When you take a course like Abstract Algebra, the professors just "let it be given" that there is only one group of order $2, \mathbb{Z_2}$. But they don't go about proving this, despite proving nearly everything else. How do we come to assert that, for example, there is only one group of order $2$ $(\mathbb{Z_2})$ and only one group of order $3$ $(\mathbb{Z_3})$? Is there a proof of it somewhere? I'm not finding anything on the internet. I suspect a proof by contradication would be helpful here, constructing a group with arbitrary values.

It says  that "By the classification of cyclic groups, there is only one group of each order[prime] (up to isomorphism)".   What is the intuition behind this and how would you go about proving this? An proof would be greatly appreciated.


I am travelling from Toronto to new Delhi. I have a valid Indian passport and a valid Canada student visa. I have stops at Munich and Frankfurt for 1 hour and 1.5 hours respectively. Do I need any kind of transit or airport transit visa?

I have single entry tourist visa for Canada. My visa is valid till 20th Dec 2013 but I am travelling to Mumbai from Toronto on oct. end via Munich (Germany). I am an Indian passport holder. Do I need transit visa for germany? I will fly with Air Canada.


I'm trying to do this:  sudo add-apt-repository \    "deb [arch=amd64] https://download.docker.com/linux/ubuntu \    $(lsb_release -cs) \    stable"   And getting:  Traceback (most recent call last):   File "/usr/bin/add-apt-repository", line 11, in <module>     from softwareproperties.SoftwareProperties import SoftwareProperties, shortcut_handler   File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 28, in <module>     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg'   OK, like , I'm removing and reinstalling python-apt and python3-apt, but then I get:  sudo add-apt-repository    "deb [arch=amd64] https://download.docker.com/linux/ubuntu \    $(lsb_release -cs) \    stable" sudo: add-apt-repository: command not found   Like , I do:  sudo apt-get install software-properties-common   But then I get the same issue as the first one: ModuleNotFoundError: No module named 'apt_pkg' and it all starts over. What should I do?

I'm rather new to Ubuntu and I'm trying to run update-manager on Ubuntu 13.10. I get:  jacopo@jacopo-laptop:~$ update-manager  Traceback (most recent call last):   File "/usr/bin/update-manager", line 28, in <module>     from gi.repository import Gtk   File "/usr/lib/python3/dist-packages/gi/__init__.py", line 27, in <module> from ._gi import _API ImportError: No module named 'gi._gi' Error in sys.excepthook: Traceback (most recent call last):   File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 64, in apport_excepthook     from apport.fileutils import likely_packaged, get_recent_crashes   File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>     from apport.report import Report   File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module> import apport.fileutils   File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>     from apport.packaging_impl import impl as packaging   File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 20, in <module> import apt File "/usr/lib/python3/dist-packages/apt/__init__.py", line 21, in <module> import apt_pkg ImportError: No module named 'apt_pkg'  Original exception was: Traceback (most recent call last): File "/usr/bin/update-manager", line 28, in <module> from gi.repository import Gtk File "/usr/lib/python3/dist-packages/gi/__init__.py", line 27, in <module> from ._gi import _API ImportError: No module named 'gi._gi'   As far as I have understood, this is a problem related to the fact that I should have python3.4 installed. I installed it in /usr/local/lib, but I always get the same error. In this way I can't even upgrade to Ubuntu 14.04.


I'm having an inconsistent user experience here. This is how I've added Firefox Developer Edition (FDE) to the dock:   Searched for FDE in the search dialog brought up with the super key. Right-clicked the icon that came up (I made sure it wasn't some redundant .desktop file floating around on my disk but the actual application launcher). Clicked on "Add to favorites".   Now, when I'm starting the application from the dock (or by searching it in the dash - it doesn't matter), instead of using the existing icon in the dock, another redundant icon appears in the dock, which does indicate open tabs (windows) but the existing icon doesn't and becomes useless.  So, when the application is running, I end up having the FDE icon twice, which looks like this.    When doing the same thing for Chromium, only one icon appears in the dock and a red point left to it indicates open tabs (windows) as expected.  How do I debug this? Is this a known thing? Thanks for your help!

I'm using Ubuntu 17.10 with GNOME shell and Numix-Circle icon theme.   When I hover over the Numix icon for Nightly Web Browser, which is pinned to the dock I get the title "Nightly Web Browser".      But when I launch the program, another icon pops up at the bottom, with the name "Nightly".


I have a dataframe that contains many rows row (order of 60000) with the three fields:  shift: a string of 96 characters indicating the location or 'r' (no location; e.g. 'rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrraaabbbbbbbrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr') start: specified startingpoint (1 indexed) stop: specified stoppoint (1 indexed)  Now I want to have a mapping for both location 'a' and 'b'. This mapping shows on which point in time, which row contains a or b. We thus have: mapping['a'] = [[]]*96 # list of length 96 with, initially, and empty list for the row-indexes. ` mapping['b'] = [[]]*96 # list of length 96 with, initially, and empty list for the row-indexes. `  for index, row in pd_shifts.iterrows():     for t in range(row['start']-1,row['stop']):         loc = row['shift'][t] # either 'a' or 'b'         if loc != 'r': # 'r' can be ignored.             mapping[loc][t].append(index)  I use the above for-loops to find loc on moment t, and append it to mapping[loc][t]. Seems like an easy job. However, each index is added for as many times the a or b is in the string. A snippet of the output: 1535,1535,1536,1536,1536,1536,1536,1537,1537,  What is happening here? Why is each index appended for as many times the a is in the shift? Attempts I have checked that each row has a unique index, and that each row is iterated only once. Also, each start point and stop point (and point in between) are visited once ('print(t)').

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


Suppose we have a standard Stars and Bars problem with a restriction that each partition has at least one star.  With $n$ indistinguishable items and $k$ buckets, we can compute this by $n-1 \choose k-1$  But what if the items were distinct?  Would it be:  $n! {n-1 \choose k-1}$ ?

How do I calculate the number of options for $k$ different balls in $n$ cells, with at least $1$ ball in each cell?   Lets say $6$ different balls in $3$ different cells, with at least $1$ ball in each cell.   like this:  $$x_1+x_2+x_3 = 6$$  I would like to see an explanation please and not just the answer.  Thanks!


I was playing with my post-Moon Lord Journey Character, and went into a new world and found the temple, drilled into it with my Laser Drill, got out some researched Power Cells (researching is basically duplication) and used it on the alter, and he didn't spawn. I killed no bosses. Can anyone tell me what is going on?

Do I have to have defeated Plantera in that world? Because when I try and use the Lihzahrd Altar that's supposed to summon the Golem, it doesn’t work and I can’t activate the Golem!


I can't install Wine 1.6 on my 14.04 Ubuntu install. I get the following error:  The following packages have unmet dependencies:  wine1.6 : Depends: wine1.6-i386 (= 1:1.6.2-0ubuntu4) but it is not installable E: Unable to correct problems, you have held broken packages.

Occasionally, when I'm installing stuff, I get an error like the following:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  package1 : Depends: package2 (>= 1.8) but 1.7.5-1ubuntu1 is to be installed E: Unable to correct problems, you have held broken packages.   How can I resolve this?


As a homework assignment, I'm supposed to find the formula for the nth partial sum of the series $$\sum_{n=1}^\infty \left(\frac{5}{4}\right)^{n-1}$$ In my efforts to solve this problem, I've computed the first four terms of the sequence of partial sums to try and find a pattern: Partial Sum $\quad\quad\quad$ Value $S_1$ = 1 $\quad\quad\quad\quad\quad\,\,\,\,\,$ 1 $S_2 = 1+\frac{5}{4}$ $\quad\quad\quad\,\,\,\, \frac{9}{4}$ $S_3 = \frac{9}{4}+\frac{25}{16}$ $\quad\quad\,\,\,\, \,\, \frac{61}{16}$ $S_4 = \frac{61}{16}+\frac{125}{64}$ $\quad\quad\ \frac{369}{64}$ I already know that this is a geometric series and that it diverges. However, I can't seem to figure out the formula $S_n$ for the $n^{th}$ partial sum that depends only on $n$, and not on the previous term (i.e. not the recursive formula). The denominator seems to be $4^{n-1}$ , but I can't find the pattern for the numerator. Any help is appreciated!

This may be a simple question, but I was slightly confused.  I was looking at the second line $S_n(x)=1-x^{n+1}/(1-x)$.  I was confused how they derived this.  I know the infinite sum of a geometric series is $1/(1-x)$.  I just can't figure out how the partial sums, $S_n(x)$, have $1-x^{n+1}$ on the numerator.  How was this derived?  Thank you.     Example 5.20.   The geometric series   $$     \sum_{n=0}^\infty x^n   = 1 + x + x^2 + x^3 + \dotsb $$   has partial sums   $$     S_n(x)   = \sum_{k=0}^n x^k   = \frac{1 - x^{n+1}}{1 - x} \cdotp $$   Thus, $S_n(x) \to 1/(1-x)$ as $n \to \infty$ if $|x| < 1$ and diverges if $|x| \geq 1$, meaning that   $$     \sum_{n=0}^\infty x^n   = \frac{1}{1-x}   \qquad   \text{pointwise on $(-1,1)$}. $$   (Original image .)


I want to use the \ast asterisk in my document. However in the PDF there is no more space after the occurrence of the star, and LaTeX wants to cram all the following text in one line which obviously isn't working. It is not only the subsequent space, it is all the spaces in the rest of the document which get ignored. So this leads to the error -Overfull \hbox The issue seems to have something to do with "Math Mode" because all LaTeX commands after the \ast will get the Warning: Command xy invalid in math mode  Is \asteating spaces?  \documentclass[a4paper,12pt,ngerman]{article} \usepackage[utf8]{inputenc} \usepackage[ngerman]{babel} \usepackage{textcomp}  \begin{document}  text text text John Doe (\ast 1958) text text text text text text text text text text text text text text text text text text text text text text text text text text  text text text text text text text text text  \end{document}

I have a definition:  \newcommand{\arnold}{Arnold Schwarzenegger}   When I refer to it by:  \arnold is a   it is rendered as:   Arnold Schwarzeneggeris a    In order to have a space in front of "is" I would need to write  \arnold\ is a   Is there some other shorter way?


