Difference between NSString *const and const NSString *?
Objective C const NSString * vs NSString * const
Installing PHP 5.6 on Xenial (16.04) I need to use php5 (5.6) because I'm working on a Drupal 7 project which doesn't support php7. The problem is I recently updated to ubuntu 16.04 Xenial which seems to .   I tried to install it from , however when It try to install it with apt I always get similar errors.  $ sudo apt-get install php5-cli Cependant les paquets suivants le remplacent :   php7.0-cli:i386 php7.0-cli`   Which means it's obsolete. How can I install PHP 5.6 on Xenial? Are layer files compatible between ArcGIS 10 and 9.3? If I save layer files in ArcGIS 10, can they be opened and modified in ArcGIS 9.3? iSight cable for mid 2009 macbook pro 13" help If my iSight camera no longer works and neither does my bluetooth, should my wifi still technically be working? Aren't they all co-dependent(if that makes sense) or can the fact that my wifi is still functional mean that the iSight camera still works and it's a software problem. Are there any disadvantages to using your companions for transporting Power Armor What is the proper way of creating installation media from Ubuntu iso? This is the third time I've tried to install Ubuntu Server 14.04.03 64-bit on the same laptop, and each time it caused different problems.  Each time I wrote the same iso image to a USB flash drive by using a different application and OS.   Universal USB Installer (pendrivelinux.com) from Windows WinImage writer from Windows built-in image writer from Linux Mint 17.2    The iso image is the same in all three cases, the USB flash drive is the same, and the laptop is the same. However each time the installation of Ubuntu gave me different installation options. For example, the last time I installed Ubuntu, it didn't show all the packages to choose while installing (Basic Ubuntu server, etc.). Does leaning (banking) help cause turning on a bicycle? I think it's clear enough that if you turn your bicycle's steering wheel left, while moving, and you don't lean left, the bike will fall over (to the right) as you turn. I figure this is because the bike's momentum keeps it moving in the direction you were going, and since your wheels have friction against the ground, the top of the bike moves forward relative to the bottom of the wheels. The top of the bike going north while the bottom of the wheels go northwest will understandably cause you to topple. So to counteract this and keep you from falling over, leaning into the turn is necessary. But is there also a direct causal relationship -- that leaning will cause the bike to start to turn? If I start leaning left, I will turn left... but maybe that's because I know that if I don't turn the steering wheel left, the bike will fall over (to the left). I experimented with unruly turns of the steering wheel when I was a kid, and got my scrapes and bruises. Now that I'm a cautious and sedate adult I'm not anxious to experiment that way. :-) (I also want to ask why airplanes bank into a turn... they don't have the same issues as a bike, i.e. the bottom part has no special friction against the ground. But that would probably make the question too broad.) Whats this white stuff on my board? Change Text Color in Blender Game Engine? I want to change the color of some text in my game. I've tried adding materials, but whenever I press P to play the game, the text stays the same white color. Any ideas? What is a magic number, and why is it bad? Should I use single or double colon notation for pseudo-elements? How to find the shortest string in a list in Python How can I position my div at the bottom of its container? Given the following HTML:   &lt;div id="container"&gt;   &lt;!-- Other elements here --&gt;   &lt;div id="copyright"&gt;     Copyright Foo web designs   &lt;/div&gt; &lt;/div&gt;    I would like #copyright to stick to the bottom of #container. Can I achieve this without using absolute positioning? Given:  DateTime.UtcNow   How do I get a string which represents the same value in an -compliant format?  Note that ISO 8601 defines a number of similar formats. The specific format I am looking for is:  yyyy-MM-ddTHH:mm:ssZ In $\mathbb{Z}/(n)$, does $(a) = (b)$ imply that $a$ and $b$ are associates? [Update: Based on the hints provided by @zcn and @whacka, I believe I have found a solution. See my answer below.]  Below, $R$ is a commutative ring with $1$.  In John J. Watkins' Topics in Commutative Ring Theory, the author observes that if $a$ and $b$ are associates in $R$, then they generate the same ideal: $(a) = (b)$. This is clearly true, because $a = ub$ and $b = va$ for some units $u$ and $v$, and so $a \in (b)$ and $b \in (a)$, whence $(a) \subset (b)$ and $(b) \subset (a)$. Indeed, we didn't even require $u$ and $v$ to be units to reach this conclusion.  The author then claims that if $R$ is not a domain, then the converse may not be true: we may have $(a) = (b)$ even if $a$ and $b$ are not associates. As a "counterexample" he gives $R = \mathbb{Z}/(6)$, with $a = 2 + (6)$ and $b = 4 + (6)$. Clearly these elements generate the same ideal: $(a) = (b) = \{0, 2 + (6), 4 + (6)\}$. The author asserts that $a$ and $b$ are not associates, but this is false: $5 + (6)$ is a unit, and $(2 + (6))(5 + (6)) = 4 + (6)$, so $a$ and $b$ actually are associates.  I figured that the author botched the example but that surely the basic fact must be true: if $R = \mathbb{Z}/(n)$ then there may be nonassociates $a,b \in R$ with $(a) = (b)$. However, I was not able to find a counterexample and eventually resorted to writing a computer program and found that there are no counterexamples in $\mathbb{Z}/(n)$ for $n \leq 100$.  So now I'm starting to think that there is no counterexample in $\mathbb{Z}/(n)$ at all, but I have not yet been able to prove this.  