Does his impossible worlds category include (and can describe) literally all impossible things/worlds?  Inconsistencies, paradoxes, impossible solutions to problems (and impossible problems); really impossible things (as there are philosophers that told me that paradoxes, for example, are not really/truly impossible things because otherwise they could not exist; "Obviously, impossible things are not, in any situation, possible. But if by "impossible things" you mean "contradictory things" or "paradoxical things," then yes. Depends on what you mean by "really impossible." If you mean things that are physically impossible, then obviously we can describe these things using logic. If you mean things that are logically impossible, then this question (is there any logic system/method or anything else that can find and describe impossible things?) doesn't make any sense.") Can it describe all the impossible worlds that even logic systems that allow impossibilities (like paraconsistent logics, dialetheism, trivialism...etc) cannot describe (due, for example, to their limitations)?  Russell's set paradox cannot have a solution (solution in the sense of representing the contents of Russell's set paradox) in a way that makes sense in naive set theory (classical logic), it is impossible and cannot exist: as a scientist told me once,  "The contents of a Russel-type set are not just non-computable in that you can't figure out the answer. You can arrive at it by exhausting all possibilities, either. That is, if you take every possible state the human brain can be in, none of them include the computation of Russel's Set's contents. That is, not only can the contents not be computed, they cannot even be represented. No stimulus can cause us to comprehend Russel's Set, since such comprehension is not possible to begin with. The solution to Russell's set does not exist. It cannot exist. There is no arrangement of atoms in the universe that spells out the solution. There is no pattern of neuronal activity in the brain that could ever represent the solution. It's like asking what democracy tastes like. It doesn't make any sense."  So could we find an impossible world from Alexius Meinong's impossible worlds where this solution would exist and could be found and represented?

A paraconsistent logic system it is defined as  "a logical system that attempts to deal with contradictions in a discriminating way. Alternatively, paraconsistent logic is the subfield of logic that is concerned with studying and developing paraconsistent (or "inconsistency-tolerant") systems of logic"  So, is there any paraconsistent logic system,or any other logic system, where illogical or impossible things would happen? Can they produce a solution to Russell's set paradox (in terms of naive set theory)?


How do I add this kind of function...  __("go")    inside:  <<<_END   ...without having to declare the variables before the heredoc? It's just too time consuming. I would like that my heredoc can read such functions __("go") without having to put them inside variables externally.  Thanks for your help.

In PHP, the HEREDOC string declarations are really useful for outputting a block of html.  You can have it parse in variables just by prefixing them with $, but for more complicated syntax (like $var[2][3]), you have to put your expression inside {} braces.  In PHP 5, it is possible to actually make function calls within {} braces inside a HEREDOC string, but you have to go through a bit of work.  The function name itself has to be stored in a variable, and you have to call it like it is a dynamically-named function.  For example:  $fn = 'testfunction'; function testfunction() { return 'ok'; } $string = <<< heredoc plain text and now a function: {$fn()} heredoc;   As you can see, this is a bit more messy than just:  $string = <<< heredoc plain text and now a function: {testfunction()} heredoc;   There are other ways besides the first code example, such as breaking out of the HEREDOC to call the function, or reversing the issue and doing something like:  ?> <!-- directly output html and only breaking into php for the function --> plain text and now a function: <?PHP print testfunction(); ?>   The latter has the disadvantage that the output is directly put into the output stream (unless I'm using output buffering), which might not be what I want.  So, the essence of my question is: is there a more elegant way to approach this?  Edit based on responses: It certainly does seem like some kind of template engine would make my life much easier, but it would require me basically invert my usual PHP style.  Not that that's a bad thing, but it explains my inertia..  I'm up for figuring out ways to make life easier though, so I'm looking into templates now.


Why if $A \in \textsf{M}_{n\times n}(F)$ and  $$I \notin \operatorname{span} \{A,A^2,\dots,A^n\}$$  so $\det (A)=0$?  I understand that $A$ is not invertible if $I \notin \operatorname{span} \{A,A^2,\dots,A^n\}$, but can't explain why.

Let $A\in M_{n\times n}(\Bbb R)$ so that $I\notin span(A,A^2,...,A^n)$. Prove that $\det(A)=0$.   I was thinking of showing $A$ is not invertible, meaning it has an eigenvalue of $0$. Since no matter the power you give to $A$, it is still not the identity, you can deduce that at least one eigenvalue is indeed $0$. However this doesn't work if you have different eigenvalues in the Matrix, so I got stuck.  Help will be most appreciated.


I know it is a letter $G$ in some equation. What I want to know is the example. Is it like chemical bond energy? I read the  on Gibbs free energy but I couldn't understand it. I don't know what exactly the non-expansion energy is. I would like explanations about what Gibbs free energy really is, preferably in a manner as if I were really watching the molecules and their interactions and movements. Edit: For example, Microscopically, the internal energy can be analyzed in terms of the kinetic energy of microscopic motion of the system's particles from translations, rotations, and vibrations, and of the potential energy associated with microscopic forces, including chemical bonds. Can you describe Gibbs free energy like this?

What is ? As my book explains:     Gibbs energy is the energy of a system available for work.   So, what does it want to tell? Why is it free? Energy means ability to do work. What is so special about this energy? Can anyone simply explain?   I just want a math-free intuition.


I need to confirm a modal popup. I have a form which I fill up and have to move to next page. When I click continue, a modal popup appears asking if the details filled are correct?  There are two button and some other description on it. One button reads cancel and other says Yes, information is correct. I tried switching to the modal element by   driver.switchTo().frame(0);  // there is only one popup   However, whatever I do with webDriver after that results in NullPointerException as no webelement is found.  This is what am trying   WebElement modalButtonContainer = AutoUtils.findElementByClassName(modalOverlay, "modalButtonContainer"); WebElement modalButton = AutoUtils.findElementByClassName(modalButtonContainer, "buttonClass"); modalButton.click();   But it all results in NullPointer. How do I click the modalButton?

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


Any idea why am I keep getting NULL Pointer Exception even I start my project from scratch already. Where did I made a mistake?


Is there such a thing as a maximum aperture that a lens can be open to?  What about a minimum aperture that it can be closed to?  Do these concepts even make any sense?  Is there a lens with the narrowest aperture in the world?  Is there one with the widest?

How does aperture affect my photographs?  Why should I care about the aperture with which a photo was taken?


What I want to happen   When press the add button, a row will be added underneath the add button's row When press the remove button, that row will be removed. When hover or click on a certain input text, an add button will show up next to it.    When mouse is not hovering over the input text or the input text is not selected, then the add button should disappear.  When hover over a certain bullet, a remove button will show up in place of the bullet.    When mouse moves away from remove button, it will revert back to a bullet.    I suspect some of my problems are occurring b/c I'm putting all my functions in $(document).ready(). If someone could type out the jQuery code that I should be using I would be really grateful!  What is happening  The Add Button   Only the first add button works.  The Remove button  The other added rows' remove buttons only show up when hover over the first bullet.   The remove button only works once. After remove one row, the remove button & add button lose their functionality. The remove and add button also don't disappear as they should.  My code  HMTL  This is the row I want to add

                                  <button type="button" class="btn btn-default button-remove" aria-label="Remove">                                                                      </button>                                 <button type="button" class="btn btn-default button-bullet" aria-label="Bullet">                                                                      </button>
                              <input type="text" name="Worksheet-Problem" class="form-control" placeholder="Problem..." aria-label="Write worksheet problem here">
                                   <button type="button" class="btn btn-default button-add" aria-label="Add">                                                                      </button>

   jQuery  These are the functions I'm using to animate the buttons and add/remove rows.  $(document).ready(function(){     $("input[type='text'][name='Worksheet-Problem']").closest('.row').hover(function()      {         $(".button-add").fadeToggle(300);     })     $(".button-bullet").closest('.input-group-btn').hover(function(){         $('.button-bullet').toggle();         $(".button-remove").toggle();     })      $(".button-add").click(function(){         var $row = $(this).closest('.row');         var $wsProbRow = $row.clone();         $wsProbRow.insertAfter($row);         console.log("Add-Button pressed");     })     $(".button-remove").click(function(){         $(this).closest('.row').remove();         console.log("Remove-Button pressed");     }) })

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


this happened after the app was called using a broadcast intend  version 1.0.71 (Google play newest)

I can reproduce that every time now, I go to a site, open an article, then to the next site, open another article. The Feed page pops up for a second, the article page lays over this with some some transparent areas (see picture). The same app-version is ok on a Smartphone with Android 4.4.2. I also sent in some bug reports.    Edit  1.0.71 isn't the solution yet. I go to Meta SE, then to an article. When I want back to Meta SE again, it crashes. Much earlier than before. I already sent in a bug report for this.  Another Edit  I can describe it better now. From the questions-page of a site I go to a post. When I use the back button, everything is ok, I can go to the next site. When I try to go to the next site directly from the post, it crashes. This only happens on the Nexus 10 with Android 5.1.1, App version 1.0.71. Hope this helps.  Edit3  This is fixed in 1.0.73 now. Thanks again.


Say I have a custom object named Book__c with fields Title__c and a checkbox named New__c, and another custom object named Author__c with field Book__c, can I use New__c field directly with Author__c object in a condition?  The requirement is to automatically create a new Obj_To_Insert__c record when a new Author__c record with Book__c field having its field New__c set to true.     For example, can I use it like this?  List<Author__c> authorList = new List<Author__c>  for(Author__c auth : authorList) {     if(auth.Book__r.New__c == true) {         //some code...     } }    The code above is a snippet from this apex class:  public class ThisIsTheClass {      public static void theMethod(List<Author__c> authorList) {          Set<Id> id = new Set<Id>();         List<Obj_To_Insert__c> otiList = new List<Obj_To_Insert__c>();          authorList = [SELECT Id, Name, Book__c, Book__r.New__c FROM Author__C where Id IN: id];          for(Author__c auth : authorList) {             if(auth.Book__r.New__c == true) {                 Obj_To_Insert__c oti = new Obj_To_Insert__c();                 oti.Field1__c = auth.Id;                 otiList.add(oti);                 }          }           insert otiList;      } }   Meanwhile, the apex class is called in the apex trigger below:  trigger thisIsTheTrigger on Author__c (after insert) {      ThisIsTheClass.theMethod(Trigger.New);       }

I'm sure this has been addressed before but I can't seem to find the answer. In a trigger on a record, aside from the actual fields on the record, what do I have access to? The parent info? that record's children? Do you just add the fields by re querying in your handler?


Is there such a saying? Futile may be either because it will fail or because it is unnecessary / already taken care of. I considered: too many chefs spoil the broth  and  It's like carrying coals to newcastle  But neither are very good... A formal sounding colloquilism is also ok.

In my native language, we use an idiom to warn someone that they're doing something which has no result at the end:     Trying to convince him is like squashing water ...   Is there any idiom in English with the same meaning?