I would like to do something similar to   But instead of only highlighting complete rows, I want to highlight arbitrary subsets of the table.   I added the code of the original question as well as the output. Which changes would have to be done to e.g. highlight the first 2 columns of the first 2 data rows in a contiguous block?  Additionally the code leads to the highlighted rows being indented, which I would like to avoid.  \documentclass{beamer} \usepackage{lmodern} \usepackage[beamer,customcolors]{hf-tikz}  \tikzset{hl/.style={     set fill color=red!80!black!40,     set border color=red!80!black,   }, }  \begin{document}  \begin{frame}{Title} \begin{center} \resizebox{\textwidth}{!}{ \begin{tabular}{lcc|ccc} \multicolumn{6}{c}{Effect of Mandate on Fertility by Age: Employed Individuals} \\ \hline \hline  & (1) & (2) & (3) & (4) & (5) \\  & Has Child & Has Child LT 5 & Has Child LT 5 & Has Child LT 5 & Has Child LT 5 \\ VARIABLES & All & All & No HS Degree & HS or College & Masters or More \\ \hline  &  &  &  &  &  \\ \tikzmarkin<2->[hl]{a} Married Women 18-20*& -0.11 & -0.08* & -0.21*** & -0.00 & 0.00 \\  After*Treatment State & [0.071] & [0.045] & [0.069] & [0.055] & [0.000] \tikzmarkend{a}    \\  &  &  &  &  &  \\ \tikzmarkin<3->[hl]{b} Married Women 20-25*& -0.07*** & -0.07*** & -0.04 & -0.08*** & -0.38* \\  After*Treatment State & [0.023] & [0.015] & [0.036] & [0.016] & [0.215] \tikzmarkend{b} \\  &  &  &  &  &  \\ Married Women 25-30*& -0.00 & 0.03** & 0.19*** & 0.01 & 0.11* \\ After*Treatment State & [0.019] & [0.012] & [0.032] & [0.014] & [0.058] \\  &  &  &  &  &  \\ Married Women 30-35*& 0.01 & -0.01 & -0.09*** & -0.01 & 0.12** \\ After*Treatment State & [0.020] & [0.012] & [0.029] & [0.014] & [0.051] \\  &  &  &  &  &  \\ Married Women 35-40*& -0.01 & -0.02** & -0.07*** & -0.03* & 0.10* \\ After*Treatment State & [0.019] & [0.012] & [0.026] & [0.014] & [0.053] \\  &  &  &  &  &  \\ Observations & 152,366 & 152,366 & 34,081 & 110,324 & 7,961 \\ R-squared & 0.38 & 0.24 & 0.28 & 0.24 & 0.17 \\  Mean of Dependant Variable & 0.48 & 0.09 & 0.07 & 0.10 & 0.08 \\ \hline \hline \multicolumn{6}{c}{ Standard errors in brackets} \\ \multicolumn{6}{c}{ *** p$<$0.01, ** p$<$0.05, * p$<$0.1} \\ \end{tabular} } \end{center} \end{frame}  \end{document}

I am trying to include some boxes around numbers in a table. I am using the method exactly described on the answer to question below:    The issue is that the first cell of the area surrounded by the box gets an extra space (if you see the example above you will see it). That's quite annoying. Why does it happen? How to solve it?


I got this error during installation.     The installer encountered an error   copying files to the hard disk: [Errno   5] Input/output error This is often   due to a faulty CD/DVD disk or drive,   or a faulty hard disk. It may help to   clean the CD/DVD, to burn the CD/DVD   at a lower speed, to clean the CD/DVD   drive lens (cleaning kits are often   available from electronics suppliers),   to check whether the hard disk is old   and in need of replacement, or to move   the system to a cooler environment.   How can I fix this and what does it mean specifically? I'm installing via USB so it can't be the CD. the laptop is recent so it cant be an old HD.

Today I downloaded Ubuntu for my laptop. It runs great from a bootable USB, but when I tried to install it, I got the following error message: The installer encountered an error copying files to the hard disk:  [Errno 5] Input/output error  This is often due to a faulty CD/DVD disk or drive, or a faulty hard    disk. It may help to clean the CD/DVD, to burn the CD/DVD at a lower   speed, to clean the CD/DVD drive lens (cleaning kits are often    available from electronics suppliers), to check whether the hard disk   is old and in need of replacement, or to move the system to a cooler   environment.     I tried everything to install it on my laptop including redownloading the Ubuntu ISO image, but nothing worked.


I was trying to upgrade the PHP packages on my Ubuntu 14.04 LTS server and I keep getting errors. I know there is a duplicate of this Qn but i removed the error causing file from /var/cache/apt/archives/ but it did not work.  I ran these commands:  sudo apt-add-repository ppa:ondrej/php5 sudo apt-get autoremove sudo apt-get update sudo apt-get -f install   Then I got this:  Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following packages will be REMOVED:   apache2-mpm-prefork apache2.2-bin apache2.2-common php5-dev php5-gd The following NEW packages will be installed:   apache2-bin apache2-data libjson-c2 php5-json php5-ssh2 The following packages have been kept back:   libgd2-xpm-dev libssl-dev openssl The following packages will be upgraded:   apache2 libssh2-php php-pear php5 php5-cli php5-common php5-curl php5-fpm php5-mcrypt php5-mysql 10 upgraded, 5 newly installed, 5 to remove and 3 not upgraded. 1 not fully installed or removed. Need to get 375 kB/8007 kB of archives. After this operation, 2457 kB disk space will be freed. Do you want to continue [Y/n]? y Get:1 http://ppa.launchpad.net/ondrej/php5/ubuntu/ precise/main php-pear all 5.5.30+dfsg-1+deb.sury.org~precise+1 [373 kB] Get:2 http://ppa.launchpad.net/ondrej/php5/ubuntu/ precise/main php5 all 5.5.30+dfsg-1+deb.sury.org~precise+1 [1220 B] Fetched 375 kB in 0s (1074 kB/s) perl: warning: Setting locale failed. perl: warning: Please check that your locale settings:     LANGUAGE = "en_US:en",     LC_ALL = (unset),     LC_CTYPE = "UTF-8",     LANG = "en_US.UTF-8"     are supported and installed on your system. perl: warning: Falling back to the standard locale ("C"). locale: Cannot set LC_CTYPE to default locale: No such file or directory locale: Cannot set LC_ALL to default locale: No such file or directory (Reading database ... 96522 files and directories currently installed.) Unpacking apache2-bin (from .../apache2-bin_2.4.16-4+deb.sury.org~precise+4_amd64.deb) ... dpkg: error processing /var/cache/apt/archives/apache2-bin_2.4.16-4+deb.sury.org~precise+4_amd64.deb (--unpack):  trying to overwrite '/usr/share/man/man8/apache2.8.gz', which is also in package apache2.2-common 2.2.22-1ubuntu1.10 dpkg-deb (subprocess): subprocess data was killed by signal (Broken pipe) dpkg-deb: error: subprocess <decompress> returned error exit status 2 Processing triggers for man-db ... Errors were encountered while processing:  /var/cache/apt/archives/apache2-bin_2.4.16-4+deb.sury.org~precise+4_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1)

For example:  $ sudo apt-get install curl Reading package lists... Done Building dependency tree Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies: bsh : Depends: libjline-java but it is not going to be installed groovy : Depends: libjline-java but it is not going to be installed rhino : Depends: libjline-java but it is not going to be installed E: Unmet dependencies.   Try 'apt-get -f install' with no packages (or specify a solution).   I get the same or similar errors when I attempt to install clojure1.3, leiningen, and several other packages.   When I try the suggestion made in the error message, this is what happens:  $ sudo apt-get -f install  Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following packages were automatically installed and are no longer required:   diffstat linux-headers-3.2.0-26-generic linux-headers-3.2.0-26 dh-apparmor dkms html2text libmail-sendmail-perl libsys-hostname-long-perl Use 'apt-get autoremove' to remove them. The following extra packages will be installed:   libjline-java Suggested packages:   libjline-java-doc The following NEW packages will be installed:   libjline-java 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. 23 not fully installed or removed. Need to get 0 B/72.0 kB of archives. After this operation, 129 kB of additional disk space will be used. Do you want to continue [Y/n]? Y (Reading database ... 226243 files and directories currently installed.) Unpacking libjline-java (from .../libjline-java_1.0-1_all.deb) ... dpkg: error processing /var/cache/apt/archives/libjline-java_1.0-1_all.deb (--unpack):  trying to overwrite '/usr/share/java/jline.jar', which is also in package scala 2.9.2-400 Errors were encountered while processing:  /var/cache/apt/archives/libjline-java_1.0-1_all.deb E: Sub-process /usr/bin/dpkg returned an error code (1)  $ sudo apt-get upgrade Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these. The following packages have unmet dependencies:  bsh : Depends: libjline-java but it is not installed  groovy : Depends: libjline-java but it is not installed  rhino : Depends: libjline-java but it is not installed E: Unmet dependencies. Try using -f.


My beautiful enzyme avatar is hosted on Gravatar, and it doesn't load on , and generally SE pages I have open.  Can someone take a look? I have Chrome version Version 53.0.2785.143 m and it seems to throw a 502 error (Bad Gateway). Others are experiencing this issue as well.

It seems that with some profiles the Gravatar image is broken. I am not sure if this is an issue with SE or Gravatar, or both, so posting here.  As an example,  shows an error on , which shows a HTTP 500 on Gravatar.  Profile image on SO:        Image on Gravatar:        Switching to the MSE profile of the user, the image is working (but has a different hash).  Is this a bug on the SE side? Can anything be done to make Gravatar fix this?    Update 2016-10-04:  It happened to me again two times today. The last user profile was . Calling the service two or three times fixes the issue.


After years on a much older version of Mac OS, I'm now on v. 10.13.2, and I observe strange behavior when I use find functionality, in various applications.   If I search for some string in one application, when I open the search interface in another application, the same string auto-populates the search field.  It happens even when the search string is not in the clipboard, so it isn't just that the clipboard is autopasting — there's an actual transfer of the search string across applications. Affected applications include current versions of BBEdit, NisusWriter, Chrome, Firefox, the built-in Dictionary, Terminal — so I assume it's happening at the level of the operating system.  This is intrusive and unwelcome default behavior, and I'd like to know how to turn it off. I see some unanswered questions about the same issue here and there (for instance, , ).

On my MacBook Pro I have found that several applications seem to share the value for a find.  For example, I searched 'applestackexchange' in Safari's unified address bar, then I switch to Xcode and click into a Find field.  The first word of my search in Safari then appears there.  iTerm2 and Sublime Text 2 also seem to participate in this sharing.  Running latest Mountain Lion on  a 2012 MBP.


So, while flipping through the PHB, I've noticed that in 5th edition, multiple abilities can give you a buff on your unarmed strike, such as a monk's Martial Arts ability, the Tavern Brawler feat or an Aarakockra's claws. If I were to make a monk with the Way of the Drunken Warrior archetype and give him the Tavern Brawler feat, is the d4 for unarmed strike from the feat rendered useless?

