I am unable to upgrade Ubuntu from 16.04 to 16.10.   Error message:  Failed to lock /var/cache/apt/archives/lock   There are numerous answers on how to fix it. I tried all. But no success. Can anybody help?  Existing posts on the same topic:         Error Message:  Calculating the changes     Calculating the changes Do you want to start the upgrade?      10 installed packages are no longer supported by Canonical. You can  still get support from the community.  16 packages are going to be removed. 293 new packages are going to be  installed. 1842 packages are going to be upgraded.  Installing the upgrade can take several hours. Once the download has  finished, the process cannot be canceled.   Continue [yN]  Details [d]y Fetching Fetched 0 B in 0s (0 B/s)                                    Upgrading Could not download the upgrades  The upgrade has aborted. Please check your Internet connection or  installation media and try again.   Failed to lock /var/cache/apt/archives/lock   Traceback (most recent call last):   File "/tmp/ubuntu-release-upgrader-kfjtjdko/yakkety", line 8, in &lt;module&gt;   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/DistUpgradeMain.py", line 242, in main   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/DistUpgradeController.py", line 1880, in run   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/DistUpgradeController.py", line 1845, in fullUpgrade   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/DistUpgradeController.py", line 1263, in doDistUpgrade   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/DistUpgradeController.py", line 1385, in abort   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/sourceslist.py", line 366, in restore_backup   File "/usr/lib/python3.5/shutil.py", line 236, in copy     copymode(src, dst, follow_symlinks=follow_symlinks)   File "/usr/lib/python3.5/shutil.py", line 138, in copymode     chmod_func(dst, stat.S_IMODE(st.st_mode)) PermissionError: [Errno 1] Operation not permitted: '/etc/apt/sources.list' Error in sys.excepthook: Traceback (most recent call last):   File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 109, in apport_excepthook     pr.add_proc_info(extraenv=['PYTHONPATH', 'PYTHONHOME'])   File "/usr/lib/python3/dist-packages/apport/report.py", line 544, in add_proc_info     self['ExecutableTimestamp'] = str(int(os.stat(self['ExecutablePath']).st_mtime)) PermissionError: [Errno 13] Permission denied: '/tmp/ubuntu-release-upgrader-kfjtjdko/yakkety'  Original exception was: Traceback (most recent call last):   File "/tmp/ubuntu-release-upgrader-kfjtjdko/yakkety", line 8, in &lt;module&gt;   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/DistUpgradeMain.py", line 242, in main   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/DistUpgradeController.py", line 1880, in run   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/DistUpgradeController.py", line 1845, in fullUpgrade   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/DistUpgradeController.py", line 1263, in doDistUpgrade   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/DistUpgradeController.py", line 1385, in abort   File "/tmp/ubuntu-release-upgrader-kfjtjdko/DistUpgrade/sourceslist.py", line 366, in restore_backup   File "/usr/lib/python3.5/shutil.py", line 236, in copy     copymode(src, dst, follow_symlinks=follow_symlinks)   File "/usr/lib/python3.5/shutil.py", line 138, in copymode     chmod_func(dst, stat.S_IMODE(st.st_mode)) PermissionError:  [Errno 1] Operation not permitted: '/etc/apt/sources.list'
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?