For example, when solving second order differential equation with constant coefficients, we start with guessing the solution is the form of the linear combination of two independent exponential functions. I read some explanations saying it's for the convenience of integral and derivation.  Is there any more reason?  I'm still an undergraduate student, please write an answer in a way that I can understand.

In a book I am reading on differential equations, the author writes about the solution to a homogenous, linear, second order differential equation with constant coefficients. The author says something like, "Let us suppose that the solution is of the form $y=e^{mx}$ " . After this the author introduces the characteristic equation of a differential equation of the form mentioned above, and proceeds to describe how to solve it w/ undetermined coefficients, variation of parameters, etc.   How did mathematicians first come up with this "assumption" that the solution was of the form $y=e^{mx}$? And, are there any other forms of solutions for these types of equations?


I have a problem with a LAMP server where Apache keeps getting lots of request "POST / HTTP/1.1" but always from new IP addresses. Blocking the IPs using iptables obviously won't help. Any ideas how to block or even reduce this traffic? I cannot install a squid proxy or similar in front of Apache, nor can I install an external firewall. Do I have to contact the ISP where the server is hosted?

This is a  about DoS and DDoS mitigation.   I found a massive traffic spike on a website that I host today; I am getting thousands of connections a second and I see I'm using all 100Mbps of my available bandwidth.  Nobody can access my site because all the requests time out, and I can't even log into the server because SSH times out too!  This has happened a couple times before, and each time it's lasted a couple hours and gone away on its own.  Occasionally, my website has another distinct but related problem: my server's load average (which is usually around .25) rockets up to 20 or more and nobody can access my site just the same as the other case.  It also goes away after a few hours.  Restarting my server doesn't help; what can I do to make my site accessible again, and what is happening?  Relatedly, I found once that for a day or two, every time I started my service, it got a connection from a particular IP address and then crashed.  As soon as I started it up again, this happened again and it crashed again.  How is that similar, and what can I do about it?


Imagine the following problem:  You listen to a radio station and take notes how often was each song played. How can you estimate based on your notes (e.g. 30 songs played once, 2 played twice, one song three times) how many songs has the radio station available when we assume all the songs are played with a uniform distribution?

If shuffle-playing playlist ×100 resulted in [10 13 10  3  2  2] different songs being repeated [1 2 3 4 5 6] times, what is the estimate for the total number of songs? (assuming shuffle play was completely random)  Update: (R code)  k <- 50 # k number of songs on the disk indexed 1:k n <- 100 # n number of random song selections m <- 20 # m number of repeat experiments colnum <- 10 mat <- matrix(data=NA,nrow=m,ncol=colnum) df <- as.data.frame(mat) for(i in 1:m){   played <- 1+floor(k*runif(n)) # actual song indices (1:k) selected    freq <- sapply(1:k,function(x){sum(played==x)})   # = number of times song with index x is being played   histo <- sapply(1:colnum,function(x){sum(freq==x)});   for(j in 1:colnum){    df[i,j] <- histo[j]   } } df   Resulting in: e.g. 20 distributions (V1=number of single plays, V2=number of double plays, etc):     V1 V2 V3 V4 V5 V6 V7 V8 V9 V10 1  15 13 11  1  2  2  0  0  0   0 2  15 12 10  1  4  0  1  0  0   0 3  12 14  7  6  3  0  0  0  0   0 4  17 16  6  4  2  0  1  0  0   0 5  17 10 12  5  0  0  1  0  0   0 6  13 15 11  6  0  0  0  0  0   0 7  10 14  9  3  2  1  1  0  0   0 8  12 17  5  6  3  0  0  0  0   0 9   9 19  8  3  1  2  0  0  0   0 10 13  9 11  6  1  0  1  0  0   0 11 16  9 12  5  2  0  0  0  0   0 12 15  9 11  6  2  0  0  0  0   0 13 19  9  7  4  4  1  0  0  0   0 14 17 11  4  7  3  1  0  0  0   0 15 11 20  8  1  3  1  0  0  0   0 16 14 12 10  5  0  2  0  0  0   0 17  9 12  8  7  3  0  0  0  0   0 18 10 15  9  4  2  0  1  0  0   0 19 14 11 12  7  0  0  0  0  0   0 20 16 14 11  3  1  1  0  0  0   0   Now I need to get from here to the Poisson modelling--my R is a bit rusty (?lmer)...--Any help would be appreciated...  Attempted Poisson modelling: disappointing fit?!  plot(1:colnum,df[1,1:colnum],ylim=c(0,30),    type="l",xlab="repeats",ylab="count") for(i in 1:m){   clr <- rainbow(m)[i]   lines(1:colnum,df[i,1:colnum],type="l",col=clr)   points(1:colnum,df[i,1:colnum],col=clr) }  df.lambda=data.frame(lambda=seq(1,5,0.1),ssq=c(NA));df.lambda for(ii in 1:dim(df.lambda)[1]){   l <- df.lambda$lambda[ii]       ssq <- 0       for(i in 1:20){         for(j in 1:10){           ssq <- ssq + (df[i,j] - n*dpois(j,l))^2         }       }       print(ssq)       df.lambda$lambda[ii] <- l   df.lambda$ssq[ii] <- ssq     }     df.lambda     lambda.est <- df.lambda$lambda[which.min(df.lambda$ssq)] lambda.est # 2.4 points(x <- 1:10, n*dpois(1:10,lambda.est),type="l",lwd=2)  100*dpois(1:10,3) n/lambda.est   the estimated lambda stays around 2.3, with an n estimate of around 43; the fitted curve seems very discrepant, and seems to worsen with rising n !?  Doesn't this have to do with the fact, that our repeats are different from the 'classical' Poisson distributions: it's not just ONE event that repeats itself x number of times, but the sum of repeats of different items (songs)?!


I print two tuples in the Xcode playground. But I get a strange result, see the following code snippet and the print result:  Code Snippet:  let x : (Double,Double) = (1.2,1.3) print(x)  let y : (Double,Double) = (1.2,3.1) print(y)   Print Result:  (1.2, 1.3) (1.2, 3.1000000000000001)   Why it prints the 3.1000000000000001 which is NOT the actual value (3.1) I set for the tuple?   In the meantime, the 1.3 is printed out correctly.  My Swift compiler version info:  Apple Swift version 3.0.1 (swiftlang-800.0.58.6 clang-800.0.42.1) Target: x86_64-apple-macosx10.9

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


What is the difference between single or double quotes in my JS and CSS? Is it a matter of opinion, of are there specific situations where one is required over the other.  In W3Schools, they use single-quotes for url(''), but they use double quotes for font-face: "". Additionally, in a JavaScript tutorial I saw, they used both single and double quotes.  What's the difference?

console.log("double"); vs. console.log('single'); I see more and more JavaScript libraries out there using single quotes when handling strings. What are the reasons to use one over the other? I thought they're pretty much interchangeable.


namespace ChemicalTest {      enum Echemicals { oxygen, hydrogen, carbon }      public class Chemicals     {         int[] chemicals = new int[3];          public Chemicals()         {             foreach (int i in chemicals)             {                 int[i] = //How can I reference each enumeration here?                          //For example (pseudocode) - (i)Echemicals             }         }     } }   I have three enum values: oxygen {0}, hydrogen{1}, carbon{2}  I'd like to put each of these enums into an array to later be referenced by their own number, so that I could call them from the array.  I can use (int)Echemicals.hydrogen to return the default value of the second enumeration {1} but I don't know how to do this in reverse.  I am trying to store each of the names of the chemicals in an array by calling them by their integer value.

How can an int be cast to an enum in C#?


this is a question from a worksheet I'm working at for several days, I'm having huge problems figuring out a nice solution, because I'm always stuck at the solution and don't know where to use that n is prime. The question is as follows:  Let $G \leq S_n$ with $n \in \mathbb{P}$ be a transitive subgroup ($\forall k, l \in \{ 1,...,n\}\ \exists \ \sigma \in S_n:\sigma (k) = l$). If G contains a transposition $(k,l)$, then $G = S_n$.  I have tried constructing several generators for $S_n$, but I couldn't construct an n-cycle (which would be the easiest way of proving it). The second attempt was to construct all possible transpositions, but I also fail here and I have no intuition on where to use that n is prime. The last thing we learned in the lecture were group operations, and the operation of $G$ on $\{ 1,...,n\} $ should also be transitive, but I got nothing out of this approach.  Any help appreciated!

Suppose $G$ is a transitive subgroup of $S_n$ such that it there exist $\sigma, \tau \in G$ such that $\sigma$ is an $(n-1)$-cycle and $\tau$ is a transposition. Prove that $G = S_n$.   I just don't understand how to mathematically use the transitive nature of the subgroup.


I'm looking at the following problem from some old qualifying exam I found:     Let $\Omega$ be a simply connected proper open subset of $\Bbb C$, let $a\in\Omega$ and suppose we are given an analytic bijection $f:\Omega\to\mathbb D:=\{z:|z|<1\}$ satisfying $f(a)=0$ and $f'(a)>0$. Prove $$\inf_{z\in\partial\Omega}|z-a|\le\frac1{f'(a)}\le\sup_{z\in\partial\Omega}|z-a|.$$   To be honest, I have no idea where to start with this; my first thought was noticing that $1/f'(a)=(f^{-1})'(0)$, and was hoping to use this to try to apply the maximum modulus principle to some function involving $f'$ or $(f^{-1})'$ and $z-a$, but the first issue I come to before even trying to write a function down was realizing that $f'$ and $(f^{-1})'$ might not even be defined on the respective boundaries, so it doesn't seem like I could use maximum modulus to determine anything about the points on the boundary with respect to those functions.  I also assumed when I saw this that this was just something proved and used in the proof of the Riemann mapping theorem, but it doesn't actually seem to show up there.

Let $\Omega \neq \mathbb{C}, \emptyset$ be a simply connected domain and $a \in \Omega.$ Let $f:\Omega \to \mathbb{D}$ be a conformal map such that $f(a)=0, f'(a)>0.$ Could anyone advise me how to prove $r=\text{min}_{z \in b\Omega}|z-a|\leq \dfrac{1}{f'(a)} \leq \text{max}_{z\in b\Omega}|z-a|=R \  ?$  Here is my attempt:   Define $\psi:\mathbb{D} \to \Omega, $ by $\psi(z)=a+rz.$   $\implies \psi(z) \in D(a,r) \subset \Omega \implies |(f \circ \psi)^{\prime}(0)| \leq 1,$ by Schwarz lemma  $\implies |f'(a)||\psi^{\prime}(0)| \leq 1$


Let $f:\mathbb{R} \rightarrow \mathbb{R}$ be defined by $f(x)=e^{-\frac{1}{x^2}}$ for $x \neq 0$ and $f(x)=0$ for $x=0$.   I want to show that $f^{(n)}(0)=0$ for all $n \ge 0$. That is, the $n$th derivative at $x=0$ is zero for all $n \ge 0$.   Any hints on how to get started? Thanks.