If a monk gets the tavern brawler feat, does his martial arts damage stack with the 1d4 damage given with tavern brawler? For example: could a 1st level monk deal 2d4 damage with his unarmed strikes if he had the tavern brawler feat?


how to get the symbol like this  ,i had tried \textdoublebarpipe, but its works in text mode only, but not in equations math mode, not working inside $ $ and align    need code for this symbol,

Is it possible to get a \neq but with a vertical bar instead of a slanted one? There are inequality operators like AMS's \gvertneqq that feature this kind of "not equal" but not without mixing it with other signs.  \documentclass[a5paper]{article} \usepackage{amssymb} \usepackage{amsmath} \begin{document} \begin{align*} a&\gvertneqq b\\ C&\neq \varnothing \end{align*} \end{document}     So what I basically would like to have is the isolated symbol under the > in the \gvertneqq above. Particularly because I don't like the different slopes of the slashes in the second line and "≠∅" is quite a common combination.


It seems absurd but all my installed image viewers can't change file association in my new Windows 8. What I'm missing?  EDIT: summary,    It is not that I can't change file association in my new Windows 8 at all. Doing in the Windows 8's way works. I am able to change all .jpg files to associate with the Windows Photo Viewer. But doing in the Windows 8's way is a PITA. I don't want to do this stupid thing again and again for gazillion of image file types, so I'm installing other image viewers to have them associate all image files at once. That's where things not working in my new Windows 8.   Long story,   In my new Windows 8, I found that image viewer is default to the photo app installed on the operating system.  Whenever I click on a image in File Explorer, I'm taken to the photo app that launches in full screen, and no easy way out.   So I went ahead and configure Windows to open all .jpg files with the Windows Photo Viewer desktop app instead of the Photos app. However, whenever I click on a .gif in File Explorer, I'm taken back to the photo app. This is really frustrating, why MS doesn't provide a way to associate all image files at once as always, but I have to do this stupid thing again and again for gazillion of image file types?   I don't want to do that, so I went ahead and install other image viewers. I ended up installing two,     But found none of their file association is working with my new Windows 8. I.e., they both provide ways to associate all image files at once, and I've tried several times, but in the end the rest of image files are still associated with the stupid photo app.   Changing file association has never been a problem before, ever since windows 3.0, why in my new Windows 8, I can't do it anymore. What I'm missing?  I tried to find the answer myself,         But I didn't find anything related to my problem. Please help. Thanks

Is it possible to easily change all file type associations that are currently associated with one program to another program in one batch?  In my case, I am trying to change all files types currently associated with Notepad to instead use Notepad++ in Windows 7.  It's a pain to go through Default Programs > Set Associations because after each type the entire list re-populates, taking several seconds.  Is there a way I can do a search and replace in the registry, or something even easier?


In my project, we are writing a file using DataOutputStream. We are writing different data types like short, byte, int and long and we are using respective methods in DataOutputStream like writeShort(), writeByte() etc.  Now, I want to edit one record in this file at a particular offset. I know the offset from which that record starts but I am not sure what is the right approach of writing to the file because only method in DataOutputStream supporting offset is the one which takes byte[].  I want to write the whole record which is a combination of different data types as mentioned above.  Can someone please tell me what is the correct approach for this?

I would like to create a simple program (in Java) which edits text files - particularly one which performs inserting arbitrary pieces of text at random positions in a text file. This feature is part of a larger program I am currently writing.  Reading the description about java.util.RandomAccessFile, it appears that any write operations performed in the middle of a file would actually overwrite the exiting content.   This is a side-effect which I would like to avoid (if possible).  Is there a simple way to achieve this?  Thanks in advance.


I know this question has been asked many times but I am completely stuck.  EDIT:  This question is different from previous questions because the problem was not with the code for the reverse function, but rather what types of values can be passed to the reverse function (ie. array vs pointer) .. see answers below for more info.  I am simply trying to reverse a c style string.  I have taken copied and pasted the code to do so directly from Cracking the Coding Interview. (see below)  void reverse(char *str) {     char * end = str;     char tmp;     if (str) {         while (*end) {             ++end;         }         --end;         while (str < end) {             tmp = *str;             *str++ = *end;             *end-- = tmp;         }     } }   This does not work for me.  I am very new to C so perhaps I am compiling the code wrong. My main function looks like:   int main(int argc, char *argv[]) {        char *string = "foobar";     reverse(string);     printf("%s\n", string);      return 0; }   I am using Cygwin with Windows 8.1 and on the command line I am running:   gcc ex1.c -Wall -o exe1 ./exe1   Everytime I get a pop up from windows saying "exe1.exe has stopped working". I tried putting a print statement in the while loop to try debug and see what is going on.  It reaches the while loop once before the windows pop up appears.  EDIT: After reading the comments I have also tried changing the code in main to :  char string[] = "foobar";  reverse(string);   When I do this my program just hangs.  What am I doing wrong?  Thanks!

How do you reverse a string in C or C++ without requiring a separate buffer to hold the reversed string?


As shown in the screenshot I have selected a rectangular region. I want to clear that section. None of the menu/toolbar items are apt for this task.  Is there a workaround?    Update It was suggested to use the Tools|Annotation|Text and put a white background text . However I see no way to configure the text - including customizing the font, fg/bg color, transparency, etc.  How to do so?  See screenshot.

What methods are there to blackout a part of a PDF?  I don't want to simply use Preview's annotation tools and then save the document, since then someone could open up the PDF and remove the annotation to reveal the part of the document which I'm trying to black out.


In the movie Arrival, Loiuse, played by Amy Adams says something to the Chinese President, which he claims were his wife's words. I think she is speaking Mandarin but no subtitles are provided. What did she say?

In the future in Arrival, the commander says that he changed his mind about going to war with the aliens because Louise called his private number and told him his wife's dying words. My question is what did Louise say to him (like in English) and why did it change his mind?


In the books and movies, the marauder's map only reveals it's true information for someone who knows the password. If the books in the restricted area of the library are so dangerous and thus forbidden to young students, why Dumbledore did not put a spell on the books so that they will not show their contents unless the reader knows a specific password?  The books claim that Dumbledore is one of the greatest wizards of the world: thus he probably knew, or could invent a spell like that.

The Restricted Section of the library of Hogwarts contained dangerous books. Why wasn't it locked or protected by some kind of spell? Certainly, Filtch (or Madam  Pince,) wasn't a good protection against a rogue wizard who could easily stun or kill him before he could call skilled wizards.


Let $F$ a field and $E$ a finite extension of $F$. I need to show that, if $D$ is a integral domain such that $F\subset D\subset E$ then, D is a field.  My attempt: As $E$ is a finite extension, it is a algebraic extension. Let $\alpha\in D$, it is sufficient to show that each element of $D$ has a inverse. So, take $\alpha\in D$ so $\alpha$ is algebraic over $F$. Suppose that $\deg(\alpha,F)=n$, then every element of $F(\alpha)$ can be written as $a_0+a_1\alpha+\cdots+a_{n-1}\alpha^{n-1}$ where $a_i\in F$. Therefore, $F(\alpha)\subset D$ and as $F(\alpha)$ is a field and it contains the inverse of $\alpha$.  I have troubles with my proof because a don't see where the fact that $D$ is integral domain is important.

I'm reading Galois Theory by Steven H. Weintraub (second edition), and finding that I'm at least somewhat short on the prerequisites. However the following proof looks wrong to me - am I misunderstanding something, or is it actually an incorrect proof?  Lemma 2.2.3. Let $F$ be a field and $R$ an integral domain that is a finite-dimensional $F$-vector space. Then $R$ is a field. Proof. We need to show that any nonzero $r \in R$ has an inverse. Consider $\{1, r, r^2, \cdots\}$. This is an infinite set of elements of $R$, and by hypothesis $R$ is finite dimensional as an $F$-vector space, so this set is linearly dependent. Hence $\sum_{i=0}^n{c_i r^i} = 0$ for some $n$ and some $c_i \in F$ not all zero.  It then goes on to show, given the above, that we can derive an inverse for $r$. However, if I consider examples like $r = 2 \in Q[\sqrt{2}]$, $r = \sqrt{2} \in Q[\sqrt{2}]$ or $r = 2 \in Q[X]/{<X^2>}$, the set $\{1, r, r^2, ...\}$ doesn't look linearly dependent to me. I do believe the lemma is true (and might even be able to prove it), but this does not look like a correct proof to me. Am I missing something? [Edit] Well yes, I am. Somehow I had managed to discount the possibility of any $c_i$ being negative, despite repeatedly looking at each fragment of the quoted text in an attempt to find what I might be misunderstanding.


I'm a bit newbie in c++ but why this code prints that the queue item is not a child while I created him as a child:  class Parent { public: virtual const char* getName() { return "Who is your daddy?"; } };  class Child : public Parent { public: virtual const char* getName() { return "La gente esta muy loca?"; } };  int _tmain(int argc, _TCHAR* argv[]) {     std::deque<Parent> queue;        queue.push_back(Child());     Parent* p = &queue.back();     if (dynamic_cast<Child*>(p) == 0) { std::cout << "I am not child"; }     else { std::cout << "Welcome, son"; }     std::cin >> c;     return 0; }

Someone mentioned it in the IRC as the slicing problem.


When running gedit with sudo, editing and saving a file causes the following error to appear (twice). Note that the first time it appears is when the file is edited in any way - even just pressing the space bar. Then it happens again when saving.  (gedit:4063): Gtk-WARNING **: Calling Inhibit failed: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files  (gedit:4063): Gtk-WARNING **: Calling Inhibit failed: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files   This did not always occur, but started recently. It seems to be a non-fatal error. Can it be corrected?  I am using 14.04 LTS. I use Unity but supplement it with Docky and Classic Menu Indicator Applet.  When running sudo nautilus, a similar error occurs:  (nautilus:4604): Gtk-WARNING **: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files Nautilus-Share-Message: Called "net usershare info" but it failed: 'net usershare' returned error 255: net usershare: cannot open usershare directory /var/lib/samba/usershares. Error No such file or directory Please ask your system administrator to enable user sharing.   Again, this did not occur until recently, so I believe the problems are related.

I've read  and am interested in this line:     You should never use normal sudo to start graphical applications as Root.   Why? What is the difference? Please provide a simple explanation, as I'm just a normal desktop user.


