Why is $p{\implies}q$ defined to have a truth value if $p$ is false?
In classical logic, why is $(p\Rightarrow q)$ True if both $p$ and $q$ are False?
Best way to build a Plugin system with Java How would you implement a Plugin-system for your Java application?  Is it possible to have an easy to use (for the developer) system which achieves the following:   Users put their plugins into a subdirectory of the app The Plugin can provide a configuration screen If you use a framework, is the license compatible with commercial developement? Showing a tensor is not a simple tensor Let $(e_1,e_2)$ be the standard basis of $\mathbb{R}^2$. Why can the element $e_1\otimes e_2 + e_2\otimes e_1$ in $ \mathbb{R}^2\otimes_{\mathbb{R}} \mathbb{R}^2 $ not be written as a simple tensor $v\otimes w$ for $v,w\in \mathbb{R}^2$?  If we suppose $e_1\otimes e_2 + e_2\otimes e_1=v\otimes w$, then can we conclude that $e_1=\lambda e_2$ for some $\lambda \in \mathbb{R}$? This would give a contradiction since $e_1$ and $e_2$ are linearly independent. However, I am not sure if the argument is valid. What is the sponsored party called? Google results for sponsee have scattered definitions in unreliable sources, so it does not appear that is a real word. I'm looking for something similar, a single word.  The specific context is a social group membership application where new members must be sponsored (as in definition 2, here - "one who assumes responsibility for some other person or thing") by existing members. I am looking for a single word to describe the target of such a sponsorship. I am about to sponsor a fraternity, but I would like to have a more general word for what I'm sponsoring. Next time, the fraternity could well be a study club, or something else.  Therefore, what is the sponsored party also called? E.g. if I sponsor somebody, that person is my __? How do I give text or an image a transparent background using CSS? Applescript run from menu bar? Enumerated description list How can a list be created, whose items are both    enumerated (a,b,c,d,...)  and allow for setting a description via \item[texthere] ?   Im am using MikTex on Windows. pdfx: incomplete CIDset in some fonts I try to compile a document as pdf/x and pdf/a with pdfx under LuaLaTeX, and I am already quite successful. One thing still poses problems though: With some fonts I get the following error if I check the resulting pdf/a file with Acrobat: "CIDset in subset font is incomplete (font contains glyphs that are not listed)" (VeraPDF gives the same error, so the issue seems to be real).  Here's a MWE:  \RequirePackage{filecontents} \begin{filecontents*}{\jobname.xmpdata} \Title{Test}       \Author{Simon Spiegel}       \Language{de-DE} \end{filecontents*} \documentclass {article} \usepackage{fontspec} \setmainfont{Palatino Linotype} [Ligatures={TeX,Common}, Extension = .ttf, ] \usepackage[a-3b]{pdfx} \begin{document} Test \end{document}   I realise that not everyone will be able to compile this MWE due to the proprietary font, but since the problem only occurs with specific fonts, I had to use this example.  The pdfx manual mentions this error, but only in relation to XeLaTeX. According to the manual, it should not occur with LuaLaTeX.  From what I understand, this seems to be at least to some degree a problem of this specific font, but since I am relying on it, I am looking for a way to fix it.  EDIT  Here's a new MWE with a bunch of fonts which are hopefully more common (the paths have to be adapted of course).  \RequirePackage{filecontents} \begin{filecontents*}{\jobname.xmpdata} \Title{Test}       \Author{Simon Spiegel}       \Language{de-DE} \end{filecontents*} \documentclass {article} \usepackage{fontspec} \setmainfont{Georgia} [Ligatures={TeX,Common}, Extension = .ttf, ]  \newfontfamily\fontone{Verdana} [Ligatures={TeX,Common}, Extension = .ttf, ] \newfontfamily\fonttwo{Cambria} [Ligatures={TeX,Common}, Extension = .ttf, Path = {/Users/simi/FontExplorerX/C/Cambria/} ] \usepackage[a-3b]{pdfx} \begin{document} Test  \fontone Test  \fonttwo Test \end{document}   All these fonts give me the same error. I wonder if this only happens with .ttf OpenType fonts. I would like to do two things   Increase the size of inmargin area (i.e., customize inner sidebar so that more contents could fit there) Reduce the empty space between the title of block environment and the slide edge (from the example below, the title of block has too much of wasted space to its left which could be used to create more readable sentences)     MWE  \documentclass[xcolor={x11names}]{beamer}  \usecolortheme{structure} \useinnertheme{rectangles} \useinnertheme{inmargin}  \usecolortheme{crane}  \usefonttheme{structurebold}   \usepackage{fontspec}  \usepackage{calc}  \usepackage[inline]{enumitem} % Description list defaults      % To change font     \newcommand{\descriptionfont}{\fontencoding{T1} \fontfamily{bch} \selectfont}      % Label indentation     \newcommand{\descLabOffset}{\widthof{\hspace{2.6mm}}}      % Left of description aligned with the left margin     \newcommand{\descLeftLabMarInd}{0mm - \descLabOffset}      % Left of description aligned with \parindent     \newcommand{\descLeftLabParInd}{\parindent - \descLabOffset}      % Set the list options     \setlist[description, 1]{font=\descriptionfont, leftmargin=*, labelsep=3mm, labelindent=\descLeftLabMarInd, align=left}  \begin{document}   \begin{frame}{Induction Motors}      \begin{block}{Why is induction motor very common?