How to run Emacs commands with sudo outside a shell?
How do I run a sudo command in Emacs?
UK visa: unsigned application form I bought an audio book from audible and want to convert it to mp3 from aa because my phone doesn't support the format. Is there any way to do that? Firstly, this is a homework problem so please do not just give an answer away. Hints and suggestions are really all I'm looking for.  I must prove the following using mathematical induction:     For all $n\in\mathbb{Z^+}$, $1+2+2^2+2^3+\cdots+2^n=2^{n+1}-1$.   This is what I have in my proof so far:     Proof: Let $p\left(n\right)$ be $\sum_{j=0}^n 2^j=1+2+2^2+\cdots+2^n=2^{n+1}-1$. Then $P\left(0\right)$ is    \begin{align} \sum\limits_{j=0}^0 2^j=1=2^1-1.\tag{1} \end{align} Hence    $P\left(0\right)$ is true. Next, for some $k\in\mathbb{Z^+}$, assume    $P\left(k\right)$ is true. Then \begin{align}  \sum\limits_{j=0}^{k+1}2^j&amp;=\left(\sum\limits_{j=0}^k  2^j\right)+2^{k+1}\tag{2}\\ &amp;=2^{k+1}-1+2^{k+1}\tag{3} \\ &amp;=2\cdot 2^{k+1}-1\tag{4}\\ &amp;=2^{k+2}-1\tag{5}\\ &amp;=2^{\left(k+1\right)+1}-1.\tag{6} \end{align}   Therefore, $P\left(n\right)$ holds for all $n$.$\;\;\;\;\blacksquare$   Is everything right? My professor went over the methodology in class quite fast (and I had a bit too much coffee that night) and I want to make sure I have it down for tomorrow night's exam. When I run the command to install the package solr-jetty, I am told   You don't have enough free space in /var/cache/apt/archives/   Here's the result of the df -H command:    I have installed Ubuntu with VirtualBox on my Mac.  How can I fix this problem? Prove that the sequence with $T(0)=1$ and $T(n) = 1 + \sum_{j=0}^{n-1}T(j)$ is given by $T(n)=2^n$ $T(0)=1 \\ T(n) = 1 + \sum_{j=0}^{n-1}T(j) \\ $  Show that $T(n) = 2^n$.  I know how to prove this by induction, but I would like to know how to show this using first principles.  Edit: The way I want to solve this problem is manipulate $T(n)$ in such a way that it ends up as $2^n$. Is there a theorem that says that QFT reduces to QM in a suitable limit? Of course, it should be, as QFT is relativisitc quantum mechanics. But, is there a more manifest one? such as Ehrenfest's theorem which dictates the transition from QM to Classical Mechanics.  I am curious as the basic object in QM is wave function whereas the basic object in QFT is quantized operator, which looks very different, and wondering how the comparison works.  (Of course, I am aware that QFT can calculate corrections for Coulomb potential energy, which may seem to be a transition from QFT to QM, but I want one more manifest than that.) If a creature with Multiattack is affected by Haste, can it make two Multiattacks? It's a fairly straightforward question.   A creature has a Multiattack option, and it also can cast the Haste spell. While under the effect of Haste, can it use the second Action to take another Multiattack Action?  My main concern is the clause of the Haste spell that limits the number of attacks made from taking the Attack Action. This is a different Action, though.   Then there is the concern of being able to use Multiattack at all, because Haste says what kinds of Actions you can take. How to start a background process in Python? I have a table tabName with the following rows:  id(PK) .. Created(datetime)     Resolved(datetime) Status(new/resolved/open) 1          2015-05-10 00:00:00   1970-01-01 ..       open 2          2015-05-10 ..         1970-01-01 ..       new 3          2015-05-10            2015-05-12          resolved 4          2015-05-11 ..         1970-01-01 ..       open 5          2015-05-11 ..         1970-01-01 ..       new 6          2015-05-11            2015-05-11          resolved 7          2015-05-12 ..         1970-01-01 ..       open 8          2015-05-12 ..         1970-01-01 ..       new 9          2015-05-12            2015-05-12          resolved   NOTE:  1970-01-01 .. is default time for all the tickets which are still open.  I have to frame a query to get the count of tickets still open, date wise. Say like on 10 May I have 3 tickets opened. Noting that for id = 3, resolved date is not 10 but it's closed on 12 May.  