Number of roots of $z^4+z^3+4z^2+2z+3=0$ in each quadrants

This question has been asked but I am stuck with my method.   I have shown that the roots can not be on the real and imaginary axis. Since the coefficients are real and thus the roots must be in conjugate pairs. So If there is no root in first quadrant (or right half plane), then we have 2 roots in second quadrant and third quadrant respectively. (this is the answer to this question)  So I am going to show that there is no root in right half plane. Consider the integral along the semi-circle in right half plane with radius $R$  $$\int_{C}\dfrac{f'}{f}dz=\int_{-Ri}^{Ri}+\int_{-\pi/2}^{\pi/2}\dfrac{4z^3+3z^2+8z+2}{z^4+z^3+4z^2+2z+3}dz$$  For the second part, $$\int_{-\pi/2}^{\pi/2}\dfrac{4z^3+3z^2+8z+2}{z^4+z^3+4z^2+2z+3}dz=i\int_{-\pi/2}^{\pi/2}\dfrac{4z^4+3z^3+8z^2+2z}{z^4+z^3+4z^2+2z+3}d\theta=4\pi i$$ as $R\rightarrow \infty$.  For the first part, \begin{align*} &\int_{-Ri}^{Ri}\dfrac{4z^3+3z^2+8z+2}{z^4+z^3+4z^2+2z+3}dz\\ &=\int^R_{-R}\dfrac{3y^2-2+i(4y^3-8y)}{y^4-4y^2+3-i(y^3+2y)}idy\\ \\ &=\int^R_{-R}\dfrac{(3y^2-3)(y^4-4y^2+3)-(4y^3-8y)(y^3-2y)+i[(4y^3-8y)(y^4-4y^2+3)+(y^3-2y)(3y^2-2)]}{(y^4-4y^2+3)^2+(y^3+2y)^2}idy\\ &=\int^R_{-R} i(even \,\,part)-(odd \,\,part) dy\\ &=\int^R_{-R} i(even \,\,part) \,\,dy \end{align*} It is expected that $\int^R_{-R} i(even \,\,part) \,\,dy=-4\pi i$, then we are done, but how?  Also is there any method using Rouche theorem?


SQL Injection PHP example, where is the vulnerability and how can I combat this?

I am trying to understand why the following bit of code has a SQL Inhection vulnerability and how I can fix it. Thanks! <?php include_once "lib/db.php"; include "lib/sql_form.php"; if(!$_GET['id']) $_GET['id'] = str_replace("/", "", $_SERVER['PATH_INFO']); $query = "SELECT * FROM listings WHERE id = ".$_GET['id']; $result = mysql_query($query); $line = mysql_fetch_array($result, MYSQL_ASSOC); if($line['status'] == "DELETED"){ print("This file is deleted."); exit;} $_POST['form_id'] = $line['form_id']; $_POST['fields'] = split(",", $line['fields']); excel_report_results(); ?>


Prove the following a tautology : (P ∧ ¬Q) ↔ ¬(P → Q)  I started with trying to seek a contradiction for (P ∧ ¬Q), but honestly I'm lost and don't know how to proceed. Any help would be appreciated.


Let $P(X)$ denote the power set of $X$ (the set of all subsets of $X$) with a partial order given by inclusion.  If $F: P(X) \to  P(X)$ is monotone (order preserving), then $F$ has a fixed point.  How are we going to prove that without using the term (complete lattice)?!


I have a file like this: "Something, something, something, something, something"  And I want to get the index of third "," with:  StreamReader sr=new StreamReader("File.txt"); string s=sr.Readline();     string c=s.Substring(0, s.IndexOf(',')));


"Failed to start session" for main and guest accounts

I was updating my Ubuntu LTS and we had a power outage. Now, when I try to "sign in", I get a "failed to start session" message in bold red under my main and guest accounts. I'm not sure how to fix this.   I'm also unable to connect to the Internet. I have tried (Ethernet, WiFi, and Hotspot)  When I try signing in with the wrong password on the main log-in screen, it says "invalid password", but when I use the correct password it says failed to start the session when I try to sign in using Ctrl+Alt+F2 it says login incorrect.


I have a problem with the interpretation of a test result in which the p-value is 1.727e-05. How should it be interpreted? What is the e for?


