EDIT: following the instructions on , I attempted to remove my old/unused kernels but could not. It looks like there's not enough space for the operation, what do I do?  Output of ls /boot/:  abi-4.2.0-42-generic         initrd.img-4.4.0-57-generic abi-4.4.0-45-generic         lost+found abi-4.4.0-47-generic         memtest86+.bin abi-4.4.0-51-generic         memtest86+.elf config-4.2.0-42-generic      memtest86+_multiboot.bin config-4.4.0-45-generic      System.map-4.2.0-42-generic config-4.4.0-47-generic      System.map-4.4.0-45-generic config-4.4.0-51-generic      System.map-4.4.0-47-generic grub                         System.map-4.4.0-51-generic initrd.img-4.2.0-42-generic  vmlinuz-4.2.0-42-generic initrd.img-4.4.0-42-generic  vmlinuz-4.4.0-45-generic initrd.img-4.4.0-45-generic  vmlinuz-4.4.0-47-generic initrd.img-4.4.0-47-generic  vmlinuz-4.4.0-51-generic initrd.img-4.4.0-51-generic   Output of dpkg -l linux-image-\* | grep ^ii  ii  linux-image-4.2.0-42-generic       4.2.0-42.49  amd64        Linux kernel image for version 4.2.0 on 64 bit x86 SMP  ii  linux-image-4.4.0-45-generic       4.4.0-45.66  amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP  ii  linux-image-4.4.0-47-generic       4.4.0-47.68  amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP  ii  linux-image-4.4.0-51-generic       4.4.0-51.72  amd64        Linux kernel image for version 4.4.0 on 64 bit x86 SMP  ii  linux-image-extra-4.2.0-42-generic 4.2.0-42.49  amd64        Linux kernel extra modules for version 4.2.0 on 64 bit x86 SMP  ii  linux-image-extra-4.4.0-45-generic 4.4.0-45.66  amd64        Linux kernel extra modules for version 4.4.0 on 64 bit x86 SMP   However, when I run sudo apt-get purge linux-image-4.2.0-42 linux-image-4.4.0-45, I get the following messages:   gzip: stdout: No space left on device E: mkinitramfs failure cpio 141 gzip 1 update-initramfs: failed for /boot/initrd.img-4.4.0-47-generic with 1. run-parts: /etc/kernel/postinst.d/initramfs-tools exited with return code 1 dpkg: error processing package linux-image-extra-4.4.0-47-generic (--remove):  subprocess installed post-removal script returned error exit status 1 Errors were encountered while processing:  linux-image-extra-4.4.0-47-generic E: Sub-process /usr/bin/dpkg returned an error code (1)   Am I doing something wrong?  ORIGINAL:  I've been getting space errors whenever I try to upgrade, and on the dist-upgrade I tried just now I got the following errors:  gzip: stdout: No space left on device E: mkinitramfs failure find 141 cpio 141 gzip 1 update-initramfs: failed for /boot/initrd.img-4.4.0-51-generic with 1. run-parts: /etc/kernel/postinst.d/initramfs-tools exited with return code 1 dpkg: error processing package linux-image-extra-4.4.0-51-generic (--configure):  subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing:  linux-image-extra-4.4.0-47-generic  linux-image-extra-4.4.0-51-generic E: Sub-process /usr/bin/dpkg returned an error code (1)   The output of df is:  Filesystem                   1K-blocks     Used Available Use% Mounted on udev                           1787060        0   1787060   0% /dev tmpfs                           361572    10496    351076   3% /run /dev/mapper/xubuntu--vg-root 236014344 38503396 185499020  18% / tmpfs                          1807848      172   1807676   1% /dev/shm tmpfs                             5120        4      5116   1% /run/lock tmpfs                          1807848        0   1807848   0% /sys/fs/cgroup /dev/sda1                       240972   227218      1313 100% /boot tmpfs                           361572       36    361536   1% /run/user/1000   and the output of uname -r:  4.4.0-51-generic   I've tried several things based on solutions offered to some of these errors individually, but I haven't had any luck yet.  Thank you sincerely for any help!
My /boot partition is nearly full and I get a warning every time I reboot my system. I already deleted old kernel packages (linux-headers...), actually I did that to install a newer kernel version that came with the automatic updates.  After installing that new version, the partition is nearly full again. So what else can I delete? Are there some other files associated to the old kernel images?  