I'm trying to install Ubuntu 14.04 on a Dell Inspiron 7537, in dual-boot with Windows 8.1, with a UEFI system. After the creation of the new partitions, I've been able to install Ubuntu 14.04 without any problem. It booted regularly, as far as I launched Windows again. Probably some program (McAfee?) has modified my EFI partition, and since that moment I've not been able to launch the "ubuntu" entry of UEFI anymore. GRUB failed to load, and the PC lauched the second option of UEFI, i.e. Windows 8.1.  Of course, I've tried to make a new installation of Ubuntu, but now I get this error when Ubiquity tries to configure Grub2:  grub-efi-amd64-signed failed to install into /target/. Without GRUB boot loader, the installed system will not boot   and then Ubiquity crashes. At this point I tried to clean up the EFI settings using both efibootmgr on Ubuntu LiveUSB and EasyUEFI on Windows. These tools remove the entry correctly, but the problem remains unsolved.  Also Boot-Repair seems to fail, as when it asks me to launch  sudo chroot "/mnt/boot-sav/sda7" dpkg --configure -a   I get the same error:  Setting up grub-efi-amd64-signed (1.34+2.02~beta2-9) ... Installing for x86_64-efi platform. grub-install: error: cannot open `/boot/efi/EFI/ubuntu/shimx64.efi': Read-only file      system. dpkg: error processing package grub-efi-amd64-signed (--configure):  subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing:  grub-efi-amd64-signed   I tried also to restore the laptop to factory settings, but fruitlessly.  It is very strange, as the first time everything worked perfectly. What can be my problem? Is there any way to delete all the references to Ubuntu from the EFI partition?  Thank you very much.
I am installing Ubuntu 16.04 in an Intel NUC computer with UEFI enabled. I am using an SSD from another computer. During the installation I chose Erase the disk and make a new full install  At the end of the process I see:  grub-efi-amd64-signed failed installation /target/ Ubuntu 16.04    And the system does not boot.  I tried to use boot-repair but apparently it does not solve the problem.
{5,15,25,35} is a group under multiplication mod 40 Show that the set $\{5,15,25,35\}$ is a group under multiplication modulo $40$. What is the identity element of this group. Can you see any relationship between this group and $\mathbb U(8)$?   I am very stuck on this question and I think my knowledge of abstract algebra is my liability at the moment. Right now I'm most confused by the fact that I learned: An element of a group of this nature must be relatively prime with the working mod.  Obviously here this is not the case, so I don't really know where to begin.  Do I need a Cayley Table?  Thanks. How do I make a Theme from scratch for Unity? I'd like to make a theme from scratch for Unity.  What knowledge and information/skills are needed? Are there any tools or templates out there for something like this already? I don't have any Python experience so tools biased towards beginners are preferable. Isomorphism between dual space and bilinear forms Studying from Roman's Advanced Linear Algebra, I want to prove that $$U^* \otimes V^* \cong (U \otimes V)^* \cong \hom(U,V;\mathbb{F})$$ The author proves that $U^* \otimes V^* \cong (U \otimes V)^*$ by showing that there is an unique linear transformation   $$\theta:U^* \otimes V^* \to (U \otimes V)^*$$  defined by $\theta(f \otimes g)=f \odot g$ where $(f \odot g)(u \otimes v)=f(u)g(v)$  I want to prove that $U^* \otimes V^* \cong \hom(U,V;\mathbb{F})$. I tried to use the universal property by fixing $f \in U^*, g\in V^*$ and defining $S: U^*\times V^* \to \hom(U,V;\mathbb{F})$ as $S(f,g)=F_{f,g}$, where $F_{f,g}(u,v)=f(u)g(v)$, but I got stuck. Ways to update Ubuntu (debian-based distros) offline What is the easiest way to update/upgrade an offline Ubuntu machine with the help of a Windows machine that has internet access?  