Is it safe to run an infected program under wine with another user?
What if I run a virus/trojan Windows EXE on Ubuntu with Wine?
Node.JS Not working on the internet I see an equation like this:  $$y\frac{\textrm{d}y}{\textrm{d}x} = e^x$$  and solve it by "separating variables" like this:  $$y\textrm{d}y = e^x\textrm{d}x$$ $$\int y\textrm{d}y = \int e^x\textrm{d}x$$ $$y^2/2  = e^x + c$$  What am I doing when I solve an equation this way?  Because $\textrm{d}y/\textrm{d}x$ actually means  $$\lim_{\Delta x \to 0} \frac{\Delta y}{\Delta x}$$  they are not really separate entities I can multiply around algebraically.    I can check the solution when I'm done this procedure, and I've never run into problems with it.  Nonetheless, what is the justification behind it?  What I thought of to do in this particular case is write  $$\int y \frac{\textrm{d}y}{\textrm{d}x}\textrm{d}x = \int e^x\textrm{d}x$$ $$\int \frac{\textrm{d}}{\textrm{d}x}(y^2/2)\textrm{d}x = e^x + c$$  then by the fundamental theorem of calculus  $$y^2/2 = e^x + c$$  Is this correct?  Will such a procedure work every time I can find a way to separate variables? Understanding backtick (`) Add parenthesis as an accepted Markdown ordered list delimiter The Markdown editor knows that an empty line, followed by a number, followed by a period, followed by a space, is a list item.  This works great It's almost magic  The problem is that I almost always use a close parenthesis for my lists. I think it's a pretty common practice, but the problem is that the editor / Markdown parser doesn't accept parenthesis as an acceptable list delimiter:  This fails horribly This is on the next line I swear What does the @ symbol before a variable name mean in C#? Possible Duplicate:          I understand that the @ symbol can be used before a string literal to change how the compiler parses the string.  But what does it mean when a variable name is prefixed with the @ symbol? Where is "Connect to Server" for ssh connections in Unity? Cannot find "connect to server" in 11.04, looks like unity doesn't have it. Is there other very similar way to connect to another Ubuntu computer via SSH? (not in terminal) Limit $\lim_{n\to \infty} \frac{1}{2n} \log{2n\choose n}$ Show that $a^n \mid b^n$ implies $a \mid b$ Texture mapping with multiple UV maps So, as a newbie relatively new to blender, I started doing some texture mapping (blender internal Render). I created a texture for the main object and a couple of transparent decals to decorate it. (basic effects made in GIMP). Simple stuff, just to know how it works.  After unwrapping, having 2 UV maps made, creating both new material and textures, enabling UV mapping coordination I always end up with:  - all - 1 faces of the cube being covered nicely in the main texture  - 1 face covered in blank material with a decal in the middle of it  - the whole thing partly coated by a huge "stain" of a decal  So, the problem is that I can't layer textures correctly. Is there a way to have one texture covering everything and more transparent ones on top of it? I am working on a bigger project right now and having this ability would be useful How do I wrap a macro definition in an environment? I'm creating a style file, and want to store the body text of the abstract environment so that I can put it on my custom titlepage. I could have required that my users enter the abstract as  \customabstract{Abstract text goes here}`   which I would have implemented as something like  \newcommand{\customabstract}[1]{\gdef\abstracttext{#1}}   However, I would prefer that the user is able to use environment notation,  \begin{customabstract}Abstract text goes here\end{customabstract}   To do this, I thought I could define something like  \newenvironment{customabstract}{\gdef\abstracttext\bgroup}{\egroup}   But this definition makes \abstracttext expand to \bgroup, which is not what I wanted. I tried to solve the problem by \expandafter,  \newenvironment{customabstract}{\expandafter\gdef\expandafter\abstracttext\bgroup}{\egroup}   but this results in a runaway error.  Is there any way to acheive what I want? Answers that helps me understand the inner workings of TeX (instead of just referring to a custom package) are preferred. WCF - Faults / Exceptions versus Messages We're currently having a debate whether it's better to throw faults over a WCF channel, versus passing a message indicating the status or the response from a service.  Faults come with built-in support from WCF where by you can use the built-in error handlers and react accordingly. This, however, carries overhead as throwing exceptions in .NET can be quite costly.  