Is it too late to get the last updates for XP?
Will it be possible to update Windows XP after April 2014?
To turn off my system, I can use one of these three commands:  sudo halt   Or:  sudo poweroff   Or:  sudo shutdown -h now   What are the differences between these commands, or are they all just aliases of each other? I was wondering if there is a viable place on Stack Exchange to ask economics-related questions.  Questions I'd have in particular could be equation-based or theoretical.  I suppose the equation-based questions could possibly fit into mathematics but I haven't checked their FAQ. Mail on Big Sur does not reliably find dollar values I want to know how EXACTLY the WPA password gets encrypted  I have been searching through and I was able to catch:   The actual password is converted to some hash Salting is applied to the hash The operation is not reversible The hash comes with the 4-way handshake   So what kind of hash is it converted? like, SHA1? MD5? and how the salting process is done? like, is the SSID appended to the password before the hashing operation?  Or maybe I have some misunderstanding here? New top bar doesn't show hot threads across Stack Exchange sites I'm working on exercises from Kunen and I'm stuck. I must proof that the following are equivalent:   There exists a sequence $\langle A_\alpha:\alpha&lt;\omega_1\rangle$ such that $\forall\alpha(A_\alpha\subset\alpha)$ and for all $A \subset \omega_1$ the set $\{\alpha \in \omega_1:A\cap\alpha=A_\alpha\}$ is stationary. ($\diamondsuit$-principle) There exists a sequence $\langle A_\alpha:\alpha&lt;\omega_1\rangle$ such that $\forall\alpha(A_\alpha\subset\alpha\times\alpha)$ and for all $A \subset \omega_1\times\omega_1$ the set $\{\alpha \in \omega_1:A\cap\alpha\times\alpha=A_\alpha\}$ is stationary. There exists a sequence $\langle f_\alpha:\alpha&lt;\omega_1\rangle$ such that $\forall\alpha(f_\alpha:\alpha\rightarrow\alpha)$ and for all $f : \omega_1\rightarrow\omega_1$ $\exists\alpha(f|\alpha=f_\alpha\wedge\alpha&gt;0)$ There exists a sequence $\langle f_\alpha:\alpha&lt;\omega_1\rangle$ such that $\forall\alpha(f_\alpha:\alpha\rightarrow\alpha)$ and for all $f : \omega_1\rightarrow\omega_1$ the set $\{\alpha \in \omega_1:f|\alpha=f_\alpha\}$ is stationary.   I have proved that $1\implies 2\implies 4\implies 3$ and that $4\implies 1,$ but I'm having problems on proving that $3\implies$ "something", because it only talks about one $\alpha$. Can someone help me? When is the message "Have you considered accepting an answer or starting a bounty for this question?" displayed? we are currently experiencing some issues with the ambiguity feature of apa for biblatex/biber (we use biber) in TexLive 2012.  What would be correct with the ambiguity feature:  Doe J., Peters M., Kramer N., Conan B. (2012) Doe J., Mayer M., Smith N., Walker J. (2012)  Citations in text (subsequent ones) - AS IS AND CORRECT Doe, Peters et al (2012) Doe, Mayer et al (2012)   But in case of different years, it shouldn't actually do this ...  Doe J., Peters M., Kramer N., Conan B. (2012) Doe J., Mayer M., Smith N., Walker J. (2009)  Citations in text (subsequent ones) - AS IS: Doe, Peters et al (2012) Doe, Mayer et al (2009)  Citations in text (subsequent ones) - HOW IT SHOULD BE: Doe et al (2012) Doe et al (2009)   Can anyone help here?  Thank you! Let $\Bbb R^+$ be the set of positive real numbers. Use Zorn's Lemma to show that $\Bbb R^+$ is the union of two disjoint, non-empty subsets, each closed under addition. What is a pull up and pull down? Can some one explain this terminology please I think I understand it but not completely sure.   I think pull down is where you place a resistor between +V and the other component and pull up is where you place the resistor between 0v and the component.    If I am completely wrong then let me know! Categories other than "off-topic" should allow custom close reasons Custom close reasons are a great boon to Stack Exchange sites, allowing the community to provide more tailored advice to site-specific situations. Their big problem (aside from being limited to three by default) is that they are all lumped under "off-topic". This is often confusing.  I suggest that all close categories but "exact duplicate" should support customized close reasons &mdash; not just the "off-topic" category.  For example, the recommendation close reason     Questions asking us to recommend or find a tool, library or favorite off-site resource are off-topic for Stack Overflow as they tend to attract opinionated answers and spam.   This would make more sense as a child of primarily opinion-based.    Similarly, the "why doesn't this work" close reason     Questions seeking debugging help ("why isn't this code working?") must include the desired behavior, a specific problem or error and the shortest code necessary to reproduce it in the question itself. Questions without a clear problem statement are not useful to other readers. See: .   This would make more sense as a child of unclear what you're asking.  Similar examples can be given for pretty much any of the Stack Exchange sites. Can Java's NullPointerException be changed to report on which variable was null? Can I use an inner tube that's too narrow for the tyre? I recently got a puncture and when I went to replace the inner tube I discovered that I'd bought the wrong size tube. My tyre is 700 x 40c, the tube is 700 x 28-35c.  What is likely to happen if I use this tube? Will the tube explode when I attempt to inflate it? I would like to reload an &lt;iframe&gt; using JavaScript. The best way I found until now was set the iframe’s src attribute to itself, but this isn’t very clean. Any ideas? "I use to", or "I used to" Which is the correct sentence, if there is a correct one?     I use to be a hitman.        I used to be a hitman.   I've read the second sentence recently in a book, but I was sure it should be I use to be a hitman. Is there a single word for "one who speaks/boasts a lot about everything"? I'm looking for a single word to most aptly describe a person possessing the following "qualities":   Appears to be superior in every technology/skill under the sun, which he deems worthy of knowing On being questioned/assigned the task, is found to have only superficial/no knowledge of the said skill. Inherent tendency to "one-up" anyone and everyone - example: "I didn't work hard at all in my undergrad days, but yet I have better/equal grades than you have! "   Could someone help?  Edit: I've got some very good responses, but despite popular opinion for "braggart", I'm going with "pretentious" as it suits what I was looking for more aptly IMHO. I need to run Firefox browser from terminal. Browser works fine, but terminal still waits for Firefox to return and if I do CTRL+C, it terminates Firefox. How to run command to make Firefox work independently from terminal? Override route helper methods From the movies we know that Obi-Wan Kenobi delivered Luke Skywalker to Owen and Beru Lars to raise on Tatooine shortly after Luke was born at the end of RotS (Episode 3).   The next think we know is Luke running into Ben Kenobi during A New Hope.   There seems to be a hint that there was at least SOME communication between Kenobi and Lars family based on him telling Luke:     Your father wanted you to have this when you were old enough, but your uncle wouldn't allow it.   (though it's possible that was referring to Kenobi offering to leave the lightsaber to Larses at the same time he dropped off Luke)  I was wondering if any details of what transpired between Kenobi and Larses in the years between RotS and ANH were noted in any canonical works (of any canon, including EU books/games/comics/etc...)? Does a differentiable everywhere function have a continuous derivative? If a function $f$ defined on $[a,b]$ and differentiable everywhere, does it mean that its derivative $f'(x)$ is continuous everywhere on $[a,b]$?  My understanding is 'yes'. Because if there were 'a gap' in $f'(x)$, we could integrate back to $f(x)$ and show that where the gap is, there would be a sharp "angle" where $f(x)$ is not differentiable.