This question also applies to installing new packages offline and not only updates/upgrades.  The Linux system shall remain completely cut off from the Windows machine, meaning there should be no ethernet connection or the likes between the two computers.  Update:  Please have patience, since I haven't updated this since two weeks. There are some complications getting apt-offline to work properly on Lubuntu and all other methods seem to be too old and deprecated:  AptOff - last update 2006 AptMedium - last update 2007 Keryx - last update 2011, looks like this project was discontinued  I hope I will be able to somehow update the offline machine, finally.  While I was still not able to update/upgrade the offline system due to authentication errors, I accepted an answer, because it's taking too long. I want to attach a code file to my question, but I am not able to find a link to do it. Is attaching files possible at all? Why does the "Unanswered Questions" tab show questions that have answers? I have some section where user can upload CV and profile images,  I'm using the native attachment functions,  $attachment_cv_id = media_handle_upload( 'candidate_cv', 0 ); if ( ! is_wp_error( $attachment_cv_id ) ) {     // We link this file to the post      // add_post_meta( $result , 'wpcf-cv-file', wp_get_attachment_url($attachment_cv_id)); } else {     $submit_candidate_errors[] = lang("Hubo error subiendo la CV"); }   Is there any way I can hide this files from the media section in the wp-admin? ( perhaps changing its folder )  Thanks  -EDIT-  i'm trying like Dave suggested, adding a meta: 'rrhh-file'  $attachment_id = media_handle_upload( 'apply_file', 0 );  if ( ! is_wp_error( $attachment_id ) ) {     // The image was uploaded successfully!     add_post_meta($attachment_id, 'rrhh-file', true); }   And even that it has the attribute:  var_dump(get_post_meta(1200)); // last id I uploaded die();   Prints out:  array(4) {   ["_wp_attached_file"]=&gt;   array(1) {     [0]=&gt;     string(20) "2017/06/image001.jpg"   }   ["_wp_attachment_metadata"]=&gt;   array(1) {     [0]=&gt;     string(666) "a:5:{s:5:"width";i:523;s:6:"height";i:122;s:4:"file";s:20:"2017/06/image001.jpg";s:5:"sizes";a:2:{s:9:"thumbnail";a:4:{s:4:"file";s:20:"image001-150x122.jpg";s:5:"width";i:150;s:6:"height";i:122;s:9:"mime-type";s:10:"image/jpeg";}s:6:"medium";a:4:{s:4:"file";s:19:"image001-300x70.jpg";s:5:"width";i:300;s:6:"height";i:70;s:9:"mime-type";s:10:"image/jpeg";}}s:10:"image_meta";a:12:{s:8:"aperture";s:1:"0";s:6:"credit";s:0:"";s:6:"camera";s:0:"";s:7:"caption";s:0:"";s:17:"created_timestamp";s:1:"0";s:9:"copyright";s:0:"";s:12:"focal_length";s:1:"0";s:3:"iso";s:1:"0";s:13:"shutter_speed";s:1:"0";s:5:"title";s:0:"";s:11:"orientation";s:1:"1";s:8:"keywords";a:0:{}}}"   }   ["rrhh-file"]=&gt; // &lt;-- here   array(1) {     [0]=&gt;     string(1) "1"   }   ["_edit_lock"]=&gt;   array(1) {     [0]=&gt;     string(12) "1498731595:1"   } }   With this action this attachment still shows up in the media library  add_action( 'pre_get_posts', 'wpse_hide_cv_media_list_view' ); function wpse_hide_cv_media_list_view( $query ) {     // Bail if this is not the admin area.     if ( ! is_admin() ) {         return;     }      // Bail if this is not the main query.     if ( ! $query-&gt;is_main_query() ) {         return;     }      // Only proceed if this the attachment upload screen.     $screen = get_current_screen();     if ( ! $screen || 'upload' !== $screen-&gt;id || 'attachment' !== $screen-&gt;post_type ) {         return;     }      // Modify the query.     $query-&gt;set( 'meta_query', [         [             'key'     =&gt; 'rrhh-file',             'compare' =&gt; 'NOT EXISTS',         ]     ]);      return; }   Any idea what i'm missing? Will fruit/seed of a bonsai yield another bonsai plant/tree? With practice one can create a bonsai; no complicated modification of the DNA in a high-end lab required. The bonsai will even beget bonsai fruit.   