Show, that the function  $$ \mathcal E: \mathbb R \to \mathbb R:  x \mapsto \begin{cases}  \exp(-\frac{1}{x^2}), & \text{if x $\neq$ 0}, \\  0, & \text{otherwise},  \end{cases} $$  is infinitely differentiable and that $\frac{d^k\mathcal E}{dx}(0) = 0$ for all $k \in \mathbb N$.  We just introduced differentiation, so the solution should not contain very advanced techniques to solve this. We also got the tip it should be done by induction.  @fgp I found that it is $$f^{(n)}(x) = P_n \left(\frac1x\right)e^{-\frac1{x^2}}$$ where $P_n$ is a polynomial with integer coefficients.  I could also do the initial step for the induction:  For $n=1:$ $$f'(x) = \frac2{x^2}e^{-\frac1{x^2}} = P_1 \left(\frac1t\right) e^{-\frac1{x^2}}$$ where $P_1(x)=2x^2.$  I am stuck at the induction step: $f^{(n+1)}(x) = $.....


How does one define the entropy of a natural network (say for example, a river network, or a morphological skeletal network of a lake in the figure below) ? For example, the following report suggests defining it in terms of a topological diameter. But,again it involves defining the generator of the fractal network.  Ref:

I also asked in SO  a few days ago, thought it may be also interesting for physics-related answers.  I would like to model a network as a system.  A particular topology (configuration of edges between vertices) is a state-of-order of the system (a micro-state). I am trying to compute the entropy of a specific topology as a measure of the complexity of information embedded in that topological structure.   I don’t have a degree in physics, I would like to have answers that can help in creating a concept of entropy applied to networks (particularly small-world networks), as systems embedding information in their topology.  Below, I share my reasoning and doubts.   I first thought to make an analogy with Shannon entropy applied to strings: Here entropy is a measure of the randomness of a string as a sum of probability to have certain digits happenings.  Similarly, I then thought that entropy may hold for an Erdős–Rényi random network, and the measure could reflect the randomness of an edge between a pair of vertexes.   Does Shannon entropy hold for non-random types of networks?  As a second approach, I thought that according to Boltzmann’s definition, entropy is the multiplicity of equivalent states.    How could equivalent topologies be modelled (or how to can we compute similarity between two networks)?  How to measure how much a state of order of a particular topology is “uncommon”, with respect to all other possible configurations?  Should I attempt to model a topology as a probability over all possible distributions of edges (complete network)?


How to prove that No solutions exist for $2a^2 + 3b^2 = 6c^2$ for $a,b,c  \in N$   Attempt: Since  $3∣3b^2$  and  $3∣6c^2$ , we must have  $3∣2a^2$   and thus  $3∣a$. Since  $2∣2a^2$  and  $2∣6c^2$ , we must have  $2∣3a^2$   and thus  $2∣b$. Let $a = 3A , b = 2B$ $18A^2 + 12B^2 = 6c^2$ $3A^2 + 2B^2 = c^2$  I am stuck here. Reducing this equation using modular arithmetic does not seem to help.

I am unable to get a start for this question      $2x^2+3y^2=z^2$ does not have a non-zero integral solution.    Can anyone please give me some hint so that I can try this , as I am unable to start.  Thanks


Would a halfling rogue mounted on a War Dog get to apply sneak attack damage to a melee attack made while mounted?  The Sneak Attack text states "You don't need advantage on the attack roll if another enemy of the target is within 5 feet of it, that enemy isn't incapacitated, and you don't have disadvantage on the attack roll."  But, a controlled mount does not attack, it's only actions are Dash, Disengage, or Dodge.  Does this remove the mount as "...another enemy of the target..."?  I'm inclined to allow Sneak Attack for a rogue mounted on a trained mount, but wanted to know if there is any official ruling on this topic.

I was working on building a Zorro character and this question came up: if a rogue is riding on a mount, is that mount considered an ally, or, specifically, an "enemy" of your target?  One of the ways Sneak attack can be trigged is...     "... if another enemy of the target is within 5 feet of it, that enemy   isn’t incapacitated, and you don’t have disadvantage on the attack   roll."   My assumption is yes. Every mount I'm aware of has some kind of attack at its disposal, and thus they represent a threat to your target in addition to the increased threat potential they grant you as the rider. Moreover, if a gnome can proc a sneak attack by acting as a distraction, I don't know why a warhorse wouldn't be able to. That said, is there anything in the books or elsewhere that defines what "enemy of the target" is allowed to include?


I have an LG running Android 7.0 that I used to be able to get to /Android/data/net.osmand.plus/files/tracks in internal storage. I would have to restart to see the new tracks though. Now I have moved Osmand files to 32GB sd card and it works but I cannot access it while plugged in. When I turn it off and plug the SD into a computer I can view the directory just fine. I was also unable to browse to other files like a video file I recorded without finding the exact folder and using adb pull command.

I am using HuaWeiNova device, and I tried to access it with aft-mtp-cli. $ aft-mtp-cli $ ls DCIM/  I got folders listed here: |-photos |-Camera ....  When I tried to list or download my photos in the Camera/ folder, I got nothing. Only the empty folders are listed and the folders that contains files are not shown at all. I am quite sure my photos are stored in the Camera folder in my cell phone. How come I could not access my photos with my computer ?


Show, that $f(x,y)=(y-x^2)(y-2x^2)$ reaches it's minimum at $M(0,0)$   for $f(t\cos\alpha,t\sin\alpha)$, but $M$ is NOT a local minimum   point.   Seemed to be an easy one, but I couldn't handle it. We have. $f(t)=(t\sin\alpha-t^2\cos^2\alpha)(t\sin\alpha-2t^2\cos^2\alpha)$ for any fixed $\alpha$ $f'(t)=8t^3\cos^4\alpha-9t^2\sin\alpha\cos^2\alpha+2t\sin^2\alpha=0$ $t_0=0$ is a root  for $f'$, and $f'(0)=0$, however it has 2 more roots since $D>0$ $f''(t_0)=24t_0^2\cos^4\alpha-18t_0\sin\alpha\cos^2\alpha+2sin^2\alpha=2sin^2\alpha>0$ so $t_0$ is a minimum. part 1 done.  $$\begin{cases}  \frac{\partial f}{\partial x}=2x(4x^2-3y)=0 \\   \frac{\partial f}{\partial y}=2y-3x^2=0 \end{cases} $$ solution is again $M(0,0)$ $$\frac{\partial^2 f(M)}{\partial x^2}=24x^2-6y=0,\frac{\partial^2 f(M)}{\partial y^2}=2,\frac{\partial^2 f(M)}{\partial x \partial y}=-6x=0$$ $$\Delta  = \begin{vmatrix} \frac{\partial^2 f(M)}{\partial x^2} & \frac{\partial^2 f(M)}{\partial x \partial y} \\  \frac{\partial^2 f(M)}{\partial x \partial y} & \frac{\partial^2 f(M)}{\partial y^2} \end{vmatrix}=0$$ I've got the determinant is zero for the particular point, and here I reached to dead end, I have no idea how to continue/conclude, please help me to finish this one. thanks

There is an exercise in my lists about those functions: $$f(x, y) = (y-3x^2)(y-x^2) = 3 x^4-4 x^2 y+y^2$$  $$g(t) = f(vt) = f(at, bt); a, b \in \mathbf{R}$$  It asks me to prove that $t = 0$ is a local minimum of $g$ for all $a, b \in \mathbf{R}$  I did it easily: $$g(t) = 3 a^4 t^4-4 a^2 t^2 b t+b^2 t^2$$ $$g'(t) = 2 b^2 t-12 a^2 b t^2+12 a^4 t^3$$ $$g''(t) = 2 b^2-24 a^2 b t+36 a^4 t^2$$  It is a critical point: $$g'(0) = 0; \forall a, b$$  Its increasing for all a, b: $$g''(0) = 2b^2 > 0; \forall b \ne 0$$ and $$b = 0 \implies g(t) = 3 a^4 t^4$$ which has only one minimum, at $0$, and no maximum  However, it also asks me to prove that $(0, 0)$ is not a local minimum of $f$.  How can this be possible? I mean, if $(0, 0)$ is a minimum over every straight line that passes through it, then, in this point, $f$ should be increasing in all directions, no?


Suppose we have a line $L$ in the projective space $ \mathbb{CP}^2$ and we choose a point $R \in \mathbb{CP}^2$, such that $R \notin  L$. For any other point $P \in \mathbb{CP}^2$, we define $L_{PR}$ to be the line  through $P$ and $R$.  Now we define the following map: $$ \phi: \mathbb{CP}^2 \setminus {\{R\}} \to L, \ \  P \mapsto \{L \cap L_{PR}\}.   $$  Here $\{L \cap L_{PR}\}$ is the unique intersection point of those two lines. The map $\phi$ is apparently holomorphic, but how would one go about proving that it is holomorphic?

I have a line $L\subset \mathbb CP^2$ and a point $R\in \mathbb CP^2-L$. I need to prove that the map  \begin{align*} \varphi:\mathbb CP^2&-\{R\} \to L\\ &P\quad\mapsto L\cap L_{RP} \end{align*} where $L_{RP}$ is the line between $R$ and $P$, is a holomorphic map between complex manifolds.  I'm having some troubles finding an explicit description of $\varphi$, so that I can make sense of the composition with the charts. Any help? Are there other ways to prove this?


I am having error:  ( SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 's a immoderate-immoderate-fine boy' WHERE id='4'' at line 1all )  I am actually trying to modify and save bulk text using the method bellow by looping but the problem is I get above error after process few text. As I found mysql reserved words getting matched while looping on bulk text. How can I modify my method to work on bulk text without mysql reserved word conflict problem. Whats the solution?  Text update method:  public function update_des($id,$des){         try         {             $stmt = $this->conn->prepare("UPDATE products SET des='$des' WHERE id='$id'");             $stmt->execute();         }         catch(PDOException $e)         {             echo $e->getMessage();         }      }

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I have built an area in the sky in the overworld and have attempted to link to it from the ground through the Nether rather than building ladders and such in the overworld. I've read that the Y coordinate does not need to be translated to the Nether since it doesn't reach as high as the overworld anyways as long as all the portals in the Nether are at the same elevation. There's also a video demonstrating this. Is that false? I drew a diagram to best describe what is happening with the attached coordinates. Both overworld portals work fine going to the corresponding portals in the Nether, however both Nether portals link to the same ground overworld portal.

I have 3 portals that link together, but I want to remove at least the middle one.  Edit for clarification:    The portals I created are 1, 4 and 5, the others were spawned by the game as the "other end". I want to remove the link between 5 and 4 and create a link between 5 and (the yet non-existent) 6.  The goal is to be able to travel to 5 in the route: 1, 2, 6, 5. I don't really need 3 and 4 now.