My questions:   If I am correct that $(a) = (b)$ in $\mathbb{Z}/(n)$ implies that $a$ and $b$ are associates, I would appreciate a nudge in the right direction toward a proof. (But if the proof is elementary, please give only a hint, not a solution :-) I'll post my solution once I have one. In either case, could you please point me to a genuine counterexample? If there is one in $\mathbb{Z}/(n)$ for some $n$, that would be ideal (no pun intended), otherwise a counterexample in any commutative ring with $1$ would be great. Is there a word to describe a highly desirable cursed treasure? Is there a single word to describe an object or idea that is so desirable that everyone wants to attain it but once they have it they are immediately cursed?  The idea is often used in literature—some examples:   In Lord of the Rings, the 'one ring' is a perfect example of this. In Guy de Maupassant's story , the necklace might be considered to be this. There are many stories of people making deals with the devil (see question: ), or being granted three wishes by a Djinn or fairy, which inevitably turn out bad. In the Twilight Zone episode , Bemis's desire to be left alone with his books would be an example of this word.   'Bane' covers the cursed part, but no one desires it.  Is there a single word to describe a most highly desired treasure that (knowingly or unknowingly) comes with a curse? Delete from uitableview + write to plist not working What are some good tutorials on writing custom styles (classes) that clearly explain commands used and some of the features that TeX has to offer in the way of styles? Why must a field whose a group of units is cyclic be finite? Let $F$ be a field and $F^\times$ be its group of units. If $F^\times$ is cyclic, then show that $F$ is finite.  I'm a bit stuck. I know that I can represent $F^\times = \langle u \rangle$ for some $u \in F^\times$ and that we must have that $|F^\times| = o(u)$, where $o(u)$ denotes the order of $u$ in $F^\times$.  I tried assuming $o(u) = \infty$, but I'm not sure exactly where to go from there. I was wondering if I could get a hint. Taking a spin off of this question:  in a new direction for 2014.  Taking into account a basic Windows infrastructure:   domain controllers Exchange 2007/2010/2013 Sharepoint SQL File Servers / Print Servers AD Integrated DNS AD authenticated 3rd party devices (let's say 802.1X for networking and maybe some content-filtering, etc.) AD/LDAP authenticated "administrative" functions on IT apps/hardware/etc. perhaps some KMS stuff throw in a CA if you'd like home grown apps 3rd party in-house apps   Now, let's rip it all out and decide we are going to the cloud.  We've contracted to move Exchange/Sharepoint/File Services to Office 365.  SQL will now be hosted as well on  something like Azure.  We've gotten away from the need for AD-DNS and simply run everything via a simple Windows DNS server.  We still need 802.1X and would like SSO if possible to our various cloud apps.  Home grown and 3rd party in-house apps would likely stay, but have the ability to use internal user databases instead of AD authentication  The question is...do we really need Active Directory at all?  Or more to the point, AD on-premise or even hosted via Azure or similar (ADFS) or running ADDS on a hosted VM through Azure or similar.  Could/Should we look to something else like a 3rd party SSO option such as  or similar that can provide SSO functionality even if it is as simple as LastPass or similar for each user?  What kind of legitimate needs does AD fulfill if everything else in the cloud?  Could a MS-centric infrastructure get away with not having AD at all if they move everything that previously relied on AD to SaaS offerings that didn't rely on AD authentication? What I am up to is to write some exercises dealing with logical formulas for my students, like:     And the students should draw these formulas on . At the end of the lesson, I really would like to print the correct answer for them. I found a great resource on a forum thread at , which helped me a lot to make up some Venn diagrams with tikz, but have some problems with visualizing complements, like ~A.  A simple, modified version of the TeX file found on the forum linked above, can be seen below, which produces the following expression:    \documentclass{letter}   \usepackage{tikz}   \def\firstcircle{(90:1.75cm) circle (2.5cm)}   \def\secondcircle{(210:1.75cm) circle (2.5cm)}   \def\thirdcircle{(330:1.75cm) circle (2.5cm)}   \begin{document}     \begin{tikzpicture}       \begin{scope}     \clip \secondcircle;     \fill[cyan] \thirdcircle;       \end{scope}       \begin{scope}     \clip \firstcircle;     \fill[cyan] \thirdcircle;       \end{scope}       \draw \firstcircle node[text=black,above] {$A$};       \draw \secondcircle node [text=black,below left] {$B$};       \draw \thirdcircle node [text=black,below right] {$C$};     \end{tikzpicture}   \end{document}   Which looks like:    Could anyone please help me out plotting/defining some expressions dealing with complements? A nice example could be:    That should look like: (image from )    I do not insist on the red color :)  I would like to use the simplest possible solution, as I would like to mass generate the exercises with the help of . So any suggestion dealing with gnuplot, R or any other opensource packages is welcome. Thank you!    UPDATE (25/01/2011): added details based on answers.  Thank you @Leo Liu, you helped me a lot! I modified a bit the code you suggested to be able to color the area outside of the two circles also (in the H universe), but have no idea how to set a background to that polygon also. The code:  \begin{tikzpicture}[fill=gray] % left hand \scope \clip (-2,-2) rectangle (2,2)       (1,0) circle (1); \fill (0,0) circle (1); \endscope % right hand \scope \clip (-2,-2) rectangle (2,2)       (0,0) circle (1); \fill (1,0) circle (1); \endscope % outline \draw (0,0) circle (1) (0,1)  node [text=black,above] {$A$}       (1,0) circle (1) (1,1)  node [text=black,above] {$B$}       (-2,-2) rectangle (3,2) node [text=black,above] {$H$}; \end{tikzpicture}   And the image generated:    I will also look for even odd rule in the near future which does not make sense for me at the moment but looks really simple and promising!