While I was reading a book, I found a sentence incomprehensible. It reads, "A danger point could have been reached had Nazi discipline and its totalitarian control been relaxed."  I can understand the meaning only vaguely through the context, though, still I'm not sure what the "had Nazi discipline" is meant to be.  And what's the exact grammatical structure of it?  Thanks!
Sometimes I hear sentences that sound conditional to me, just because of the (unassertive) ordering of the words. I don't know if I can come up with a proper example. Consider this:          I'd be a lot better, had she stayed with me.        And I guess it's equivalent to this conditional form: If she had stayed with me, I would have been a lot better.  So, this is my question: In what ways can you make a sentence conditional without using conditional conjunctions (if, unless, etc)? And what are their equivalent conditional forms?
Looking for a command to create the geometry line symbol (\overline with arrows on both ends) I need a way of encoding the geometry line symbol. $\overline{AB}$ gives me the line segment symbol and $\overrightarrow{AB}$ gives me the ray symbol, I need a way to get a bar over the letters that has arrows on both ends. $\overrightleftarrow{AB}$ does not work.   Thanks! Uncertainty principle and multiple observers How can I find and replace specific words in a text file using command line? What type of path in shebang is more preferable? In scripts, first line should specify the path to interpreter. But on different servers Linux, Unix, or BSD this path could be different.  What is more preferable?  #!/usr/bin/env bash    or  #!/bin/bash Calculating Optimal Geohash Precision from Bounding Box I'm using Elasticsearch's  to plot clusters on a map (using Leaflet). I understand that for larger areas a lower precision setting should be used to limit the number of buckets created/returned.  How should I determine the appropriate precision value to request?  Is there a standard or recommended formula for calculating the optimal precision based on a bounding box and/or zoom level? Is it better to just map zoom levels to precision values (I know that's probably easiest.) How to fully delete a git repository created with init? So I was configuring VS code on my Notebook when suddenly I noticed that my interface font got really small on my desktop, terminal and files. I use Gnome Tweaks Tool to increase my scaling factor to 1,15 , but, even though it was active, the font stayed tiny. The solution I found was moving my scaling factor, which instantly fixed my font issue, however, every time I restart my Notebook the font gets tiny again and I have to repeat the process. I tried reseting my font configuration using this command, but had no success. gsettings reset org.gnome.desktop.interface text-scaling-factor  I also tried using the command dconf reset -f /  Finally, I tried using dconf-editor, but still had no success altering the font rendering DPI or changing the scaling factor. All of the steps I mentioned fixed my fonts temporarily, but the issue still persists when I restart my Notebook I am out of ideas and even considered getting a fresh Ubuntu install by now... My video card: NVIDIA GeForce GTX 1050 GPU I install virtualBox on Ubuntu 16.04, but after install and create new virtual Host shows this error:     Kernel driver not installed (rc=-1908)      The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please install virtualbox-dkms package and load the kernel module by executing  modprobe vboxdrv       as root. If it is available in your distribution, you should install the     DKMS package first. This package keeps track of Linux kernel changes and   recompiles the vboxdrv kernel module if necessary.  where: suplibOsInit what: 3 VERR_VM_DRIVER_NOT_INSTALLED (-1908) - The support driver is not installed. On linux, open returned ENOENT.     How to address this modprobe vboxdrv error? Setting CSS pseudo-class rules from JavaScript I'm looking for a way to change the CSS rules for pseudo-class selectors (such as :link, :hover, etc.) from JavaScript.  So an analogue of the CSS code: a:hover { color: red } in JS.  I couldn't find the answer anywhere else; if anyone knows that this is something browsers do not support, that would be a helpful result as well. Pretty self descriptive, without being able to view the source of the noise how can we tell the difference between a sound in front of us and a sound behind us if pitch, volume and distance are all the same.   