So I am trying to figure out how to teleport someone within a radius, but only when there is one entity left within that radius. I was trying this:  /tp @p[c=1] x y z   But the c is only for how many people you wish to teleport. So my mind jumped to:  /tp @p[entity=1] x y z   But as far as I'm aware you, can't specify entity under @p. I am rather new to command blocks in general. Is it possible, and if yes, how? I would normally like to figure it out myself because I learn better that way, but this is too confusing for me. If it is possible I would rather just be told how to figure it out without giving me the complete answer, but at this point I'll be content with anything.
I want to make it so I always have 50 entities in an area. So when 1 dies/despawns/leaves the area I want it to detect that and summon in a new entity, and yes I do want them to die/despawn/leave the area so preventing those things is not an option.
Circle Rolling on Ellipse I've gotten interested in describing a circle rolling on an ellipse; specifically, the curve traced out by a point on the circumference of the circle. I want a symbolic solution to the general case, radius $r$, axes $a$ and $b$. I've written nine polynomial equations in terms of various angles and lengths.  Exactly what "solution" means is subject to debate.  Let $(u,v)$ be the point on the circle. Similar to the cycloid, I would like an equation for $u$ in terms of a "natural" angle in the problem.  Similarly, an equation for $v$.  Perhaps it is necessary to have a differential equation, so maybe $du/dt$, $u$, and $t$, where $t$ is an angle in the problem.  I would have thought this was known, but I can't find it anywhere. How to close ports / disable services? I just portscanned my system with nmap and got the following result:  PORT    STATE SERVICE 25/tcp  open  smtp 631/tcp open  ipp   what are these services and how i do disable them? probably i don't need them. How to type \sim above another symbol x? I want to put a "~" above x, just like \hat x but replacing \hat with \sim.   How to do that? Duplicate explanation should encourage improvement of original The new closed-as-duplicate banner says:     This question has been asked before and already has an answer. If those answers do not fully address your question, please .   I think it should instead say     This question has been asked before and already has an answer. If answers there do not fully address your question, please  or  to the pre-existing one.   &mdash; to discourage re-re-asking the same question. (I also changed "those answers", which has no plural , to "answers there", which doesn't need one.)    As of September 19, 2013, the original text quoted above has returned here. I need help to advance in the resolution of that limit: $ \lim_{n \to \infty}{\sqrt[n]{\frac{n!}{n^n}}} $ Suppose that we do not know anything about the complex analysis (numbers). In this case, how to calculate the following integral in closed form? $$\int_0^\infty\frac{\cos x}{1+x^2}\,\mathrm{d}x$$ Correct interpretation of a "double-negative" in American Pop Culture (i.e. "I ain't afraid of no ghost!") How should you deal with (deliberate) selective deafness? What is the fastest lens available for a DSLR? I've seen references to f1.2 lenses. I was wondering, are there any faster lenses available for a DSLR mount? If $\sum (a_n)^2$ converges and $\sum (b_n)^2$ converges, does $\sum (a_n)(b_n)$ converge? If $\sum (a_n)^2$ converges and $\sum (b_n)^2$ converges, does $\sum (a_n)(b_n)$ converge?  Could someone help me to solve this or at least give me a hint?, I have tried using Cauchy's criterion, the Dirichlet test for convergence, etc, but I can´t prove it.Honestly I don´t know where to start. Any help will be appreciated. I'd like to assign a frequently used string to a shortcut key, so when I press it, it types it in whatever application I'm in. So for example, when I type Shift-F12, it types "This is wonderful!" in whatever Gnome app I'm in at that time. I am trying to print a List of Appendices (LoA) for my thesis, separate from the Table of Contents (ToC).   I wish for my ToC to look like this, with depth up to subsections (2?):  CONTENTS  CHAPTER   I. Introduction......1    1.1 Section title...1     1.1.1 Subsection...1  Appendices ..... 2   and for an LoA on a new page, with depth 0, thus:  APPENDICES  APPENDIX A. Proof of Theorem 1...1 B. Proof of Theorem 2...1   I am trying to achieve this using the report class, in a way that allows me to type appendices using the hierarchy that I obtain from the chapter, section commands. This is as opposed to defining a custom myappendix command into which I insert my appendix content. (I realize that I only need the titles from the appendix chapters for the LoA, but I'd like for the appendix content to have such structure.)   For instance, this approach would solve my problem:   \chapter{Introduction} \section{Section title} \subsection{Subsection} % \begin{appendices} is also acceptable \appendix   % Some settings are changed now \chapter{Proof of Theorem 1} \chapter{Proof of Theorem 2} % \end{appendices} if environment is begun   whereas the following approach would not:  \chapter{Introduction} \section{Section title} \subsection{Subsection} \myappendix{Proof of Theorem 1} \myappendix{Proof of Theorem 2}   I realize several questions have been asked regarding this before, but none of them quite solved my problem. Notably,  defines a custom appendix command;  defines two custom commands to maintain some hierarchy, but I will have to do more work to handle the inclusion of another layer (subsection) into the appendix.    