Reading from Iterator yields new value before it gets incremented in next argument
Order of evaluation in C++ function parameters
Pop up option are not popping up after snipping the area How to prove $D^n/S^{n-1}\cong S^n$? In my textbook it is said that the quotient space $D^n/S^{n-1}$ is homeomorphic to $S^n$. I can imagine it for $n=2$, but fail to make a mathematical proof for any dimension.  Can anyone provide a rigorous proof? I know people prefer using CorelDraw or Adobe Illustrator, but I want to know if there is a technique I can follow to use Adobe Photoshop to make vector Images. Why does the speed of light in vacuum have no uncertainty? I could understand that the definition of a second wouldn't have an uncertainty when related to the transition of the Cs atom, so it doesn't have an error because it's an absolute reference and we measure other stuff using the physical definition of a second, like atomic clocks do.  But why doesn't the speed of light have uncertainty? Isn't the speed of light something that's measured physically?  Check out that . Can I use extra wire from two separate cables to add a washing machine in a garage? After I saw that post i wanted to solve the first one which is $a\mid b^2,b^2\mid a^3,a^3\mid b^4,b^4\mid a^5\cdots$ Prove that $a=b$  Now i started by proving that $a$ and $b$ have same prime divisors,proving that is trivial,after doing so I checked do those factors have to have the same power.I tried with $$a=p^2,b=p^3$$ I noticed it exactly goes for 3 terms,or that $a^3\mid b^4$ doing $$a=p^{n-1},b=p^n\\p^{n-1}\mid p^{2n}\\p^{2n}\mid p^{3n-3}\\p^{3n-3}\mid p^{4n}\\p^{4n}\mid p^{5n-5}\\\cdots\\p^{n(n-1)}\mid p^{n(n-1)}\\p^{n(n-1)}\mid p^{n(n+1)}\\p^{n(n+1)}\not\mid p^{(n-1)(n+1)}$$ Now yeah I guess that would be a proof,but wouldn't setting $n=n+1$ infinitely many times make every term dividable? Navigation page buttons are orange everywhere On a similar note to this question:  (which only covers two examples only on the profile page, this question mentions more places on and outside the profile page where this bug occurs).  I've noticed that whenever there are these page buttons now, for example, the profile page, /questions and tag pages they are orange.  Per the other post I'm assuming this is a bug but if it was intentional then this is a feature request to make them theme-able per site again. Alignment issue in 'Your Sites' section in the Android app There is some unwanted extra spaces in between each site in the Your Sites section.  Steps to reproduce:   Touch the Nav Icon in the left top corner Touch the EDIT link in YOUR SITES Scroll the screen; there is unwanted spaces in between the each site   For reference I recorded the same:    Configurations:   App Version: 1.0.85 Device Manufacturer: Motorola Device Model: XT1033 OS Version: 5.1 (2) Is Bezout's lemma enough to confirm the GCD of a number. Is Bezout's lemma enough to confirm the GCD of a number?  So suppose we have $$ax+by=z$$ does this mean $$\gcd(a,b)=z$$ I'm using GNU Emacs from  After Migration to OSX 10.11 "El Capitan", Auctex can't run the *tex utilities anymore:  Running `LaTeX' on `poisson' with ``pdflatex  -file-line-error   -interaction=nonstopmode "\input" poisson.tex'' /bin/sh: pdflatex: command not found   There is no problem running for example pdflatex on the shell:  #pdflatex This is pdfTeX, Version 3.14159265-2.6-1.40.16 (TeX Live 2015) (preloaded format=pdflatex)  restricted \write18 enabled.   but it seems that auctex calls /bin/sh pdflatex instead, and that does not work anymore:  /bin/sh pdflatex /Library/TeX/texbin/pdflatex: /Library/TeX/texbin/pdflatex: cannot execute binary file   maybe due to El Capitan's changes to Gatekeeper sandboxing.  How can I configure auctex to run pdflatex again? Access nested dictionary items via a list of keys? CSS background opacity with rgba not working in IE 8 How to upload LaTeX-generated pdf paper to arXiv without LaTeX sources arXiv is smart enough to detect whether your PDF is generated by LaTeX. If it is, arXiv asks for the sources of the PDF instead of the PDF file itself. This is really annoying and inconvenient.  I ask a way to fool the arXiv and avoid PDFs being detected as generated by LaTeX (even if they were indeed).  I have tried this: : "create a pdf from word and then simply insert pages from your article, and delete the word's page".  And it did not work. On a whim the other day, I changed my meta name from Lord Torgamus to Popular Demand.  I just noticed that the old name has "stuck" to the author tag of ; everywhere else on meta, my new name displays as expected.  