I would like to move a file via the terminal using the mv command. The syntax is  mv file_old_dir file_new_dir  I am already in the directory where I want the file moved. I just did mv file_old_dir which didn't work.  How can I do this?  mv file_old_dir "here"

When i use the cp or move command in a terminal window, i'm currently with bash in a certain folder like this.  NES@server:~/Desktop/dir1$   And now i wanna copy a file from here ~/anotherdir/dir2 into the current chosen folder in bash (dir1) i would use the command  cp ~/anotherdir/dir2/file ~/Desktop/dir1   does a shortcut string exist to refer to the current chosen directory? So that in this example i don't have to provide the full path to the target dir, but the command knows it should use the current chosen directory in bash? i.e. as ~ stands for the home directory?


Today I got some new Bluetooth headphones (i900000 max - Airpods Pro replica) and I know what you'll say - "You got a replica of Airpods, what did you expect?", but hey, I read a review before I bought them and people said that there is no delay, but I have a little delay when watching videos.. I'm using an Android phone (Samsung Galaxy A8 2018) and the only codec that the headphones support is SBC. Is there something I can do to fix the delay?  Thanks.

Recent android phone.  I initially observed this issue just with Boom and Megaboom bluetooth speakers, but I now have Jabra buds, and see the same issue:  The first 100-500 milliseconds of audio do not play.  This is an issue if it is a language app (that says a word), or a workout app (that says "start" and then 30 seconds later says "stop") because all or most of the sound does not play at all.  What is the resolution?  I have been forced to use wired buds for language learning (which is NO fun!)  When I used apple airpods I did NOT have this issue. (I no longer use airpods because they  or battery-replaced)


Someone contacted me and said that someone with a similar last name died and left me a large amount of money.  He gave me information and forms from a bank, and other pertinent information.   I then got a message that there is fee and that I need to send it before any money could be released to me. I checked and his office really exists but I think he just trying to pull a fast one.  What should I do?

About 12 months ago, I received a letter ostensibly from a company carrying out genealogical research for law firms. It said that they were dealing with the estate of someone who had left money to my late mother, who died about 20 years ago. They wanted me to authorise them to take action to transfer the bequest to me, while taking a percentage of the sum as commission. The letter did not state the size of the bequest, but noted that it would depend on their success or failure in processing other claims on the same estate.  The letter was accompanied with a professional-looking multi-page brochure, and the company had an extensive professional-looking website.  My thought was that, at the best this was a mix-up of names, but since the company was not asking for any personal or financial information about me or my late mother that they had not already stated in the letter, except for confirmation of my date and place of birth, I decided to go along with it and authorised them to proceed.  I heard nothing until a few days ago, when a letter arrived ostensibly from a different firm of solicitors, stating they were dealing with the person's estate (she had died without making a will), had used the genealogy research company to trace a more than 100 relatives of the deceased who were beneficiaries of the estate, and enclosing a cheque for my share of the total. Given the large number of claimants, I was a little surprised by the size of the cheque - close to a 5-figure sum.   This firm of solicitors also looks legitimate - they have a website, a high street address in the area where my mother used to live, etc. The cheque is apparently drawn from the company's named account with major UK bank, not an anonymous money transfer company.  The name and date of death appears genuine - a Google search found a report of her death (she was living in a care home, aged over 90) in the obituary column of a local newspaper.   All that seems fine, but there are a few "red flags" lurking in my mind:    The first letter contained absolutely no information about the deceased person, except her name, which was a very common one (Mary Smith) - probably the sort of name one would choose, if setting up a scam? The story has changed from "someone left money to your mother, who is dead, and we want to pass it on to you" in the first letter, to "someone died without making a will, and you are one of their relatives" in the second. The name itself did not "ring any bells" regarding friends of relatives of my mother who I knew of. My mother had lived in this area for the whole of her life, and never mentioned any relatives she had lost touch with. An email to the solicitor named in the second letter produced an immediate out-of-office reply, but no further response. I have not (yet) tried to contact them by other means - e.g. by phone or via their website.   Cash the cheque and celebrate my good luck, or call the police?  UPDATE 10 Nov 2018:  Curiouser and curiouser: Today I received a letter from someone in another part of the UK, headed "Dear Family" and purporting to explain the circumstances surrounding the end of Mary Smith's life.    To add to the mixed messages, it states that two of her relations have been "spent many months working hard" on the administration of the estate - no mention of the two legal firms who (ostensibly) sent the previous letters!  After a couple of pages of family history, the punchline is "we have decided to gift whatever sum we are entitled to, to [yet another private individual, who was involved in caring for her at the end of her life] and we invite you do to the same, by sending a personal cheque to [contact details] ...  Now that's the sort of scam I have heard about before!!


Assume that the metric space $(X, d)$ is not compact then there exist a $f: X \to \Bbb R$ which is continuous but not bounded.  I am finding difficulty in constructing such a function!!

Suppose $(M,d)$ a metric space. I want to show that      If every continuous real-valued function on $M$ attains a maximum, then $(M, d)$ is compact.   I was trying to do this by assuming $M$ non-compact and showing explicitly a function which does not attain a maximum. If $M$ is not bounded it's enough to take the distance from a fixed point as we can always find a sequence which "exits" every compact and pushes the distance at infinity. But what if $M$ is bounded?


I am suffering from the same old wireless problem. I tried everything I could find on the net as well as Ubuntu forums, but nothing works.  How can I fix this??  my device information from lshw -C network:  ***product: BCM4311 802.11a/b/g vendor: Broadcom Corporation configuration: driver=wl latency=0***   To me, what I was able to learn from the net, the driver is just the right one. but still it isn't working.  iwconfig shows:  **lo   no wireless extensions. eth0 no wireless extensions.**   What other information do you need?

I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible.   What are the steps to install Broadcom wireless drivers for a BCM43xx card?  I'm a user with no advance knowledge in Linux, so I would need clear explanations on how to make, compile, etc.    lspci -vnn | grep Network showed:   Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller [14e4:432b]      iwconfig showed:  lo        no wireless extensions. eth0      no wireless extensions.   NOTE: Answer below is updated every time new information is added and confirmed working.


Is there a way to suppress the warning for fopen (VS 2012 is suggesting I use fopen_s)? The following commands don't seem to work  #define _CRT_SECURE_NO_DEPRECATE #define _CRT_SECURE_NO_WARNINGS

On Visual Studio 2005 C++ compiler, I get the following warning when my code uses the fopen and such calls.  1>foo.cpp(5) : warning C4996: 'fopen' was declared deprecated 1>        c:\program files\microsoft visual studio 8\vc\include\stdio.h(234) : see declaration of 'fopen' 1>        Message: 'This function or variable may be unsafe. Consider using fopen_s instead. To disable deprecation, use _CRT_SECURE_NO_DEPRECATE. See online help for details.'   How do I prevent this?


Is there a Stack Exchange site to ask about PC configurations? I didn't find something obvious. I guess you could ask a question about general pc questions in one of the technology groups but it would be kind of out of context..  It would be nice to create one.   By PC configurations I mean, examples:     someone wants to buy a new pc and assemble it piece by piece someone wants to upgrade set up different screens and resolutions which graphics card to buy    etc.

Stuff like polls, recommendations based on subjective constraints, puzzles, webcomics etc. do not belong on the serious main SE sites, where professionals should be considered at work and having just a few spare minutes ("code's compiling") to answer questions, so they should not be distracted by such things. However, I'd also like to have a home for these things still using the SE engine. For the reason I mentioned before, this needs to be a separate place though. Let's call it four.[sitename-here].com.


I have read  that mass is an invariant and that it is the momentum that approaches infinity when your speed approaches the speed of light. That is why infinite energy is required to accelerate an object to the speed of light.  But, why doesn't mass increase as velocity increases? I have read that relativistic mass is $$m_{rel} = \gamma m$$ More generally, why exactly do we say that mass is an invariant?   EDIT:  is a good treatment on the controversy created by relativistic mass, and it covers why invariant or rest mass is preferable over the relativistic ones. But what I want to know, is why is mass invariant in the first place?

Some people say that mass increases with speed, some people say that the mass of an object is independent of its speed.  I understand how some (though not many) things in physics are a matter of interpretation based on one's definitions. But I can't get my head around how both can be 'true' is any sense of the word.  Either mass increases or it doesn't, right?  Can't we just measure it, and find out which 'interpretation' is right? e.g.: (in some sophisticated way) heat up some particles in a box and measure their weight?  ------------------------------  UPDATE  Right, so I've got two identical containers, each with identical amounts of water, each on identical weighing scales, and each in the same g field. If one container has hotter water, will the reading on its scale be larger than the other? If the answer is yes, and g is constant, does this mean that the m in w=mg has got bigger?


It is a well-known fact that the set of rationals $\mathbb{Q}$ is countable. The proof for $\mathbb{Q^+}$, the strictly positive rationals, is the classic "snaking" pattern detailed in a bunch of textbooks and internet sources, e.g . ProofWiki has 4 (!) different proofs outlined , but the proofs of (2), (3) and (4) all assume proofs that the cartesian product of countable sets is also countable, or that the union of $k$ countable sets is also countable. My Discrete Math class will not have been exposed to those facts at the time that I discuss the countability of $\mathbb{Q^+}$, whereas proof (1) is an informal, non-rigorous proof of the "snaking" pattern which is not particularly satisfying to me (or to my best students).  What I'm interested in is a mathematically accurate characterization of the "snaking" pattern; i.e I'm looking to find the formula $f(n)$ for a bijection $f$ from $\mathbb{N}^*$ (strictly positive integers) to $\mathbb{Q^+}$.

I remember my professor in college challenging me with this question, which I failed to answer satisfactorily: I know there exists a bijection between the rational numbers and the natural numbers, but can anyone produce an explicit formula for such a bijection?


I am trying to wrap text around a figure, but I would like this figure to be centered in the middle of the page. I have been using the wrapfig package. My code is below. \begin{wrapfigure}{r}{0.5\textwidth}   \centering     \includegraphics[width=0.7\textwidth]{AvgReLease.png}   \caption{AvgReLease}  \end{wrapfigure}  My code aligns the image to the right. Is it possible to align the image in the centre of the page instead, such that it separates two bodies of text (say, in between paragraphs)? I have also tried to use the code below, \begin{wrapfigure}{R}{0.5\textwidth} \textbf{\begin{figure}[htp]     \centering     \includegraphics[width=10cm]{AvgReLease.png}     \caption{Average Re-Lease (days) vs Storage Type}     \label{fig: Average Re-Lease vs Storage Type} \end{figure}} \end{wrapfigure}  but the image appears on a different page.

I'm trying to include an image, and keep it centered, and prevent from wrapping from the next page.  The following code works for that:  \begin{minipage}{\textwidth}     \begin{center}         Caption for image          \includegraphics[scale=0.5]{myimage.png}      \end{center} \end{minipage}   I'd like this image to be in a figure, with a caption.  The following doesn't compile:  \begin{minipage}{\textwidth}     \begin{figure}         \includegraphics[scale=0.5]{myimage.png}         \caption{Caption for image}         \label{fig:sample_figure}     \end{figure} \end{minipage}   I get the errors:  ! LaTeX Error: Not in outer par mode. ! Undefined control sequence.   How can I fix this?