}          Induction motors are very practical for the following reasons          \begin{description}             \item[Rigid] Rigid             \item[Cheap] Cheap             \item[Low Maintenance] Low Maintenance             \item[Self-Starting] Self-starting             \item[No Excitation Needed] No Excitation Needed         \end{description}      \end{block}  \end{frame}  \end{document} How can I get fireworks? What are the requirements for making fireworks appear at the end of a level in the original Super Mario Bros.? What are the limits on how I can cast, change, and retract votes? What limits are there on how I can vote?  How often can I vote? How do my votes become locked/unlocked? Dynamic loading of python modules In my assignment I have to prove that the following function doesn't have a limit:  $$f(x)=\frac{x}{x-\lfloor{\sin x}\rfloor}$$ when $${x \to 0}$$  In other words, I have to prove that for every $\delta$ such that $0&lt;|x-{x_0}|&lt;\delta,$ $|f(x)-L|&gt;\epsilon$.  In fact, I don't even know how to start. Do I choose my $\delta$? I know that the sin function has certain values that's supposed to help me. How do I use it?  I have to prove this by definition, so I can't use limit arithmetic for example  Thanks. Trigger Setup Wizard at next boot using command-line I am looking for a way to use ADB to trigger Setup Wizard at next boot. I know I can run the following command and get it to pop up. However, I can't figure out what triggers it to start at boot.  adb shell am start -a android.intent.action.MAIN -n com.google.android.setupwizard/.SetupWizardTestActivity   The phone I am currently using is stock and I would like to keep it that way.   I've read the  question: Subject/verb agreement when a title ends in a plural 1) "The book 'The Three Musketeers' is a wonderful example of..." Here we have a proper noun, a title that happens to end in a plural, and I have no sense that the verb should be plural. "Musketeers"/is seems proper/natural/correct, and 'are' not at all.   However, such certainty begins to wane in other examples: 2) "'The Heidi Chronicles' is a wonderful example of..." doesn't completely shake my confidence, but it moves the needle, at least a little bit. But, practically speaking, I wouldn't have a second thought about correcting a student who used 'are' instead of 'is'.  Here's the one that really bothers me: 3a) " 'The Basement Tapes' are a wonderful example of..." I don't think this sounds any less proper/natural/correct than 3b) " 'The Basement Tapes' is..." In fact, 3a seems less awkward than 3b.  Why? How do you get JavaScript/jQuery Intellisense Working in Visual Studio 2008? Does an classical charge that is stationary in a gravitational field radiate? The well known Larmor formula tells us that an accelerated classical charge radiates a power proportional to the square of the acceleration. It has been  that a charge in free fall in a gravitational field does not radiate. Since gravity is locally equivalent to acceleration, one may wonder whether a charge at rest in a gravitational field radiates. The  is that it does. However this radiation is not  to an observer in the same reference frame! Apparently, the radiation does not carry energy or momentum, or it would be observable, in this reference frame and this would mean that charged matter behaves differently from neutral matter in gravity.    How does unobservable EM radiation without energy and momentum make sense (Q1)?  Does the physical origin of charge acceleration determine whether radiation is observable or not (Q2)?  Is the answer to the question in my title "It depends?"?   Note added:  I did not find the discussion at  and  sufficiently enlightening. Keep items in inventory on death in Minecraft I once played a vanilla Minecraft adventure map (called "Herobrine's Mansion") that prevented the player from losing their items on death. Which commands can be used to prevent the player from losing their items on death (in vanilla Minecraft)? How to prove Euler's formula: $e^{i\varphi}=\cos(\varphi) +i\sin(\varphi)$? How can I use text-processing tools to insert a new line after every N lines?  Example for N=2:  INPUT:   sadf asdf yxcv cxv eqrt asdf   OUTPUT:   sadf asdf  yxcv cxv  eqrt asdf I need to round the edges of this object.  The bottom edges are going to be rounded in conjunction with another object, so, I guess, this should be left out right now.  I tried using the bevel tool (and a bevel modifier) on an edge (series of Blender edges), but I got the problems you see on the images. When selecting all edges, the bevel doesn't know any limit and isn't applied symmetrically.  When selecting only the edges shown (or only the other ones), I can't proceed with the rest of the bevel, and strange little artifacts appear.  FYI: The top surface is derived from an icosphere.    Without the subdivision shown above, a stair comes into existence (bad):    Whole object: