How do I fix 404 error when updating package lists?
How can I fix a 404 Error when using a PPA or updating my package lists?
Can I vent my dryer into the crawl space without creating mold and moisture problems? We have a crawl space with a combination of sandy and clay soil in it.  The crawl space is about 3' deep.  To eliminate a long dryer vent run, I'd like to vent the dryer directly into the crawl space.  We have vents built into the foundation that I open each spring and close in the fall.  Will this help dissipate the moisture enough to prevent mold? Consider the vectorspace of all real $m \times n$ vectors and define an    inner product $\langle A,B\rangle = \operatorname{tr}(B^T   A)$.    "tr" stands for "trace"        which is the sum of the diagonal entries of a matrix.   How do you prove that $\operatorname{tr}(B^T   A)$ is indeed a inner product?  Kind regards java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuterFilter Non-numerical citation mark like [Str91] [Samar] [Tro77] Salutation for two doctors (not married) How do I just restart the nautilus after adding a nautilus script without having to log out. I'm making a mini game (bomb squad) and the armor needs to be enchanted. I know that armor can be enchanted through command blocks and that is what I intend to do. I am wondering if it is possible to enchant armor twice in one command block or should I need multiple command blocks as I have done in the past? For which values does the Matrix system have a unique solution, infinitely many solutions and no solution? Given the system:  $$\begin{align}  &amp; x+3y-3z=4 \\   &amp; y+2z=a \\  &amp; 2x+5y+(a^2-9)z=9 \end{align}$$  For which values of a (if any) does the system have a unique solution, infinitely many solutions, and no solution?    So I am getting that it has: infinitely many solutions at: (-1)    No solution at (1)    Unique solution at (-1,1)    AM I RIGHT?? Can the Ubuntu logo be used for a commercial website? Is there an Ubuntu logo that can be used on a commercial website to indicate that Ubuntu can be installed for customers? Is there any short way to save the pipe output to the same file that it's processed. For example, this is what I am actually doing  $ cat filename | sort | uniq &gt; result $ rm -f filename $ mv result filename   I was wondering if there was a way to do it in just one line (not appending those commands using &amp;&amp;)  This is not the way, but to get an idea  $ cat filename | sort | uniq &gt; filename Another word for a troll not on the internet The definition of an internet troll:     In Internet slang, a troll (/ˈtroʊl/, /ˈtrɒl/) is a person who sows   discord on the Internet by starting arguments or upsetting people,   by posting inflammatory,[2] extraneous, or off-topic messages in an   online community (such as a forum, chat room, or blog), either   accidentally[3][4] or with the deliberate intent of provoking readers   into an emotional response[5] or of otherwise disrupting normal   on-topic discussion.[6]      This sense of the word troll and its associated verb trolling are   associated with Internet discourse, but have been used more widely.   Media attention in recent years has equated trolling with online   harassment. For example, mass media has used troll to describe "a   person who defaces Internet tribute sites with the aim of causing   grief to families."[7][8]     What is the equivalent for a person who does this type of thing in real life (non-cyber) troll? Why doesn't my command work when aliased? I use ps -ef | grep catalina | grep -v grep to print the tomcat process running on the system:  kshitiz   7099     1  0 May11 ?        00:02:29 /usr/lib/jvm/jdk1.8.0/bin/java -agentlib:jdwp=transport=dt_socket,suspend=y,address=localhost:38156 -Dcatalina.base=/home/kshitiz/Documents/workspaces/ggts/.metadata/.plugins/org.eclipse.wst.server.core/tmp1 -Dcatalina.home=/opt/tomcat-7.0.42 -Dwtp.deploy=/home/kshitiz/Documents/workspaces/ggts/.metadata/.plugins/org.eclipse.wst.server.core/tmp1/wtpwebapps -Djava.endorsed.dirs=/opt/tomcat-7.0.42/endorsed -Dfile.encoding=UTF-8 -classpath /opt/tomcat-7.0.42/bin/bootstrap.jar:/opt/tomcat-7.0.42/bin/tomcat-juli.jar:/usr/lib/jvm/jdk1.8.0/lib/tools.jar org.apache.catalina.startup.Bootstrap start   Then I use ps -ef | grep catalina | grep -v grep | awk -F' ' '{print $2}' to extract the process id:  7099   But when I alias the whole command alias tomcat_id="ps -ef | grep catalina | grep -v grep | awk -F' ' '{print $2}'" and use it via alias, it prints the whole text and awk doesn't seem to work.  type tomcat_id gives:  tomcat_id is aliased to `ps -ef | grep catalina | grep -v grep | awk -F' ' '{print }'' Animating eye texture in a head mesh I'm trying to animate a mesh with different eye textures but it's not working.     This is a texture made by me to animate but I still couldn't figure out how to do it. I've seen tutorials on the internet but they don't work to me. Bats and rats are mammals. 1 and 2 are positive integers. Oaks and maples are trees. Carrots and cake are food.   I seek a word to describe this, the process of finding a concept that encompasses several given concepts. Is there such a word? Can I use a present-tense verb when writing about a past event? find exclude directory I can't understand how the "cryptographic functions" are to be selected RSA + OAEP which are used in OAEP. How to choose these "cryptographic functions"(G and H)? In the Android app, left sidebar, there is an editable list of "Your Sites". In the editing pane, the sites are re-orderable (although awkwardly), and the order one places the sites in there is preserved, even after quitting the app and returning to this pane. One expects that order to be reflected in the "Your Sites" portion of the left sidebar when the editing pane is closed, but it is not.  I'm not sure what is determining the order of the sites in the left sidebar, it doesn't seem to be by date they were "pinned" into the list one wants to show, either. Using the Well Ordering Principle to Show that n^3 - n is divisible by 6. I read the following two sources and I think I understand the structure of proofs involving WOP, but I am stuck on the open-ended part where you prove P(n-1) for the  following problem:    Use the well-ordering principle to show that n^3 - n is divisible by 6.    Any help would be greatly appreciated!   Note: After factoring out (n-1)^3 - (n-1) it took the form of n^3 - 3n^2 + 2n and the only difference between that and n^3 - n is "3n^2 - 3n" which I proved was divisible by 6 via induction. Is there a better way to solve this problem?  Edit: , post is useful however I not supposed to use induction for the main part of the proof. Using SUMPRODUCT with ARRAYFORMULA I have the following random data in sheet one  A  orange D  yellow C  yellow B  orange B  orange C  blue A  yellow D  blue C  orange C  blue   In sheet two I use the following query function:  A1=UNIQUE(QUERY(Sheet1!A1:B10,"select A, B order by A asc")) C1=sumproduct(Sheet1!A:A=A1,Sheet1!B:B=B1) C2=sumproduct(Sheet1!A:A=A2,Sheet1!B:B=B2) C3=sumproduct(Sheet1!A:A=A3,Sheet1!B:B=B3) . . .   Which returns the following:  A   orange 1 A   yellow 1 B   orange 2 C   yellow 1 C   blue   2 C   orange 1 D   yellow 1 D   blue   1   Instead of using sum product in each row, I want arrayformula to expand automatically.  When I use E1=ArrayFormula(sumproduct(A1:A10=C1:C,B1:B10=D1:D)) I get     Error: Array arguments to EQ are of different size.   Please help me out.