I have never posted on the  yet.  I just wrote my first question, but when I click "Post Your Question", I get "You can only post once every 40 minutes."  I haven't posted any question today on any Stack Exchange site.  I tried to report this on the , but I got the same issue.  Let's try here...

This morning I posted a question on a SE site. Then realized a different SE site would be more appropriate.   I proceeded to delete the question on the first site and copied it to the second, but I got the dreaded "You can only post once every 40 minutes.", even if the question was deleted from a different SE site.   I have only the affiliation reputation on both of those sites. Now I'm sitting here waiting for the 40 minutes to pass.  Paradoxically, as a trusted user in SO, I'm more likely to come to other SE sites to ask a few things about topics that are new to me (as opossed to answering in SO), yet I feel more limited.   Maybe trusted users from other sites should have slightly lower restrictions than <125 on the fellow communities? In particular in order to ask a couple of questions.


Is there a word for when a word is pleasing to say? I've found the word:  Euphonious (of sound, especially speech) pleasing to the ear.  But I'm looking for one that is specifically nice to say. E.g.  Phychopathy Specificity

I'm looking for a single word for words that are fun/easy/pleasant to say—words that roll off the tongue, so to speak.


Can't show Azerbaijan characters ?? Help me please, How to fix this ?

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


I need to reverse the action of buffer tool. I had two polyline layers from two different sources with different attributes for a section of a city, that I needed to combine. In order to spatially combine those, I made created a buffer of one of those and then used that to spatially join. Now the joined attributes are in the buffer layer and I need to get the polylines for the that layers. I couldnt do the other way around ( join the features to the lines instead of the buffer) because of the characteristics of the layers.   Is there any way to convert buffer layer to road polyline layer? I tried spatially joining the buffer layer to the original road layer,but the files are large and the "memory not enough" error pops on.  or is there an any simpler way to merge attributes of two road polyline layers?

I want to create center lines from road polygons.   Are there any automated tools in ArcGIS for Desktop to do this?  I am including a Screenshot of my vector file below.


I'm trying to make a service that calls an external system using the NTLM auth. I thought that it should be very likely the BASIC auth - but perhaps I'm wrong. I'd like to know the right way to auth via this way. What I did so far is : HttpRequest req = new HttpRequest(); HttpResponse res = new HttpResponse(); Http h = new Http();  req.setEndpoint('https://someURL'); req.setMethod('GET'); req.setTimeout(120000); String username = 'Username'; String password = 'passwod';   Blob headerValue = Blob.valueOf(username + ':' + password); String authorizationHeader = 'NTLM ' + EncodingUtil.base64Encode(headerValue); req.setHeader('Authorization', authorizationHeader);              res = h.send(req);  System.debug(res); System.debug(req);  But I'm getting Unauthorized from the external system, while from POSTMAN its works as expected. Postman :  Many thanks,

Is it possible calling a Webservice using NTLM authentication from apex? It is a Microsoft Navision Webservice, I tried to do it in Java following this  and it works.


I am trying to use the std::rename() function to move a .docx file, however, the name of the file may vary. How can I use a std::string within std::rename() so that it does not have to be a hardcoded filepath, like this std::rename(filepath, destination);?

How can I convert an std::string to a char* or a const char*?


I saw this question online  "We define a series $\{a_i\}_{i=0}^\infty$ like so: $a_0 = 1, \; a_{n+1} = sin(a_n)$  prove that $a_n$ converges"  that is rather easy because if $\forall x>0 ,\;sin(x) < x$ that mean $a_n$ is monotonically decreasing and positive and thus converges.  It's pretty obvious $a_n$ converges to $0$, My question is, at what rate does $a_n$ converges to $0$.  Spoiler, I used my computer to show that the answer is probably $\frac{\alpha}{\sqrt{n}}$ where $\alpha \approx 1.732$ but I wasn't able to prove it mathematically

Consider the sequence defined as  $x_1 = 1$  $x_{n+1} = \sin x_n$  I think I was able to show that the sequence $\sqrt{n} x_{n}$ converges to $\sqrt{3}$ by a tedious elementary method which I wasn't too happy about.  (I think I did this by showing that $\sqrt{\frac{3}{n+1}} < x_{n} < \sqrt{\frac{3}{n}}$, don't remember exactly)  This looks like it should be a standard problem.   Does anyone know a simple (and preferably elementary) proof for the fact that the sequence $\sqrt{n}x_{n}$ converges to $\sqrt{3}$?


I don't know how to prove that $$\lim_{n\to\infty} \frac{n}{\sqrt[n]{n!}} =e.$$ Are there other different (nontrivial) nice limit that gives $e$ apart from this and the following $$\sum_{k = 0}^\infty \frac{1}{k!} = \lim_{n\to\infty}\left(1+\frac{1}{n}\right)^n = e\;?$$

I'm trying to find  $$\lim_{n\to\infty}\frac{n}{\sqrt[n]{n!}} .$$   I tried couple of methods: Stolz, Squeeze, D'Alambert  Thanks!  Edit: I can't use Stirling.


In a java class i have the following code:  private class Couple<V extends Comparable<V>>{      private V v1;     private V v2;      public Couple(V v1, V v2){         this.v1 = v1;         this.v2 = v2;     } }   I use an HashMap and i want to use keys with the Couple type. For example if i want to insert a new element in the HashMap i do the following:  HashMap<Couple<V>, Integer> map = new HashMap<Couple<V>, Integer>(); map.put(new Couple<V>(v1, v2), new Integer(10));   How should i Override the equals and hashCode methods in the Couple class using Generics?

What issues / pitfalls must be considered when overriding equals and hashCode?


I'm getting an obscure error using FreeFillableForms.  The error does not appear to be on the .     Issue      : Business Rule X0000-005 - The XML data has failed schema validation. cvc-complex-type.2.4.b.  The content of element 'WagesNotShownSch' is not complete. One of '{"":WagesNotShownAmt}' is expected.      The following information may help you determine the form at issue:   Field/Xpath: /efile:Return/efile:ReturnData/efile:WagesNotShownSchedule/efile:WagesNotShownSch/efile:WagesLiteralCd   How can I fix this?

I attempted to file my U.S. Federal taxes via Free Fillable Forms, and got a rejection for the following reasons:  Field/Xpath: /efile:Return[1]/efile:ReturnData[1]/efile:WagesNotShownSchedule[1]/efile:WagesNotShownSch[1]/efile:WagesNotShownAmt[1] Issue      : Business Rule X0000-005 - The XML data has failed schema validation.   Field/Xpath: /efile:Return[1]/efile:ReturnHeader[1]/efile:SelfSelectPIN[1]/efile:PrimaryPriorYearPIN[1] Issue      : Business Rule X0000-005 - The XML data has failed schema validation.     Now how can I correct these? I entered the numbers from the paperwork, rounded down as per prior years, and I noticed that dollar and cent amounts were rounded to the nearest dollar rather than simply down. And I need to know how to retrieve or create an appropriate PIN for federal tax returns.  I also find the error messages disappointing; I expect to need to see error messages, and I'm familiar with XML as a software developer, but to a usability person the English translation of "Business Rule X0000-005 - The XML data has failed schema validation." is "We don't know how to appropriately communicate with the general public."  So what have I run aground on? For the first issue, do I need to re-enter my wages in dollars and cents? And for the second one, how can I retrieve, create, etc. a working PIN?  --EDIT--  The PIN issue is now resolved, partly thanks to @Eric's suggestion. However, after going through and checking and correcting my W2 information, I still get:  Field/Xpath: /efile:Return[1]/efile:ReturnData[1]/efile:WagesNotShownSchedule[1]/efile:WagesNotShownSch[1]/efile:WagesNotShownAmt[1] Issue      : Business Rule X0000-005 - The XML data has failed schema validation.   Also, when I am on the main screen (1040), the "Do the Math" button is active but the "Done with this form" button is inactive, and nothing I do seems to seems to make it active.  Advice?


I can't type letter 'A' in terminal. However, I can type A any other program, like google, notes etc. This happened suddenly.  What could be the problem, and how can I fix it?

Update I can't even paste a b. I am trying to upgrade to Ubuntu 15.04 but I need to delete some files in the /boot directory. When I cd /oot I can't type a b. So, I thought, I will list the files in the / directory and copy/paste, but to no avail. I can't even paste a b. Update 2 I recently added some lines to the /etc/inputrc file in order to get better tab auto-completion: set completion-ignore-case on set show-all-if-ambiguous on TAB: menu-complete bind TAB:menu-complete   Original Question When I ssh into my ubuntu server I can't type the letter "b". I can however type a capital "B" using either shift keys. I'm using a MacBook Pro with Retina display from 2012, and I'm ssh-ing into a custom built ubuntu box. It is here that I can't type a lower case "b". I have restarted the server and yet I still can't type a "b". Every other letter is fine. It hasn't done that before, I've had the server up and running for about two years and haven't come across an issue like this before. I also haven't done anything notable to cause it to do that. At first I thought the keyboard was a little sticky but when I closed the connection it works fine. I've restarted the server, ssh'd back in and the "b" key stops working again. I've tried my bluetooth keyboard and still no luck. Could this be something that is a rule in a .profile or .bashrc file or something similar? A setting to not allow certain characters. When I try to type the letter "b" I get the terminal bell sound as if it is not allowed.


I have already known one way to solve this formula but I just want to know the easier way to do so: $$\lim_{ u \to 0} \frac{\sin(u)}{u}=1$$  Please kindly help me!! Thank You.

How can one prove the statement $$\lim_{x\to 0}\frac{\sin x}x=1$$ without using the Taylor series of $\sin$, $\cos$ and $\tan$? Best would be a geometrical solution.  This is homework. In my math class, we are about to prove that $\sin$ is continuous. We found out, that proving the above statement is enough for proving the continuity of $\sin$, but I can't find out how. Any help is appreciated.


I have to check that file exists or not, and if it does, have to return path to it , the main problem is that os.path.isdir returns only True or False depending on existence, so it seems it does not fit. Any hints? Current schema in my mind  is:  def get_config_path():     if exists(path1):         return path1     if exists(path2):         return path2

How do I check whether a file exists or not, without using the  statement?


I have a problem with SSD free space.  It says, that free space on drive C is around 5GB but  it says, that I used only 44GB. If i'm not bat at maths there is still around 75GB of free space but my PC says, that I have only 5GB.  and I'm looking forward for your answers.  Explanatory Notes :   "Všetko v priečinku C:" - everything in C: folder  "Využité miesto" - used space  "Voľné miesto" - free space

I have an external hard disk, and for some reason, it is reporting wrong free space.  In Windows Explorer, it is showing the used space is 378 GB.    I tried running chkdsk H: /f /r, it seems to report the same usage as Windows Explorer, and it says that there is no problem.    But when I tried selecting all the files inside this drive, it is showing much lesser usage.    I've already set the setting to show all hidden files and folders, also show the protected OS files, but it still cannot find about those missing files. And the difference is huge (282 GB). I've already cleaned the Recycle bin as well.    What I am missing here and how do I identify those missing spaces?  [UPDATE]: I used  to help identify and it seems to find some gigantic files, of which filename is quite weird. Anyone knows what this is and is it safe to delete?


Why are mysterious jpg files being created in my home folder?  They seem to be thumbnails with file names containing word moth.   me@desktop:~$ cd $home me@desktop:~$ ls 01diplo1-moth.jpg            Documents 30CAR-moth.jpg               dog-slater-obit-moth.jpg 30COVER-moth.jpg             Douthat_New-moth.jpg 30DRINKINGsub-moth.jpg       Downloads 30-DRUGTRIALS-JP1-moth.jpg  30eat-moth-v2.jpg            ecuador-moth.jpg 30FASTFOODsub-moth.jpg       EXECUTE-1-moth.jpg 30FRANCE-moth.jpg            Friedman_New-thumbStandard.jpg 30GERMANY-moth.jpg           JP-CLINTON-moth-v2.jpg 30-GRET1-moth.jpg            jp-qatar-moth.jpg 30JPHIRSCH1-moth.jpg         justice-moth-v4.jpg 30MOB1_SPAN-moth-v2.jpg      mag-30pot-t_CA0-moth.jpg 30NATURE1-moth.jpg           memory-moth-v2.jpg 30-next-span-moth.jpg        My GCompris 30stone-img-moth.jpg         Pictures 30SUBCOVER_SPAN-moth-v2.jpg  Public 30Tour_2-moth.jpg            rivera1-moth-v2.jpg audiobooks                   SAMESEX-FLOATER-2-moth.jpg audiobooks-moth.jpg          STATUE-moth.jpg BASE-1-moth-v2.jpg           SUB-DELOS-COVER-moth.jpg Bike-moth-v2.jpg             sunscreen-look-slide-T9SW-moth.jpg chinagold1-moth-v2.jpg       Templates Desktop                      tennis-1-moth-v2.jpg

Here's an odd problem I've had for a while. Every so often, I find that I have several jpeg images sitting in my home directory that I didn't put there. I'm fairly sure this isn't a security breach but rather, there's something writing these files in there that I've forgotten about.  Here's what I'm looking at today:  oli@bert:~$ ls -l *.jpg -rw------- 1 oli oli  8061 2010-11-19 18:30 An-alien-from-Mars-Attack-002.jpg -rw------- 1 oli oli 24362 2010-11-19 18:30 An-alien-from-Mars-Attack-006.jpg -rw------- 1 oli oli  8147 2010-11-05 18:08 Avatar-Film---2009-002.jpg -rw------- 1 oli oli 35602 2010-11-05 18:08 Avatar-Film---2009-006.jpg -rw------- 1 oli oli  6058 2010-12-03 18:42 Britney-Spears-victim-of--002.jpg -rw------- 1 oli oli 28330 2010-12-03 18:42 Britney-Spears-victim-of--006.jpg -rw------- 1 oli oli  8135 2010-11-12 19:19 charlie-brooker-twitter-p-002.jpg -rw------- 1 oli oli 22115 2010-11-12 19:19 charlie-brooker-twitter-p-006.jpg -rw------- 1 oli oli  8059 2010-10-29 18:47 Leonardo-DiCaprio-002.jpg -rw------- 1 oli oli 29988 2010-10-29 18:47 Leonardo-DiCaprio-006.jpg -rw------- 1 oli oli  8064 2010-10-22 16:41 Spot-the-difference-.-.-.-002.jpg -rw------- 1 oli oli 29188 2010-10-22 16:41 Spot-the-difference-.-.-.-006.jpg   They all seem like they're TV or film related... But I honestly don't have a clue what could be writing them. They don't bother me enough to go on a full-scale witch hunt but if anybody knows of something that writes images in the home directory like this, please let me know.


If a compressed spring is dissolved in acid what happens to the elastic potential energy of the spring?

Suppose we take a spring and compress it in a clamp. There is a potential energy due to the compression of the spring. It is now placed into a bath of acid that will dissolve the spring but not the clamp. What happens to the potential energy?  In a realistic situation one (weak) point on the spring could break, so it would then just ping out of the clamp and lose the energy that way. But in the ideal scenario where it dissolves at a uniform rate, this wouldn't happen, so what happens at the instant that it is completely dissolved?   I thought maybe some kind of change of temperature would occur, due to the assumption that the compression would cause the atoms to be more tightly compacted causing a repulsion. As you remove layers this would gradually decrease, but there is still an inherent increase in energy for each atom, so this would most likely be expelled as something (like) heat.  I'm mainly interested in the detail of the mechanisms for the energy tranfers on an atomic level as opposed to the broad picture. Specifically the transfer from coulomb repulsion to heat in the acid. The more low-level detail the better.


Could you please give advice on whether a comma is needed before the and in the following  sentence?  And if it is, why?     This autistic dance group has made history at the European   championships, and now they want to change the way we all see young   people with autism.

I read this sentence on an educational website:     Now times have changed and you are ready for situations involving forces in two dimensions.   Shouldn't there be a comma before and, since the subject of the sentence has changed (things vs. you)?      Now times have changed, and you are ready for situations involving forces in two dimensions.   What is the exact comma rule for joining two clauses with and?


I don't have a usb drive or cd, all I have is a sd card, could I wipe my hard drive and install ubuntu with some sort of file I can put onto an sd card? I don't really know how any of this works please help

Could someone explain how to install Ubuntu from an SD card? I don't have any CDs or USB sticks around. My current operating system is Windows 10 64 bit.


I just performed a search on SO and clicking on the last page of the result list I see .  Some results are listed with too much details IMO. I suppose that since my query was body:"same problem" the engine is trying to highlight the same problem string, but it seems that it gives too much context around the occurrences of that string.  Is this a bug or is it by design?

So, the latest question here on Meta prompted me to do a quick search for . Everything looked all fine and dandy until I switched to the votes tab, where I was prompted with this nice book of text on my screen:           What did I break? o.o I'm pretty sure I'm not supposed to be presented with that much text.


It is showing error -> at com.thoughtworks.mythoughtworks.MainActivity.onCreateOptionsMenu(MainActivity.java:66)  .It is showing null pointer exception  when I load notification badge in onCreateOptionMenu...  Please help     MainActivity.java   public class MainActivity extends AppCompatActivity {   ProgressDialog progress; ListView ls; int count = 0; SearchView searchView; NotificationBadge badge;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);     ls = (ListView)findViewById(R.id.listView);     progress = new ProgressDialog(this);     BackgroundTask process = new BackgroundTask();     process.execute(); }  @Override public boolean onCreateOptionsMenu(Menu menu) {     getMenuInflater().inflate(R.menu.menu_main,menu);     View mview = menu.findItem(R.id.cart).getActionView();     badge = (NotificationBadge) mview.findViewById(R.id.badge);     //updateCartCount();     return true; } private void updateCartCount(){     if(badge == null) return;     runOnUiThread(new Runnable() {         @Override         public void run() {             badge.setVisibility(View.VISIBLE);             badge.setText("2");         }     }); } @Override public boolean onOptionsItemSelected(MenuItem item){     switch(item.getItemId()){         case R.id.cart:             Toast.makeText(this, "cart", Toast.LENGTH_SHORT).show();             break;

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I am using Groovy and Java for the first time and keep getting exception while running my simple main project.  Exception:     Exception in thread "main" java.lang.NullPointerException: Cannot invoke method sell() on null object   class App Java:  public void start() throws CompilationFailedException, IOException {      File trades = uploadGroovyScript();      Binding binding = new Binding();     GroovyShell shell = new GroovyShell(binding);     shell.evaluate(trades);     TradeDsl tradeDsl = new TradeDsl();     Closure c = (Closure) binding.getVariable("trades1");      c.setDelegate(tradeDsl);     c.call(); }   file Groovy:   trades1 = {             buy 100,200 from "MSFT"              buy 1000,200 from "APPL"              buy 500,200 from "VMW"              sell 50,200 from "MSFT"              buy 1200,200 from "MSFT"              sell 200,200 from "VMW"              buy 1200,200 from "APPL"            }   class TradeDsl:  public void buy(int quantity1 , int quantity2) {     System.out.println("Buying " + quantity1 + " or " + quantity2); }  public void sell(int quantity1) {     System.out.println("Selling " + quantity1); }  public void from(String epic) {     System.out.println("from " + epic); }


I have always assumed that I should go to the crew rather than use the button (unless in emergency etc.) as they have more important things to do than giving me a glass of water.  However recently I leaned that cabin crew does not necessarily like for passengers to go around airplane for safety/organizational reasons. Which approach is preferred by crew when I'm indifferent?

I fly Abu Dhabi - Amsterdam - Portland, OR and back frequently.  Each leg is about 8 to 10 hours.  For most people, it is their one 'long flight,' and are sleeping, but for me, because I have two of them, it is a much longer day.  The shades are drawn and everyone's asleep, but I'd like to have a couple beers and watch a movie with my headphones.  Would cabin crew prefer I walk quietly to the back and ask them for a beer (this is what I usually do), or to press the call button.  I want to be as polite as possible.  I understand this might be subjective, but I'm hoping there's a universal rule-of-thumb.


I've always used a larger mouse icon in Windows (made it easier to find when zipping around multiple screens :p). Recently switched to using OSX and discovered that the option to enlarge the mouse icon does just that, literally.  It just zooms the mouse up... Normally this wouldnt be an issue, except when I use photoshop, the icons are all larger than their effect area (ie, brush size is inaccurate) due to the mouse literally being scaled up.  Is there another application that can replace the system mouse rather than just scaling it up??

Due to a stroke, I have had some vision impairment in that I sometimes have a hard time locating my mouse pointer on the screen.  I have tried making the mouse pointer larger which helps but is still not the solution.  I am new to the Mac world and would appreciate your help.  In Windows, there is an option where pressing the CTRL key will help to identify the mouse pointer using a temporary display of several radiating concentric circles around the mouse pointer.  Is there something like this on OS X?


