Dual passports in Saudi Arabia
I have two passports/nationalities. How do I use them when I travel?
Prove that if $(ab)^i = a^ib^i \forall a,b\in G$ for three consecutive integers $i$ then G is abelian I've been working on this problem listed in Herstein's Topics in Algebra (Chapter 2.3, problem 4):     If $G$ is a group such that $(ab)^i = a^ib^i$ for three consecutive integers $i$ for all $a, b\in G$, show that $G$ is abelian.   I managed to prove it, but I'm not very happy with my result (I think there's a neater way to prove this). Anyway, I'm just looking to see if there's a different approach to this.   My approach:  Let $j=i+1, k=i+2$ for some $i\in \mathbb{Z}$.  Then we have that $(ab)^i = a^ib^i$, $(ab)^j = a^jb^j$ and $(ab)^k = a^kb^k$.  If $(ab)^k = a^kb^k$, then $a^jb^jab =a^jab^jb$.   We cancel on the left and right and we have $b^ja = ab^j$, that is $b^iba = ab^j$.  Multiply both sides by $a^i$ on the left and we get $a^ib^iba = a^jb^j$, so $(ab)^iba = (ab)^j$. But that is $(ab)^iba = (ab)^iab$.   Cancelling on the left yields $ab=ba$, which holds for all $a,b \in G$, and therefore, $G$ is abelian.  Thanks! What does the notation like 8.6e-28 mean? What is the 'e' for? Long transit in Cairo (Egypt) Can't change mouse influence in proportional editing mode I press O and I see it change to Proportional Editing mode, but when I press G and mouse wheel down/up, or arrow keys down/up, it doesn't change the influence area.    And I am, I press G and then I tried to scroll to change influence, but it's not working.    Done this aswell and it's not working Login screen loops unless you login as Guest I am running a VMWare Player with a Ubuntu 12.04 LTS Precise Pangolin as Guest on my Windows 7. Sometimes I get the shutdown blue screen error in Windows, this time it happened when I was running the Player. When I restarted everything Ubuntu gave me the &quot;Login Loop&quot; on adminstrator login. I log in and there's this black screen where I can only read:  piix4...smbus:0.0.0.07.3 Host Smbus controller not enabled .    When I go to the prompt in root mode it fails to update and only upgraded, specially some plugins ( I think graphic plugins) which also appear in one an error message after quitting the prompt, but they´are successfully installed. They are not the error message. After that I have been working with the Fail/safe Mode recovery panel. When I try to update via Root I get errors like this: W:failed to fetch http://extras.ubuntu.com/ubuntu/dists/precise/release.gpg could not        resolve 'extras/ubuntu.com  There are 8 more like this referring to areas like: -archive/canonical.com -ppa.Launchpad.net -security.Ubuntu.com -Us.archive.ubuntu.com - release.gpg                         precise-updates/release.gpg                         precise_backport/release.gpg   Final Message: some index files failed to download.....they have been ignored or old files are used. The black screens most of the time pass by too fast for me to pick up any information. But in general I think I have done everything I was able to in the recovery panel including updating network and graphic packages and recovering filesystem packages and the basic stuff ( I am a beginner regarding Linux ) in the root prompt. Now I am stuck in this screen with graphic options: - Run in low-graphics mode just for one session - Reconfigure Graphics - Troubleshoot the error - Exit to console login  I am trying to choose to reconfigure graphics but the mouse disappears in the virtual machine screen and sometimes when options change it´s only the first and last option. But this happens from the blue without messages. This particular option menu is in the regular GUI style against a black screen in Terminal style. Really strange. I am a history teacher and I like to make my own maps (I can never find exactly what I want).  I am using QGIS 1.8 and .  I want to reproject their cross-blended hypso rasters into projections that are more familiar looking to my students, like Lambert Conic Conformal.  I have tried changing the crs for the whole project, and the warp and assign functions from the raster menu, and changing the crs for the raster layer itself.  None of these seem to work properly - the resulting maps are unrecognizable and extremely large (file size).  I feel like I am making some kind of basic mistake but I don't know where to begin with this.  Any help would be appreciated. I wasn't forcing myself to say anything, or/nor trying to be funny.   "Or" sounds more grammatically correct to me. But "nor" has more Google results. So I'm confused. JavaScript displaying a float to 2 decimal places I'm trying to generate a secret key to be used for HMAC SHA-256 signature processing. I've seen many sample of keys with variable length from 32 characters to 96 characters.  What is the ironclad rule for this key size? alias to take a parameter and exit after execution How can I embed a View inside a content of a node? How can I embed a view inside a content of a node in Drupal 8?   I found something similar, for example in the question about "" or the  module, but it is all for Drupal 7.  I tried with an Entity reference field pointing to a View but it display only a label and from the Manage Display tab I can choose only from Label and Entity ID. I need something like the "Rendered entity" option that is present on Entity reference fields pointing to other nodes. Is it possible to reference an excel cell in a comment? I have an Excel balance sheet with a total at the bottom. On that cell I have a comment that says that the reason the total is X is because of what happens in J2. What happens if I insert another row before that, now my comment is wrong because all the rows jumped up a value.  Is there any way to reference a cell dynamically in an Excel commment? Is there a way to programmatically change the screen resolution or enable/disable multiple monitors in Windows XP?  For example to change from 1024x768 with one monitor to 1280x104 on two monitors?  I would be most interested in a win32 function to do this but anything that can be tied to a windows shortcut would suffice. Why does Captain Antilles in a New Hope say they're on a diplomatic mission? What would the collision of two photons look like? How can I replace a string in a file(s)? Can SMT give worse performance than normal CPU? alias multi commands as one alias I made an alias for youtube-dl  with some options  like that  yd="youtube-dl -cit -f 18"   so I can download it like   yd URL   I want to modify it to show only the two lines from the output using   grep -e "Downloading video #" -e ETA  I can make it in two aliases using the |   but is there a way to make it one alias I'd wish to visit Dubai with my girlfriend, but after reading  and  I started to get a little worried about it. How should I book an hotel? Must I book two singles? Could it be a problem if we walk together in the city and go together to restaurants and malls without being married? I can see that this works for any integer $n$, but I can't figure out why this works, or why the number $42$ has this property.