How can I put a bit mask on /dev/zero so that I can get bytes other than zero? How can I put a bit mask on /dev/zero so that I can have a source not only for 0x00 but also for any byte between 0x01 and 0xFF? Let $f_n(x) : \mathbb{R} \rightarrow \mathbb{R}$ be defined as $\dfrac{x}{n}$. Is $f_n$ uniformly convergent?   With "$(a_n)$ is limited and $(b_n)$ converges to 0 $\Rightarrow (a_nb_n)$ converges also to 0" i would guess that $x\cdot \dfrac{1}{n}$ converges uniformly but $x$ is not limited in this case. So does ist converge uniformly or not? I need to learn basic optics for a high school academic competition. Does anyone know any good places, preferably free and online, to learn the basics of optics, like lenses, angles of incidence, etc.? I can't seem to find an MIT OpenCourseWare course addressing the issue. First part :  I want to prove the following De Morgan's law :  ref.(dfeuer)  $A\setminus (B \cap C) = (A\setminus B) \cup (A\setminus C) $    Second part:  Prove that $(A\setminus B) \cup (A\setminus C) = A\setminus (B \cap C) $    Proof:  Let $y\in (A\setminus B) \cup (A\setminus C)$     $(A\setminus B) \cup (A\setminus C) = (y \in A\;  \land y \not\in  B\;) \vee (y \in A\; \land y \not\in C\;)$      $\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;= y \in A\ \land (  y \not\in B\; \vee \; y \not\in C ) $      $\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;= y \in A \land  (\lnot ( y\in B) \lor \lnot( y\in C) )$   According to De-Morgan's theorem :  $\lnot( B \land C) \Longleftrightarrow (\lnot B \lor \lnot C)$ thus     $y \in A \land (\lnot ( y\in B) \lor \lnot( y\in C) ) = y \in A \land y \not\in (B \land C)$   We can conclude that  $(A\setminus B) \cup (A\setminus C) = A\setminus (B \cap C)$ proving the inequality $\triangle\leq \frac{1}{4}\sqrt{(a+b+c)\cdot abc}$ Reopened questions get a "modified" time stamp in the questions list just showed up on 's front page like this:    ... which makes no sense, because the question hasn't been modified since May 25th, and the person who edited it wasn't CatLord anyway:    Turns out what actually happened was that CatLord cast a fifth reopen vote to reopen the question.    So that stamp in the questions list should probably say this instead:     reopened 4m ago CatLord 10.7k   Or just:     reopened 4m ago If two limits don't exist, are we sure the limit of sum doesn't exist? This is a true/false question.     If the limits $$\lim_ {x\to a}\ f(x)\quad \text{ and }\quad  \lim_ {x\to a}\ g(x)$$ don't exist, limits $$\lim_ {x\to a}\ (f(x)+g(x))\quad \text{ and }\quad \lim_ {x\to a}\ (f(x)g(x))$$ don't exist also.   My idea is, that, because $$\lim_ {x\to a}\ (f(x)+g(x))=\lim_ {x\to a}\ f(x)+\lim_ {x\to a} g(x)$$ then the limits doesn't exist, correct? I have just created a Minecraft 1.13.1 server and was wondering if there was any way to give everyone the teleport command even if they are not op. If not, is there a way that I could make them op but only have access to the teleport command? Aligning multiple figures/tikzpicture vertically and horizontally I'm trying to align four figures vertically and horizontally. But I couldn't get it right in spite of repeated tweaks.  Can someone help me out?   Here is a MWE -- there are no errors, but the figures don't come out scaled properly.  \documentclass[12pt]{llncs}  \usepackage{fullpage} \usepackage{graphicx}  \pdfoutput=1 \usepackage{epsf} \usepackage{epsfig} \usepackage{epstopdf} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsmath} \usepackage{latexsym} \usepackage[all]{xy} %\pagestyle{empty} \pagestyle{plain} %\usepackage{algorithmic} %\usepackage{algorithm} \usepackage{hyperref} \usepackage{nameref} %\usepackage{MnSymbol} \usepackage{tikz} \usepackage{caption} \usepackage{subfig}  \begin{document}  \begin{figure} \captionsetup[subfigure]{width=2in} \begin{minipage}[t][4em][s]{.5\textwidth} \subfloat[First]{ %\begin{subfigure}[b]{\textwidth} \begin{tikzpicture}[every node/.style={circle, draw, scale=1.0, fill=gray!50}, scale=1.0, rotate = 180, xscale = -1]  \node (1) at (0, 0) {$a$}; \node (2) at (3.0, 0) {$s$}; \node (3) at (4.5, 0) {$s'$}; \node (4) at (7.5, 0) {$t'$}; \node (5) at (9.0, 0) {$t$}; \node (6) at (12.0, 0) {$b$};   \draw[-&gt;] (1) -- (2); \draw[-&gt;] (2) -- (3); \draw[-&gt;] (3) -- (4); \draw[-&gt;] (4) -- (5); %\draw (8) -- (7); \draw[-&gt;] (5) -- (6);  \end{tikzpicture} %\label{fig:sto} } %%\qquad % %\bigskip % \subfloat[Second]{ \label{fig:st} %\begin{subfgure}[b]{\textwidth} \begin{tikzpicture}[every node/.style={circle, draw, scale=1.0, fill=gray!50}, scale=1.0, rotate = 180, xscale = -1]  \node (1) at (0, 0) {$a$}; \node (2) at (3.0, 0) {$s$}; \node (3) at (4.5, 0) {$s'$}; \node (4) at (7.5, 0) {$t'$}; \node (5) at (9.0, 0) {$t$}; \node (6) at (12.0, 0) {$b$};   \draw[-&gt;] (1) -- (2); \draw[thick, dashed, -&gt;] (2) to[out=-100,in=-150] (1); %\draw (3) -- (2); \draw[-&gt;] (3) -- (4); \draw[thick, dashed, -&gt;] (4) to[out=-100,in=-150] (3); %\draw (5) -- (4); \draw[thick, dashed, -&gt;] (2) to[out=-250,in=-350] (4); \draw[thick, dashed, -&gt;] (3) to[out=100,in=150] (1);     %\draw (8) -- (7); \draw[-&gt;] (5) -- (6); \draw[thick, dashed, -&gt;] (6) to[out=-100,in=-150] (5);   \end{tikzpicture} } \end{minipage} \begin{minipage}[t][4em][s]{0.5\textwidth} \subfloat[Third]{ %\begin{subfigure}[b]{\textwidth} %\centering \begin{tikzpicture}[every node/.style={circle, draw, scale=1.0, fill=gray!50}, scale=1.0, rotate = 180, xscale = -1]  \node (1) at (0, 0) {$a$}; \node (2) at (3.0, 0) {$t$}; \node (3) at (4.5, 0) {$t'$}; \node (4) at (7.5, 0) {$s'$}; \node (5) at (9.0, 0) {$s$}; \node (6) at (12.0, 0) {$b$};   \draw[-&gt;] (1) -- (2); \draw[-&gt;] (2) -- (3); \draw[-&gt;] (3) -- (4); \draw[-&gt;] (4) -- (5); %\draw (8) -- (7); \draw[-&gt;] (5) -- (6);   \end{tikzpicture} } %%\qquad % \subfloat[Fourth]{ \label{fig:ts} %\begin{subfigure} \begin{tikzpicture}[every node/.style={circle, draw, scale=1.0, fill=gray!50}, scale=1.0, rotate = 180, xscale = -1]  \node (1) at (0, 0) {$a$}; \node (2) at (3.0, 0) {$t$}; \node (3) at (4.5, 0) {$t'$}; \node (4) at (7.5, 0) {$s'$}; \node (5) at (9.0, 0) {$s$}; \node (6) at (12.0, 0) {$b$};   \draw[-&gt;] (1) -- (2); \draw[thick, dashed, -&gt;] (4) to[out=-100,in=-150] (1); %\draw (3) -- (2); \draw[-&gt;] (3) -- (4); \draw[thick, dashed, -&gt;] (5) to[out=100,in=150] (1); %\draw (5) -- (4); \draw[thick, dashed, -&gt;] (2) to[out=100,in=150] (5); \draw[thick, dashed, -&gt;] (4) to[out=-100,in=-160] (2);   %\draw (8) -- (7); \draw[-&gt;] (5) -- (6); \draw[thick, dashed, -&gt;] (6) to[out=100,in=150] (3);  \end{tikzpicture} } \end{minipage} \end{figure} \end{document} Read only field not working in page layout I have custom object called candidate. I have created field name called first name which is read-only in the page layout. Once a record is created with first name field populated I am able to edit that field. Why I am able to edit (I mean getting pencil icon). Can anyone suggest me for this issue? How many named characters died in Avengers: Infinity War? How many named characters have died       and/or disintegrated      by the end of Avengers: Infinity War. It is difficult to speculate who died on         Xandar and the Asgardian ship.       