Within the Stack Exchange ecosystem, is there a place for indie developers to post links to their software? Promote, test, discuss, and brag about it? If no, then why not?

I noticed that there are a bunch of questions asked on how to advertise or link to open-source contributions in the Meta section, but they all seemed to be geared towards actual advertising of open-source projects.  Out of all the StackExchange sites, I have the most reputation in the SharePoint site. While working on SharePoint projects I have compiled a library of SharePoint object extensions and helper classes that I would like to contribute to the public. Since I've found the best source of answers to my questions at the SharePoint StackExchange site I would love to contribute back by posting a link to my libraries there.   I'm looking to specifically target the SharePoint StackExchange so that users going to it may stumble across this library that may help them not duplicate efforts that are already done. What is, if there is, the Best Practice to provide a link to this library I've built?


So i'm making an uno game where the user can ony play a card that has the same value or the same color as the card in the stock pile I currently have this as my code:  if(topPileCard().getColor()==card.getColor() || topPileCard().getValue() == card.getValue())   but if a user, for example, plays a green card the condition turns true only if the color matches and the value no longer works and vice versa  Is there any way I can get around this?  and here is the code with uno cards class that has the getValue() and getColor() methods  public class UnoCard { enum Color {     RED, BLUE, GREEN, YELLOW,BLACK;      private static final Color[] colors = Color.values();     public static Color getColor(int i){         return Color.colors[i];     } }      enum Value {         ZERO, ONE, TWO, THREE, FOUR, FIVE, SIX, SEVEN, EIGHT, NINE, SKIP, DRAW_TWO, REVERSE, WILD, WILD_FOUR;         private static final Value[] values = Value.values();         public static Value getValue(int i){             return Value.values[i];         } }  private final Color color; private final Value value;  public UnoCard(final Color color, final Value value){     this.color = color;     this.value = value; }  public Color getColor(){     return this.color; }  public Value getValue(){     return this.value; }  @Override public String toString() {     return color + "_" + value; }   }

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I am a new dungeon master that is DMing for some of my friends that want to play but are beginners. I am turning an adventure called Khyber’s Quest, 4th edition, into a 5th edition game to play. Can someone tell me what recharge is? On encounter 5, there is a monster called Dolgaunt Acolyte that has an ability with recharge next to it. Maddening Whispers is the ability. This is what the ability looks like.      Maddening Whispers (standard; recharge ⚃ ⚄ ⚅)    Close blast 5; targets enemies; +5 vs. Will; 1d6 + 4 psychic   damage and the target slides 3 squares.   I know what all of this is, except for the recharge. If you have played Khyber’s Harvest or know what recharge is, thanks for the help.

How often should I roll power recharge rolls and at which point in the monster's turn do I re-roll them?  I'm trying to find the official definition of the recharge mechanic in the online compendium and I'm not seeing it there.


Where is the difference between one-class, binary-class and multinominal-class classification?  If I like to classify text in lets say four classes and also want the system to be able to tell me that none of these classes matches the unknown/untrained test-data.   Couldn't I just use all the methods that I mentioned above to reach my goal? e.g. I could describe C1, C2, C3 and C4 as four different trainings-sets for binary-classification and use the trained models to label an unknow data-set ...  Just by saying, Training-Set for C1 contains class 1 (all good samples for C1) and class 0 (mix of all C2, C3 and C4 as bad samples for C1).  Is unlabeled-data C1 -> 1 or 0  Is unlabeled-data C2 -> 1 or 0 ... and so on ...  For multinominal classification I could just define a training-set containing all good sample data for C1, C2, C3 and C4 in one training-set and then use the one resulting model for classification ...  But where is the difference between this two methods? (except of that I have to use different algorithms)  And how would I define a training-set for the described problem of categorizing data in those four classes using one-class classfication (is that even possible)?  Excuse me if I'm completely wrong in my thinking. Would appreciate an answer that makes the methodology a little bit clearer to me =)


I have a convergent sequence, {${a_n}$}$_{n\in\Bbb{N}}$. The sequence is of positive numbers and has a limit, $L$. I must prove that $\lim_{n\to\infty}s_n=L$, where $s_n=\frac{a_1+a_2+a_3+...+a_n}{n}$, using the definition of convergence. I thought it was noteworthy that $s_n=\frac{\sum{a_n}}{n}$, though I am unsure as to how this would help me. It would be great if anyone had any hints in regards to how to solve this as I would like to give it a good go, though I am just struggling with starting it. Thank you in advance!

I have this problem I'm working on. Hints are much appreciated (I don't want complete proof):  In a normed vector space, if $ x_n \longrightarrow x $ then  $ z_n = \frac{x_1 + \dots +x_n}{n} \longrightarrow x $   I've been trying adding and subtracting inside the norm... but I don't seem to get anywhere.  Thanks!


I would like to remove, or in other situations customize, the separation line before the footnotes. At this moment I am working with \documentclass{beamer}. Solutions that are beamer-specific or class-agnostic are equally welcome.  Minimal working example:  \documentclass{beamer} \usetheme{Warsaw} \title[Footnotes and separation lines]{Footnotes and separation lines} \institute[]{Tex StackExchange} \author{Xavier Stuvw} \date{11 Sept 2018}  \begin{document} \begin{frame}{This is the first title} This is the first frame \footnote{first footnote: it has a line on top} \end{frame} \end{document}

I am using pdflatex and just want to know how to change the footnote line (thickness, length).  Besides that: How can I set the distance between text-lines in the text.


Unless I have to shot a person or an object which moves, I set my camera to use only one focus point at the middle.  It feels just more natural and so easy: when I need to focus on something which is not in the center of the photo, I start by focusing on it, then move my camera to take a shot. When doing otherwise, I failed to capture numerous moments because of the camera deciding to focus somewhere else.  On the other hand:   My Nikon D7000 has 39 focus points, and newer and more expensive cameras have even more. Also, the factory settings are to keep all the available focus points active, including, I believe, on professional cameras such as Nikon D4. I often see people doing DSLR reviews keeping all the focus points active.  keeping the default auto-focus settings, highlighting the fact that the camera figures very well which point should be used to focus.   Have I misunderstood how to use properly all auto-focus points settings? What could explain that I find it much easier to use a single focus point, while it's not the case for many people?

My Nikon D300 has quite a few autofocus points. There's a button I can operate with my thumb to change the autofocus point but I find that quite difficult to use. So I almost exclusively use the center point to focus and then hold and compose the picture.   Are there any advantages to use any of the other autofocus points (Am I missing out on something)?


While playing with templates in c++ I encountered a problem converting typename T to string. For example:  template <typename T> class Matrix {    public:         Matrix() {            //my_type = string type of T. i.e. if T is char. I want my_type to be "char".         }    string my_type; }   How do I convert T to a string that says what T is.  Note: I'm just playing around so please do not worry about when one might need such a thing.

For example:  int a = 12; cout << typeof(a) << endl;   Expected output:  int


I want to place a board on the side of the road where people are about 5/10 meters away when viewing.     The board is going to be 2 meters by 3 meters.   I was wondering which resolution photo do I need for it to still be sharp when viewing from about that distance.   Also, what size does the text need to be to be readable?

(This question is meant to be a resource to direct others to given that this is a common question.)  Given the task of creating an image that will be printed at a certain size, what pixel dimensions and resolution should I be setting my file at?


I am new to sequences and encountered a task where I am to show that a sequence $(a_n)$ that fulfills the following criteria is a Cauchy sequence. $\forall n > 1 : |a_{n+1} - a_n| \leq q \cdot |a_n - a_{n-1}|$ with $0 < q < 1$. This means that the following is true as well: $|a_{n+1} - a_n| \leq q^n \cdot |a_1 - a_0|$ $\frac{|a_{n+1} - a_n|}{|a_1 - a_0|} \leq q^n$ $0 \leq \frac{|a_{n+1} - a_n|}{|a_1 - a_0|} \leq q^n$ Since $q^n$ converges to 0, I can use the Squeeze theorem to conclude that the sequence $(a_n)$ converges to 0 as well. Every converging sequence is a Cauchy sequence which concludes my proof. However, I am really unsure because I also found sequences that look like they would fulfill the description but are not converging like this one:  Where did I go wrong and how can I show that it is a Cauchy sequence? I was made aware of a post dealing with the same problem and using Cantor's lemma:  However, I am not allowed to use Cantor's lemma for this task, so any help would be appreciated.

Be $ 0 < q < 1, (a_n)_{n \in  \mathbb{N}} $ a sequence in $\mathbb{R}$ and $ n_0  \in  \mathbb{N} $  One has: $ |a_{n+1} -a_n| \leq q |a_n-a_{n-1}|$  for all $n \geq n_o$. Show, that the sequence $(a_n)_{n \in  \mathbb{N}}$ convergates.  I tryed to verify, that its a Cauchy-sequence, but i didn't gone very far..


I create  a few aliases in terminal like below:  alias k=kubectl source <(kubectl completion bash)   And then I open a tmux session with command: tmux.  Now inside of tmux pane, when I try using the alias and expect the behaviour of source command run in terminal, it fails! :(  Why does this happen and how do I get it right?   The context is that I end up using multiple panes in tmux and I don't want to re-peat the same set of aliases creation again and again as I open every tmux pane. Possible?

I am using a scrtipt with instruction 'SH -c command', where command is an alias from bash, this alias can not be interpreted into Bourne shell. ¿Do you have any idea for set this alias into Bourne shell and getting that it works in the new shell? Thanks everyone !


I often come to a point, where I want a plot of a set of data or just a simple function to be included into my TeX file. The usual naive approach would be to save the plot as a vector or pixel graphic and just import it with the graphicx package.  But this has a downside. Axeslabels for example are often over or undersized.  So another option I tried is gnuplot and the terminal option epslatex. Although this fixes the problem with the axeslabel writing both a vector graphic file and a tex file I found this method to be very impractical when I wanted to change (a small mistake e.g.) in the axeslabel.  So I wanted to know what is the most practical way of creating and including a plot in a LaTeX file making it compatible with size and font of the pdfLaTeX output?  EDIT: The emphasis lies on plotting data points from a file (not plotting an analytic function, thats just to show some limiting behavior).

Which is the best way to put function plots into a LaTeX document?


