Repetition of function when called
List of lists changes reflected across sublists unexpectedly
Does a List guarantee that items will be returned in the order they were added? Does a List&lt;T&gt; always guarantee that items will be returned in the order they were added when enumerated?  Updated: Thanks for all the answers folks, puts my mind at ease. I had a quick poke around the List&lt;T&gt; class with .NET Reflector (should've probably done that in the first place) and indeed the underlying store is an array of T (T[]). How do I figure out if someone is a first cousin, second cousin, cousin once-removed, etc? What is a word/idiom for 'unable to decide'? Let's say I have an important decision to make and I can't decide between two competing things (like break up with a girl or not break up with her). What would be a word/idiom to express that? I have the low battery alarm disabled in the BIOS settings on my Lemur laptop, but the alarm still sounds when the battery is low.  The sound is a very loud and annoying beep that repeats every couple seconds. The laptop will last another 20 minutes without being plugged in so the battery level isn't properly being detected anymore anyways. I found that if I mute my audio then the beep stops but I obviously cannot listen to anything anymore. If i turn the volume back on even to just 1% the battery alarm is audible again at full volume.  I remember there used to be a mixer somewhere that could control the internal speaker and so if I could find that again then maybe i could mute that and fix this problem.   I have Ubuntu 14.04.  Note that I'm not talking about a low battery notification, which is something through gnome; as opposed to a low battery ALARM which is this very loud beep every couple seconds coming through the internal speaker.  Nevertheless, here are my gnome power settings:  $ gsettings list-recursively org.gnome.settings-daemon.plugins.power org.gnome.settings-daemon.plugins.power button-power 'interactive' org.gnome.settings-daemon.plugins.power critical-battery-action 'nothing' org.gnome.settings-daemon.plugins.power percentage-low 1 org.gnome.settings-daemon.plugins.power priority 0 org.gnome.settings-daemon.plugins.power lid-close-suspend-with-external-monitor false org.gnome.settings-daemon.plugins.power idle-dim false org.gnome.settings-daemon.plugins.power button-hibernate 'hibernate' org.gnome.settings-daemon.plugins.power sleep-inactive-ac-type 'suspend' org.gnome.settings-daemon.plugins.power button-sleep 'suspend' org.gnome.settings-daemon.plugins.power button-suspend 'suspend' org.gnome.settings-daemon.plugins.power sleep-inactive-battery-timeout 0 org.gnome.settings-daemon.plugins.power time-low 1200 org.gnome.settings-daemon.plugins.power lid-close-ac-action 'nothing' org.gnome.settings-daemon.plugins.power notify-perhaps-recall true org.gnome.settings-daemon.plugins.power percentage-critical 1 org.gnome.settings-daemon.plugins.power percentage-action 1 org.gnome.settings-daemon.plugins.power sleep-inactive-battery-type 'suspend' org.gnome.settings-daemon.plugins.power time-action 120 org.gnome.settings-daemon.plugins.power lid-close-battery-action 'nothing' org.gnome.settings-daemon.plugins.power idle-brightness 30 org.gnome.settings-daemon.plugins.power sleep-inactive-ac-timeout 0 org.gnome.settings-daemon.plugins.power time-critical 300 org.gnome.settings-daemon.plugins.power active true org.gnome.settings-daemon.plugins.power use-time-for-policy false $ How many individual lights can an arduino control I want to use a regular Arduino board to control LEDs - what is the most lights I can control individually from the board?  Is there a tutorial on how to hook it up? Use Data From Class Without A New Init There are a plethora of words for user accounts, like logon, login, signon, and also the action of logging in (or logging on) or signing in.  Are there any usage guidelines here? What do repeating '^@' symbols in a logfile mean? A few times I have come across this in a log file:  Sep 17 09:35:57 00187d378926 ovpn-00187d378926[1701]: /sbin/ifconfig tun0 0.0.0.0 Sep 17 09:35:57 00187d378926 kernel: Kernel logging (proc) stopped. Sep 17 09:35:57 00187d378926 rsyslogd: [origin software="rsyslogd" swVersion="4.6.4" x-pid="1707" x-info="http://www.rsyslog.com"] exiting on signal 15. ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@   What does it mean?  Sometimes it is a single line, other times it is lots of lines.  I usually see it happen on Debian 6 machines. Suppose $n$ divides $3^n + 4^n$. Show that $7$ divides $n$. Suppose $n \geq 2$ and $n$ is a divisor of $3^n + 4^n$. Prove that $7$ is a divisor of $n$.  My work so far:  I had a hypothesis that if $n| 3^n + 4^n$, then $n = 7^k$ for some $k\in\mathbb{N}$. But this is not necessarily so. Take $n = 7⋅379$, where $3^7 + 4^7 = 7^2⋅379$. Then, $3^7+4^7$ divides $3^n + 4^n$, and since $n$ divides $3^7+4^7$, we must have $n|3^n+4^n$. What is a disputed flag? In my flagging summary under the statistics, there is 1 flag listed as "disputed".  