App crashes after my app has been closed
What is a NullPointerException, and how do I fix it?
What's the reasoning behind phrase "dissertation submitted in partial fulfillment of the requirements"? Phrase "dissertation submitted in partial fulfillment of the requirements" seems strange. Can one submit dissertation in full fulfillment of the requirements? Position of a relative clause before/after a verb I'm not sure about the sentence structure below:  All kinds of problems arise that smaller animals or plants do not have to cope with.  It looks like that works as a relative pronoun for all kinds of problems, but I couldn't find such usage in my dictionary or online. This sentence could be divided into  There are all kinds of problems. Smaller animals or plants do not have to cope with all kinds of problems.  But, I can't figure out where 'arise' fits. If you have any thoughts, please share them. On the proof that the product of diagonal matrices is a diagonal matrix? Let $A [a_{i,j}]$  and $B =[b_{ij}]$   be two diagonal matrices in   $M_n(F)$. Let $i \ne j \in \left\{1, \ldots, n \right\}$. Using the   product rule, we obtain      $$(AB)_{ij} = \sum_{k=1}^{n} a_{ik}b_{kj}$$      We claim that $a_{ik}b_{kj} =0$ for all $k \in \left\{1, \ldots, n \right\}$ thus $(AB)_{ij}=0$ for all $i \ne j$ and $AB$ is diagonal. To    prove the claim, note that since $i \ne j$ , we have $i \ne k$ or $    k\ne j$. Thus either $a_{ik} = 0$ (since $A$ is diagonal) or $b_{kj} =  0$ (since $B$ is diagonal), thus in all cases $a_{ik}b_{kj}=0$ and the   claim is proved.   Where does the bit "we have $i \ne k$ or $k\ne j$" come from? I understand that since $i \ne j$, and $k$ and $j$ run over the same set of natural numbers, we also have $i \ne k$. But the "or $k \ne j$" baffles me. I understand that $k \ne j$ implies that we can have $i=k$. But that's from the other direction ($\Longleftarrow).$  Also, when it says $a_{ik}=0$ or $b_{kj}=0$ it's talking about when $i \ne k$ or $k \ne j$ right? Many thanks. How I would go about getting the current users username or first and last name?  I have been looking at this for the last couple of hours - I was just wondering how I would go about getting their name and then displaying it on the page.  For example the current user is 'John Smith' and in the lightning component I want to output John Smith's name like:     Welcome to our community John Smith! How do users navigate to Meta? bash profile works for user but not sudo Probability of a painted cube being reassembled into itself Suppose 27 cubes are stacked together, suspended in the air, to form a larger cube.  The cube is then painted on all the exposed surfaces and dried.  The smaller cubes are then randomly permuted in both spatial position and spatial orientation to form another large cube.  What is the probability that new larger cube is identical to the original?  This is not homework, it was passed on by a friend who found it somewhere on the internet, and they do not remember where. Footnotes layout in multicols environment I am using the package multicol to typeset a one-column (spanning the entire text width) heading and a two-column main text block. In order to do so, I begin the multicols environment along with the start of the text block. The one-column heading spans a small fraction of the text height in the front page and I need to set a footnote there, before starting the two-column environment. I'd like to have that footnote typeset under the first column in the two-column running text. How could I possibly do this?   Moreover, I'd like to have the footnotes typeset in a single column under one of the text columns -- I don't even mind having them as two-column footnotes, but what I do not want is a footnotes layout spanning the entire text width. I have tried with the command \twocolumnfootnotes from the class memoir, with the packages ledmac, dblfnote, and even with ftnright (the latter complains about its being used in a single-column document, due to that one-column heading). None has proved useful in this setting. As a less than MWE, just to convey a more concrete depiction of my scenario, let us consider:  \documentclass{memoir}  \usepackage{multicol}  \begin{document}  A single-column heading\footnote{Here I have my footnote.}  \begin{multicols}{2} Here I am in the two-column environment, and I want my footnotes being set in accordance with the document's ``columnwidth''.\footnote{A footnote in the two-column environment.