Prevent excel from considering date based on system's date format
How to set date format when manually inserting date on excel, without changing regional settings?
How to implement an abstract class in ruby? I know there is no concept of abstract class in ruby. But if at all it needs to be implemented, how to go about it? I tried something like...  class A   def self.new     raise 'Doh! You are trying to write Java in Ruby!'   end end  class B &lt; A   ...   ... end   But when I try to instantiate B, it is internally going to call A.new which is going to raise the exception.  Also, modules cannot be instantiated but they cannot be inherited too. making the new method private will also not work. Any pointers? \nameref breaks for star versions of section/paragraph when titlesec is loaded \nameref breaks for the star versions of section, paragraph when titlesec is loaded. I have a document that numbers paragraphs by default, but I have a few I do not want to number but would like to refer to. These are marked with \paragraph*, however, if the titlesec package is loaded at the same time, it causes nameref to display an empty string (the link box of hyperref is still visible).  MWE:  \documentclass[12pt]{article} \usepackage[sf]{titlesec} %comment this out and it works fine. \usepackage{hyperref} \begin{document} \section{Sections} \label{sec} This is \nameref{sec} \paragraph{A named Paragraph} \label{par} This is \nameref{par} \paragraph*{A starred named Paragraph} \label{par:star} This is \nameref{par:star} \end{document}   I suspect titlesec causes this defect for ALL star variants of sectioning commands but have not tested this. For me only paragraph* is relevant however a fix for all variants would be the best.  I have a hunch it might be related to this:  however this happens to go way beyond my latex knowledge and is just "magic" for me. How exactly does Knuth's Up-Arrow notation work? Every time Windows 10 runs updates (which I see no way to control), it updates my graphics driver.  I like the old one because it is faster.  So, I have to reinstall it.  This is getting to be a pain.  Is there any way to stop Windows 10 from updating it again? Where are some good places to find royalty free stock images? How can I determine if a used game is pirated? Automatically put PGFPlots xtick scale label in x axis label Should I capitalise "or" between examples? On this site, there are often many different options as an answer, for example both with and without the Oxford comma.  When giving multiple options, should I capitalize the word "or" between them?  Option 1:     Eggs, butter and milk are dairy products   Or   Eggs, butter, and milk are dairy products     Option 2:     Eggs, butter and milk are dairy products   or   Eggs, butter, and milk are dairy products     Notice in Option 1 the "or" is capitalised. In Option 2 the "or" isn't. Browsing the internet from the command line How can I browse the Internet from the command line in Ubuntu? We have a broadband line coming into our building which delivers around 8-10Mbps, which is okay but not great. Fiber is available in our area (30-100Mbps) but it's not available where we are just yet.   Is there some way we could connect two lines (which we would take from two different providers so we would have redundancy if one failed) and merge them into one signal which we could distribute?  Is there some sort of setup that can do this?  