I've noticed on a acer travelmate 5720, that runs Ubuntu 13.04, it doesn't show or pickup the latest 13.10 version. I did check die update settings and it is set pickup/show the latest updates. But with the necessary settings set, it doesn't pickup the latest version. And it does have access to full free internet. Is there some solutions? Or can I update via terminal?
I would like to know how to upgrade from my current version of Ubuntu to the next stable from the Command line interface?
propositional calculus problem, how to prove this right or wrong? $A$$\rightarrow$$(B$ $\vee$ $C$ ) , $B$ $\rightarrow$ $C$ $\vDash$ $A$ $\rightarrow$ $D$  I think it's wrong but I have no idea how to prove. Details on how the Yearling badge works Jawa asked me this  and I didn't know the answer. So I present it to the meta SO community:     [To get the Yearling badge] Do you need to earn the 200 rep within that one year or is it enough to get 200 at some point after being a member for a year? And does 'a year' mean the very first 12 months or the last (sliding window of) 12 months?    I would assume that if you hit 200 reputation after you've already been around for a year, then you would get the Yearling badge. But I don't know. Different probability density transformations due to Jacobian factor Is any aspect of the supernatural testable? What level of proof is possible for the supernatural? Multi-geometry shapefiles Since a shapefile can only contain a single geometry type (e.g. point, polygon, etc), how could I persist both?   If I must create a shapefile for each geometry type, how can I pass them to a colleague to load?  In kml I can just pass the single kml to load.  Is there a shapefile manifest equivalent that I am missing? Show that $(2,0,4) , (4,1,-1) , (6,7,7)$ form a right triangle What I tried:  Let $A(2,0,4)$, $B(4,1,-1)$, $C(6,7,7)$ then  $$\vec{AB}=(2,1,-5), \vec{AC}=(4,7,3), \vec{BC}=(2,6,8)$$  Then I calculated the angle between vectors:  $$\begin{aligned} \alpha_1 &amp;= \cos^{-1}\left(\frac{(2,1,-5)(4,7,3)}{\sqrt{2^2+1^2+(-5)^2}\sqrt{4^2+7^2+3^2}}\right) \\ &amp;= \cos^{-1}(0)=90° \\ \alpha_2 &amp;= \cos^{-1}\left(\frac{(4,7,3)(2,6,8)}{\sqrt{4^2+7^2+3^2}\sqrt{2^2+6^2+8^2}}\right) \\ &amp;= \cos^{-1}\left(\frac{74}{\sqrt{74}\sqrt{104}}\right)=32.49\\ \alpha_3 &amp;= \cos^{-1}\left(\frac{(2,6,8)(2,1,-5)}{\sqrt{2^2+6^2+8^2}\sqrt{2^2+1^2+(-5)^2}}\right) \\ &amp;= \cos^{-1}\left(\frac{-30}{\sqrt{104}\sqrt{30}}\right)=122.5° \end {aligned}$$  As you can see, these angles don't even form a triangle, what am I doing wrong, any thoughts? "Try and" versus "Try to"? Dini's Theorem - Proof. I'd like to prove the following:  If $f_j$ are continuous functions on a compact set $K$, and $f_{1}(x) \leq f_{2}(x) \leq \dots$ for all $x \in K$, and the $f_j$ converge pointwise to a continuous function $f$ on $K$ then in fact the $f_j$ converge uniformly to $f$ on $K$.  Attempt:  Let $g_{j}(x) = f(x) - f_{j}(x)$ for all $j$. Then, since $f_j \rightarrow f$ pointwise, we see $g_j \rightarrow 0$ pointwise.  Now, let $\varepsilon &gt; 0$ . And examine { $x \in K : g_{j}(x) &lt; \varepsilon$ }.  I've been told that the next step should be to  show that { $x \in K : g_{j}(x) &lt; \varepsilon$ } is equal to the intersection of $K$ with some open set $U_j$. But I'm not certain why this is true?   Advice? Insight? Extracting numbers from vectors of strings have lived vs have been living Here are my configurations: DB type: postgresql (9.3 if that's necessary) Table name: product_sections Column names: section_id (integer) &amp; section_path (ltree)    Detail: I have one reference value: section_id: 15 &amp; section_path: Automation_Solutionz. So, when I want to rename Automation_Solutionz to, say Chrome, I want all references of Automation_Solutionz to be updated.      FROM:  Automation_Solutionz Automation_Solutionz.Test_Case_Creation Automation_Solutionz.Test_Case_Creation.Automation Automation_Solutionz.Test_Case_Creation.Manual   TO:  Chrome Chrome.Test_Case_Creation Chrome.Test_Case_Creation.Automation Chrome.Test_Case_Creation.Manual     Similarly, when I update a value which is in the middle, it should rename those too. In the case above, Test_Case_Creation should be renamed to something like TestCase or anything else. The same goes for any item which is either in the middle, end or at the start.  Hope, I explained things correctly. Thanks in advance :) In the construction of types of numbers, we have the following sequence:  $$\mathbb{R} \subset \mathbb{C} \subset \mathbb{H} \subset \mathbb{O} \subset \mathbb{S}$$  or:  $$2^0 \mathrm{-ions} \subset 2^1 \mathrm{-ions} \subset 2^2 \mathrm{-ions} \subset 2^3 \mathrm{-ions} \subset 2^4 \mathrm{-ions} $$  or:  "Reals" $\subset$ "Complex" $\subset$ "Quaternions" $\subset$ "Octonions" $\subset$ "Sedenions"  With the following "properties":   From $\mathbb{R}$ to $\mathbb{C}$ you gain "algebraic-closure"-ness (but you throw away ordering). From $\mathbb{C}$ to $\mathbb{H}$ we throw away commutativity. From $\mathbb{H}$ to $\mathbb{O}$ we throw away associativity. From $\mathbb{O}$ to $\mathbb{S}$ we throw away multiplicative normedness.   The question is, what lies on the right side of $\mathbb{S}$, and what do you lose when you go from $\mathbb{S}$ to one of these objects ? Why do elementary matrix operations not affect the row space of a given matrix? Dynamic dispatch and binding What is the purpose of the 'nobody' user? After I read  I noticed that there is a user account named 'nobody' in my Ubuntu system.   