I framed a query like  SELECT DATE_FORMAT(Created, '%d-%m') AS createdd, COUNT(1) FROM tabName WHERE DATE_FORMAT(Resolved, '%d-%m') &gt; DATE_FORMAT(Created, '%d-%m')       AND YEAR(Created) = '2015' GROUP BY createdd;   The above query gets all the tickets whose Resolved date is greater than the date which is considered for the count. This may count newer tickets as well. And also if the older tickets which are not resolved yet is not counted.  Is there any other way to frame the required query? I have been juggling with this query from last 3 days. Not able to find out still.  Updated: As suggested by Abhik, i have tried in sqlfiddle site.  Here is what i created:  CREATE TABLE test    (idint,createddatetime,resolveddatetime, status varchar(15), PRIMARY KEY (id));    INSERT INTO test       (id,'created','resolved',status`) VALUES       (1,'2015-05-10 00:00:00','1970-01-01 00:00:00','open'),    (2,'2015-05-10 00:00:00','1970-01-01 00:00:00','new'),    (3,'2015-05-10 00:00:00','2015-05-12 00:00:00','resolved'),    (4,'2015-05-11 00:00:00','1970-01-01 00:00:00','open'),    (5,'2015-05-11 00:00:00','1970-01-01 00:00:00','new'),    (6,'2015-05-11 00:00:00','2015-05-11 00:00:00','resolved'),    (7,'2015-05-12 00:00:00','1970-01-01 00:00:00','open'),    (8,'2015-05-12 00:00:00','1970-01-01 00:00:00','new'),    (9,'2015-05-12 00:00:00','1970-01-01 00:00:00','open')    ;   `   When i run  ` select created_date, @open:= @open+open_ticket-resolved as open from(  select   date_format(created,'%d-%m') as created_date ,  sum( case when status='open' then 1 else 0 end )+  sum( case when status='new' then 1 else 0 end )+  sum( case when status='resolved' and ( date(resolved) > date(created) or  date(resolved) = date(created)) then 1 else 0 end ) as open_ticket,  sum(case when status = 'resolved' and date(resolved) = date(created) then 1   else 0 end) as resolved  from test  where  YEAR(Created) = '2015'  group by created_date )x,  (select @open:=0)r order by created_date ; `  I got following output  created_date   open 10-05   3 11-05   5 12-05   8  Here count of still open tickets for 12-05 must be 7. The above query includes ticket id "3" , which is closed on 12-05. So is there any way to exclude this? If i am able to get this right, then i will have full fledged query. Vertically align horizontal inline-block elements Corrupt MXD Causes? There are no compact minimal surfaces This is one of the exercises of 'Do Carmo' (Section 3.5, 12)     How do you prove that there are no compact (i.e., bounded and closed in $\mathbb{R}^3$) minimal surfaces?   Thanks! How to create a filter in Gmail to identify messages forwarded from Zimbra? Understanding dummy (manual or automated) variable creation in GLM If a factor variable (e.g. gender with levels M and F) is used in the glm formula, dummy variable(s) are created, and can be found in the glm model summary along with their associated coefficients (e.g. genderM)  If, instead of relying on R to split up the factor in this way, the factor is encoded in a series of numeric 0/1 variables (e.g. genderM (1 for M, 0 for F), genderF (1 for F, 0 for M) and these variables are then used as numeric variables in the glm formula, would the coefficient result be any different?  Basically the question is: does R use a different coefficient calculation when working with factor variables versus numeric variables?  Follow-up question (possibly answered by the above): besides just the efficiency of letting R create dummy variables, is there any problem with re-coding factors as a series of numeric 0,1 variables and using those in the model instead? How to calculate $\lim \limits_{n \to \infty}(1 +\frac{a}{n})^n$? What does accepting an answer actually convey (2015 edition)? $x^2$ is congruent to $-1 \bmod p$ In general, how do you solve $x^2$ is congruent to $-1 \bmod p$, where $p$ is an odd prime and $x$ is an integer.  Specifically, I need to solve $x^2\equiv-1 \pmod{29}$ Are data members allocated in the same memory space as their objects in C++? How can I debug my JavaScript code? NSString instance reports its class as NSCFString My objective here is really simple -- I'm trying to set an NSString to some test data, then return the class, which should be NSString. Here's my code:  NSString* stringer = [NSString stringWithFormat: @"Test"]; NSLog(@"%@", [stringer class]);   The log says that the class is NSCFString, not NSString. What's going on here?