Here is a list of files that are on my /boot partition:  :~$ ls /boot/ abi-2.6.31-21-generic         lost+found abi-2.6.32-25-generic         memtest86+.bin abi-2.6.38-10-generic         memtest86+_multiboot.bin abi-2.6.38-11-generic         System.map-2.6.31-21-generic abi-2.6.38-12-generic         System.map-2.6.32-25-generic abi-2.6.38-8-generic          System.map-2.6.38-10-generic abi-3.0.0-12-generic          System.map-2.6.38-11-generic abi-3.0.0-13-generic          System.map-2.6.38-12-generic abi-3.0.0-14-generic          System.map-2.6.38-8-generic boot                          System.map-3.0.0-12-generic config-2.6.31-21-generic      System.map-3.0.0-13-generic config-2.6.32-25-generic      System.map-3.0.0-14-generic config-2.6.38-10-generic      vmcoreinfo-2.6.31-21-generic config-2.6.38-11-generic      vmcoreinfo-2.6.32-25-generic config-2.6.38-12-generic      vmcoreinfo-2.6.38-10-generic config-2.6.38-8-generic       vmcoreinfo-2.6.38-11-generic config-3.0.0-12-generic       vmcoreinfo-2.6.38-12-generic config-3.0.0-13-generic       vmcoreinfo-2.6.38-8-generic config-3.0.0-14-generic       vmcoreinfo-3.0.0-12-generic extlinux                      vmcoreinfo-3.0.0-13-generic grub                          vmcoreinfo-3.0.0-14-generic initrd.img-2.6.31-21-generic  vmlinuz-2.6.31-21-generic initrd.img-2.6.32-25-generic  vmlinuz-2.6.32-25-generic initrd.img-2.6.38-10-generic  vmlinuz-2.6.38-10-generic initrd.img-2.6.38-11-generic  vmlinuz-2.6.38-11-generic initrd.img-2.6.38-12-generic  vmlinuz-2.6.38-12-generic initrd.img-2.6.38-8-generic   vmlinuz-2.6.38-8-generic initrd.img-3.0.0-12-generic   vmlinuz-3.0.0-12-generic initrd.img-3.0.0-13-generic   vmlinuz-3.0.0-13-generic initrd.img-3.0.0-14-generic   vmlinuz-3.0.0-14-generic   Currently, I'm using the 3.0.0-14-generic kernel.
Show that all horses are of the same color. Im trying to understand the solution about this, and all the other solutions are.. a bit weird for me and dont answer all my questions!  Reference :   Im using the answer there as reference, but my understanding is a bit different!     Find the error in the following proof that all horses are the same   color. CLAIM: In any set of h horses, all horses are the same color.      PROOF: By induction on h.      Basis: For h = 1. In any set containing just one horse, all horses   clearly are the same color. Induction step: For k > I assume that the   claim is true for h = k and prove that it is true for h = k + 1. Take   any set H of k + 1 horses. We show that all the horses in this set are   the same color. Remove one horse from this set to obtain the set H1   with just k horses. By the induction hypothesis, all the horses in H,   are the same color. Now replace the removed horse and remove a   different one to obtain the set H2 . By the same argument, all the   horses in H2 are the same color. Therefore all the horses in H must be   the same color, and the proof is complete.   Here's what i have come up with :  Suppose a set of 1 horse. $H_a = { horse_{1} }$  Obviously, all the horses in set $H_a$ are the same, since theres just 1 horse.  So using that as the Basis of the induction we can proceed and try to prove its true for $N$ horses.  -- I dont fully understand the part below   As an example : set $H_0$ :   $H_0 = { horse_{1}, horse_{2}, horse_{3}... horse_{n} }$  In my understanding, its because, I can make a subset  formed by 1 horse :  $K_1  = {horse_{1}}$ $K_2  = {horse_{2}}$ ...  I don't get it. I clearly know that this proof is a lie.  And for me, its because you cant claim theres a relation on a set with size $&gt;= 2$ , since :  $H_1 = { horse_{1}, horse_{2}}$  Theres nothing that says $horse_{1}$ equals $horse_{2}$. The basis was for one horse. But that alone is not a proof.  So what should I do ? Taking a skyline photo with a person closer to the camera during night time How can I take a photo which shows the skyline and the person who is standing around six feet away from the camera with proper lighting at night?   For taking just the skyline I've used long shutter speed and it turned out great, but when including a person on it, the person becomes  blurry because it's impossible for a person to remain static for that long.   Ps.  I do have two flashes, 35mm prime lens as well as 18-300mm zoom lenses as well. The camera I use is Nikon D7200. Finding all group homomorphisms of $S_n\to\mathbb{C}^*$ and $A_n\to\mathbb{C}^*$ I need to find all group homomorphisms of $S_n\to\mathbb{C}^*$ (for $n\ge2$), and also all group homomorphisms of $A_n\to\mathbb{C}^*$ (for $n\ge2$).  Someone on this site, two years ago, seems to have already asked the same question (). I understand what the questioner says there, but I don't understand it when he says:     Therefore there is exactly one $g:\mathbb{Z}/2\mathbb{Z}\to\mathbb{C}^*$, so all elements of $a\in\mathbb{C}^*$ give us $\operatorname{ord}(a)\mid g[\mathbb{Z}/2\mathbb{Z}]$, so $a$ can only be $-1$ or $1$. Now we know that $f:S_n\to\{-1,1\}$ &hellip;   What is he saying there? And how to go on from there? (I do not understand the answer given either &hellip;)  I hope that someone here can help me further. (And if I'm not allowed to ask this question because is has already been asked two years ago, please tell me what to do instead).  