This is the first time I've ever seen a disputed flag in my summary, so I'm just curious, what is a disputed flag? How would you even dispute a flag? Is this the same as voting a flag as invalid? Ship an application with a database If your application requires a database and it comes with built in data, what is the best way to ship that application? Should I:   Precreate the SQLite database and include it in the .apk? Include the SQL commands with the application and have it create the database and insert the data on first use?   The drawbacks I see are:   Possible SQLite version mismatches might cause problems and I currently don't know where the database should go and how to access it. It may take a really long time to create and populate the database on the device.   Any suggestions? Pointers to the documentation regarding any issues would be greatly appreciated. Has anyone used PostgreSQL with PostGIS successfully?   I am a semi-experienced ArcGIS user and want to build out a database and connect it to ArcCatalog.   I've scoured the internet for resources but nobody has really given a good walkthrough. $a^m=b^m$ and $a^n=b^n$ imply $a=b$ Let $D$ be an integral domain and let $a^m=b^m$ and $a^n=b^n$ where $m$ and $n$ are relatively prime integers, $a,b \in D$.   How do I show $a=b$? I have a polygon shape file that has many overlapping features. Each feature represents an area used by polar bears. So some of the polygons overlap and some don't, and there are separate clusters of overlapping areas.   I would like to get a measure of how much overlap there is in a particular area. But I have no clue how to do this. I'm pretty new to GIS and am still learning the ropes, it just seems I can't find an answer. Set "default" monitor I would like to be able to set my "default" monitor to be my external 25' monitor instead of my laptop one when I have my external monitor connected.  Many applications always open on the laptops monitor instead of the "big" one. Currently, the only way I know to disable this behavior is to disable the laptop monitor, however, as I use a laptop stand to bring it higher, Id like to be able to use my laptop monitor as a "secondary" monitor, without dock (launcher) and without any windows opening on it.  The only way for a window to reach it would be to actually manually grab it and drag it over.  Some known applications that ALWAYS open on the laptop monitor and drive me crazy: Slack, Rocket Chat, Thunderbird, Sky, System Settings, Guake (specially annoying since i cant move it). Why doesn't Mac OS X source ~/.bashrc? What Scoping Class Will  Use? In reading through the release notes I was excited to discover the introduction of a new  tag. That should help lower the barriers to entry! However, the release notes do not specify what the name of the scoping class should be. And since , we're left guessing.  To be explicit about what I'm trying to understand, take  for example:  &lt;apex:page showHeader="false" standardStylesheets="false" sidebar="false" applyHtmlTag="false" applyBodyTag="false" docType="html-5.0"&gt;     &lt;html xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" lang="en"&gt;         &lt;head&gt;             ...             &lt;apex:stylesheet value="{!URLFOR($Resource.REPLACE_WITH_NAME_OF_SLDS_STATIC_RESOURCE, 'assets/styles/salesforce-lightning-design-system-vf.min.css')}" /&gt;         &lt;/head&gt;         &lt;body&gt;              &lt;!-- REQUIRED SLDS WRAPPER --&gt;             &lt;div class="REPLACE_WITH_NAME_OF_CUSTOM_SCOPING_CLASS"&gt;             ...         &lt;/body&gt;     &lt;/html&gt; &lt;/apex:page&gt;   If I replace the &lt;apex:stylesheet&gt; with &lt;apex:slds&gt;, what should I specify for REPLACE_WITH_NAME_OF_CUSTOM_SCOPING_CLASS? Finding determinant for a matrix with one value on the diagonal and another everywhere else Let us look the the matrix  $\left(\begin{array}{ccccc} a &amp; b &amp; b &amp; b &amp; b\\ b &amp; a &amp; b &amp; b &amp; b\\ b &amp; b &amp; a &amp; b &amp; b\\ b &amp; b &amp; b &amp; a &amp; b\\ b &amp; b &amp; b &amp; b &amp; a \end{array}\right)$  It has one value, $a$, on the main diagonal, and another value, $b$ everywhere else. Let us assume that we are over a ring and that $a$ is invertible.  I wish to find the determinant of every $n\times n$ matrix of this form ($a$ on the diagonal, $b$ everywhere else). Using row and column operations I have managed to transform the matrix to upper-triangular form and found formula for specific cases. Generalizing it I got to the following formula:  $\det(A) = a\left(a-b\right)^{n-2}\left(a+\left(n-2\right)b-\frac{\left(n-1\right)b^{2}}{a}\right)$  I think I can prove it with row-operations in the general case with a little patience.  However, I'm wondering if there is a "smart" way of getting to this formula that I'm missing and if there is a nicer representation of it. Also, what can be said when $a$ is not invertible? (esp. the case where we are over a field and $a=0$). Under what assumptions can a semigroup $(S,*)$ be embedded into a group? Notation for infinite product in reverse order