deserializing an xml file and adding data without destroying the integrity
xml serializing of saved game data
The top bar is showing (again) the suggested edits count and 10K flags count, like it was before.  On Stack Overflow it looks like this: (that's the original color, same as in old top bar)        And on this very Meta site:        Same top bar. But different colors! Consistency broken.  I've just noticed the suggested edits count on Meta:        Black on black, I can see just a floating number - really confusing and out of any context.  In the name of Consistency, can we please have the same color on all sites? Ordered N-Tuples as Cartesian Products of Indexed Families In Introduction to Topology, Mendelson defines the Cartesian Product of an Indexed Family as follows:     DEFINITION  Let $\{X_\alpha\}_{\alpha \in I}$ be an indexed family of sets. The product  of the sets $\{X_\alpha\}_{\alpha \in I}$,    written  $\prod_{x\in I}X_\alpha$ consists of all functions $x$ with domain the indexing set $I$ having the property that for each $\alpha \in I$, $x(\alpha)\in X_\alpha$.    Halmos, in Naive Set Theory, makes the following observation about this sort of product:     Ordered triples, ordered quadruples, etc., may be defined as families whose index sets are unordered triples, quadruples, etc.   However, it is not immediately apparent to me why this is true. It makes sense if we understand the prior assertions in Halmos that $\prod_{i \in I} X_i = X_i$ and that $\prod_{i \in I} X_i = X_a \times X_b$ when $I = \{a, b\}$, but these already pose difficulty for me.  Let $I = \{0, 1\}$, let $X_0 = \{A, B\}$, and let $X_1 = \{C, D\}$. Then by Mendelson's (and Halmos's) definitions, it would seem to me that . . .  $$\prod_{i \in I} X_ i = \{\{(0, A), (1, C)\}, \{(0, A), (1, D)\}, \{(0, B), (1, C)\}, \{(0, B), (1, D)\}\}$$  This would appear to me to be the set of all functions matching the definition given, but it is not equal to $X_0 \times X_1$. Moreover, extending this to a case where the index set $I$ is a triple, we would not end up with ordered triples, but with each subset of the product containing three ordered pairs.  When Halmos posits the equalities he does, the idea seems easy to grasp, but the peculiar wording of Mendelson's definition suggests something different to me. How to remove accents / diacritic marks from a string in Qt? I recently wanted to add some RAM to my old computer, but unfortunately I mixed together "good" RAM with chips that I extracted from a computer that failed after getting too much voltage. I know it sounds like a bad idea to just plug it into a motherboard, so I figured I'd ask first - is there usually any protection in the motherboards against this kind of faulty chips? Also, how likely is that RAM got damaged when computer got his deadly current or failed for internal reasons (something shorted because of dust, failed components etc.)? Magnetic field lines When I searched the net about magnetic field lines,  told something about contour lines and that magnetic materials placed along a magnetic field has some specific loci, which i did not understand. Can someone explain it to me in details.  Also how do we know that tangent to a magnetic field line gives the direction of magnetic field? I am very confused. Kill process spawned by ssh when ssh dies find command: -or option doesn't work I want to execute a command for an each file that matches a pattern. But the command that seems to be right, doesn't work for me, I have no idea why.  $ find . -type f -name '*.c' -or -name '*.h' -or -name '*.cpp' -exec ls {} \; $ ls script.sh  test.c  test.h Does one need a visa to transfer between two airports during a transit through the Schengen area? I am an Indian citizen travelling from New York to Delhi with a layover in Paris where I need to transfer between Paris Orly Airport (ORY) and Paris Charles de Gaulle Airport (CDG).  Do I need to have a visa to make this transfer?  I didn't notice that while booking the ticket. Linear regression prediction interval Set the maximum character length of a UITextField If the brain has no pain receptors, how come you can get a headache? I've read many years ago in books, that the brain has no nerves on it, and if someone was touching your brain, you couldn't feel a thing.  Just two days before now, I had a very bad migraine, due to a cold. It's become better now, but when I had it I felt my head was going to literally split in half, as the pain was literally coming from my brain.  So it lead me to the question: How come people can get headaches if the brain has no nerves? I'm a bit surprised from my US Visa. I plan to go to a conference on 3rd of April. Amazingly though, the visa expiration date is written as April 3rd.  So what does that mean. Can I enter the US on April 3rd? or should I enter one day earlier? I applied to a program that I had been striving for in my undergrad, at a top school, but I've since felt overwhelmed with the thought of going this year. I think I should have waited until I was absolutely sure I could handle grad school emotionally and financially. I am so anxious now, thinking I've ruined my opportunity with this school if I don't go.   I am seriously considering withdrawing my application, but I'm very worried about how it might hurt me in the future when I reapply.  Otherwise I may have to decline if I am accepted and reapply. $(\frac 3p)$ is the Legendre symbol here, not a fraction, if that wasn't clear.  This is what I have so far:  We know by Gauss's Lemma that $(\frac qp) = (-1)^v$ where $$v = \#\left\{1 \le a \le \frac{p-1}{2} \mid aq \equiv k_a \pmod{12}),\space -p/2 &lt; k_a &lt; 0\right\}$$  And we also know that multiples of $(\dfrac{p-1}{2}) \times 3$ must be between $0$ and $p/2$, between $p/2$ and $p$, or between $p$ and $3p/2$.   Representing $p$ as $12k + r$ seems like the next step, but I'm not sure where to go from there. I need help with this:  If a is an element of $\mathbb Z_n$ and $\gcd(a,n) &gt; 1$ , then a is not invertible.   First you show that if $a$ is an element of $\mathbb Z_n$ and $\gcd(a,n)&gt;1$, then there  is an element $b$ of $\mathbb Z_n$ and ($b$ is not equal to the zero element) from which $ab = 0$.   The second part I cant get. i.e. show if $b$ is not the zero element  and $ab=0$ then $a$ is not invertible. There have been a few questions regarding installing this package in the past, but they now seem to be out of date. I'm using MiKTeX 2.9 and TexMaker. When I try \usepackage{mathtools} in TexMaker it will try to install the package for me but will fail. I took the advice given in this thread:   As suggested I tried installing the mh package using the MiKTeX Package Manager, unfortunately I get the "unknown archive size" error, which I have read means that the package no longer exists. Another thread (lost the link) said you can use the MiKTeX Package Manager to directly install mathtools, however I do not see mathtools listed anywhere in the MiKTeX Package Manager...   So I ask, is the package under a different name? Are there any other ways to install this package? My /boot partition hit 100% and now I can't upgrade. Can't remove old kernels to make room Which focal-length lens is usually used for portrait photography, and why? What focal length or range of focal lengths are usually used for portraits?   What is used by professionals? Why would one select a certain focal length? What are the advantages and disadvantages of different choices, and are there certain situations where an unusual choice might be better? Is Lambert Academic Publishing a reputable company? I was contacted by the Acquisition editor of Lambert Academic Publishing (LAP) to publish my bachelor's thesis as a printed book. Is LAP any good? I have no idea about it; I have just heard that it's a freelance publishing house. What is ground and what does it do?