From Euler's identity $e^{i\pi} = -1$ ⇒ $e^{2\pi i} = 1$ ⇒ $[e^{2\pi}]^i = 1$ ⇒ $i = \log_ {e^{2 π }}1$ ⇒ $i = 0$ But how is this possible? Please help me in finding that where i am going wrong.

We know that $e^{\pi i} = -1$ because of de Moivre's formula. ($e^{\pi i} = \cos \pi + i\sin \pi = -1).$  Suppose we square both sides and get $e^{2\pi i} = 1$(which you also get from de Moivre's formula), then shouldn't $2\pi i=0$? What am I missing here?


I have a directory full of files.  I want to rename all the files that match *.py to -backup.py.  How do I do that.    I know I can use for i in *.py, but from there I'm not sure how to keep the initial name and just append backup to all of them.

I would like to change a file extension from *.txt to *.text. I tried using the basename command, but I'm having trouble on changing more than one file.  Here's my code:  files=`ls -1 *.txt`  for x in $files do     mv $x "`basename $files .txt`.text" done   I'm getting this error:  basename: too many arguments Try basename --help' for more information


For example, assume people were asked to rate a movie on a scale from 1 to 10, and their rating had to be a whole number in this range (so no decimals).   Would this rating be classified as a numeric or categorical variable?  Also to take this a step further, say we asked them to rate 2 movies on the same scale, and then summed the result to produce a "result" variable. Would this be categorical or numeric?  I would be inclined to say numeric for both, but technically, there are only a set number of ratings they could give which would mean the "result" variable would have to be a number between 1 and 20 therefore, they could potentially be classified as categories?  What would you classify these variables in these scenarios as?

I've read in a number of places that calculating the mean of an ordinal variable is inappropriate. I'm trying to get an intuition for why it might be inappropriate. I think it is because, in general, an ordinal variable is not normally distributed and so calculating the mean will give an inaccurate representation. Could somebody give more detailed reasoning for why calculating the mean of an ordinal variable might be inappropriate?


I installed xubuntu-desktop metapackapge on my system and after this action unity-greeter no longer appears. I've purged lightdm twice, then reinstalled lightdm and unity-greeter. But still no result. Copying all files from /usr/share/lightdm/lightdm.conf.d/ to  /etc/lightdm/lightdm.conf.d/ returned my Unity greeter but it works incorrectly, for example it asks for my password each time when locking the screen. I've rechecked this option in system settings many times, but it doesn't respond. How to get lightdm and Unity greeter back without reinstall of the system?

I've installed XFCE Desktop environment, but when I decide to switch back to Unity, while uninstalling the XFCE packages, the LightDM keep starts like XFCE, and I want to restore the Unity one. I think that is called Unity Greeter. Can someone help me?


The title should be self-explanatory. If you die in Dragon Age Inquisition, as in all party members die, do you loose anything? Experience, gold, gear, etc?

I've had a couple of encounters so far where I stumbled into enemies that were higher level than expected and gotten wiped out. At the game over screen, I chose the option "Continue". After doing so, I didn't notice any negative consequences. I was plopped back just a few metres from the area I died, and was free to continue on as if nothing had happened. Am I missing something? Is there some negative effect from a party wipe?


I've got error message at my terminal. Whenever i am using sudo command, my terminal is showing:   no talloc stackframe at ../source3/param/loadparm.c:4864, leaking memory

Everytime I try to sudo something at the terminal, I get a warning message:  alexandre@XPS-15Z $ sudo mount file.iso /mnt/ -o loop [sudo] password for alexandre:  no talloc stackframe at ../source3/param/loadparm.c:4864, leaking memory   It's just annoying to get that all the time. How do I solve that? I'm on Ubuntu 14.04 (upgraded from 13.10)


I can boot Ubuntu easily and choose options but when I select install inside windows 8 and press continue , a black screen appears and Ubuntu CD comes out and if I press a button, the computer restarts. I have windows 8 acer laptop.

I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:


Imagine I'm in /Users/beauthi/Documents in Finder. I want to launch commands in my default terminal, which is iterm, in that location. Is there a specific trick in the Finder app to launch iterm and get directly to the directory /Users/beauthi/Documents ? Thank you very much !

I was wondering if there was any was I could right click inside any instance of a "Finder" window such that I have an option that says "Open Terminal Here". It would be really helpful.


Web search: $p$ is a prime, $a$ is any integer for which $a^p-a$ is a multiple of $p$. My research: I found that if $p$ is smaller than a then the remainder of $a^p/p$ is not going to be a which is contradict to the theorem. Examples: $$p=2,a=17$$ $$17/2=8+1/2$$ $$17^2/2=144+1/2$$ Contradiction shown.

I am trying to write the Euclidean algorithm in the following way:  $A = \lfloor A \div B \rfloor \times B + (\text{remainder of}) \: A \div B $   Now is there any symbol I can use  to say "remainder of A $\div$ B"? I know that in the C programming language there is the operator % for modulus; is that a valid symbol in maths? Can I write A % B? Or is there some other way?


I recently found this picture   And I wanted to do something like that with tikz. Can someone do to me a MWE?

creates word clouds based on the frequency on words in a text, similar to tag clouds. What makes it unique is that it can lay out words in arbitrary directions without too much white space. See the  for many examples.  Given a list of words together with their frequency, is there some package that provides at least some of the functionality in (La)TeX? If not, is there some way to abuse the TeX layout engine to produce word clouds?  (This is not meant as advertisment for wordle, I just do not know of anything that is similar.)


I recently crossed into Mexico from the US, forgot to bring my passport. Could I go back using my learner driving permit? I am 17 years old.   OP comment: US citizen, born and raised in Arizona.

Suppose I am a naturalized citizen of the US, but also a citizen of another country, "XYZ". I then boarded a plane and left the US to another country (maybe not necessarily to XYZ), without first getting a US passport, but using my old, but valid XYZ passport.   In this case what would be the best documents to have for me to gain entry back into the US as a US Citizen without a passport?  Would I need to contact the US Embassy for help in order to be able return?  If the airline does let me aboard to return to the US, even without the US passport, what are the best documents could I show at the border to prove I am a US citizen but that I just don't have a passport, for whatever reason?


The restaurant has a lot of customers stand in line every lunch time   The restaurant has a lot of customers standing in line every lunch time      I know for the fact that the verb "has" in sentence 1 functions as a causative verb like "make" or "let". But, how about the one in sentence 2?   I am not so sure.  I think the verb has in sentence 2 is not a causative verb but functions as a general verb with standing as a modifier.  Could you help me clarify it? Thank you.

For example, in the following sentence, can I replace have them with makes them, or is there another verb that more correctly I could use instead of has?     Since the manufacturers are so deeply involved, in some cases Wal-Mart even has them handle their own distribution, saving the retailer big bucks and increasing profit margins on cheaper goods.   Another example could be the following one.     The doctor sends my father and Uncle Johnnie out for all the ice they can get. Then he has them dump the ice in the bathtub, add cold water almost to the top, whereupon my aunt is wrestled into the tub and submerged.


I have two independent random variables which follow binomial distributions $X \sim B (n_1, p_1)$ and $Y \sim B (n_2, p_2)$.  Can we say that $Z = X + Y$ is also binomially distributed $Z \sim B (n_1+n_2, (p_1+p_2)/2)$? Can you explain the answer to me please?  I have read many articles without finding the answer. I know that if $p = p_1 = p_2$ then we can say that $Z \sim B (n_1+n_2, p)$. But what can we say when $p_1\neq p_2$?

So for a bit of recreational spreadsheet creation I've been pondering probabilities.  Let's say I have two types of trial, A and B, with a 40% and 25% chance of success respectively. How can I calculate the probability, for instance, that I get at least two successes if I run trial A three times and B twice?  As I understand it, I can use a binomial distribution to calculate each one individually: 35.2% for at least two successes from A, or 6.25% from B. In addition, I would reckon the probability of getting at least one success in the combined set to be 87.85%, as I calculate a 12.15% chance of getting exactly zero successes on all five trials.  I'd greatly appreciate a little help working this out, because it's been bothering me for a couple of days.


int Mystery(int N) {   int Sum = 0;   for (int i = 0; i < N; i++)     for (int j = 0; j < i * i; j++)       for (int k = 0; k < j; k++)         Sum++;   return Sum; }   I am learning about complexity, but don't know about this, anyone has any ideas?

Most people with a degree in CS will certainly know what . It helps us to measure how well an algorithm scales.   But I'm curious, how do you calculate or approximate the complexity of your algorithms?


This is a follow up question to these two (similar story, just for latexmk):      I have the following MWE  \documentclass{article} \usepackage[ backend=biber, sortcites=true,   sorting=ynt,bibstyle=authoryear -comp,   citestyle=authoryear -comp ]{biblatex}  \bibliography{mybib} \begin{document}   \parencite{Sample:01,Sample:02}  \begin{refcontext}[sorting=nyt] \printbibliography \end{refcontext} \end{document}   and a bib file that looks like this    @Article{Sample:01,   title                    = {Some Title},   author                   = {Zhu, Zhang z.},   year                     = {1900},   pages                    = {1-2},   journal                  = {Really Cool Journal},}    @Article{Sample:02,   title                    = {Different Title},   author                   = {Abe, Alp A.},   year                     = {2000},   pages                    = {3-4},   journal                  = {Other Cool Journal},}   I am using Miktex and latexmk to compile this. I want that citations are sorted withing the text using ynt in the bibliography I want nyt. I follow @Moewe in the related question. When watching pdf updates while latexmk runs, I observe the following:   First run: no citations picked up Second run: intext citation order correct, no bibliography Third run: citations correct and bibliography correct Fourth run: in text citations sorted like the bibliography.   So in the end I end up with this result:    Why does the fourth run happen? Why is the option of refcontext applied globally rather than locally?

