Right now I am experiencing some very, very weird behaviour on a Ubuntu 14.04.2 LTS server I am managing.  Connecting to the server over ssh either from cygwin(mintty) or a terminal on a Linux machine, I can't type the letter e.  I have done the following debugging:   The letter e can be typed in vim on the remote server The letter e can be typed in the terminal on the local machines $TERM is set to xterm $LANG, $LANGUAGE and $LC_ALL are set to de_DE.utf8 locale charmap returns UTF-8   Right now, I am completely out of ideas what could be causing this.   I'd be very happy about some advice on how to fix this.
After a few days of operation on my new ec2 build, the following happens:   I log into SSH, everything is fine, I do my coding I return the next day, and log into SSH I cannot type a lower cased e anymore--I get the error ding when I type it I try to ssh from a different computer, same problem I reboot the server, same problem I open nano or vi and e works fine, just not in bash or sh I terminate the server, create a new one, install from scratch, a few days later it happens again   This is baffling! Where do I even start to troubleshoot?  My Local Machine Setup(s):   windows XP or 7 putty (latest) or cygwin/openssh   The EC2 setup   Amazon Linux (default options) node.js iptables forwarding port 80 to node on port 8003 emacs, npm, and openssl-devel no other mods       Output of stty -a while I can't type an e  sh-4.1$ stty -a speed 38400 baud; rows 30; columns 95; line = 0; intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = &lt;undef&gt;; eol2 = &lt;undef&gt;; swtch = &lt;undef&gt;; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0; -parenb -parodd cs8 -hupcl -cstopb cread -clocal -crtscts -cdtrdsr -ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc -ixany -imaxbel -iutf8 opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke   In case it helps someone else with a similar issue, I created a script (called sub) to convert upper-cased E to lower-cased, then echo the command back. Then I run it in backticks to get an e on the command line::  #!/bin/sh echo ${@//E/e}  &gt; `sub Emacs /Etc/profilE`   UPDATES   This breaks for all users In bash only (csh works fine) In emacs edit mode only   I've created  and hone in the solution.
Help with proof that $\mathbb Z[i]/\langle 1 - i \rangle$ is a field. Value of having done applied math research when applying to PhD programs in pure math I will be a second year math under-grad in September, and currently doing an internship at applied math research institute. Most probably, I will come up with a research paper at the end of the internship.  However, my interest after my bachelors is to do PhD in pure math from a top math school.My question is this:     Would the admission committee consider my current research since it is in applied math?    In addition, if anyone can suggest me some ideas on how can I bridge the gap between my paper in applied math and my interest in analysis, I would be extremely grateful.  P.S.:  is a related but different question also of mine. Limit $ a_{n+1} = \frac{1}{3}(2a_n + \frac{5}{a_n^{2}}), a_1 > 0 $ Let $ a_{n+1} = \frac{1}{3}(2a_n + \frac{5}{a_n^{2}}), a_1 &gt; 0 $. Show the sequence converge and find it's limit.    I did the following:  We see that $a_n$ is positive for every n obviously (considering $a_1 &gt; 0$). Then:  $$ a_{n+1} - a_n = \frac{2a_n^{3} + 5}{3a_n^{2}} - a_n = \frac{5 - a_n^{3}}{3a_n^{2}}$$  We see that for each $a_n &gt; ^3\sqrt{5}$ the sequence is decreasing. That means the proof collapses to prove  $a_n &gt; ^3\sqrt{5}$ in order for $a_n$ to be decreasing. Suppose $ a_n &gt; ^3\sqrt{5}$ then obviously $a_{n+1} = \frac{2a_n^{3} + 5}{3a_n^{2}} &gt; \frac{2(\sqrt[3]{5})^{3} + 5}{3(\sqrt[3]{5})^{2}} = \sqrt[3]{5}$ so we deduced $a_{n+1} &gt; ^\sqrt[3]{5} $.  (It's important to note $a_1$ might be less then $\sqrt[3]{5}$, hence the sequence will decrease from the second element.) So we observed $a_n$ is always positive and decreasig hence it's bounded below so it's bounded. As for it's limit:   $$\begin{align} L = \lim_{n \to \infty} a_{n+1} = \lim_{n \to \infty} \frac{1}{3}(2a_n + \frac{5}{a_n^{2}}) = \frac{1}{3}(2L + \frac{5}{L^{2}}) =  \sqrt[3]{5}\end{align}$$  I'm not sure as of the correctness of the solution. I'm aware that it's not a contradiction because it only implies it's in the epsilon-environment of $\sqrt[3]{5}$, or rather in this case $(\sqrt[3]{5}, \sqrt[3]{5}+\epsilon)$.  Is it correct?  