What I am curious about is - if such bonsai fruit is planted again, will it give rise to a normal, or a bonsai tree? Can I visit the UK as a tourist before my Student Visa starts? For example, if I revisit a memory of mine where I'm inside a castle and talking to someone, can the present-me explore different parts of the castle meanwhile the past-me continues her conversation? Is that possible? Removing small spaces (slivers) between polygons? Using ArcPy to get all database names within server? I am trying to populate a folder with ArcSDE database connection files for all the databases within a server instance.  I need to be able to do this for several of our servers.  Although I know within SQL Server how to get a list of DB names from the sys.databases table, using the arcpy function CreateDatabaseConnection I cannot specify "sys" or "master" to make the connection.  Therefore, I need to know the name of a database currently in the server.  I am not sure how to make the check without hard-coding a name.  import arcpy arcpy.env.overwriteOutput = True  #Input the location where the database connection files will be stored connectionLocation = "F:/FolderName"  #Get the list of servers arcpy.CreateDatabaseConnection_management(out_folder_path= arcpy.env.scratchFolder,out_name= "GIS_USERCONFIG" ,database_platform="SQL_SERVER",\                                           instance = "XXXXXXX" ,account_authentication="DATABASE_AUTH",username="user",password="password",\                                           save_user_pass="SAVE_USERNAME",database= "GIS_USERCONFIG",schema="#",version_type="TRANSACTIONAL",version="dbo.DEFAULT",date="#") sdeConn = arcpy.ArcSDESQLExecute(arcpy.env.scratchFolder + "/GIS_USERCONFIG.sde") serverListSQL = sdeConn.execute("Select name from userservers") serverList = [] for i in range(0,len(serverListSQL)):     serverList.append(serverListSQL[i][0])  #Make a folder for each server instance and build the connection files for all DBs in the server instance for server in serverList:     folder = connectionLocation + "/" + server     if arcpy.Exists(folder):         print server + " folder already created"     else:         try:             arcpy.CreateFolder_management(connectionLocation, server)             print "Created Folder " + server         except:             print "failed to create folder " + server      #     arcpy.CreateDatabaseConnection_management(out_folder_path= arcpy.env.scratchFolder,out_name= server ,database_platform="SQL_SERVER",\                                           instance = server ,account_authentication="OPERATING_SYSTEM_AUTH",\                                           database= "master",schema="#",version_type="TRANSACTIONAL",version="dbo.DEFAULT",date="#")     sdeConn = arcpy.ArcSDESQLExecute(arcpy.env.scratchFolder + "/" + server + ".sde")     dbListSQL = sdeConn.execute("Select name from sys.databases")     dbList = []     for i in range(0,len(serverListSQL)):         dbList.append(dbListSQL[i][0])     for db in dbList:         arcpy.CreateDatabaseConnection_management(out_folder_path= folder ,out_name= db,database_platform="SQL_SERVER",\                                           instance = server ,account_authentication="OPERATING_SYSTEM_AUTH",\                                           database= db,schema="#",version_type="TRANSACTIONAL",version="dbo.DEFAULT",date="#")   Basically my issue is with the 2nd call for the function "CreateDatabaseConnection_management" since it needs a database that exists in the database (and I could not use "master or sys").  If you open this as a tool in arcmap, the input is a drop-down box that populates choices based on the databases in the chosen server instance.  