I wish to cite several sources at once and sort my in-text citations in a different manner to how they appear in my bibliography. I want my citations to be sorted by year and my bibliography to be sorted by author. I am using BibLaTeX with Biber. I used  to achieve this with TeX Live 2015 but since upgrading to 2016 (as well as upgrading all my packages) this does not work.  Below is a minimal working example (with a second bibliography for illustrative purposes). I wish for the citations to be sorted ascending by year (2001, 2002, 2003) and the bibliographies to be sorted alphabetically (a, b, c) and descending by year (2003, 2002, 2001) respectively, but below is an image of the result; the bibliographies stay true to the desired sorting but the citations in-text are sorted descending by year.  If I remove the last \newrefcontext then everything (citations and bibliographies) is sorted alphabetically, and if I remove both \newrefcontexts then everything is sorted ascending by year (which was the option specified when originally calling BibLaTeX). It seems that the citations follow the last sorting referenced; ynt as per BibLaTeX options when both \newrefcontexts are removed or else whatever sorting is specified in the last \newrefcontext.  I am compiling in order pdflatex, biber, pdflatex, pdflatex and am on MacTeX.  It seems this would have worked as desired in TeX Live 2015 so is this a bug or has something changed which requires the citation sorting to be set in some other way?  \documentclass{article}  \usepackage[            backend=biber,            style=authoryear,            sorting=ynt,            sortcites,            ]{biblatex}  \usepackage{filecontents} \begin{filecontents}{lib.bib} @article{test1,   author = {b},   title = {b},   year=2003, } @article{test2,   author = {c},   title = {c},   year=2001, } @article{test3,   author = {a},   title = {a},   year=2002, } \end{filecontents}  \addbibresource{lib.bib}  \begin{document}      Hello World! \parencite{test1,test2,test3}      \newrefcontext[sorting=nyt]     \printbibliography      \newrefcontext[sorting=ydnt]     \printbibliography  \end{document}     Edit  I have a workaround but it's super crap: Typeset the document with global sorting=ynt, copy the pdf to another file, then typeset the document with global sorting=nyt; using a PDF editing tool (Apple's Preview suffices) cut the pages containing the bibliography with the desired sorting from one PDF and paste into the other. As I said super crap. I'm not sure if I'd even do this as I'd feel dirty, but it's a workaround nonetheless.  If a solution does not exist or this is a bug without a patch, then what would be similar but much better would be some kind of package (which probably doesn't exist) which only changes certain pages at a time within the PDF (while still actually 'compiling' the whole document so that all the citations are done). It might look something like:  % document preamble % ...  \usepackage{onlychange} \onlychangerange{10,12}  % Bibliography found on pages 10--12 % On next compilation will typeset all pages except 10--12  % ...   It's a long shot but maybe someone knows of such a package or this rambling has inspired an actual solution.


This might be too much of an open ended question, but I'm just now learning about metaclasses in Python and I don't understand how a metaclass is any different than just having a child class inherit from the parent class, like  class child(parent):   Wouldn't this serve the same purpose of a metaclass?  I guess maybe I don't understand the purpose of a metaclass.

In Python, what are metaclasses and what do we use them for?


hello i'm trying ton understand a programm and a line giving me some trouble. Can you explain me the Construction of this line because i have never seen a "For" like that  for (Iterator<IBaseVO> itMachine = machinesSelected.iterator(); itMachine.hasNext();) {             MachineVO mach = (MachineVO) itMachine.next();             idsMachines.add(mach.getMchId());         }   thanks you

When I use an Iterator of Object I use a while loop (as written in every book learning Java, as Thinking in Java of Bruce Eckel):  Iterator it=...  while(it.hasNext()){     //... }   but sometime i saw than instead somebody use the for loop:  Iterator it=... for (Iterator it=...; it.hasNext();){     //... }   I don't' understand this choice:    I use the for loop when I have a collection with ordinal sequence (as array) or with a special rule for the step (declared generally as a simple increment counter++).  I use the while loop when the loop finishes with I have'nt this constraints but only a logic condition for exit.   It's a question of style-coding without other cause or it exists some other logic (performance, for example) that I don't' know?  Thanks for every feedback


How do I keep questions from splitting between pages in exam? For example in the MWE below, I'd like to have a page break after Question 2 so that Question 3 can start on a new page. I don't particularly care how this is done but I imagine a vertical fill would work. Is there a command within exam that does this? I only see the commands that specify what to do with the header/footer if there is continuation but nothing about disabling continuation.  EDIT: Is there a way to make exam do this automatically instead of having me specify where to have a page break?  \documentclass[addpoints]{exam} \usepackage{blindtext}  \begin{document}  \begin{questions}  \question \blindtext[3] \begin{choices} \choice  \choice  \choice  \choice  \choice  \end{choices}  %  \question \blindtext \begin{choices} \choice  \choice  \choice  \choice  \choice  \end{choices}  %  \question \blindtext \begin{choices} \choice  \choice  \choice  \choice  \choice  \end{choices}  %  \end{questions} \end{document}

I'm using the exam class to prepare a test. Unfortunately, the package allows page breaks inside the solution list of a question. Considering this toy example: \question Example of question. Choose a solution: \begin{checkboxes} \choice A \choice B \choice C \CorrectChoice D \end{checkboxes}  It could be that a pagebreak happens between \choice B and \choice C. How could I prevent that? Update The solution proposed by Mico works unless we want to print the solutions to the test AND the last answer of a question is a \CorrectChoice. Here's a MWE that reproduces the problem: \documentclass[answers]{exam} \usepackage[utf8]{inputenc} \usepackage[a4paper]{geometry} \usepackage{etoolbox} \AtBeginEnvironment{checkboxes}{\par\medskip%      \begin{minipage}{\textwidth}} \AtEndEnvironment{checkboxes}{%      \end{minipage}}   \CorrectChoiceEmphasis{}  \begin{document}  \begin{questions}  \question Random text for question 1 \begin{checkboxes} \choice answer 1 \choice answer 2 \choice answer 3 \choice answer 4 \choice answer 5 \CorrectChoice answer 6 \end{checkboxes}  \question Random text for question 2 \choice answer 1 \choice answer 2 \choice answer 3 \choice answer 4 \choice answer 5 \CorrectChoice answer 6 \end{checkboxes}    \question Random text for question 3 \choice answer 1 \choice answer 2 \choice answer 3 \choice answer 4 \choice answer 5 \CorrectChoice answer 6 \end{checkboxes}  \question Random text for question 4 \choice answer 1 \choice answer 2 \choice answer 3 \choice answer 4 \choice answer 5 \CorrectChoice answer 6 \end{checkboxes}      \question Random text for question 5 \choice answer 1 \choice answer 2 \choice answer 3 \choice answer 4 \choice answer 5 \CorrectChoice answer 6 \end{checkboxes}      \end{questions}  \end{document}  I've solved it by following the 2nd suggestion given , that is, surround what you don't want to be broken by \parbox. (For the records, using \samepage didn't work.)


So I'm still pretty new to 4e and I had a concept for a primarily "spellcaster" Human Cleric that uses a bow instead of a regular melee weapon. (A close comparison is Kikyo/Kagomae from Inuyasha.) Basically what I'm looking for is either a way to utilize a ranged instead of a melee weapon to execute powers such as "Righteous Brand" or "Healing Strike" that have a melee keyword. If that's impossible, then I'd like to look for a way to either (bless/enchant/use a ritual) to put the spell on my arrows OR find poisons/enchantments with similar effects. Either solution solves my problem.  My cleric also carries a dagger and isn't that squishy, but I'd still prefer her to stay out of the main fight if possible. I have access to most of the books but I would need help finding enchanted arrows, rituals, or poisons.    P.S. And forgive me but no, I wouldn't want to play another class because that would require learning a new class in the middle of our campaign.

In my 4E game, a player is going to try an elven cleric with a longbow (and a mace, just in case). She chose mostly ranged powers. Are there any caveats to playing such a character, or any builds that I could recommend for her?


Say you find a usb drive on the street and you want to be 100% sure it hasn't been tampered with, neither via software nor by modifying its hardware (adding or modifying components, etc.), so that there is zero risk of malware.  Is fully formatting it enough to be 100% certain no malware remains? If so, is fully formatting it with the standard slow process from within Disk Utility in Tails 3.2 enough to do so?  Asume the highest possible technical ability from the attacker. Not just reasonable or plausible scenarios.

I work at an embedded software company. This morning I found a USB stick in the parking lot in front of the building. With all the stories of "dropped USB stick attacks" in mind, I'm obviously not going to just plug it into my laptop. OTOH, I'm curious to know whether this was actually an attempt to compromise our systems, or it's really just an innocent case of somebody accidentally losing a USB stick. How do I safely inspect the USB stick without risking exposure?  I'm worried not just about malware and crafted file system images; there's also stuff like power surge attacks:.  EDIT: Many of the answers seem to assume I want to keep the drive and use it afterwards. I have no interest in that at all, I know USB sticks are cheap, and that it wouldn't be mine to keep anyway. I only want to know whether this was indeed a semi-targeted attack, partly out of curiosity whether this actually happens in real life and not just in security papers, but also so that I could warn my coworkers.  I want to know how I would figure out whether the stick contains malware. And that's not just a matter of looking at the drive contents and seeing a suspicious autorun.inf or a carefully crafted corrupt file system - I very much also want a way to inspect the firmware. I sort-of expected that there were tools for extracting that and comparing to known-good or known-bad binaries.


I'm taking an intro to topology course, and am having trouble with this question. What is the fundamental group of $\mathbb{C^*}/\{e,a\}$, where $e$ is the identity homomorphism and $az=\overline{z}$.   My thoughts are that $\mathbb{C^*}$ is a $G$-space with $G=\{e,a\}$, so if I know what $\mathbb{C^*}/\{e,a\}$ is isomorphic to then I'll be able to figure out the fundamental group for this quotient space. But so far, we only know the fundamental group of simply-connected spaces, the circle, and products of spaces, so I guess it has to be isomorphic to one of these spaces.   Can someone please help out?

What is the fundamental group of $(\mathbb{C} \setminus {\{0\}})~/~\{e,a\}$, where $e$ is the identity homeomorphism and $az = -\bar{z}$?  Clearly this is homeomorphic to the half cylinder , which is homotopy equivalent to the half circle.  But what is the fundamental group of the half circle?


I have read lots of topics but i still couldn't lower the hardware reserved memory which is over 1GB  There is only 2.21 GB RAM that is being usable by the OS. I had another computer where the usable RAM was 3.5GB. Though, that was Gigabyte motherboard which has no built-in graphic.  The OS is Windows 7 Ultimate 32Bit  Most of the hardware reserved memory i saw is being reserved for the PCI Express with most of its addresses are being reserved for the AMD Radeon.    You can see that there is the reserved addresses from 90000000 to DFFFFFFF on PCI bus.  I have updated the BIOS but that didn't help. I also tried the Msconfig boot settings to uncheck the maximum memory but it did nothing.  Motherboard is ASUS TUF Z270 MARK 2  Are there any BIOS settings that i can disable to save more RAM?

Possible Duplicate:        I just bought a used MacBook on  that came installed with 4 GB of . The first thing I did was installing Windows 7 using . Here's where it gets weird. When I finally booted it up in Windows 7, I checked the Computer properties, and it said that there were 4 GB of RAM, but only 2.97 GB is usable. Why is that? Is there anything I can do about this?


I think complete ring $R$ with respect to some ideal $I⊂R$ is always Hausdorff, because the topology is inherited from direct some of discrete space, which is Hausdorff. For example, well known complete ring p-adic integers or pro finite completion of integers is of course Hausdorff. Are there counter examples, that is, complete ring which is not Hausdorff? Thank you for your help.

I would like to know what does it mean to say " a ring $R$ is complete with respect to some ideal $I \subset R$.  Is it like, we define a metric by saying two elements in $R$ is "close" if the difference lies in a higher power of $I^n$ and $R$ is a complete metric space?