So restrict it to on-screen deaths only. How to prove this limit composition theorem? All internal links on Stack Exchange sites should be protocol-relative In preparation for the eventual deployment of full HTTPS support on Stack Exchange, and also to make the currently available "alpha" HTTPS support more usable, all links from Stack Exchange sites to other Stack Exchange sites should be .  Currently, at least the following places still feature links with explicit http: protocol prefixes:   the page footer, the "Hot Network Questions" and "Community Bulletin" modules in the sidebar,  (the site switcher menu is OK, though),   and, of course,   lots and lots of user-supplied links in post and comment content.   I've posted this feature request with the intent to provide a single central place for tracking these issues, rather than having them scattered across multiple meta threads.  If you find more places on SE where protocol-relative links should be used, please report them below.  I fully expect this request, in its full sense, to be treated as  for the time being; however, these issues do need to be fixed at some point before our HTTPS support is ready for "prime time".  Ps. Yes, the next release of  (v1.10) is going to include a general client-side fix for most of these issues.  In the mean time, the  plugin effectively provides the same functionality, and much more besides. I have for quite some time now tried to find a satisfactory answer to this, but I haven't yet. In perturbation theory, with small parameter $\lambda$, we expand the eigenstate as  $$| E \rangle=| E^{(0)} \rangle + \lambda | b \rangle + ...$$  Where $| E^{(0)} \rangle$ is an eigenstate of the unperturbed Hamiltonian. The problem is that when there is degeneracy, there is a choice of these eigenstates. I know the answer is that they are chosen to be eigenvectors of the perturbing Hamiltonian, but my question is why. How do I combine the NBT tags from two separate commands? I have two commands I'd like to combine into one, but I'm not sure how to go about combining them. Is this possible?   Here are the commands. They work individually, I just can't seem to get them to work together:  /give @p jukebox 1 0 {CanPlaceOn:["minecraft:melon_block"]}     /give @p jukebox 1 0 {display:{Name:"Box"}}   Can you help me to add one of the commands to the other one? My friend is buying a digital point-and-shoot camera, which he wants to use to click family pictures including a lot of pictures of their newborn son.  What camera qualities should he be looking for while buying? Where are packages stored installed with APT in Ubuntu 16.04? Is there an elementary proof that $\sum \limits_{k=1}^n \frac1k$ is never an integer? How do I calculate my skill modifier? I'm trying to fill out the skills section on my first character, but when I look at the character sheets in the Starter Set as examples of how to make a character, the skills that are circled have higher modifiers than their Dexterity or Strength or whatever should make them.  I've filled out all skills but those. What do I add to the ability modifier to get those numbers?   My abilities are Strength 13, Dexterity 14, Constitution 11, Intelligence 15, Wisdom 8, and Charisma 8. Proficiencies are Arcana, Athletics, History, Investigation and Stealth. My saving throws are Strength and Dexterity.   I just started D&amp;D and have the Player's Handbook, DM's Guide, Monster Manual, and the Starter Set. Why aren't these loops homotopic? Let $S^1 = \{z \in \mathbb{C} : |z| = 1\}$.  Take the loops $f,g : [0,1] \rightarrow S^1$, $f(t) = 1$, $g(t) = e^{2\pi it}$.  I know these represent different elements in $\pi_1(S^1, 1)$, but I don't see why $F(t,s) = e^{2\pi its}$ isn't a homotopy between $f$ and $g$.