Is there a way to do this in the code? I've been trying to install 12.04 for a while now, I'm running on Windows 7 and I already made the partition (it's dynamic). I've tried booting from a disc and also the Windows installer. I haven't tried used any repair-boot programs or anything. Every time I tried to load from either, I get an error:  command=C:\windows\sysnative\bcdedit.exe /set {03f9077f-661f-11e1-845a-d08b36406c3d} device partition=U;  retval=1  stderr=An error has occured setting the element data. The request isn't supported  stdout=   Then after that, it makes a log file with information that I don't understand.  If it is simply due to the fact of it being a dynamic partition, someone please help. If it is more extensive, anyone with details on possible solutions or definite ones please express them. If $z_n \to z$ then $(1+z_n/n)^n \to e^z$ We are dealing with $z \in \mathbb{C}$. I know that $$ \left(1+ \frac{z}{n} \right)^n \to e^{z} $$ as $n \to \infty$. So intuitively if $z_n \to z$ then we should have $$ \left(1+ \frac{z_n}{n} \right)^n \to e^{z}. $$ If $z_n \in \mathbb{R}$ I would be happy writing $$ \exp \left(n \log\left(1+ \frac{z_n}{n} \right) \right) = \exp \left(z_n \frac{\log\left(1+ \frac{z_n}{n} \right)-\log(1+0)}{\frac{z_n}{n}-0} \right) \to \exp(z \cdot 1) $$ where here we are using the definition of derivative. But if $z \in \mathbb{C}$ the logarithm is multivalued and I'm not sure that the same calculation is allowed. Is there a different way to show this for complex $z$? After the last update of TeXLive 2018 (pretest) I get an error with csquotes' macro MakeAutoQuote:  \setcounter{errorcontextlines}{100} \listfiles \documentclass[fontsize=11pt,paper=a4,pagesize,ngerman]{scrartcl} \usepackage[utf8]{inputenc} \usepackage{babel} \usepackage[T1]{fontenc} \usepackage{csquotes} \MakeAutoQuote{»}{«}  \begin{document} ABC \end{document}   The error:  ! Package csquotes Error: Invalid argument.   My versions:  inputenc.sty    2018/04/06 v1.3b Input encoding file babel.sty    2018/02/14 3.18 The Babel package csquotes.sty    2018/02/11 v5.2c context-sensitive quotations (JAW)   I use pdfLaTeX. What is wrong here? How can I find the number of partitions of $n$ into exactly $k$ distinct parts, where each part is at most $M$?  The number of partitions $p_k(\leq M,n)$ of $n$ into at most $k$ parts, each of size at most $M$, is given by the generating function: $$  \binom{M+k}{k}_{x} = \prod_{j=1}^{k}\frac{1-x^{M+k-j+1}}{1-x^j}= \sum_{n=0}^{kM} p_{k}(\leq M,n) x^n $$  For the number of the partitions $p_k(\mathcal{D},n)$ of $n$ into at most $k$ parts there is the recurrence relationship: $$   p_{k}(\mathcal{D},n) = p_{k}(\mathcal{D},n-k) + p_{k-1}(\mathcal{D},n) $$  But what, if I want to count only the partitions with distinct parts and restricted number of parts and restricted part size?  Update: Now I know the generating function for the number of distinct restricted partitions $p_k(\leq M, \mathcal{D},n)$ of $n$ into exactly $k$ distinct parts, all at most $M$ is $$    \prod_{j=1}^{M} (1+xq^{j}) = \sum_{k,n=0}^{\infty}p_k(\leq M, \mathcal{D},n)x^{k}q^{n} $$ and there is also a recurrence relation $$    p_k(\leq M, \mathcal{D},n) =         p_{k-1}(\leq M-1, \mathcal{D},n-k) +         p_k(\leq M-1, \mathcal{D},n-k) $$ How can I prove this? Could you recommend a book, where I could read about this? What is an example of Gâteaux differentiable but not Fréchet differentiable at a point in a finite-dimensional space? Let $V,W$ be nonzero normed spaces over $\mathbb{K}$ such that $V$ is finite-dimensional.  Let $E$ open in $\mathbb{K}$ and $p\in E$.  Let $f:E\rightarrow W$ be Gâteaux-differentiable at $p$.  Is $f$ necessarily Fréchet-differentiable at $p$ in this case?  I think this is not true in general, but cannot find a counterexample. What would be a counterexample? Calling delete on variable allocated on the stack Is there a way to find out if I need a transit visa for Canada? How to make a Rigid Body fall off a conveyor belt? I've created conveyor belt and and two objects with rigid body physics. But the first object won't fall and second object falls backwards.  How can I fix it?