Thank you in advance! Aliased edge around light source in cycles Often when a mesh light is visible in the camera, the edges are not anti-aliased.  No matter how many samples I do, the lamp border always looks jagged and pixelated.  Is this a rendering error? How can I get around this issue?    And zoomed in 4x: How do I jump to the next or previous word with CTRL + arrow keys in a console? In terminal emulation applications, pressing CTRL + Left / Right arrows jumps from one word to the previous or next one. Is it possible to have the same functionality in a Linux console, whether it is in text or in framebuffer modes?  In my configuration, the CTRL + arrow keys are transformed into escaped character sequences and not interpreted. Are omniscience and omnipotence mutually inconsistent? I see this in The God Delusion by Richard Dawkins:       If God is omniscient, he must already know how he is going to intervene to change the course of history using his omnipotence. But   that means he can't change his mind about his intervention, which   means he is not omnipotent.   Is this argument sound? Create line heatmap with QGIS I have loaded my bike tours as .gpx files into QGIS.    It already looks quite nice but I was wondering if it might be possible to create something similar to the strava heatmap with tools of QGIS.     I have tried to generate points along the lines and use kernel density but it just does not look nice as a raster layer.  Any suggestions? Forward/Inverse Search Does Not work on certain tex files How can I concatenate regex literals in JavaScript? Is it possible to do something like this?  var pattern = /some regex segment/ + /* comment here */     /another segment/;   Or do I have to use new RegExp() syntax and concatenate a string? I'd prefer to use the literal as the code is both more self-evident and concise. Imagine your college buddy is now running a multi-billion dollar company, while you're still stuck at the same white-collar day job 5 years after graduation. You chat with him and want to express the idea that you're happy for him and fancy having his lifestyle--something like "I wish I could buy a yacht and cruise around the world like you do; I'm glad you're doing really well!"  Basically, it's the feeling of envy when you take out the resentment from it. Is there a word for it?   (I thought about "admire", but found it too strong and broad) What are the differences between Holmes, Moldvay, and Mentzer D&D? Let $\Omega$ be an open subset in $\mathbb{C}$. Let $\{f_n\}$ be a sequence of holomorphic functions on $\Omega$ such that $f_n\to f$ pointwise and converges uniformly on any compact subset $K\subseteq \Omega$. Then by Cauchy Theorem and Morera Theorem, $f$ is holomorphic. Let $f_n$ and $f'$ be the derivatives of $f_n$ and $f$ respectively. Prove that $f_n'\to f'$ uniformly on any compact subset $K\subseteq \Omega$.   How to prove? I am trying to think/know about something, but I don't know if my base premise is plausible. Here we go.  Sometimes when I'm talking with people about pure mathematics, they usually dismiss it because it has no practical utility, but I guess that according to the history of mathematics, the math that is useful today was once pure mathematics (I'm not so sure but I guess that when the calculus was invented, it hadn't a practical application).  Also, I guess that the development of pure mathematics is important because it allows us to think about non-intuitive objects before encountering some phenomena that is similar to these mathematical non-intuitive objects, with this in mind can you provide me historical examples of pure mathematics becoming "useful"? ceiling fan from a switch with only black and red wires? The current switch controls an outlet in the corner of the room for a lamp. I pulled it out and noticed three sets of individual wires: two set of wires coming up into the box from the bottom, and one set with a red wire coming down into box.  All the white and grounding wires are capped.  Also all the black wires are capped; one set I’m assuming is the hot since I see it contains a red wire. On the back of the switch, the top two ports have black wires and the bottom right has the one red wire.  