I wish to permanently "delete" a board from my account.  There is one entry in the forum asking this question already, but the reply states that you should "close" the board. I am looking for the answer to the question if a board can be permanently removed from the account?  I've just started to play around with Trello and created several boards that are not relevant any more, will never be relevant and I never want to see them again. So, is it possible to "delete" a board? I cannot find a way to do it.

Is it possible to delete a board in Trello? I see how to pin or unpin it, or add it to an organization. Best I can come up with is remove everyone else from it and set it to member visibility. Guess I could create a dummy user to assign deleted boards too.


I want to write the limits under all three summation means starting from summation left side going towards right side ( dependent limits) , Please help on this.   $$\sum \sum \sum_{0 \leq i < j <k \leq n } 1 }$$   thanks..

I would like to place a lower limit under two consecutive \sums, somewhere in between. So I have \sum_{j=1}^{\infty}\sum_{k=1}^{\infty} and would like to place j>k in the lower limit between the two sums. I believe the multiple integral operator has this kind of functionality.


The addition of Real numbers is commutative, so instead of saying we can find the sum of a sequence $\{a_1,...,a_n\}$ of real numbers that are pairwise not equal, we can say that there is a sum of a finite set $A=\{a_i:1\leq i \leq n\}$ of real numbers, since the order of summation does not matter.  The same thing is true for infinite sequence. Instead of saying we can find the sum of a infinite sequence(series) $\{a_1,...\}$(i.e. $\sum_{i=1}^\infty a_i$) of real numbers that are pairwise not equal, we can say that there is a sum of an infinite set $A=\{a_i: i \in \mathbb{N}\}$ of real numbers, since the result of summation is NOT changed if we put $a_i$ in different order.  Question: Can we define a sum of a uncountable subset of real numbers? Does the order of summation matter in this case?

Obviously, “most” of the terms must cancel out with opposite algebraic sign.  You can contrive examples such as the sum of the members of R being 0, but does an uncountable sum, with a finite sum, ever occur naturally as part of a larger scenario (eg, proof of a theorem, or preparation for a definition)?


Every so often, I get dialogue boxes that look like this:    Selected the text, pasted it into another editor, and lo and behold:     “Slack” cannot be open during installation.      Click Continue to quit “Slack” and begin the update. The application   will open when the update is complete.   So this is just one of those regular Mac App Store dialogues. I tried clearing the font caches with sudo atsutil databases -remove, to no avail.  Another other ideas for how to address this font corruption issue?

I just reinstalled high Sierra after my Mac wouldn't restart. The moment it loads up I am presented with this screen. My login credentials don't work. Can someone explain to me what this screen is and what I'm supposed to input?


I was amazed to see that this code is working. I couldn't figure out why  #include<stdio.h> int main(){   int row,col,i,j;   scanf("%d %d",&row,&col);   int a[row][col];   for(i=0;i<row;i++)       for(j=0;j<col;j++)            scanf("%d",&a[i][j]);    for(i=0;i<row;i++){       for(j=0;j<col;j++)            printf("%d ",a[i][j]);        printf("\n");    } }   Since C is a compiled language then How it is allocating memory for the array a[row][col] ? Since at the time of compilation the value of row and column are not known, then how it is able to make machine code and set the address space for the program? Why this is working as an interpreter language would have worked, If this is a way to create a dynamic array then why are we taught to use malloc for creating dynamic array in C.

On the discussion of dynamic memory here:   The author states:     A memory block like this can effectively be used as a more flexible array. This approach is actually much more common in real-world C programs. It's also more predictable and flexible than a "variable size array"   The type of memory block he is talking about is as such:  const int size = 5; int * array = calloc(size, sizeof(int));   and then using another pointer to iterate over the array:  int * index = array; for (i = 0; i < size; i++) {     *index = 1; // or whatever value     index++; }   My question is how is this method better than a standard variable sized array like this?:  int array[variable];   or dynamic:  char name[] = "Nick";   The author doesn't really shed much light as to why I should prefer the former method to the latter. Or more specifically: How is it more "predictable and flexible"?


I have Ubuntu 12.04 LTS and it was working fine two nights ago and now all day today it has shown me this:   Error:unknown filesystem grub rescue>  I know how to recover from this, but are all my files gone because of this? Please help.

I get this error:  Error: unknown filesystem. grub rescue>   I'm not exactly sure what I did. I believe I installed Ubuntu over Windows on my Acer netbook. I then tried to install , but it wouldn't start installing.  I turned the netbook off and back on. Now I get the error.  I have read a lot of other questions like this, but in my case I cannot boot a CD. If I put a Ubuntu CD or a Linux Mint CD into my external CD/DVD drive and change my BIOS to boot the CD-ROM first, it just gives me the same error screen.  Update copied from comment dated 2012-05-26 02:54:29Z  Here are some results from my commands:   grub rescue>ls (hd0) (hd0,msdos5) (hd0,msdos1)  grub rescue>ls (hd0,msdos5) unknown filesystem  grub rescue>ls (hd0,msdos1) unknown filesystem  grub rescue>ls (hd0) unknown filesystem


I have a situation where it appears as if I've lost data in a single table.  I have a .NET Core API, with a logging middleware. This middleware takes the entire request and response and stores in the database, for debug and support purposes. Other than the request and response, the logging table also contains an IDENTITY(1,1) column (which is the primary key) and other various columns.  Over a duration of about 15 minutes, it appears as if 2798 rows have "disappeared" from the table. The primary key simply jumps from 3561297 to 3564095.  During the same time period, I've got debug logs from clients of this API which indicates that something went wrong during the request. My IIS log notes that any request which causes database access during this time period had taken between 30000 and 40000 ms to complete.  The odd thing is, that other tables does not appear to have similar gaps. In fact other tables have had data inserted and updated in them, without issue it appears. So it doesn't appear to be a full system crash.  Through my Google-Fu I've come across the fact that gaps in a IDENTITY(1,1) key can be caused by a restart of the server -- and in that case the gap is roughly 1000. However, in this case I'm 100% certain that the database has not been restarted, yet I have this gap.   I've tried reproducing this error by inserting rows and adding a THROW statement in the end, in my test environment to no avail. I've tried to simulate timeouts by both adding a WAITFOR DELAY and making a TABLOCKX, HOLDLOCK on the table, while trying to do a lot of inserts through the application. Every database operation is done through stored procedures btw.  I'm quite frankly stumped. Does anyone have any ideas / hints as to why I've got this apparent data loss in one table? Or what can cause a massive gap in the primary key like this?  As far as I can tell I have no transactions in the logging middlewares SQL. And IMPLICIT_TRANSACTIONS is OFF on the server, and I'm not using XACT_ABORT in the query. How can a transaction rollback occur, if I do not execute a BEGIN TRANSACTION? I thought SQL Server only made "auto transactions" if IMPLICIT_TRANSACTIONS was set to ON?

I'm trying to generate unique purchase order numbers that start at 1 and increment by 1. I have a PONumber table created using this script:  CREATE TABLE [dbo].[PONumbers] (   [PONumberPK] [int] IDENTITY(1,1) NOT NULL,   [NewPONo] [bit] NOT NULL,   [DateInserted] [datetime] NOT NULL DEFAULT GETDATE(),   CONSTRAINT [PONumbersPK] PRIMARY KEY CLUSTERED ([PONumberPK] ASC)     );   And a stored procedure created using this script:  CREATE PROCEDURE [dbo].[GetPONumber]  AS BEGIN     SET NOCOUNT ON;      INSERT INTO [dbo].[PONumbers]([NewPONo]) VALUES(1);     SELECT SCOPE_IDENTITY() AS PONumber; END   At the time of creation, this works fine. When the stored procedure runs, it starts at the desired number and increments by 1.  The strange thing is that, if I shut down or hibernate my computer, then the next time the procedure runs, the sequence has advanced by almost 1000.   See results below:    You can see that the number jumped from 8 to 1002!   Why is this happening?  How do I ensure that numbers aren't skipped like that?  All I need is for SQL to generate numbers that are:   a) Guaranteed unique.  b) increment by the desired amount.    I admit I'm not a SQL expert. Do I misunderstand what SCOPE_IDENTITY() does?  Should I be using a different approach? I looked into sequences in SQL 2012+, but Microsoft says that they are not guaranteed to be unique by default.


I have come across many homework questions poorly made, with no efforts to solve and steps taken. Apparently the askers haven't gone through the homework policy yet. These questions are almost always flagged for closing. The asker is often annoyed at the closing.   I believe that instead of flagging, commenting the homework policy links, and allowing the asker to edit his question and show the efforts he has made. We can give up to two days for the question to be edited, otherwise it can be flagged and closed.  This will allow the asker to know about the homework policy, as well as get his homework question clarified. Does anyone agree with my views?

Since it's currently impossible to delete a "vote to close",* when I see a poorly asked question, should I immediately vote to close, or should I comment, and give the OP a chance to improve his question?  Waiting increases the chance that I'll forget, and never vote to close, potentially leading to a cluttered site.  Voting to close immediately increases the chance that the question will be closed, and the author will be forced to re-post his (hopefully improved) question, which leads to a cluttered site. :)  *It is now possible to , but that doesn't change the fundamental nature of this question.


What makes the discard pile locked or frozen? I've never heard of this term.

Is this a correct understanding of when you are allowed to pick up the discard pile?  If not frozen, you can pick up the discard pile if you can use the top card to make a meld from your hand OR to simply take the top card and put down and add to an existing meld on the table.  If the discard pile is frozen you can only pick up if the top card can make a meld from cards solely in your hand.  In other words if the top card is an 8 and you have an existing meld of 8's on the table but no 8's in your hand ( or wild card and 8) -you can't pick up the frozen discard pile?


Here is my function:     public boolean loadPaper(Paper paper) {     boolean success = false;     try {         FileInputStream file_in = new FileInputStream(getDbFileName(paper));         ObjectInputStream in = new ObjectInputStream(file_in);         paper = (Paper)in.readObject();         in.close();         file_in.close();                  success = true;     }     catch (IOException | ClassNotFoundException i) {         i.printStackTrace();     }     return success; }  When I pass a Paper object to the loadPaper method, the method de-serializes the Paper in question and stores it successfully in "paper." However, when the method returns to the calling method, the "paper" object passed in as a parameter no longer stores the data that was loaded. For example, after this code executes: Paper paper = null; loadPaper(paper);  "paper" no longer stores any data, even though it did up until the end of the loadPaper method. Any idea why?

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


Simple question: what does $2^{3^4}$ equal to? I am asking this because some calculators take this as $2^{(3^4)}$ and others as ${(2^3)}^4$.

Does $x^{y^z}$ equal $x^{(y^z)}$? If so, why?   Why not simply apply the order of the operation from left to right? Meaning $x^{y^z}$ equals $(x^y)^z$?  I always get confused with this and I don't understand the underlying rule. Any help would be appreciated!