Of course we have the option of a leased line but for 12Mbps symmetrical upload/download we'd be looking at around £500 per month compared to £15 per month for normal or fiber broadband.  I made a small pseudo flow chat of the setup below: Obtaining consistent one-hot encoding of train / production data $\dfrac{pq}{r}+\dfrac{qr}{p}+\dfrac{pr}{q}\in\Bbb Z\,\Rightarrow\, \dfrac{pq}{r},\dfrac{qr}{p},\dfrac{pr}{q}\in\Bbb Z$ Let $p,q,r$ be integers such that the symmetric sum of fractions $\dfrac{pq}{r}+\dfrac{qr}{p}+\dfrac{pr}{q}$ is an integer. Prove that each of the numbers: $\dfrac{pq}{r},\dfrac{qr}{p},\dfrac{pr}{q}$ is an integer. How to do this? Someone posted but deleted soon. I'm programming a presentation in LaTeX using the beamer class.  However, it defaults to 4:3 aspect ratio slides, while everything I use is 16:9. Is there an easy way to change this using a command or two? Which singular names ending in “s” form possessives with only a bare apostrophe? How do users get started on new Stack Exchange sites? How do users on the new Stack Exchange sites get started? Each user starts with 1 rep, and can't upvote until they have 15 rep.  It struck me that this creates a bit of a deadlock. If a new user asks a question and a new user answers, neither can upvote the other.  Are we relying solely on existing SE users to join these exchange sites (with their bonus 100 rep) so that they can get started? I'm trying to get my csv table aligned to the left of my graph. The graph is appearing below (and indented) the table. Any ideas?  \begin{minipage}{0.5\textwidth} \pgfplotstabletypeset[col sep=comma, columns/distance/.style={column name={Col1}, column type={|c|}}, columns/loss/.style={column name = {Col2},column type={c|}}, every head row/.style={before row=\hline}, after row={\hline} ]{graph-data/data.csv} \end{minipage}  \begin{minipage}{0.5\textwidth} \begin{tikzpicture} \begin{axis}[ xlabel = Distance ($m$), ylabel = Loss ($dB$)] \addplot table [col sep=comma]{graph-data/data.csv}; \end{axis} \end{tikzpicture} \end{minipage} Good GameBoy Advance Emulator? Is there any good GameBoy Advance Emulator for ubuntu which supports loading gameshark or action replay saves? Strong Induction Proof: Fibonacci number even if and only if 3 divides index The Fibonacci sequence is defined recursively by $F_1 = 1, F_2 = 1, \; \&amp; \; F_n = F_{n−1} + F_{n−2} \; \text{ for } n ≥ 3.$ Prove that $2 \mid F_n \iff 3 \mid n.$   Proof by Strong Induction : $\bbox[5px,border:1px solid green]{\color{green}{n = 1 }}$ $2 \mid F_1$ is false. Also, $3 \mid 1$ is false. The implication [False $\iff$ False] is vacuously true.  $\bbox[5px,border:1px solid green]{\color{green}{\text{Induction Hypothesis}}}$ Assume that $2 \mid F_i \iff 3 \mid n$ for every integer $i$ with $1 ≤ i ≤ k$.  $\bbox[5px,border:1px solid green]{\color{green}{k + 1 \text{th Case}}} \;$  To prove:  $\quad 2 \mid F_{k + 1} \iff 3 \mid k + 1.$   $\bbox[5px,border:1px solid green]{\color{green}{n = k + 1 = 2}} \;$ $2 \mid F_2$ is false. Also, $3 \mid 2$ is false. So [False $\iff$ False] is vacuously true.  Hence assume that $k + 1 ≥ 3.$ We now consider three cases:  $\bbox[5px,border:1px solid green]{\color{green}{\text{Case 1: } k + 1 = 3q}}$ Thus $3 \require{cancel}\cancel{\mid} k$ and $3 \require{cancel}\cancel{\mid} (k − 1)$. By the ind hyp, $3 \require{cancel}\cancel{\mid} k    \iff F_k$ odd &amp; $3 \require{cancel}\cancel{\mid} (k − 1) \iff F_{k - 1}$ odd. Since $F_{k+1} = F_k + F_{k−1}$, thus $F_{k+1}$ = odd + odd = even.  $\bbox[5px,border:1px solid green]{\color{green}{\text{Case 2: } k + 1 = 3q + 1}}$  Thus $3 | k$ and $3 \require{cancel}\cancel{\mid} (k − 1).$ By the ind hyp, $3 | k \iff F_k$ even &amp; $3 \require{cancel}\cancel{\mid} (k − 1) \iff F_{k - 1}$ odd. Thus $F_{k+1}$ odd.  $\bbox[5px,border:1px solid green]{\color{green}{{\text{Case 3: }} k + 1 = 3q + 2}}$ Thus $3 \require{cancel}\cancel{\mid} k$ and $3 | (k −1).$ By the ind hyp, $3 \require{cancel}\cancel{\mid} k \iff F_k$ odd and $3 \mid (k − 1) \iff F_{k - 1}$ even. Thus $F_{k+1}$ odd. $\blacksquare$  $\Large{1.}$ Does the proof clinch the $(\Leftarrow)$ of the $(k + 1)$th case?   $\Large{2.}$ Since the recursion contains $n, n - 1, n - 2$, thus the recursion "time lag" is $3$ here. So shouldn't $3$ base cases be checked?   $\Large{3.}$ Further to #2, shouldn't "assume $k + 1 \geq \cancel{3} 4$" instead?   $\Large{4.}$ Shouldn't the $n = k + 1 = 2$ case precede the induction hypothesis?  I referenced . Source: Exercise 6.35, P152 of Mathematical Proofs, 2nd ed. by Chartrand et al    Supplement to peterwhy's Answer:  $\Large{1.1.}$ I wrongly believed that all 3 Cases proved the $\Leftarrow$. I now see that Case 1 is $\Leftarrow$ via a Direct Proof. Cases 2 and 3 are $\Rightarrow$ via a Proof by Contraposition. Nonetheless, how would one foreknow/prevision to start from $3 \mid n$  for both directions of the proof? LaTeX Error: Option clash for package xcolor I have an option clash between package xcolor and another package, but I don't know which. Here is my MWE  \documentclass[10pt]{beamer} \setbeamertemplate{navigation symbols}{} \usepackage{caption} \usepackage{subcaption} \usepackage{url} \usepackage{color} \usepackage[usenames]{xcolor}  \author{The author} \title{Package conflicts} \date{October 3rd, 2012}  \begin{document}  This is supposed to be \textcolor{olivegreen}{olivegreen} \end{document}   And the error message is :  This is pdfTeX, Version 3.1415926-1.40.10 (TeX Live 2009/Debian) entering extended mode (./error_xcolor.tex LaTeX2e &lt;2009/09/24&gt; &lt;blablabla&gt; ! LaTeX Error: Option clash for package xcolor.   I hope this is enough log for you guys. At this time of the day, I'm hoping for America to save my french ass ... again : ) Help with multirow table I am trying to wrap text in the multirow column (1st one) and only have the vertical lines inside the table if that makes sense.   Can anyone help me? `  \begin{table*}[!htbp] \centering \renewcommand{\arraystretch}{1.4} \begin{tabular}{|c| p{2cm}|c|c|c|c|} \cline{3-6} &amp;&amp;\multicolumn{2}{c|}{\textbf{Gravité du Dommage G1}} &amp; \multicolumn{2}{c|}{\textbf{Gravité du Dommage G2}}\\  \cline{3-6} &amp;&amp;\textbf{Fréquence F1} &amp; \textbf{Fréquence F2} &amp; \textbf{Fréquence F1} &amp; \textbf{Fréquence F2}\\ \hline \multirow{ 2}{*}{\textbf{Probabilité Occurence O1}}&amp;\textbf{Possibilité Evitement P1}&amp;&amp;&amp;&amp;\\ \cline{2-6} &amp;\textbf{Possibilité Evitement P2}&amp;&amp;&amp;&amp;\\ \hline \multirow{ 2}{*}{\textbf{Probabilité Occurence O2}}&amp;\textbf{Possibilité Evitement P1}&amp;&amp;&amp;&amp;\\ \cline{2-6} &amp;\textbf{Possibilité Evitement P2}&amp;&amp;&amp;&amp;\\ \hline \multirow{ 2}{*}{\textbf{Probabilité Occurence O3}}&amp;\textbf{Possibilité Evitement P1}&amp;&amp;&amp;&amp;\\ \cline{2-6} &amp;\textbf{Possibilité Evitement P2}&amp;&amp;&amp;&amp;\\ \hline \end{tabular} \end{table*}