Is this a feature?  Is it a bug?  Mostly I'm just curious, as I can't think of a strong reason in favor of keeping this behavior or a strong reason for changing it.  A question somewhat like this has been raised before as , but the previous poster implied that the issue had something to do with migration, which my situation shows is not the case. Question  The test scores of three groups of people are saved as separate vectors in R.  set.seed(1) group1 &lt;- rnorm(100, mean = 75, sd = 10) group2 &lt;- rnorm(100, mean = 85, sd = 10) group3 &lt;- rnorm(100, mean = 95, sd = 10)   I want to know if there is a significant difference in the medians between these groups. I know that I could test group 1 versus group 2 using the Wilcoxon test, like so.  wilcox.test(group1, group2)   However, this compares only two groups at a time, and I would like to compare all three simultaneously. I would like a statistical test that yields a p value at the 0.05 significance level. Could someone please help?  Edit #1 - Mood's median test  Following user Hibernating's suggested answer, I tried Mood's median test.  median.test &lt;- function(x, y){     z &lt;- c(x, y)     g &lt;- rep(1:2, c(length(x), length(y)))     m &lt;- median(z)     fisher.test(z &lt; m, g)$p.value }  median.test(group1, group2)   However, this approach allows me to test for a significant difference between the medians of only two groups at a time. I am not sure of how to use it to compare the medians of all three simultaneously.  Edit #2 - Kruskal-Wallis test  User dmartin's suggested answer appears to be more or less what I need, and allows me to test all three groups simultaneously.  kruskal.test(list(group1, group2, group3))   Edit #3  User Greg Snow helpfully notes in his answer that the Kruskal-Wallis test is appropriate as long as it makes strict assumptions that make it also a test of means. Is it safe to delete the file Caches, in the Library of the Mac OS X Hard Drive?  It's a pretty big file, 3.56 GB, Caches reminds me of logs i don't need or browser cookies.   Is it safe to delete the folder "Caches"? Show that any prime ideal from such a ring is maximal. Let R be a commutative ring with an identity such that for all $r\in$ R, there exists some $n&gt;1$ such that $r^n = r$. Show that any prime ideal is  maximal. (Atiyah and MacDonald, Introduction to Commutative Algebra, Chapter 1, Exercise 7.)    Any hints? I am stuck on the following problem that says:       a) Find a weak formulation for the partial differential equation $${\partial u\over\partial t\ }+ c{\partial u \over \partial x\ }=0$$    b) Show that $u=f(x-ct)$ is a generalized solution of $${\partial u\over\partial t\ }+ c{\partial u \over \partial x\ }=0$$ for any distribution $f$    My Attempt:   I know that in order to find a weak form of a pde, we need to multiply it by a test function, then integrate it. Also, to find a generalized solution, we need to find a weak solution and just multiply it by the Heaviside function.  Let's take any test function $\phi $, then we have (integrating by parts second part of the integral) $$\int_{\Omega } ( {\partial u\over\partial t\ }+ c{\partial u \over \partial x\ })*\phi(x) dx= \int_{\Omega } {\partial u\over \partial t}\phi(x) dx - c\int_{\Omega } u(x,t)\phi'(x)dx$$ where $\phi $ vanishes at boundaries. So, is it the final form or can we proceed further? And how am I supposed to find a generalized solution?  Can someone help me out? Thanks in advance for your time. Time travel short story where dinosaur doesn't taste like chicken I was recently in a bit of a quandary over which answer to accept to .  Of the answers I got, two were the clear leaders and, of course, I up-voted both. Choosing a 'winner' was more difficult though as their approaches were quite different.  Answer A addressed my question and provided a clear and well thought out response. I'd anticipate that this answer would be of most use to a user who found my question via a search. Selecting this would probably be the more community-focused way to go.  Answer B took a more lateral approach and made some guesses at the business logic behind my request, suggesting that I might be asking the wrong question. Their solution was based on this assumption - and they were spot on. Answer B formed the basis of my fix for the problem.  So... Best answer to the question or best solution to the problem - they may not always be the same thing.   I took the selfish approach and went with B. I'm not losing sleep over it, but I do wonder if I did the right thing?