clojure - access element of 2d vector
How do I access a specific element in a vector of vectors clojure
Cannot change lock screen background on Ubuntu 18.04 Before you mark the question as a duplicate, I read all of the posts regarding this, but nothing helped me. I'd like to change the background picture of the lock screen.    I changed the ubuntu.css and gdm3.css accordingly to   #lockDialogGroup {   background: #000000 url(file:///usr/share/wallpapers/minimalistic-gray_00323985.jpg);   background-repeat: no-repeat;   background-size: cover;   background-position: center; }   Which results in a change of the Background of the log in screen, not the lock screen. When I press super + L the screen containing time has the correct background. When I swipe it up to tipe in my password, the purple Ubuntu screen still appears. If I click to change the user, the log in screen appears with the right background. I have the same background picture enabled in gnome tweaks for desktop background and lock screen.   I'm running Ubuntu 18.04 GNOME on a TuXedo Laptop. And I use Communitheme - maybe thats the problem?  Any ideas why it doesn't work? (I rebooted multiple times, so that's not the problem.)  EDIT: The output of sudo nano /usr/share/gnome-shell/modes/ubuntu.json is  {     "parentMode": "user",     "stylesheetName": "ubuntu.css",     "enabledExtensions": ["ubuntu-dock@ubuntu.com", "ubuntu-appindicators@ubuntu.com"] } How do I calculate someone's age based on a DateTime type birthday? How many RSA keys before a collision? I installed the VMware bundle on my Ubuntu 11.04 successfully but when I open it it gives me this window     and I don't know the path to this C headers. Baking with oven without bottom heating element My mom wants to do baking but her oven doesn't have bottom heating element. It only has an element on top, with a fan at the back.  She told me that she can't make me a good pizza or cake without it.  Is there any way around? Points of a Measure Zero Sets Covered by Intervals Infinitely Many Times Given a measure zero set $E$, by definition we have forall $\varepsilon &gt; 0$, a covering of $E$ by intervals whose lengths sum to $&lt; \varepsilon$.  I want to prove that we can cover $E$ in intervals such that the sum of the lengths the intervals is $&lt; 1$ and each point in $E$ is contained in infinitely many of the intervals.  Do you know how to prove this? Thank you I am trying to draw a cantor set in LaTeX and I am having issues doing this. I am trying multiple \put commands, but they just go to the right of one another. Does anyone know how to do this?  Any help would be much appreciated. Word for phrases that are examples of what they describe Sources missing in /etc/apt/sources.list, how do I get them back? Finding sharing settings OWD Show that $8 \mid (a^2-b^2)$ for $a$ and $b$ both odd If $a,b \in \mathbb{Z}$ and odd, show $8 \mid (a^2-b^2)$.   Let $a=2k+1$ and $b=2j+1$. I tried to get $8\mid (a^2-b^2)$ in to some equivalent form involving congruences and I started with $$a^2\equiv b^2 \mod{8} \Rightarrow 4k^2+4k \equiv 4j^2+4j \mod{8}$$ $$\Rightarrow k^2+k-j^2-j=2m$$ for some $m \in \mathbb{Z}$ but I am not sure this is heading anywhere that I can tell.  Second attempt: Use Euler's Theorem and as $\gcd(a,8)=\gcd(b,8)=1$ and $\phi(8)=4$, $a^4 \equiv b^4 \equiv 1 \mod 8$ so $a^4-b^4\equiv 0 \mod{8}$.  I haven't gotten too much further are there any hints? When in Demon Form, are demons vulnerable to mortal frailties? When a Demon is in Demonic Form, does he gain any intrinsic protection against mundane concerns like breathing or falling unconscious? In particular, when in Demonic Form do/are demons:  need to breath? immune to poisons? fall unconscious? (ie do they stay conscious on full lethal?) suffer from wound penalties for having damage in last 3 boxes? need to consume food/water? need to sleep?  The last two are only really a concern to demons who have burnt their last cover. However this can happen in play, and is pretty significant for any burnt NPCs. Is seems odd that a swarm of glass beetles clinging together into the shape of a man might have any issues with being poisoned. But I can't find it clearly stated, whereas it is clearly stated in Werewolf (the Forsaken). Are static class variables possible in Python? Rendering of Favorite/Ignored Tags in Firefox I have spotted a bug in rendering of Favorite Tags and Ignored Tags section in Firefox. This rendering issue is present on both stackoverflow.com and meta.stackoverflow.com sites.  I'm using Firefox 17.0.1 on Windows 7 x64. In Google Chrome page is rendered correctly.  Screenshots:  Firefox (please note cropped right part of both Add buttons)    Chrome (buttons are rendered correctly) How to prove the property of the Lemoine point of a triangle? Change .jpg quality of terminal screenshots xslt, javascript and unescaped html entities i have a tiny little problem with xslt, js and html entities, eg. within a template:  &lt;script type="text/javascript"&gt;     &lt;xsl:value-of select="/some/node"/&gt;     for (var i = 0; i &amp;lt; 5; i++) {         //            ^^^ js error     } &lt;/script&gt;  &lt;script type="text/javascript"&gt;     &lt;xsl:value-of select="/some/node"/&gt;     for (var i = 0; i &lt; 5; i++) {         //            ^ xslt error     } &lt;/script&gt;  &lt;script type="text/javascript"&gt;     &lt;xsl:value-of select="/some/node"/&gt;     // &lt;![CDATA[     for (var i = 0; i &lt; 5; i++) {         //            ^ becomes &amp;lt;     }     // ]]&gt; &lt;/script&gt;   &lt;script type="text/javascript"&gt;     &lt;xsl:value-of select="/some/node"/&gt;     for (var i = 0; i &lt;xsl:value-of disable-output-escaping="yes" select="string('&amp;lt;')"/&gt; 5; i++) {         // works of course     } &lt;/script&gt;   does anyone have an idea where my problem could come from? i always thought the xslt processor would leave the content of a &lt;script/&gt; element unescaped when using the html output method ...  i run libxslt2 version 1.1.24 on OSX which was installed using macportsports ... More and more frequently in the review queues, I am spending time either fixing a post or considering whether an edit is valid, etc, only to make changes and have them denied/not count because someone else has blindly hit the approve button in the meantime.  My proposal is for the system to "lock" a post in the review queue once it has been presented to someone for review.  Do not let anyone else (in the review queue) do anything with it until it is released by the last user it was presented to (or a certain amount of time has elapsed).    By "lock" I mean that it won't show up in anyone elses list until released.  I did NOT mean that it would be in multiple queues and be unactionable in some of them.  This would fit well as the queues only present one at a time anyway.  This will allow people trying to make good decisions the time to do it and prevent someone else from making that effort a waste of time.  As support, look to some of the published reasoning behind the auto-question ban.  A large portion of it is that bad questions waste the time of the community.  Taking the time to ensure you are making a good decision in the /review queue only to have it not count because someone was badge-whoring and clicking the approve button as fast as they could also wastes the users time... arguably the more (for lack of a better way to put it) valuable user who is willing to invest some time and thought into making the site better. Multiple Bluetooth speakers simultaneously I would like to pair two sticky dude Bluetooth speakers, at one time with my iPhone. With two of them at once it would be like stereo sound. Is there an app or something maybe? Calculate line distances inside of polygons using ArcGIS for Desktop? I'm working with two data sets:   NHD polyline stream layer for my entire state HUC Watershed boundary Polygons for the entire state   I am looking for a way to calculate the total length of streams within each watershed boundary polygon, and would ideally like to have each polygon then attributed with the sum of stream miles within its boundary.  Can anyone help me?