List extending strange behaviour
Different behaviour for list.__iadd__ and list.__add__
How do I unlock all the other ships in the hangar? Cardinality of the Cartesian Product of Two Equinumerous Infinite Sets Is the cardinality of the Cartesian product of two equinumerous infinite sets the same as the cardinality of any one of the sets? I couldn't find this explicitly stated in any handout or text. This certainly seems to be true from the examples I have seen:  The Cartesian product of two infinitely countable sets is again infinitely countable. The Cartesian product of two sets with cardinality of continuum again has cardinality of continuum. I just started trying to undestand the notion of stationary in time series. Basically I have 2 questions:  Can stationary time series contain regulary cycles and thus seasonality patterns? For exmaple in this tutorial it is stated that stationary time series can not have seasonal components (predicitable cycles)  whereas in this figures () the green time series that clearly has cycles (and thus seasonality) is labeled as 'stationary' (and I have seen these kind of figures quite often if you just google 'stationary time series) Can a stationary time series have periods with no fluctuations and periods with high fluctuations? As far as I understood the variance and the (aut)covarianz should not change over time making such a time series not stationary. But here in this picture () the time series below is labeld as stationary altough it has periods with changing fluctuations.  I hope you can help me as I am confused about the concept of stationarity. I'd appreciate every comment. The bounty is to expire quite soon. So I'd be happy if some could at least give me one answer to my questions. It will help me a lot. Why is nobody answering the questions? Are they not clear enough? If so, please tell me. I think they are important and fundamental as the concept of stationarity is quite important. Pure virtual destructor in C++ Why are my sauces splitting? Update pgfmath macro in foreach loop I need to update a variable defined in a pgfmathsetmacro command inside a foreach loop. Apparently, the var is only updated when it is used after the update command. Here is a MWE:  \begin{tikzpicture} \draw [help lines] (0,0) grid (3,3); \pgfmathsetmacro{\a}{1} \foreach \b in {2,3} {     \node [blue] at (\a,0) {\a};     \pgfmathsetmacro{\a}{\b}     \node [red] at (0,\a) {\a}; } \end{tikzpicture}   The red nodes are printed at updated positions and the value printed is also updated; the blue nodes are not: they keep their initial value (1) and are located at the initial position (0,1).  Why is this? Thanks José Mixing plural and singular list items with a single verb A friend wants to write,   There is no hardware to purchase, no additional software to install and no key fobs to worry about.   This is awkward because the verb "is" doesn't match up with the third item, which is plural and demands "There are" as the subject. However,    There is no hardware to purchase, no additional software to install and there are no key fobs to worry about.   sounds awkward as well.  Is there a good workaround for this problem where some list items are singular and some are plural, so they don't share a common verb? Clear item with custom name? How do you clear 1 item from the inventory that has a custom name? What I'm trying to do is make a torch that when you hold it, it gives you Night Vision effect but after like 400 ticks or so I want the torch to run out of fuel and clear 1 torch away from the inventory, I have the potion effects (giving and taking away) working and the testfor command but how do I clear the item? this is my code I'm trying to use /clear @a torch 1 1 {display:{Name:"Special Torch"}} I have my Xbox One set up to automatically download and install updates, the rest of my settings are shown below:    Is there a reason my games will show an update symbol on their tile, but they still don't download the update until I start the game manually? This is not for homework. (I am a grader for a class.)  The case in which $G$ is finite is trivial. (That is, use a corollary to Lagrange's Theorem, and set $[G:H] = \dfrac{|G|}{|H|}$, and similarly for $[H:K]$.) How do you prove this for when $G$ is infinite?   The proof of this statement that I know well tries to show that $[G:K]$ is finite iff $[G:H]$ and $[H:K]$ are finite, but I am not a fan of that proof. For pedagogical purposes, I'm looking for a better proof. (The course uses right cosets by convention.)  The course has just started covering normal subgroups, so things like the Isomorphism Theorems are not known yet. Relay: higher voltage allowed at lower current? Is it safe to use a 30VDC/1A relay for a voltage of 60V but a current of &lt;100uA? E.g. this one: How did Groot manage to raise the axe of Thor when even Hulk failed? In Avengers Hulk tried to raise Thor's hammer and failed miserably. In Avengers: Infinity War, Groot raises Thor's new axe and holds it for a few seconds! Is the axe made of some other light material, or is Groot stronger than Hulk? Why did Hogwarts Library carry a book containing information on horcruxes if it was a banned subject? How can I repair grub? (How to get Ubuntu back after installing Windows?) I installed Windows 7, which ate Ubuntu's boot file. When starting up the computer, it now goes straight to Windows, without giving me the option of booting Ubuntu.   How can I get Ubuntu back? How do I efficiently compute $a^b\bmod c$:  When $b$ is huge, for instance $5^{844325}\bmod 21$? When $b$ is less than $c$ but it would still be a lot of work to multiply $a$ by itself $b$ times, for instance $5^{69}\bmod 101$? When $(a,c)\ne1$, for instance $6^{103}\bmod 14$?  Are there any other tricks for evaluating exponents in modular arithmetic?  This is being asked in an effort to cut down on duplicates, see  and . replace often used Tex-Literals ($ and $$) for math regions into \( or \) and \[ or \] Is there an editor or IDE (or a script) for substituting the TeX-Commands $ and $$ for opening and closing math regions into the corresponding LaTeX-Commands \(,\) and \[,\]? I'm sure there is a tool - and I'm searching for. I think, this will result in better readable code. A simple search and replace wont do that - but with regular expressions, that should not be problem. I simply do not want to invent the wheel a second time. How to change a default application in Ice Cream Sandwich? I used the ADWLauncher EX by default while having Gingerbread 2.3.6.  Today I have manually updated my Nexus S to Ice Cream Sandwich 4.0.3, and I wanted to give the new default launcher a shot, but I cannot find anymore where to select / forget the default application for an action.  I've turned the settings of my phone inside out, googled and crawled the forums, but without success. If anybody can tell me how to change a default application in ICS, I'd be grateful!      Yeah, I never thought I'd want to see that Complete action using... window again! :D Why does Boolean.ToString output "True" and not "true" true.ToString()  false.toString();  Output: True False   Is there a valid reason for it being "True" and not "true"? It breaks when writing XML as XML's boolean type is lower case, and also isn't compatible with C#'s true/false (not sure about CLS though).  Update  Here is my very hacky way of getting around it in C# (for use with XML)  internal static string ToXmlString(this bool b) {     return b.ToString().ToLower(); }   Of course that adds 1 more method to the stack, but removes ToLowers() everywhere. How do humans dominate the Federation in Star Trek? How do I create a vertical version of \not?