is the closest to what I want: it does give me a separate LoA, but it also adds appendices to ToC and I can't quite figure out how to suppress the entires in ToC. The moment I use   \addcontentsline{toc}{\setcounter{tocdepth}{-1}}   the line   \xpatchcmd{\@chapter}{\addcontentsline{toc}}{\addcontentsline{toa}}{}{}%   fails because I am not adding anything to the ToC anymore.   My approach: Since I was using titlesec and tocloft packages anyway, I tried to do the following:   Stop ToC once appendix command is issued Start a new counter for appendices using tocloft Using the &lt;after-code&gt; option of titlesec, add contents line after every chapter.    My MWE   \documentclass[a4paper]{report} \usepackage{lipsum} % for arbitrary text  \usepackage{tocloft,etoolbox,titlesec} \newcommand{\listappendixname}{List of Appendices} \newlistof{appendix}{apc}{\listappendixname}  \makeatletter \g@addto@macro{\appendix}{     \clearpage     \addcontentsline{toc}{chapter}{Appendices}     \addtocontents{toc}{\protect\setcounter{tocdepth}{-1}}     \titleformat      {\chapter}      [display]     {\huge\bfseries\filcenter}      {\Large \MakeUppercase{\@chapapp} \thechapter}      {1.5ex}{}     {\refstepcounter{appendix} \addcontentsline{apc}{appendix}{\protect{\@chapapp \thechapter}}} } \makeatother  \title{Title} \author{Author}  \begin{document} \maketitle \tableofcontents \clearpage \listofappendix  \chapter{Introduction} \lipsum[1] \section{Section} \lipsum[2] \subsection{Subsection} \lipsum[3]  \appendix  \chapter{Proof of Theorem One} \lipsum[4] \chapter{Proof of Theorem Two} \lipsum[5]  \end{document}   produces the following LoA:  List of Appendices  Appendix...... 5   It doesn't get the Appendix title or number, and fails after the first one.  Could you please help me obtain a separate LoA in a way that I can still use LaTeX's chapter, section, ... hierarchy? (I am okay with using different packages, the book class, or any approach other than mine.) Modelling a spiral around a sphere I'm trying to figure out the best way to model the sphere-spiral here:    Is it possible to make this shape directly? Or do you have to make it as a cylinder and wrap it to a sphere? I tried to write out the aura if statement but I am getting stuck if someone can explain it to me in detail. thank you  &lt;aura:if isTrue=&quot;{!lessthan(v.Tl.time, v.Tl.End_Date_Time1__c)}&quot;&gt;                            &lt;/aura:if&gt; Proof verification: column rank = row rank $\newcommand{\span}{\operatorname{span}}\newcommand{\rank}{\operatorname{rank}}$I would like to prove that for every martix, column rank = row rank Let $A\in M_{m\times n}$ be some matrix. fix $R_A$ = vector space of the rows of $A$ , $C_A$ = vector space of the columns of $A$  $$\rank (R_A) = dim \ (\span \{R_1, R_2, \ldots, R_m\})$$ $$\rank (C_A) = dim \ (\span \{C_1, C_2, \ldots, C_n\})$$  let $x$ be some vector. $$x\in \operatorname{Null}(A) \Leftrightarrow \forall i  \ \ (1 \leq i \leq m) : \langle x,R_i\rangle = 0$$ (to be clear - I'm referring to the inner product of $x$ with each row of $A$) Using the rank nullity theorem, $\dim \operatorname{Null}(A) =  n - \rank(R_A)$ as $n$ =  number of columns. what I would like to do is to say: $$\dim \operatorname{Null}(A) =  n - \rank(R_A)$$ $$\dim \operatorname{Null}(A) = n - \rank(C_A)$$ therefore,  $\dim \operatorname{Null}(A) = n - \rank(R_A)= n - \rank(C_A)  \Longrightarrow \rank(R_A) = \rank(C_A) $ it that false? is using the rank- nullity  theorem this way is cheating? or just doesn't prove what needs to be proven formally? Modern textbook on statistical field theory with an emphasis on applications to non-equilibrium phenomena? I'm currently using  but it sometimes falls over when the RSS or Atom feed isn't well formed. Are there any other options for parsing RSS and Atom feeds with PHP? Deploy a project using Git push Movie featuring  space crew, murders, a forbidden door and ending with a revelation I searched wide and far and couldn't come up with a title for a movie I watched somewhere around the mid-90ies up to early 00's as a rerun in late-night television (in Germany, specifically on Vox; but I'm sure it was an American movie to begin with).  Basically, what I remember from the story revolves around a crew in a space station or maybe space ship of some sort. Some crew members murder other crew members and there is some kind of door they are not supposed/unable to go through. Late in the movie they do go through the door and I'm pretty sure one of the first views is a skeleton of a dead security guard. It turns out the whole thing was some kind of simulation gone wrong and they find themselves to be in a (nuclear?) wasteland. And that's pretty much the revelation/wrap-up of the movie, as I recall it.  I would be delighted if somebody had any idea what movie this could be :) Thanks!  EDIT: The whole movie was in color and I think it was feature-length, not just 45 mins. Possible to bake texture to new UV map?