Also assume that it is not biased to one side more than the other, e.g its not to your left or right but directly in front or behind.   I'm interested in knowing if it is a part of the ear that makes this distinction, or a function of the brain. Vote for Tag Synonyms Directly on the Page Before:  After:   The pros:  Speeds up the tag synonym voting process. Easier to locate (as opposed to navigating to each individual tag wiki page). Encourages users to vote on more than one at a time.  The cons:  Serial up/downvoting. But this really isn't even an issue because, (1) only experienced users can vote on tag synonyms, and (2) more than one vote is required to approve a tag synonym, so the occasional serial up/downvoter won't significantly impact the overall process. Why is the ampere a base unit and not the coulomb? I always thought of current as the time derivative of charge, $\frac{dq}{dt}$. However, I found out recently that it is the ampere that is the base unit and not the coulomb. Why is this? It seems to me that charge can exist without current, but current cannot exist without charge. So the logical choice for a base unit would be the coulomb. Right? How to customize MacBooks' keyboard? I spilled a juice on my MacBook-Pro keyboard. Consequently, some keys like 2, esc and tab don't work anymore on my keyboard.   Is there anyway to change those disabled keys with combination of some other keys, like Fn,Ctrl, Option+ something, using an app or a command? Proving an infinite number of primes of the form 6n+1 Constraint the camera to look at an object In my scene I have a camera sitting at the origin. I would like to contraint it so that it always looks at the center of a given object. But the camera should not change its position.  I found some answers using a "TrackTo" or "LockedTrack" constraint but could not manage to make it work.  Could I probably use a Driver for this and if yes, how can I adjust it?  Thanks in advance! ls command operating differently depending on recipient How to prove that exponential grows faster than polynomial? In other words, how to prove:  For all real constants $a$ and $b$ such that $a &gt; 1$, $$\lim_{n\to\infty}\frac{n^b}{a^n} = 0$$  I know the definition of limit but I feel that it's not enough to prove this theorem. List all sites in multisite I want to list all sites in the multi site network in alphabetical order? Right now, the code lists by registered date  &lt;?php // Query for getting blogs             $blogs = $wpdb-&gt;get_results( $wpdb-&gt;prepare("SELECT blog_id, domain, path FROM $wpdb-&gt;blogs WHERE site_id = %d AND public = '1' AND archived = '0' AND mature = '0' AND spam = '0' AND deleted = '0' ORDER BY registered DESC", $wpdb-&gt;siteid), ARRAY_A );              // put it in array               foreach ( (array) $blogs as $details ) {$blog_list[ $details['blog_id'] ] = $details;}             unset( $blogs );             $blogs = $blog_list;              // if is valid array             if (is_array( $blogs ) ){                     echo '&lt;ul&gt;';                     $array= array();                     // reorder                     $array= array_slice( $blogs, 0, count( $blogs ) );                     for($i=0;$i&lt;count($array);$i++){                     // get data for each id                     $blog = get_blog_details( $array[$i]['blog_id'] );                     // print it                     echo '&lt;li&gt;&lt;a href="'.$blog-&gt;siteurl.'"&gt;'.$blog-&gt;blogname.'&lt;/a&gt;&lt;/li&gt;';                     }                     echo '&lt;/ul&gt;';             }             ?&gt; Why xargs can't work with tail -f? I want tail -f /var/log/syslog | grep it with pattern "arpwatch" and send every line to myself via jabber: xmpp username@jabber.server using xargs  tail -f /var/log/syslog | grep arpwatch | xargs sendxmpp username@jabber.server   no working.  but tail  /var/log/syslog | grep arpwatch | sendxmpp username@jabber.server   works well.  I think it's some fundamental thing about xargs and tail -f that I don't understand. How to find the roots of $x^4 +1$ I'm trying to find the roots of $x^4+1$. I've already found in this site solutions for polynomials like this $x^n+a$, where $a$ is a negative term. I don't remember how to solve an equation when $a$ is a positive term as the equation above.  Thanks