an infinity loop (due to Python's shallow copy?). The source of this infinity loop and why it doesn't get expanded while expanding when accessed is something I'm completely lost to, however   &gt;&gt;&gt; a [[[[[], [], 8, 3], [[], [], 3, 2], 6, 3], [], 1, 4], [[], [], -4, 2], 0, 0] &gt;&gt;&gt; Keys(a)#With a+b [0, 1, 6, 8, 3, -4] &gt;&gt;&gt; Keys(a)#With [a,b] [8, [...], [...], 3, [...], [...], 6, [...], [...], 1, [...], [...], -4, [...], [...], 0, [...], [...]] &gt;&gt;&gt; Keys(a)[1]#?? [8, [...], [...], 3, [...], [...], 6, [...], [...], 1, [...], [...], -4, [...], [...], 0, [...], [...], 8, [...], [...], 3, [...], [...], 6, [...], [...], 1, [...], [...], -4, [...], [...], 0, [...], [...]]     Version using a+b  def Keys(x,y=[]):     if len(x):y+=[x[2]]+Keys(x[0],y)+Keys(x[1],y)#Though it seems I was using y=y[:]+, this actually outputs an ugly mess     return y   version using [a,b]  def Keys(x,y=[]):     if len(x):y+=[x[2],Keys(x[0],y),Keys(x[1],y)]     return y   So what exactly is [...]? Let $ f $ be a continuous function defined on $ [0,\pi] $. Suppose that      $$ \int_{0}^{\pi}f(x)\sin {x} dx=0,   \int_{0}^{\pi}f(x)\cos {x} dx=0 $$   Prove that $ f(x) $ has at least two real roots in $ (0,\pi) $ In Ubuntu 18.04.1, I would like to use my left Super-key only to simply open the Show Applications menu (aka Dash) like a left click on the dock-icon (with the 9 dots) does and preferably close it again without showing me any open programs.   I can open it with Super + A and even close it again with Super R, but Super L appears to do nothing at all.   In Xfce, something similar was possible by adding a custom keyboard shortcut for Super L and setting the command to xfce4-popup-whiskermenu, which would open and close a menu with favourite applications. Unfortunately, I don't know the command that opens and closes the Show Applications menu.   Is there any way to add such a shortcut in the new Gnome Shell? I would like to have a paper's bibliography entries inside its .tex file instead of outside in a .bib file. Is this possible with biblatex?  My reason for asking this is that I want to find the most convenient way to produce documents that uses biblatex from just one file to make collaboration on papers easier and to be able to handle submissions of papers to journals. Does iTunes work (well) on Ubuntu? Proof of linear independence of $e^{at}$ I would like to typeset the top part of Pascal's triangle. To get the triangle with the names of the binomial coefficients, i.e., {n \choose k}, I used the following code  \begin{tikzpicture} \foreach \n in {0,...,4} {   \foreach \k in {0,...,\n} {     \node at (\k-\n/2,-\n) {${\n \choose \k}$};   } } \end{tikzpicture}   The result is this   Now I want to be equally lazy and do something like this for the values of the binomial coefficients, i.e., replace {\n \choose \k} in the node label with \CalculateBinomialCoefficient{\n}{\k} where \CalculateBinomialCoefficient is a hypothetical macro that calculates the binomial coefficient. Has anyone done something like that?  The result should look like this: Some text lines are italicized with no spaces between words Explanation behind Second Derivative of a Parametric Equation Formula How does one get started with web test automation using Selenium? So I've been testing web based analytical software now for the past 4 years or so with mostly manual techniques. But for 2015, I've set myself the goal of getting setup and start writing automated tests and to introduce automated testing into my company.  I've done a little research and it seems that Selenium is quite big when it comes to writing automated tests, but most of the tutorials I've come across reference the Java language.  Some questions:   Is Java the primary language used for Selenium tests?  Do you recommend it over C# ?  Wat is the process of writing test scripts?  Are there Frameworks that I should use that can make the process even easier? How can I make a perfect sweep with bevel object in Bezier curve(3d) (Pipe) Correct tracked camera orientation C# Regular Expressions with \Uxxxxxxxx characters in the pattern In natural language parsing, what is the feature function? I'm working in the area of natural language processing, to be specific I'm reviewing the parsers that take advantage of data-mining techniques.   I've read an introduction to natural language processing, specifically the  by Della Pietra and others. In that paper, the authors explain that features are indicator functions that take into account certain aspects of the text. The problem is that this aspects affect the maximum entropy function.  In the case of parsing, I have problems understanding the concept of features. For parsing one must have:   Two sets, $X$ for the sentences and $Y$ for the parses For each sentence $x \in X$, one must have the N-best list of candidate parses; denoted $GEN(x) \subset Y$. Training samples $(x_j,y_j)$. The $x_j$ are sentences and the $y_j$ are parses. And a feature mapping $\Phi(X,Y)$ that maps each pair (x,y) to a vector of feature values.   The problem of parsing will consist of finding the weight vector such that the following expression is minimized  $$ -\sum log P(y_j|x_j,w) + \lambda ||w||_1 $$  where   $$ P(y_j|x_j,w) = \frac{exp \{w^T \Phi(x_j,y_j)\}   }{ \sum_{u \in GEN(x)} exp\{ w^T\Phi(x_j,u) \}  } $$  My question is, what are the features in this case? Some codified version of the parsing tree? Are the features a statistical concept?  I will also appreciate any bibliography that can be useful in tackling this issue.  UPDATE: I've talked to a professor and he had just told me that the features are obtained after doing a classification algorithm based on the parse-tree. Do you know what kind of classification is done with the parse tree? How do you prevent web pages from appearing in the Google search index? I have some web pages that Google has indexed. I have now added a robots.txt file to exclude them, but should I also add a noindex tag? If so, then how do I do so? An example of a group such that $G \cong G \times G$ I was trying to find an example such that $G \cong G \times G$, but I am not getting anywhere. Obviously no finite group satisfies it. What is such group? For those who duplicated my previous question - ; am NOT asking how to install Skype for God's sake!!   The question was rather - I already have Skype installed, the thing is there is no possible option for me to do group video call or group screen share. The interface itself resembles the times when Skype was newly born. While on Windows, Skype's latest version is around 6.(something), here it's only 4.3. In Windows group video call is now free on Skype, here I can't even do video call! I think this is a major drawback for an otherwise so good OS! Is there anything that can be done about it?  Thanks for any help!  For those who don't have an answer for me, I still thank you for at least understanding my question!!  Have a good day! Lost my Downloads folder both from Dock and Finder I did something stupid apparently and lost my Downloads folder both from Dock and then when I opened Finder to drag it down to the Dock it somehow got deleted in the desktop.  Now although I can see the folder exists (e.g. by searching in Spotlight) I do not know how to restore it in the Dock and in Finder as well. Any help please? Adding table of certain attributes to map layout? I am using ArcMap 10.2 and I'm looking for a way to add  a table containing certain fields from select elements from a featureclass to my map. Ive tried the add table option from the attribute table, but it doesn't quite give what I want (the table must be editable to look a certain way).   Are there any options out there for 10.2 like arcpy.mapping.tableview or will upgrading to 10.3 so I can get access to the "graphic table element" function be best? I'm a citizen of India and I'm travelling to Nepal by air. Is an Aadhaar Card a valid document used for travelling to Nepal by air?