EDIT: If anyone encounter a question in the likes, to sum it up you obviously should show the sequence is montonic and bounded. In this case for example we can show it using AM-GM inequality to see the sequence is bounded by $\sqrt[3]{5}$ and then in the difference of two consequective elements we see the difference is negative due to every element being greater then the third root of 5. From here we know the sequence is bounded below and decreasing hence it's bounded. If we plug in the limit of the sequence to itself we will see it's the third root of five. And that's it. Deleting self-answered question gets "Delete this answered question" warning Meaning of the chemical potential for a boson gas My lecturer told me that $\mu$, the , is zero or negative, and in the following example, mathematically it acts as a normalization constant. But is there any physical insight about why boson gas can be zero or negative? I think it is due to the fact the photon gas can pop up from nowhere (i.e. vacuum fluctuation). $$ f_{BE}(\varepsilon)=\dfrac{1}{e^{(\varepsilon-\mu)/(k_B T)}-1}$$ Today I lost 25 reputation points and I'm just curious why? Apparently it was an upvoted and accepted answer and I thought that questions with answers can't be deleted easily. Talking about the general case, when a question gets removed by a Moderator, I'd think it'd be unfair to lose the points, because one still took the time to answer the question and probably invested a significant amount of work.   Unfortunately I don't have a link to the question. All I have is this:        but the "link" to the question is not clickable.  A syntax error question is a bad example for "probably invested a significant amount of work", I know, but again, I'm just curious what happened and want to know, why one does loose the reputation points ? How do I remove Windows but keep Ubuntu? Confusion with floating point numbers After a reinstall of Ubuntu 12.04 ,it's impossible to install commercial games, e.g Oil Rush. It gives this error:  Failed to fetch https://private-ppa.launchpad.net/commercial-ppa-uploaders/oilrush/ubuntu/dists/oneiric/main/binary-amd64/Packages  The requested URL returned error: 401 Failed to fetch https://private-ppa.launchpad.net/commercial-ppa-uploaders/oilrush/ubuntu/dists/oneiric/main/binary-i386/Packages  The requested URL returned error: 401 Some index files failed to download. They have been ignored, or old ones used instead.   I bought these games in 11.10, but I installed these games in 12.04 before... How can I solve this problem? How does water evaporate if it doesn't boil? When the sun is out after a rain, I can see what appears to be steam rising off a wooden bridge nearby. I'm pretty sure this is water turning into a gas.  However, I thought water had to reach 100 degrees C to be able to turn into a gas.  Is there an edge case, for small amounts of water perhaps, that allows it to evaporate? How do I flatten this vector logo leaving only the visible black paths? download.01.org certificate verification failed - CRLfile missing? So I had intel-Linux-graphics-installer on my computer  but lately when I   sudo apt-get update   I get the following error  Err https://download.01.org trusty/main amd64 Packages                          server certificate verification failed.  CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none   Tried reinstalling intel-linux-graphics-installer but nothing happend. And various solutions found here on askubuntu.com on certificates problems but didnt end up anywhere.  Any ideas on how to get that CRLfile? Also is this problem on my side or on the servers side? Sharing Open Source Python/ArcPy Code and Models for ArcGIS Desktop? I will be writing scripts for ArcGIS Desktop in Python with ArcPy.   Is there a community or open source project where code and models can be shared? I left myself signed in to my work Gmail account on my personal computer. I am not using Chrome. I had an internet session that was not suitable for work. At all. This included Google searches and YouTube searches.  Will my employer be able to identify what I have been searching? Are there any subtle differences between "somebody" and "someone", or can they be used completely interchangeably? Similarly, can you imagine a situation in which you would prefer "anybody" to "anyone" or vice versa? How to enable iptables (instead of firewalld) services on RHEL 7 and Fedora 18? The newest fedora has firewalld as new firewall aplication. I liked old iptables services. I want them back but have no idea how to do that. I have tried :  systemctl disable firewalld.service systemctl stop firewalld.service systemctl enable iptables.service systemctl enable ip6tables.service systemctl start iptables.service systemctl start ip6tables.service   But it does not work! Didn't find any help on wiki or google.  Disabling firewalld work ok, but when I'm trying to enable iptables.service I get:  systemctl enable iptables.service Failed to issue method call: No such file or directory To find:  $$\int \sqrt{1+\sin(x)} dx$$  What I  tried:  I put $\tan(\frac{x}{2}) = t$, using which I got it to:  $$I = 2\int \dfrac{1+t}{(1+t^2)^{\frac{3}{2}}}dt$$  Now I am badly stuck. There seems no way to approach this one. Please give a hint. Also, can we initially to some manipulations on the original integral to make it easy? Thank you. Triple integral limits over pyramid According to some source or other (I forget which now) it is theoretically impossible for bumblebees to fly by virtue of their size/bulk/aerodynamic properties. Is this old adage apocraphyal or true? And if its true, how come they do fly? Given $y_n=(1+\frac{1}{n})^{n+1}$ show that $\lbrace y_n \rbrace$ is a decreasing sequence Given  $$ y_n=\left(1+\frac{1}{n}\right)^{n+1}\hspace{-6mm},\qquad n \in \mathbb{N}, \quad n \geq 1. $$ Show that $\lbrace y_n \rbrace$ is a decreasing sequence. Anyone can help ?  I consider the ratio $\frac{y_{n+1}}{y_n}$ but I got stuck.