I want to add views count inside playlist to show views-count on each track like this sample:

My aim is to get the total number of listens so I was thinking I could save a 'listen' count to the audio file's post meta using update_post_meta()  Is there a hook that fires each time an audio file is played?  Background: I'm using wp_audio_shortcode() to output the (mediaelement) player.   Refs:


Similar to , there is a gap between the title bar of a maxmized window and the menu bar.  I have a full-screen iTerm window in the background, with "use Lion-style Fullscreen windows" disabled.  When content in the iterm window changes, it's visible in this gap and also the also it makes the title bar of the foreground window flash.  Is it possible to remove the gap between title bar and menu bar?

When you hide the Dock, OS X leaves a small gap at that edge. Is there a way to get rid of it?  In case you have never noticed the gap before here is a screenshot. Guess which side of the screen has the Dock:


I was trying to understand the static keyword in c++, for that I wrote following program  #include <iostream> using namespace std;  class class1 {  private:     int a;  public:     void seta (int a)     {         this->a = a;     }     void printa ()     {         cout << a;     } };  class class2 {  public:     static class1 c;  private:     int b; };  int main() {      class2 cls;     class2 cls2;      class2::c.seta (20);     cls.c.printa ();     cls2.c.printa ();      return 0; }   This program is not compiling and is giving following error.  prog.cpp:(.text.startup+0x12): undefined reference to `class2::c' prog.cpp:(.text.startup+0x21): undefined reference to `class2::c' collect2: error: ld returned 1 exit status   I am not able to understand why it is giving error for the statement class2::c.seta (20); and the lines below it.  can somebody please help me understand the same?

Very simply put:  I have a class that consists mostly of static public members, so I can group similar functions together that still have to be called from other classes/functions.  Anyway, I have defined two static unsigned char variables in my class public scope, when I try to modify these values in the same class' constructor, I am getting an "unresolved external symbol" error at compilation.  class test  { public:     static unsigned char X;     static unsigned char Y;      ...      test(); };  test::test()  {     X = 1;     Y = 2; }   I'm new to C++ so go easy on me. Why can't I do this?


Is there a built-in method for computing an SHA-1 or MD5 hash in Windows 7?

Is there any small utility that integrates with the Windows shell and computes md5 of files on demand? I'm too lazy to launch the command line.


I want a proof of the identity $${n \choose n} + {n+1 \choose n} + {n+2\choose n} +\cdots + {N \choose n} = {N+1 \choose n+1}$$ where $N\geq n$, by algebraic or combinatoric methods.

After reading , the most popular answer use the identity $$\sum_{t=0}^n \binom{t}{k} = \binom{n+1}{k+1}.$$  What's the name of this identity? Is it the identity of the  modified.  How can we prove it? I tried by induction, but without success. Can we also prove it algebraically?  Thanks for your help.    EDIT 01 : This identity is known as the  because, on Pascal's triangle, when the addends represented in the summation and the sum itself are highlighted, a hockey-stick shape is revealed.


How to Uninstall system apps without rooting? I have tried many applications but all of them require root permissions. Please help.

I'm using a Samsung I9000 and I have some annoying apps that came pre installed by the phone vendor, like a music store, a custom web browser and other memory leaking apps.  Those crappy apps can't be uninstalled neither by Manage applications tool, nor by editing the apps tiles in the front menu.  I guess I have to be a root user or something to get rid of those apps, but I don't know how.


This afternoon, I went out to take some pictures using a ZEISS Tele-Tessar T 300mm f/4 Lens, with a Tamron x2 Teleconverter adapted to a Sony alpha 6000.  Unfortunately, I have been noticing an unwanted effect. Sometimes objects in my pictures appear to have purple fringing around them. What is the cause of the purple fringing, and is there any way to avoid it? Is it because my lens is of low quality?  You can see the effect in this picture of a local bird judging you.

I have just bought a Nikon 50mm f/1.8D prime lens.  I took this picture (leg of my glasses frame on a mouse, and a LED desk lamp is on top of it) : f1.8, 1/80s, ISO 200   The purple fringing is right in the middle of the picture. Does it happen very often to this lens?


Whenever I tried to install synaptic or other libraries like sudo apt-get install git-core, etc... it's showing errors.   When it starts running but stops at 22% and also with many errors.   I am not able to install anything. When I tried to install synaptic using   sudo apt-get install synaptic   it says unable to locate package synaptic.   The internet connections are also working. firefox is working but I am unable to download anything through terminal.

My apt-get doesn't install any programs. I try to install programs with apt-get install but always it shows same error: unable to locate package. For example I try to install the xbmc media center; here's what happens:  $ sudo apt-get install xbmc     Reading package lists... Done     Building dependency tree            Reading state information... Done     E: Unable to locate package xbmc   I have updated my package list with sudo apt-get update.


Which of the above is correct usage and why. I saw  edit in a stackoverflow question and it got me wondering why was it edited. Is it just because the first one sounds better?

What is the difference between:        "How it works?"      and        "How does it work?"


my Cassandra version is 1.2.4 and i'm trying to upgrade it to 2.0.5 and i know that in the first part i have to upgrade it to 1.0.14 and after that try to upgrade it to the 2.0.5 ,   when I try to run nodetool -h localhost removenode Host ID it gives me :     Exception in thread "main" java.lang.UnsupportedOperationException: Cannot remove self       at org.apache.cassandra.service.StorageService.removeNode(StorageService.java:3199)   .....   before running that command i tried nodetool upgradesstables   what is the problem ? and how can i resolve it ?     OS:Ubuntu 12.04 lts

I have a single node cassandra database running since 2 years now... never had any issues with it, but I would like to upgrade it to the latest cassandra (2.1.2 at the time I write those lines), of course without having to shutdown the service.  I have multiple servers at my disposal, that can be brought up to add nodes into a cluster if needed, what would be the procedure to update from my 1.1.0 version to the latest version without having any downtime ?  I know that it will be hard work, since I can't upgrading from 1.1.0 to 2.1.2 straight, I'll have to go through steps because of un-interoperable versions...


My site is getting a ridiculous amount of spam user sign ups every day. The second I enable 'allow anonymous users to create accounts', 10 spam accounts exist inside of the first 20 seconds of enabling. This seems completely insane. How do I stop this from happening? I'd also prefer not to use the Captcha method, as it does very little from my experience.   So far, I've tried: Honeypot, captcha, ReCaptcha, Antibot, Badbot... And none seem to fix the problem.

I'm going a little nuts here. The entire point of my site resides on the idea of people registering for the site to contribute content. But I get spam accounts created at least once every minute. Im mass deleting these accounts and the content they create every single time I visit my own site.   I currently use  with the CAPTCHA as the default method (not text analysis) and I have text analysis set to every other form across my site, I use the  module set to and properly configured Akismet (had good results from Wordpress), and also have Spamicide enabled and properly configured.   But spam users are still being made in some very insane amounts, and generating content all over my site; which leads me to wonder if they're even using the forms at all any more to generate content on my site..   EDIT  may have been a little paranoia but I changed the user credentials to my database just to be sure. And yeah, user accounts by the dozens still being created..   I just tried out the  module by exposing the form element with Firebug and writing anything in it. Sure enough the form doesn't register the account.   The Captcha works perfectly too.  Note: I understand Captchas is not good enough (Spam bots these days can solve captchas), but its the only option I get from Mollom.


Let $K$ be a field and $I,J$ are ideals of $K[X].$ Then if $K[X]/I \cong K[X]/J$     with $I \subset J$ then can one say that $I=J$ ?

Let $A$ be a commutative Noetherian ring and let $I$ and $J$ be ideals of $A.$  Suppose that $I\subseteq J$ and that $A/I \cong A/J$ as rings.  I want to prove that $I=J.$    Observations so far:  1) If we drop the hypothesis $I\subseteq J,$ then the result is false:  $$\mathbb{Q}[X,Y]/(X)\cong \mathbb{Q}[X,Y]/(Y) \text{ but } (X)\neq (Y).$$  2) If $A/I\cong A/J$ as $A$-modules, then $I=J$:  $$I=\mathrm{Ann}_A(A/I)=\mathrm{Ann}_A(A/J)=J.$$  I'm now a bit stuck as to how to proceed. Any hints would be most helpful!  Many thanks :)


I want to have my footnotes look just like citations in the text, and to have their content contained in the bibliography, so the code in the body would look like:  ...blah blah\footnote{Incidentally, this question was first posed by Smith.}.   while the bibliography (which remains at the end of the article) would look like this:   J. Doe, Rev. Mod. Phys. 19 (1758) Incidentally, this question was first posed by Smith. J. Doe, Nature 27 (1086)   I realize this has to be a duplicate, but every similar question I could find was about putting a bibliography element in the footnotes, not a footnote in the bibliography.

I've been searching for a way to create "Custom References" with biblatex, but haven't found a solution to my problem. Among "normal sources" like Journal Articles, I need other references where I can put a custom sentence in it. Like "[3] This was performed by someone else".  Is there an option to do that?   \documentclass{scrreprt} \usepackage[refsection=chapter,style=chem-angew]{biblatex} \usepackage[english]{babel} \usepackage[T1]{fontenc} \usepackage[ansinew]{inputenc} \begin{filecontents}{biblio.bib}  @article{entry1,      author = "George D. Greenwade",     title = "The {C}omprehensive {T}ex {A}rchive {N}etwork ({CTAN})",     year = "1993",     journal = "TUGBoat",     volume = "14",     number = "3",     pages = "342--351",            url=" www.ctan.org" }  \end{filecontents}  \addbibresource{biblio.bib}  \begin{document} \chapter{Test Chapter One} \cite{entry1} So far so good, now I need another reference that says 'This was performed by someone else'. \printbibliography[heading=subbibliography]  \end{document}


I'm using many basic commands of unix/linux. In Mac OS X Mavericks, I type cat for a file, but output was faulty.  In example, content of the file named bar:  foo    bar   Then:  kaanklky-air:foo-folder kaanklky$ cat bar foo barkaanklky-air:foo-folder kaanklky$   cat command give last line of file with shell's last status, so I want edit cat command to fix it.  How I can do it?

What I get:  host:~ user$ cat example.txt some texthost:~ stas$   What I want to get:  host:~ user$ cat example.txt some text host:~ stas$   Is there a way I can make cat behave like this?  I'm using bash on Mac OS X.