There are two black pigtail wires coming off the black capped wires. I tried to connect a separate switch to control a ceiling fan with remote. I ran new wire making the old switch box into a two switch. I ran 14/2 gauge wire to ceiling for fan / light remote combo. Fan didn’t work after multiple re-wiring  combinations. The breaker did pop and half click when it popped. Then I thought to re-wire the ceiling fan wires as if I was going to make it into outlet only and use a tester to indicate an open ground, or a wiring error but the two light on tester are both orange indicating correct wiring. I heard that sometimes the ceiling fan remote transformer goes bad. Should I check batteries and/or unit placement? I’m really confused at this point why the light is not working at least with remote after follow wiring installation instructions that were included with the fan. I think it’s my wiring with the switch. The way I left the wiring is that it has constant power. As if we’re a outlet the current switch does not turn it off. Cleaning ‘staining’ off bottom of MacBook screen A couple months ago, I started to see some very small stain spots on the bottom of my MacBook Pro early 2015 screen. It's very annoying to see while I'm using it. When the screen is turned off, I see it as in the picture below. But when it's turned on, I see it as very small water-ish drops. I tried to clean it using water, screen cleaner, and even alcohol, but it didn't go away.  Also that area doesn't feel as smooth as the unaffected area. So, I think it's on the outside of my screen not inside.  Have you ever seen this before? Any suggestions on how to remove it without the need of replacing the whole screen? JSON and escaped double quote I'm currently making a callout to a 3rd party vendor and I'm getting a huge response. What is currently messing me up is this section:   "MessageSeq":13,"Description":"config file: config-qa1.txt\"","MessageTS":"2014-02-17T14:46:58","MessageLevel":4,"IsSystemMessage":false   As you can see here, the portion at the end of the Description value is ended with backslash double quote. If I attempt to parse this via the JSONParser I get an exception. Does anyone have an recommendations on how to resolve this?  Exception Message:  System.JSONException: Unexpected character ('"' (code 34)): was expecting comma to separate OBJECT entries at [line:1, column:3699]  Updated with sample Code   public class ResponseWrapper{     // fields from JSON to auto map     public Integer messageSeq;     public String Description;     public String messageTS;     public Integer messageLevel;     public Boolean isSystemMessage;     // parsing fields     private ResponseWrapper theResponse;     private JSONParser parser;      public void parse(String jsonString){         parser = JSON.createParser(jsonString);         parseJSON();     }      private void parseJSON(){            while (parser.nextToken() != null) {             if (parser.getCurrentToken() == JSONToken.START_OBJECT) {                 theResponse = (ResponseWrapper)parser.readValueAs(ResponseWrapper.class);                            }         }     } }  String responseString = '{"MessageSeq":13,"Description":"config file: config-qa1.txt\"","MessageTS":"2014-02-17T14:46:58","MessageLevel":4,"IsSystemMessage":false}'; system.debug('\n\nBEFORE\n' + responseString); ****Place code in here to test such as ReplaceALL*** ResponseWrapper parser = new ResponseWrapper(); parser.parse(responseString); What is the difference between kernel drivers and kernel modules? How to determine the size of a package while using apt prior to downloading? When using apt-get install &lt;package_name&gt;, and there are dependencies that need to be downloaded, the terminal outputs names of additional packages and total size, and asks for confirmation before downloading.   But, when dependencies are satisfied and nothing but the named package needs to be downloaded there is no size output and no confirmation.  When using Synaptic, I can see the total size that new packages that will use after installation but no way to see the size that needs to be downloaded, except to go from package to package and use properties to see the compressed size.  I would like to know if there is a way to see the size of a package(s) in terminal and Synaptic prior to downloading and installing it/them? I plan to attach my 2014 and 2015 annual leave letters to prove I was on leave, and a letter from my sales manager who was in charge of the business during my vacation.  I intend to explain all my sources of income in additional letter because the ECO calculations of my income were different from mine.   How else can I improve my new application? How to add a modifier to a collection? My goal is to reduce the faces of an object using the decimate modifier. The object I'm editing has lots of vertex groups. Blender 2.8 only lets me add the decimate modifier to a single group at once which would take quite some time. I have already put all groups in a single collection.  How can I add the decimate modifier to the entire collection?  Do I have to add the modifier group by group?