Messages can contain the necessary information to determine what happened with your service call without the overhead of throwing an exception. It does however need several lines of repetitive code to analyze the message and determine actions following its contents.  We took a stab at creating a generic message object we could utilize in our services, and this is what we came up with:  public class ReturnItemDTO&lt;T&gt; {     [DataMember]     public bool Success { get; set; }      [DataMember]     public string ErrorMessage { get; set; }      [DataMember]     public T Item { get; set; } }   If all my service calls return this item, I can consistently check the "Success" property to determine if all went well. I then have an error message string in the event indicating something went wrong, and a generic item containing a Dto if needed.  The exception information will have to be logged away to a central logging service and not passed back from the service.  Thoughts? Comments? Ideas? Suggestions?  Some further clarification on my question  An issue I'm having with fault contracts is communicating business rules.  Like, if someone logs in, and their account is locked, how do I communicate that? Their login obviously fails, but it fails due to the reason "Account Locked".  So do I:  A) use a boolean, throw Fault with message account locked  B) return AuthenticatedDTO with relevant information Computing limit of $(1+1/n)^{n^2}$ Does someone falling into a black hole see the end of the universe? Norms Induced by Inner Products and the Parallelogram Law Let $ V $ be a normed vector space (over $\mathbb{R}$, say, for simplicity) with norm $ \lVert\cdot\rVert$.  It's not hard to show that if $\lVert \cdot \rVert = \sqrt{\langle \cdot, \cdot \rangle}$ for some (real) inner product $\langle \cdot, \cdot \rangle$, then the parallelogram equality $$ 2\lVert u\rVert^2 + 2\lVert v\rVert^2 = \lVert u + v\rVert^2 + \lVert u - v\rVert^2 $$ holds for all pairs $u, v \in V$.  I'm having difficulty with the converse.  Assuming the parallelogram identity, I'm able to convince myself that the inner product should be $$ \langle u, v \rangle = \frac{\lVert u\rVert^2 + \lVert v\rVert^2 - \lVert u - v\rVert^2}{2} = \frac{\lVert u + v\rVert^2 - \lVert u\rVert^2 - \lVert v\rVert^2}{2} = \frac{\lVert u + v\rVert^2 - \lVert u - v\rVert^2}{4} $$  I cannot seem to get that $\langle \lambda u,v \rangle = \lambda \langle u,v \rangle$ for $\lambda \in \mathbb{R}$.  How would one go about proving this? Today I found my first ever (to the best of memory) emoji in a post.        Having no idea this was even possible I came here looking for some history. I found there is an  tag. There seems to be consensus that they add little to no value on SE per  &amp;  we also know they don't translate well on all devices    I don't find any history other then this one post  where there is any focused attempt to support them. I don't find any history of discussion on supporting them.    Two questions   Is it possible to disable emojis across Stack Exchange?   If yes   Should we disable emojis across Stack Exchange? Name lookups in C++ templates "DataBinding: 'index+NewsItem' does not contain a property with the name 'Link'", but property exists (Not a Typo) Does it make a difference to CP if you feed candies before or after evolving? Engines that play Mangala? I am reading Velleman's "How to Prove it", and in one example he proves  $\neg \exists x P(x)  \implies \forall x \neg P(x)$    in the following way:    Suppose $\neg \exists x P(x)$. Let x be arbitrary. Suppose $P(x)$. Since we have a specific $x$ for which P(x) is true, it follows that $\exists x P(x)$, which is a contradiction. Therefore $\neg P(x)$. Since $x$ was arbitrary, we can conclude that $\forall x \neg P(x)$, so $\neg \exists x P(x)  \implies \forall x \neg P(x)$    What makes me confused is the line in bold text, that is "Suppose $P(x)$". The reason is that he writes that he is doing proof by contradiction, but $P(x) \not\iff \neg\forall x \neg P(x)$. He is not treating all possible cases where $\forall x \neg P(x)$ is false by assuming $P(x)$, does he? So how can this be a valid proof by contradiction?    Edit: I deleted my first example since it was clearly not representative for the problem.  Edit 2: So the thing that I am opposing I guess is that $\neg \forall x \neg P(x)$ is not $P(x)$. And from what I have undestood, a proof by contradiction should use the negation of the consequent which I do not think that Velleman does.