I have seen several definitions of conservative fields, where we always assume that the domain of a vector field $ \pmb F $ is simply connected before giving the definition of a conservative field.  QUESTION:     If we find a function $ f $, where $ \pmb F = \pmb \nabla f $ , and also   $ \pmb F $ and $ f $ have the same domain, then:      Can we ignore whether the domain is simply connected or not and label   the vector field $ \pmb F $ as conservative ?   Thank you in advance

My question is really ''what is the definition of a conservative vector field''?  I've consulted 3 textbooks that all say a vector field $\vec{F}$ is conservative by definition if there exists a scalar potential $\phi$ such that $\nabla \phi = \vec{F}$. Then, they go on to talk about connected domains, path independence and the equality of mixed partials and how they are all related.   In particular, they emphasize that e.g. in $\mathbb{R}^2$ given $\vec{F} = \bigl<F_1,\,F_2\bigr>$, if $\frac{\partial F_1}{\partial y} = \frac{\partial F_2}{\partial x}$ on a simply-connected domain, then $\vec{F}$ is conservative on that domain.  However, without fail, all of them then offer the example of $\vec{F} = \bigl< \frac{-y}{x^2+y^2},\, \frac{x}{x^2+y^2} \bigr>$, pointing out:   it's line integral is not path independent, even though $\frac{\partial F_1}{\partial y} = \frac{\partial F_2}{\partial x}$   and this is explained by pointing out that the domain is not simply connected (if the path contains the origin).  That much makes sense to me: we cannot conclude $\vec{F}$ is conservative based on the partial derivatives, because the domain is not simply connected - totally consistent with what has been presented.  What none of them address is why $\vec{F} = \bigl< \frac{-y}{x^2+y^2},\, \frac{x}{x^2+y^2} \bigr>$ is not conservative when there exists a potential $\phi = \arctan(y/x)$ such that $\nabla \phi = \vec{F}$. None of the texts mention any necessary conditions on the scalar potential. So is the existence of a scalar potential the definition of a vector field being conservative or not?


Is there any workaround to overcome the above governor limit without aborting the job.  Thanks !

I launch a batch which call a lot of scheduled job. But I reach the governor limit :     Maximum number of Apex classes scheduled concurrently : 100   I'm wondering what happens when this limit is reached. The next scheduled jobs are waiting the number of scheduled jobs is lower than 100 for being executed or are they all cancelled ?  And is there to way to manage the number of scheduled jobs to avoir reaching this limit ? For example wait before schedule a new job if we are near the limit.


I am trying to create a website and up the SEO rating for rocket-media.co.uk. The company covers a lot of different design, print, exhibition and digital services. They currently have a one-page site but after some tips from a previous post I am thinking of making it into multi-page site and wanted to check that there is a benefit to having mutli-pages over one page/  I also had an idea of multi subdomains and wanted to know if subdomains are better or worse for SEO. So for example print.rocket-media.co.uk, design.rocket-media.co.uk rather than a print and design page within rocket-media.co.uk.  Thanks for any guidance.

I'm considering re-designing my personal website to promote my web services in my local area.  My issue is whether to do a one page website with a scroll-to navigation system. What effect does this have on SEO. As i understand it, you set stuff like h1's and meta description on specific page content. How does this work when all of your different content is on one page?


I have this exercise:  $a,b$ are positive integers. Get all $a,b$ numbers that satisfies $a^{b^2} = b^a$  Is hard to me, but I have these advances:  $a,b$ must be both even or both odd, since $a, b$ are the base.  Besides, if $a > b$, the exponent and the exponent of $a$ is $b^2$ and the exponent of $b$ is $a$, therefore $a > b^2$  So far I have managed to develop the exercise, what can I do? How do you work with these types of mathematical problems? Thanks in advance

I saw this in quora.  What are all the integer solutions to $a^{b^2} = b^a$ with $a, b \ge 2$?  Solutions I have found so far:  $a = 2^4 = 16, b = 2, a^{b^2}  = 2^{4\cdot 4} =2^{16}, b^a = 2^{16} $.  $a = 3^3, b = 3, a^{b^2} = 3^{3\cdot 9} =3^{27}, b^a = 3^{3^3} =3^{27} $.  In the general case, $a$ and $b$ have the same set of prime divisors, so let $a =\prod_P p_i^{a_i}$, $b =\prod_P p_i^{b_i} $ with each $a_i \ge 1, b_i \ge 1$.  $b^a =b^{\prod p_i^{a_i}} =(\prod p_j^{b_j})^{\prod p_i^{a_i}} =\prod p_j^{b_j\prod p_i^{a_i}} $  $a^{b^2} =a^{\prod p_i^{2b_i}} =(\prod p_j^{a_j})^{\prod p_i^{2b_i}} =\prod p_j^{a_j\prod p_i^{2b_i}} $  Therefore, for each $p_j$, $b_j\prod p_i^{a_i} =a_j\prod p_i^{2b_i} $.  I haven't gotten any further than this.  I conjecture that there are no other solutions.


Possible Duplicate:          I am a dedicated user of Stack Overflow, and now my team seems also interested in getting a similar website setup internally.  I am just wondering where I could find details about this, and terms and conditions also, as I am not that sort of business person to consider them always.

Is the Stack Exchange engine that powers Stack Overflow available to download or install internally for an enterprise or company?  I think Stack Exchange's engine is very great and could be very cool to use for internal enterprise patterns and practices, like the engine of Wikipedia.


I'm using a simple technique to convert binary numbers to hexadecimal.  parseInt('1011110000',2).toString(16) == '2f0' parseInt('111110011111101111100111011011001',2).toString(16) == '1F3F7CED9'   With larger binary numbers, I'm encountering a problem:  parseInt('11000011010011001100110011001100110011001100110011001100',2).toString(16);   Returns c34cccccccccd0 instead of correct value c34cccccccccc.  Minus four bits solve the problem:  parseInt('1100001101001100110011001100110011001100110011001100',2).toString(16);   Returns c34cccccccccc.  Why does this happen? How can I avoid this problem and convert large binary numbers into hexadecimal numbers?

Is this defined by the language? Is there a defined maximum? Is it different in different browsers?


I would like to read a graph from the input file and store it in list of arraylist.First list of the input file contains no.of vertices followed by number of edges. then the next line contains edges of the graph. I tried the following code and i'm getting error which is added at the end  import java.io.File; import java.util.Scanner; import java.util.ArrayList; import java.util.List; public class ReadGraph {      public static void main(String[] args) {          try {             int vertices,edges;             Scanner input = new Scanner(new File("in.txt"));             vertices = input.nextInt();             edges = input.nextInt();             List<Integer>[] tree = new List[vertices];             for (int i = 0; i < edges; i++) {               tree[input.nextInt()].add(input.nextInt());             }             System.out.println(vertices);             System.out.println(edges);             input.close();             System.out.println(tree);          } catch (Exception ex) {             ex.printStackTrace();         }     }  }   Error  java.lang.ArrayIndexOutOfBoundsException: 2 at ReadGraph.main(ReadGraph.java:30)

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I am trying hard to understand how to properly determine the difference.   A gold watch. --A watch that is made of gold A golden watch --A watch that looks like and could be made of gold   But why then I cannot use the same logic for the following:   A gold T-Shirt -- why not golden? A shirt with gold stripes --why not golden? They look like gold but they are not   wrapped in gold and silver paper. -- the same problem    How would you perceive it if I used golden instead?

I always thought that if something is made of gold, it is a gold thing, if it looks like gold but might not be, it is golden. But looking in the dictionary, I can see I was wrong.  In the Cambridge dictionary, for both  and  it reads:     made of gold, or the colour of gold   For "golden" it reads in also:     made of gold   Example sentences for gold:     She always does her presents up beautifully in gold and silver   paper. She was wearing a gold Lurex top with a pink mini skirt.   There are a couple of fish with blue markings, and a few more with   gold stripes down the side.    I understand in those examples "gold" refers to the color but why it is not golden? How would the meaning change if I put "golden" there? How to tell which one should I use?


The way to earn 'Civic Duty' badge is to have Voted 300 or more times. Is there any way to find how many votes I have already made?

I am trying to obtain more badges on Stack Overflow. For example, to gain Archaeologist I need to edit 100 inactive posts but I am not keeping track of the number of posts I've edited. For Deputy I need to raise 80 helpful flags, etc. How can I view all my statistics about the badges, such as how many more edits I need to do, etc. I'm not doing it for badges, but I can spend a bit more effort if I'm close to getting a badge.


I’m a sri lankan citizen currently living in Japan. Can I get a tourist visa from Japan to Korea? If it’s possible, how to do it?

I'm a Vietnamese citizen and currently living in Japan. Can I apply for a South Korea tourist visa at the Korean embassy in Japan, or must I do it at the Korean embassy back in Vietnam?


When landing on  ( redirects to this URL) the search bar at the top is pre populated with   [facebook] or [facebook-graph-api] or [facebook-like] or [facebook-javascript-sdk] or [facebook-fql] or [facebook-php-sdk] or [facebook-c#-sdk] or [facebook-opengraph] or [facebook-apps] or [facebook-ios-sdk] or [facebook-android-sdk] or [facebook-login] or [facebook-page] or [facebook-comments] or [facebook-social-plugins] or [facebook-oauth] or [facebook-access-token] or [facebook-authentication] or [facebook-iframe] or [facebook-canvas]   and no further search terms can be added. :-(

I have a favorite Tag including a wildcard  in my Favorite Tags list to get all question tagged with wpf. (Currently 63,210 question)  Now when i click on a Related Tag, such as  (the count behind the tag states that there are 26,324 question), the c#-Tag gets ignored and the result is still all the 63,210 questions.   The result of the tag-filtering above, should be equal to the search [


I noticed that ExtJS has changed drastically since last time I've checked it out. Right now it can only be used for free in an open source application - otherwise it requires a commercial license.  Is there something free/open source these days that's a viable alternative for extjs? My main goal is to have a javascript framework that can help me build together attractive UIs with minimal work. I'm not a designer, and ExtJS used to let me put together presentable UIs for mockups.

So what I'm looking for is a javascript framework I can use that has several UI controls. I have taken a look at  but those controls are very basic compared to ExtJS. Are there any other competitive alternatives?     This question exists because it has historical significance, but it is not considered a good, on-topic question for this site, so please do not use it as evidence that you can ask similar questions here. More info: .


wordcount = {}     for vocab in file.read().split():         if vocab not in wordcount:             wordcount[vocab] = 1         else:             wordcount[vocab] = wordcount[vocab] + 1     for (word,number) in wordcount.items():         print (word, number) print (word_count(0))

It seems like there should be a simpler way than:  import string s = "string. With. Punctuation?" # Sample string  out = s.translate(string.maketrans("",""), string.punctuation)   Is there?


I am having Refresh Token to generate Access Tokens in Salesforce and by using api calls I can successfully retrieve data using Postman... But my problem is I am automating one of the scenarios in Salesforce including login... So is there a way to login into Salesforce by using Access Token in Web Browser so that I can skip the verification step which is asking each time when I start my test Automation?  My instance is  and I need to proceed to this page after login

I am currently able to login inside salesforce using just a session id   I now want to be able to redirect to a record page by passing 1 additional parameters &retUrl=/0032400000GRVvYAAX  Can anyone help with this?