} \end{multicols}   \end{document} When in Demon Form, are demons vulnerable to mortal frailties? When a Demon is in Demonic Form, does he gain any intrinsic protection against mundane concerns like breathing or falling unconscious? In particular, when in Demonic Form do/are demons:  need to breath? immune to poisons? fall unconscious? (ie do they stay conscious on full lethal?) suffer from wound penalties for having damage in last 3 boxes? need to consume food/water? need to sleep?  The last two are only really a concern to demons who have burnt their last cover. However this can happen in play, and is pretty significant for any burnt NPCs. Is seems odd that a swarm of glass beetles clinging together into the shape of a man might have any issues with being poisoned. But I can't find it clearly stated, whereas it is clearly stated in Werewolf (the Forsaken). Is it possible to disable CPU throttling on a MacBook Pro with a completely dead (not recognized) battery? I have a MBP late 2011 running El Capitan, recently my battery died (x over the icon and "no battery available" in the dropdown.) I've noticed since then that CPU intensive tasks are very slow, and I read that without a battery macs will throttle the CPU to half capacity.  So now I'm looking for one of two solutions:  1) Either somehow disable the throttling, or  2) Trick the computer into thinking it has a battery.  In regard to the first one I've tried a few things such as described , removing a plist file that supposedly controlled it, but that hasn't helped. Any help would be greatly appreciated, TIA.  Edit: I've looked over the question about a 2006 MacBook, it's similar but I've tried everything outlined there and nothing has worked. I'm curious if there are any new ideas. I think the difference may be El Capitan. Is there a way to disable WAC String for a specific link (ex. Tracking Link) with AMPscript or otherwise? I read some articles, and seen some videos about a github project that do a sort of thing, but it's a little bit outdated things.I wanna see if this thing is possible to do, nowadays. Thanks Understanding the formula for the Confidence Interval of the difference between two sample proportions Site-specific spellcheck? I often see misspelled words in titles and bodies of questions, only to see them spelled properly in the tags. I have to imagine that tags are always spelled right because it's hard to type arbitrary text into the tag box. I also have to imagine that sometimes autocorrect and spellcheck provided by browsers tend to turn programming terms and package names into English words. For example, see   Would it be possible to have some sort of spellchecker that compares text of titles (and maybe bodies) to known tags and offers some sort of correction (maybe red squiggles or something) when there's some statistical probability of a misspelling?  Since this would be using a site's tags, "magneto" would get corrected to "magento" on SO, while "magento" would get corrected to "magneto" on aviation.stackexchange.com.  In theory this could reduce a lot of stupid typos and prevent trivial edits just to fix the spelling of key words.  Note that this is not solving a problem that a user's browser can already solve because browsers ship with English dictionaries, not dictionaries of programming terms. In fact, it's potentially correcting a problem created by the browser (which might have already autocorrected "magento" to "magneto"). problem with surfaces on tkz-fct i am using this wonderful tool that tkz-fct is for creating nice documents but I have a weird result from recently. This is my document :  \documentclass[10pt,a4paper]{article} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{calc} \usepackage{color} \usepackage{pifont}                     %pour utiliser la police Ding \usepackage[left=1.5cm,right=1.5cm,top=2cm,bottom=2cm]{geometry} %marges du document \usepackage[french]{babel} \usepackage[usenames,dvipsnames]{xcolor} \usepackage[L]{thmbox} \usepackage{eurosym} \usepackage{enumitem}               %pour modifer itemize et enumerate \usepackage{amsmath,amsfonts,amssymb} \usepackage{mathrsfs}               %pour utiliser mathscr \usepackage{array,multirow,makecell} \usepackage{fancyhdr}               %package pour modifier les en-têtes \usepackage{fancybox}               %pour boîtes spéciales \usepackage{tikz,tkz-tab,tkz-fct} \usepackage{tikz-dependency}        %permet de créer des schemas \usepackage{sectsty}                %permet de modifier les styles des sections (voir \sectionfont l.21) \usepackage{fourier-orns} \usepackage{shadethm}               %pour theoremes en gris \setcellgapes{1pt} \makegapedcells \newcolumntype{R}[1]{&gt;{\raggedleft\arraybackslash }b{#1}}   %pour redéfinir les colonnes dans tabular \newcolumntype{L}[1]{&gt;{\raggedright\arraybackslash }b{#1}} \newcolumntype{C}[1]{&gt;{\centering\arraybackslash }b{#1}} \renewcommand{\thesection}{\Roman{section}} %permet de changer la numérotation en chiffres romains des sections \newshadetheorem{defi}{Définition}  %crée un nouveau type de théorème \newshadetheorem{thm}{Théorème} \newshadetheorem{ppte}{Propriété} \sectionfont{\sectionrule{3ex}{3pt}{-1.5ex}{1pt}} %mettre un trait de séparation dans les sections (package sectsty) \pagestyle{fancy} %style en-têtes \lhead{} %en-tête gauche \chead{Lois à densité} %en-tête centrale \rhead{T\up{ale}} %en-tête droite \begin{document} \begin{tikzpicture}      \tkzInit[xmin=-4,xmax=4,ymax=1]      \tkzDrawX[label={},noticks]      %\tkzDrawY      \tkzFct[domain=-2:2]{exp(-x**2)}      \tkzDrawArea[color=blue, domain = -0.5:1]      \tkzText(-1,0.75){$\mathscr{C}_{f}$} \end{tikzpicture} \end{document}   But from now, it doesn't produce the result I would like as the surface start from the point (-0.5,f(-0.5)) and not as an integral from -0.5 to 1. This is a picture of the result :   Which is obviously not what I would like and this extends now to all my "old" docs which were "normal" before. I don't think I have done anything special except updating my Tex distribution ... If someone has an idea ?? I'm trying to use a mask to hide a part of a render layer, so that when the render layer is shown over a movie, some parts in the movie will appear to be in front of the render layer.  For example, assume I want to add a box to this image, so that it would look like it's behind the person:    I created the following simple object:    If I render the object, it looks great - the object is solid, everything else is transparent (I didn't use any 'sky'):     Now I create a mask to describe the standing person (or at least the part that would otherwise be covered by the box):    What I want now is to create a "hole" in the rendered box, so that when I use Alpha-over, the box look as if it's behind the person, but I can't find an easy way to do that. My first guess was to use 'Set alpha' to apply the mask (inverted) as an alpha for the rendered layer, but this doesn't look good:    The mask did create a "hole" where it should, but now all the other pixels are not transparent. How can I "retain" the transparent pixels while setting more pixels to be transparent based on the mask (use it as a matte)?  Note: I can do this with (I'm ashamed to say) some math work on the alpha channel, but it just doesn't seem right:    Thanks, and sorry for the [oh so] long question. How can I automatically add some skeleton code when creating a new file with vim When creating a new file with vim, I would like to automatically add some skeleton code.  For example, when creating a new xml file, I would like to add the first line:    &lt;?xml version="1.0"?&gt;   Or when creating an html file, I would like to add:  &lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"&gt; &lt;html&gt;   &lt;head&gt;     &lt;title&gt;&lt;/title&gt;   &lt;/head&gt;   &lt;body&gt;   &lt;/body&gt; &lt;/html&gt; How to test @future methods with setup objects and avoid MIXED_DML_OPERATION Can a shell script set environment variables of the calling shell? I'm trying to write a shell script that, when run, will set some environment variables that will stay set in the caller's shell.  setenv FOO foo   in csh/tcsh, or  export FOO=foo   in sh/bash only set it during the script's execution.  I already know that   source myscript   will run the commands of the script rather than launching a new shell, and that can result in setting the "caller's" environment.  But here's the rub:  I want this script to be callable from either bash or csh.  In other words, I want users of either shell to be able to run my script and have their shell's environment changed.  So 'source' won't work for me, since a user running csh can't source a bash script, and a user running bash can't source a csh script.  Is there any reasonable solution that doesn't involve having to write and maintain TWO versions on the script? How to enable root login again after changing password? I had enabled root login before and tried to change its password using this . But after successfully changing the password and locking it via sudo passwd -dl root. I cannot login back to SSH, it says Access is denied.  I have two users on my machine. root and admin, admin does not have su permission. When I try to use sudo on admin user, it says that admin is not in the sudoers file. That is why i need my su user back.