I'm stuck on the last exercise of the level 14 in Vim-Adventures. According to the following picture, could anyone be able to tell me what I have to do here? Which command do I have to use (c,y,a,d or i) and how ?    Thanks in advance!
I've already defeated the Big Bug.   I see the hint that the small bugs disguised as cursors are vulnerable to the three words "Charity", "Uganda", and "Bram".  I think I have all keys available, I've tried undoing with the bugs on the three words, I've tried motions which include the three words in their range, I have each of the three words stored in a named register, but I haven't figured out how to defeat the three small bug minions underground in Level 14 of Vim Adventures.  I suspect I should have defeated them before defeating Big Bug, maybe even before finding 'undo'. Is there instead something I should do in the 'lorem' buffer where I found the three cursors (Blue, White, and Pink) at the beginning of the level?  How does one defeat the three small bug minions in Level 14?
Why won't this work?  I'm trying to make an instance of a class delete itself.  &gt;&gt;&gt; class A():     def kill(self):         del self   &gt;&gt;&gt; a = A() &gt;&gt;&gt; a.kill() &gt;&gt;&gt; a &lt;__main__.A instance at 0x01F23170&gt; Examples and further results about the order of the product of two elements in a group When is a review task "completed" or "invalidated"? Do you have to want to hurt someone for the cruciatus curse to work? The Winter Bash is back and the hats are listed below.  As always, there are only two answers: one for the secret hats, and one for the regular hats. The secret hat list will be updated as we learn them.  Only edit the secret hat answer with definitive and correct triggers. This is not the place to post guesses.    If you'd like to discuss Winter Bash, hats or just have a question about the WB please come over to the .  Please keep the comments here clean. As always comments are not meant for discussion, conversation, "I just got hat X", etc use the  for that (the remaining meta mods will periodically clean the comments). I know you are excited you just got a secret hat, but please instead of posting a comment come over to the  and tell us all there.  Provided that "It's important to know your history... in more ways than one"  again this year, here are the hats from prior years: 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: Sum from $n=1$ to $N$ of $\sin(nx)/2^n$ The question states:    I'm not sure what to do here. I used the geometric sum to do $2^{-n}$, but I can't think of a way to sum $\sin(n\theta)$ to get the required RHS.    Further working     Apologies for maybe being slow or missing something obvious here... I don't know how to get it into required form. How does leave-one-out cross-validation work? How to select the final model out of $n$ different models? I have some data and I want to build a model (say a linear regression model) out of this data. In a next step, I want to apply Leave-One-Out Cross-Validation (LOOCV) on the model so see how good it performs.  If I understood LOOCV right, I build a new model for each of my samples (the test set) using every sample except this sample (the training set). Then I use the model to predict the test set and calculate the errors $(\text{predicted} - \text{actual})$.  In a next step I aggregate all the errors generated using a chosen function, for example mean squared error. I can use these values to judge on the quality (or goodness of fit) of the model.  Question: Which model is the model these quality-values apply for, so which model should I choose if I find the metrics generated from LOOCV appropriate for my case? LOOCV looked at $n$ different models (where $n$ is the sample size); which one is the model I should choose?   Is it the model which uses all the samples? This model was never calculated during the LOOCV process! Is it the model which has the least error? Given $n$ independent geometric random variables $X_n$, each with probability parameter $p$ (and thus expectation $E\left(X_n\right) = \frac{1}{p}$), what is $$E_n = E\left(\max_{i \in 1 .. n}X_n\right)$$    If we instead look at a continuous-time analogue, e.g. exponential random variables $Y_n$ with rate parameter $\lambda$, this is simple: $$E\left(\max_{i \in 1 .. n}Y_n\right) = \sum_{i=1}^n\frac{1}{i\lambda}$$  (I think this is right... that's the time for the first plus the time for the second plus ... plus the time for the last.)  However, I can't find something similarly nice for the discrete-time case.    What I have done is to construct a Markov chain modelling the number of the $X_n$ that haven't yet "hit". (i.e. at each time interval, perform a binomial trial on the number of $X_n$ remaining to see which "hit", and then move to the number that didn't "hit".) This gives $$E_n = 1 + \sum_{i=0}^n \left(\begin{matrix}n\\i\end{matrix}\right)p^{n-i}(1-p)^iE_i$$ which gives the correct answer, but is a nightmare of recursion to calculate. I'm hoping for something in a shorter form. Unable to disable Hyper-V in Windows 10 Hi I installed Docker for Windows which enabled Hyper-V on my windows 10 machine. Unfortunately this caused Virtual Box to not work anymore, therefore I removed Docker again, but Hyper-V is still activated.  If I try to disable Hyper-V with any of those ways:  on the reboot it will first try to apply the changes and than say that the changes couldn't be applied and reverts, so Hyper-V is activated again.  Has anybody an idea what could be the issue here? Why do people sometimes use the past perfect form of a verb when the past would suffice? (e.g. "you had mentioned") How do I write a mathematical equation for ARIMA (2,1,0) x (0,2,2) period 12 "Unable to locate package sudo" when i try to install sudo on new Debian I would like to create a reminder on Google Calendar every month on the 15th, but if the 15th in that month is a Friday/Saturday, I want it automatically to set it to the closest Sunday/Thursday. Is this possible? What is the difference between using a colon and a semi-colon to join two sentences? I've seen a few questions on this site relating to semi-colons, which I believe I correctly understand, but what I'm not as clear about is colons.  For example:     The man ate the apple; it tasted good.   Is this not correctly also written as:     The man ate the apple: it tasted good.   In this case, what is the difference between the two sentences? If $f^2$ is an analytic function then so is $f$ I want to show the following:  If $f(z) $ is a continuous  function on a connected open subset of the complex plane and $f(z)^2$ is an analytic function, then $f(z)$ is analytic.  Clearly if $f(z) \neq 0$ then $$\frac{f(z+h)-f(z)}{h}=\frac{f(z+h)^2-f(z)^2}{h}.\frac{1}{f(z+h)+f(z)}$$  which shows $f^\prime(z) $ exists if $f(z)\neq0$.  What do I do when $f(z) =0$? Replace a string in a text file using a shell script not working properly I have a text file containing this:  0 0 -1 0 1 0 0 0 0 -1 0 0 1.5 0.0 1.0 1   and I want to replace the 1.0 to 2.0 so that it becomes:  0 0 -1 0 1 0 0 0 0 -1 0 0 1.5 0.0 2.0 1   so I use this command:  sed -i 's/'1.0'/'2.0'/g' /home/user1/file1.txt   or this:  sed -i 's/1.0/2.0/g' /home/user1/file1.txt   but this is the result that appears and I don't know how to fix this:  0 0 -2.0 2.0 0 0 0 -2.0 0 1.5 0.0 2.0 1 What are the best practices for modeling inheritance in databases?  What are the trade-offs (e.g. queriability)?  (I'm most interested in SQL Server and .NET, but I also want to understand how other platforms address this issue.) Imgur is over capacity - some user avatars fail to load I see a lot of 'white' avatars in the question lists, e.g.  and . Some user avatars aren't loaded, e.g.  and  – they just timeout for me. Sometimes (but not always) I do get a nice "Imgur is over capacity!" image, which I'm (rather surprisingly) able to upload to imgur - but you might not see it. how to have a custom zsh auto_cd command Instead of the normal cd I've created my own function  function cd {     builtin cd "$@" &amp;&amp; ls -F }   This works great for when I use commands like cd someDir/subDir but not when I change directories via zsh's auto_cd someDir/subDir.  Is there a way to customize what command gets called for auto_cd?