Also I noticed that I can login in this account from terminal using the following command and my password:  sudo su nobody     It doesn't mind me at all, but I want to know what is the purpose of this user? Is it created by default on a fresh install of Ubuntu or is created by installing a particular package? About two weeks ago I had a problem with my PC that my brother wrote a question about at .  I still haven't solved the problem, so my PC is unusable now.  Now I think that it would be simpler to re-install both Win7 &amp; Ubuntu than repair them, but there're some data on their partitions. I want to recover this data.  These partitions are not mountable for some reason. I don't know why.  sudo fdisk -l about the problematic partitions:     Device    Boot      Start         End      Blocks   Id  System /dev/sda1            2048     147912703    73955328   83 Linux /dev/sdb2            206848   174079999    86936576    7  HPFS/NTFS/exFAT   And in GParted:      And the error of the mount command:  Failed to mount '/dev/sdb2': Invalid argument The device '/dev/sdb2' doesn't seem to have a valid NTFS. Maybe the wrong device is used? Or the whole disk instead of a partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?   And the exact same message for /dev/sda1  How can I recover my data from those HDDs?  EDIT     I have tried to specify the type of the drive:  $ sudo mount -t ext4 /dev/sda1 /olddisk mount: wrong fs type, bad option, bad superblock on /dev/sda1,        missing codepage or helper program, or other error        In some cases useful info is found in syslog - try        dmesg | tail  or so $ sudo mount -t ntfs /dev/sdb2 /olddisk NTFS signature is missing. Failed to mount '/dev/sdb2': Invalid argument The device '/dev/sdb2' doesn't seem to have a valid NTFS. Maybe the wrong device is used? Or the whole disk instead of a partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?   EDIT     sudo ntfsfix /dev/sdb2 returns:  Mounting volume... NTFS signature is missing. FAILED Attempting to correct errors... NTFS signature is missing. FAILED Failed to startup volume: Invalid argument NTFS signature is missing. Trying the alternate boot sector Unrecoverable error Volume is corrupt. You should run chkdsk. Last login: Mon Jun  7 22:43:40 on ttys000 samadams@Sams-MacBook-Pro-2 ~ % diskutil cs list No CoreStorage logical volume groups found samadams@Sams-MacBook-Pro-2 ~ % diskutil list /dev/disk0 (internal, physical):    #:                       TYPE NAME                    SIZE       IDENTIFIER    0:      GUID_partition_scheme                        *121.3 GB   disk0    1:                        EFI ⁨NO NAME⁩                 536.9 MB   disk0s1                     (free space)                         60.5 GB    -    2:                 Apple_APFS ⁨Container disk1⁩         60.1 GB    disk0s2  /dev/disk1 (synthesized):    #:                       TYPE NAME                    SIZE       IDENTIFIER    0:      APFS Container Scheme -                      +60.1 GB    disk1                                  Physical Store disk0s2    1:                APFS Volume ⁨MacOS Big Sur - Data⁩    30.0 GB    disk1s1    2:                APFS Volume ⁨Preboot⁩                 233.2 MB   disk1s2    3:                APFS Volume ⁨Recovery⁩                652.6 MB   disk1s3    4:                APFS Volume ⁨VM⁩                      1.1 GB     disk1s4    5:                APFS Volume ⁨MacOS Big Sur⁩           24.4 GB    disk1s5    6:              APFS Snapshot ⁨com.apple.os.update-...⁩ 24.4 GB    disk1s5s1    7:                APFS Volume ⁨Untitled⁩                860.2 KB   disk1s7 I have a Alcatel onetouch model 50540 running android 5.1.1 as in the title. it is rooted and began uninstalling pre-installed bloatware on my device. I do not have a complete list of uninstalled apps because I had only kept track after the first few, but ill list the ones I do know about    Download Manager Downloads Talkback Hangouts Cricket Wi-Fi Manager Camera Email Onetouch Launcher   That is the essence of what I did. I do have an edited hosts file as a makeshift adblock.  Play store gives me an error code 0 to which I removed app data and tried again, same problem.  I have tried installing local apps which brings up an "app not installed" box.  Lastly I have tried do directly extract the app into /data/app and rebooting which didn't work. What focal length lens do I need for photographing the moon? I would like to know whether it is possible to photograph moon without any flaws with a canon EOS 550d..   Also to get an image of the moon as close as the following image, what kind of equipment(lens,etc) is need to be used with the 550d Body Beamer: Change only several bullets in the list I would like to change the bullets in the second itemize to arrows.  \begin{alertblock}{The Aim of this Research}      \begin{itemize}         \item Item 1         \item Item 2             \begin{itemize}                 \item Item 2-1                 \item Item 2-2             \end{itemize}     \end{itemize}  \end{alertblock}   Form above, I would like to make:  ・Item 1  ・Item 2    =&gt; Item 2-1  (change bullet to arrow)    =&gt; Item 2-2   I've tried inserting \renewcommand{\labelitemii}{$\rightarrow$} before and after the second \begin{itemize} and , but they don't work.