What is the problem with that code?  Öncelikli olarak \textbf{#include &lt;mpi.h&gt;} header'ını programımıza ekliyoruz.  Ardından MPI programımızı başlatacak olan \textbf{MPI_Init(&amp;argc, &amp;argv);}  fonksiyonumuzu yazıyoruz. Bu iki satır her MPI programında bulunmaktadır.   Error  Illegal parameter number in definition of \re served@a. &lt;to be read again&gt;                     i l.512 Öncelikli olarak \textbf{#include &lt;mpi.h&gt;}                                               header'ını programımız..
I know what my symbol or character looks like, but I don't know what the command is or which math alphabet it came from. How do I go about finding this out?
Cannot open adobe reader on Ubuntu 12.10 64bits I downloaded AdbeRdr9.5.1-1_i386linux_enu.deb from the official website and installed it. Nothing wrong happened during the installation. But when I click Adobe Reader's icon, it has no response. Neither can I open a pdf file with Adobe Reader.  I checked that the package name is adobereader-enu:i386. Prove: $\gcd(a,b) = \gcd(a, b + at)$. I know that $\gcd(a,b)$ divides $a$ and $b$, and must also then divide $(a)(t)$ ($t$ being some integer).  This makes sense to me, but how do I prove it?  It seems that the addition of $(a)(t)$ is a continuation of the linear combination of $\gcd(a,b) = av + bu$ for some $v$, $u$ being elements of $\mathbb{Z}$.    Any help? Recently I had to change the folder permissions of /usr folder. Now the whole sudo is not working. If I try to update my system using this command:  sudo apt-get update   I get the following message:  sudo: /usr/lib/sudo/sudoers.so must be only be writable by owner sudo: fatal error, unable to load plugins   So I tried to change the folder permissions by opening Nautilus as root by using this command  gksudo nautilus   But nothing happened. Nautilus didn't open. This is an emergency as the whole of sudo is not working. when I tried searching the solution from Google many suggested re-installation. I don't prefer re-installation. so is there any other solution? Question on the stability of the solar system One of the pertinent questions about many body systems that causes me much wonder is why the solar system is so stable for billions of years. I came across the idea of "resonance" and albeit an useful concept, it hardly explains the long stability of the solar system. Normally an N body problem with inverse square mutual interaction is an example of a chaotic system. Is there any real progress about this stability issue? Proving that $\lim\limits_{x\to\infty}f'(x) = 0$ when $\lim\limits_{x\to\infty}f(x)$ and $\lim\limits_{x\to\infty}f'(x)$ exist How to input a specific Pantone color number in Illustrator? Collage of six photos, not Facebook Lookback movie I'm using Linux (centos) machine, I already connected to the other system using ssh. Now my question is how can I copy files from one system to another system?  Suppose, in my environment, I have two system like System A and System B. I'm using System A machine and some other using System B machine.  How can I copy a file from System B to System A? And, copy a file from System A to System B? How To Create A 'Two-Sided' Unique Index On Two Fields? How can I efficiently create a unique index on two fields in a table like this: create table t (a integer, b integer);  where any unique combination of two different numbers cannot appear more than once on the same row in the table.  In order words if a row exists such that a=1 and b=2, another row cannot exist where a=2 and b=1 or a=1 and b=2.  In other words two numbers cannot appear together more than once in any order.  I have no idea what such a constraint is called, hence the 'two-sided unique index' name in the title.  Update: If I have a composite key on columns (a,b), and a row (1,2) exists in the database, it is possible to insert another row (2,1) without an error.  What I'm looking for is a way to prevent the same pair of numbers from being used more than once in any order... What do (lambda) function closures capture? Could someone explain this shebang line which uses sh and then does exec perl? This is from . It's about executing a Perl script.     Finally, if you are unfortunate enough to be on an ancient Unix system   that doesn’t support the magic #! line, or if the path to your   interpreter is longer than 32 characters (a built-in limit on many   systems), you may be able to work around it like this:   #!/bin/sh -- # perl, to stop looping eval 'exec /usr/bin/perl -S $0 ${1+"$@"}' if 0;   Can you explain step by step what's going on here? I'm trying to make it work or encompass, but to no avail.  At execution of just the above, I'm getting this:  /bin/sh: 0: Illegal option -- Cannot delete directory with Directory.Delete(path, true) How can we prove that a binomial coefficient $n\choose m$is divisible by the ratio of $n$ and $\gcd(n,m)$? "Thus" vs. "so" in formal English Why are my PHP sessions dying? And why can't I restore them? I have an app using PHP and the PayPal API. The basic way it works to get a payment is that you do a web service call to PayPal to get a token and then do a browser redirect to PayPal with that token for the user to pay. After the payment details have been confirmed, PayPal redirects back to the URL you originally set in the service call.  This all works, millions of people use it every day, et cetera.  Strange thing is, when PayPal redirects back, the PHP session is gone. It's a .  First question: why is this happening? Both pages are on the same domain, both use HTTPS. The session works for all requests up until the PayPal redirect back.  The linked forum thread suggests a workaround, to persist the session ID in the PayPal request and then to retrieve it later and restore the session. Great, except it doesn't seem to work.  I can add some log statements:  log(session_id());   before and after the various redirects. When coming back from PayPal, I log some more.  log("session id is " . session_id()); $session_id = get_session_id_from_paypal(); log("setting it back to " . $session_id); session_id($session_id); session_start(); log("session id is now " . session_id());   The result is not at all what I'd expect:     session_id is fc8f459a186a3f4695ff9ac71b563825   setting it back to 82460dcf8c8ddd538466e7cb89712e72   session_id is now 360ba3fd99d233e0735397278d2b2e55     Second question: why is the session id not at all what I set it to? What am I doing wrong? Or, at least, why do none of the session variables come back? How to remove "phone style" Gnome swipe to unlock Why do electrons not fully fill up all the orbitals sequentially? Why do electrons not fully fill up all the orbitals sequentially? By this I mean: why don't the electrons fully take up the previous orbit first and then move onto the next orbit? Take calcium for example, it's electron config is 2, 8, 8, 2. Why isn't it 2, 8, 10? Why does another orbit need to be created when there are still many spots to fill up?  (I know that this is a chemistry question in a physics forum, but I really could not find a chemistry or even a broader science type forum here ) 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. My friend is buying a digital point-and-shoot camera, which he wants to use to click family pictures including a lot of pictures of their newborn son.  What camera qualities should he be looking for while buying? On 23rd of June, 2016, the UK . This leads to the following questions:   Are UK citizens traveling to the EU affected? Are EU citizens traveling to the UK affected? Are UK/EU family members traveling both way affected? Are Commonwealth citizens traveling to the UK affected? Are other visa-free nationals (such as US/Canada citizens) affected? What other consequences might 'Brexit' have on travelers?   Also, see the  on Expats.SE.