I want to ssh to remote machine within shell script but remote machine require password. How should i provide password in my script?  I tried below but its not working. Please suggest  #!/bin/bash SSH <hostname> <password>

I tried writing a shell script which can do automatic login into a ssh server using password which is mentioned in the script. I have written the following code:  set timeout 30 /usr/bin/ssh -p 8484 root@172.31.72.103 expect  {    "root@172.31.72.103's password"     {       send "password\r"     } }   This code is not running properly, still it is asking for the password. Can somebody please help me in solving this


I am trying to update some entries in existing excel sheet .Below is my code   System.out.println("Update excel block");          FileInputStream fsIP= new FileInputStream("C:\\Users\\SXR8036\\Downloads\\LANE-804.xls");          // System.out.println(Path);          System.out.println("Trying to update the file");          HSSFWorkbook wb = new HSSFWorkbook(fsIP);//Access the workbook          HSSFSheet worksheet = wb.getSheetAt(0);//Access the worksheet, so that we can update / modify it           Cell cell = null;          cell = worksheet.getRow(2).getCell(2);// Access the second cell in second row to update the value           cell.setCellValue("OverRide Last Name");          fsIP.close(); //Close the InputStream           FileOutputStream output_file =new FileOutputStream(new File("C:\\Users\\SXR8036\\Downloads\\LANE-804.xls"));  //Open FileOutputStream to write updates           wb.write(output_file); //write changes           output_file.close();  //close the stream      I am getting NUll pinter exception as error >i have read quite about null pointer exception now but not able to find a solution to this.

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


Is the result of the product of metric tensors $\eta^{\mu\nu} \eta_{\mu\nu} = 1$?   If so how would I prove this?  I know that tensors are represented as matrices but I don't know how I'd prove this (if it is true).

Metric tensor multiplied by its inverse. I always see this with different indices.


I attempt to write my edit summaries with the utmost care, but on occasion, I'll be moving to fix something else, and I'll end up with a messed up summary.  I have found that if I re-edit within a certain time frame, I can change the summary.  However, I'm wondering if there is a way that I'm not aware of to edit the editing summary without having to make any additional changes.  If there is, or if this feature could be added, the readers of millions of future "fixed spe" messages would thank you.  I did search a bit on this, but searching "editing of edits of edit summaries" confounded the works.

It often occurs to me to add an edit summary to a question-edit immediately after submitting the edit, especially if the changes aren't obvious (formatting etc.). So I:   Click "edit" again. Fill in the summary Click on "Save Edits".   The 'edit' (no actual change has been made to the title/body/tags)  is accepted, but the summary doesn't show up, i.e. it is silently rejected.   I don't think it should work this way because the summary has been added by the original editor within the original edit's edit-window. In fact if I remember correctly, it to used to work as expected earlier; so perhaps this is a recent change.


Prove by induction that $$\sum_{k=0}^n k\cdot k! = (n+1)!-1$$  I cannot manage to proceed after assuming that the equality works for $p$.

Prove the summation:  $$\sum_{i=1}^n i! \cdot i = (n+1)! - 1$$ using induction.   base case:  $n=1$: \begin{align*} \sum_{i=1}^1 i! \cdot i &= (1+1)! - 1 \\ 1 &= 2 - 1 \\ 1 &= 1 \end{align*}   This is a question from my test review packet, currently have the base case completed and I am a bit lost on where to go from there. Any help/hints are appreciated.


When I issue sudo apt-get update on the command line I get the following error:  E: Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable) E: Unable to lock directory /var/lib/apt/lists/   How can I fix that?

I get this error when trying to use apt-get:  E: Could not get lock /var/lib/dpkg/lock - open (11 Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/) is another process using it?     How can I fix this?


I am trying to install java8 in ubuntu 14.04.5 but got the above error Following commands were used  $sudo apt-get install python-software-properties $sudo add-apt-repository ppa:webupd8team/java $sudo apt-get update $sudo apt-get install oracle-java8-installer   Below is the log of final command      $ sudo apt-get install oracle-java8-installer     Reading package lists... Done     Building dependency tree            Reading state information... Done     E: Unable to locate package oracle-java8-installer

I am trying install Oracle Java 8 on Ubuntu 18.04 LTS.  $ java --version  Command 'java' not found, but can be installed with:  sudo apt install default-jre             sudo apt install openjdk-11-jre-headless sudo apt install openjdk-8-jre-headless     According  i added ppa:  sudo add-apt-repository ppa:webupd8team/java   and after that i updated my os:  $ sudo torsocks apt-get update Hit:1 http://ppa.launchpad.net/webupd8team/java/ubuntu bionic InRelease         Ign:2 http://dl.google.com/linux/chrome/deb stable InRelease                    Hit:3 http://us.archive.ubuntu.com/ubuntu bionic InRelease                Hit:4 http://dl.google.com/linux/chrome/deb stable Release               Hit:6 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease       Hit:7 http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease Hit:8 http://us.archive.ubuntu.com/ubuntu bionic-security InRelease Reading package lists... Done   and then I ran:  sudo apt-get install oracle-java8-installer   But I got :  $ sudo torsocks apt-get install oracle-java8-installer Reading package lists... Done Building dependency tree        Reading state information... Done Package oracle-java8-installer is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'oracle-java8-installer' has no installation candidate   I found this  but it is not working and I got same error


can I customize branding community?  For example add custom value between "Text color" and "Detail text color"?  This is posible ?

I've been testing the customization capabilities of communities with napili template. One of the very basic things I cannot easily do is, branding. I can update the logo, but not the background. It seems I need to override the CSS, found the below snippet that helps to change the background,  .default-bg-overlay {     background: white none repeat scroll 0 0 !important; }  The above one change the header color, but not the body, I also cannot set the background image. What would be the right way to do it?


I have recently started studying RS flip-flops. I noticed that for the SR NOR Flip-Flops most of the images online, as well as my text, have the 'Set' input attached to the NOR gate that outputs 'not-Q', some sources said that it is designed this way because we want Q to be '1' when S is pulsed '1' and vice versa.    However when dealing with NAND SR Flip Flops this rule of making Q '1' by pulsing S to '1' does not work. Futhermore some of the online images of NAND SR Flip-Flops have the 'Set' input on the gate that outputs Q and others have the 'Set' input on the gate that outputs the compliment of Q.    Please excuse my rather elaborate question but in summary, I would like to know: 1) Does the R and S inputs have to be attached to specific gates in the flip-flop. 2) If yes to '1)' can someone please explain  why this is, for both the NAND and NOR SR Flip-Flop.  Thank you in advance.

I started studying flip-flops recently and I am stuck at this point: At some video tutorials, people explain the SR flip-flop like this:  So they use NAND gates, producing a transition table like this: |     t     | t+1 |  S  |  R  |  Q |  0  |  0  |  INVALID |  0  |  1  |  1 |  1  |  0  |  0 |  1  |  1  |  ?  However, some other people explain the SR flip-flop using NOR gates:  (source: ) which has a different transition table. Are both correct? Why do both exist?


As a point of clarification for , I'm just trying to figure out if it's actually possible to take an enemy's item directly from them during combat, all in the scope of one turn. Since Disarm doesn't technically allow you to directly steal an item (it falls to the ground and opportunity attacks also seem debatable), is there an action or feature that allows you just take an enemy's wielded item and put it in your hand in one fell swoop?

DMG 271 describes the disarm action and states that if the attack roll is successful, the defender "drops the item."  SRD 92 lists things you can do on your turn in tandem with your move and action. One of these options is "pick up a dropped axe," which I can infer means "pick up a dropped anything."  So by the rules as written, can you disarm someone as an action, and then just take the item at no additional cost? Is this really how stealing happens in combat? (I'd always kind of imagined that Sleight of Hand would be involved somehow)  (If it doesn't, )


This problem has got me absolutely stumped, I have looked through other answered questions on stack overflow and none of them answer my question.  **  Code:  **      function inputVCA(){     global $dbh;     $count = 0;     if(isset($_POST['vca'])){         $pcid = mysql_real_escape_string($_POST['ID']);         $vca = $_POST['vca'];         $tok = strtok($vca, ";");         while($tok !== false){                   $countNew = countDataToHour($count);             $stmt = $dbh->prepare("UPDATE $pcid SET $countNew = :token WHERE ID='1'");             $stmt -> bindParam(':token', $tok);             echo "
".$pcid."
";             echo countDataToHour($count)."
";             echo $tok."
";             if($stmt->execute()){                 // do nothing             }else{                 die("failed to execute query");             }             $count++;             $tok = strtok(";");         }     }  }   **  Output (including the error message):  **  888 00:00 40  Warning: PDOStatement::execute(): SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens in C:\xampp\htdocs\practice\src\dataChecker.php on line 170 failed to execute query  **  What do I already know about the issue?  **  The reason this problem has me so stumped is because when I test variables etc. everything seems to output correctly. Anyway:   I've tested the sql query without the :variables. That works The variables outputted are the ones I entered into the form so I assumed it cannot be a problem there   **  Extra info  **  The one bit of my program that I am unsure about is the:  WHERE ID='1'   in my sql query. The reason I do this is because I only will ever need one line in the sql table for the moment.    Any help appreciated, thank you :). Also as a sidenote, whoever voted me down should not have the privileges to vote anyone down. I presented my problem very clearly. My php code is a little bit sketchy but if you are voting me down for this reason this is counter productive and may discourage new users to posting questions on this site. If new users don't come then you will lose out to other competitors. Thank you to all those who gave helpful contributions.

Why can't I pass the table name to a prepared PDO statement?  $stmt = $dbh->prepare('SELECT * FROM :table WHERE 1'); if ($stmt->execute(array(':table' => 'users'))) {     var_dump($stmt->fetchAll()); }   Is there another safe way to insert a table name into a SQL query? With safe, I mean that I don't want to do  $sql = "SELECT * FROM $table WHERE 1"


This question is to try to understand what the asterisk(*) works. As known, * could be used with args to make the function accept positional keywords later. Also, it could work as an operator to unpack a container. So my question is:  how to know its functionality?   def product(*num):     prod = 1     for i in num:         prod*= i     return prod  def product2(num):     prod = 1     for i in num:         prod*= i     return prod  num = [2,3,5]   So when you use different function, you will get different result. I just wanted to know what happened here? Thanks.

In the following method definitions, what does the * and ** do for param2?  def foo(param1, *param2): def bar(param1, **param2):


I uninstalled Cortana because I found it was an annoying feature that bothered me more than it helped me. After uninstalling it though I realized that some other windows features such as the search option disappeared with it, which is why I want it back.  I used this method to uninstall it -   It seems to have completely removed all Cortana files, which is why all other options of installing/re-installing it that I have found don't seem to work. If instead of adding it there were a way of just getting the search option back I would appreciate that also.

With reference to:    I removed the Cortana packages from my running Windows 10 using the method posted by magicandre1981 and using  win6x_registry_tweak.   My question is how can I re-install Cortana (or for that matter any other package removed similarly)?  I have opened up the install.wim image (converted from a Win 10 install.esd file) and found Cortana in the system apps folder, but don't know how / what to use to re-install it.  Any help please?