In Drupal 8, I have a content type, that has an "entity_reference" field and I wish to access the referenced node's fields in twig template. the kint() output for the field is:   In this list I can't find the referenced node's field values. How can I (if at all possible) load the node or node fields/values in twig?  Best,  Alari


We have a 2012 Server which is failing to install updates, just searching online, WSUS forever to get updates. I tried rebooting and running the WSUS stop, renaming the Softwaredistribution folder and tried to install some patches manually, but the installation is taking forever too.  Even the manual installation is also taking forever. I checked windowsupdate log file and the logs says no approved patches, but when i checked online and for WSUS updates, for the effectiveness, it is taking forever to search for updates.  Please help me in getting this resolved.  Thank you.


How can I install Ubuntu on an external hard drive so that I can boot it on different computers?

I need to be able to use Ubuntu on different computers with my external hard drive, with varying devices. And it needs to be a full (normal..ish) install. (No bootable+overlayfs persistence for me!)  I'll probably be using computers with an i386 architecture, but the 32/64-bit could change.  Or, I'll just hope for the best and just repart my drive and install.


Let $f:=X^5-9 \in \mathbb{Q}[X]$. Show: $f$ is irreducible.   So I can't use the criterion, that f has no roots in $\mathbb{Q}[X]$, beacuse $\deg(f)>3$. Eisenstein is also not possible, because the only divider of $9$ is $3$. So I tried the reduction criterion, which doesn't really help me because $\deg(f)$ is still $5$. And in $\mathbb{Z}/7$ for example there are no prim elements, So I can't use Eisenstein. Is there another way I don't see?


No Wi-Fi adaptor found - Ubuntu 20.04.1 after update

I did a fresh install of Ubuntu 20.04 LTS on my Lenovo G510 laptop which also runs Windows 10 such that dual boot is enabled. On completion of installation, everything was working fine (I include Wi-Fi in this statement), and I connected to the internet via Wi-Fi. I got an "Update Package" of about 500 MB which I installed and rebooted. On rebooting Wi-Fi does not seem to work and searching for it in Settings shows No Wi-Fi adapter found. Make sure you have a Wi-Fi adapter connected and turned on. I'm new to Linux and Ubuntu and tried a couple of solutions on the forum which don't seem to have made a difference. I really don't want to keep trying without really understanding the issue and which could only make my situation worse. Let me know any information needed which can help diagnose the issue. ~$ sudo lshw -class network -short H/W path         Device      Class          Description ======================================================= /0/100/1c.1/0                network        BCM43142 802.11b/g/n /0/100/1c.2/0    enp3s0      network        QCA8172 Fast Ethernet   ~$  lspci | grep -i broadcom 02:00.0 Network controller: Broadcom Inc. and subsidiaries BCM43142 802.11b/g/n (rev 01)    Thanks,


In c++, how can I iterate through each line in a string? There have been plenty of questions regarding reading a file line by line, but how can I do this with a std::string?  For example, if I have the following string:  1051 2232 5152 3821 0021 3258   How would I iterate through each number?


by repeatedly asking the same question. The user would ping individuals with the same message. I've asked the user to please stop bugging people and moved the messages to bin (message trashcan). Unfortunately, the OP continued, so I started to flag his messages (about 5). I deliberately flagged all those to give those able to moderate the chance to have some sense of context about whats happening. Then the OP started to accuse us of being unhelpful. We explained once more what we think of his behavior. He started to flag some of our messages in turn. Shortly afterwards, someone from the C++ chat comes in and complains about the flagging and a new argument started. Since this is not about pointing fingers or who said what to whom in what channel and to what effect, I'll just give you the quintessence:  Every time you guys flag something, all 10k+ users across the whole chat are asked to validate a flag given only a context free message and a link to the chat. That is terribly annoying. […] That button popping up irks me to no end. It's like a phone ringing, I cannot concentrate on anything else, and just have to pick it up.  Regardless of whether you agree with this or not, here is my suggestion: Since there has been  about how the  works in the past, I think we should add an opt-out for those not wanting to participate in chat moderation (or improve the process in some other way). If people simply mass-(in)validate just to get rid of the flags, the tool is ineffective. I'd rather have those willing to participate handle flags with care instead.


Checking for reverse causality with lead regression, should the lead model be in its original state i.e. no transformation?

Im checking for reverse causality with a regression including leads. The reasoning is that the coefficient of the lead should not be significant if no problem with endogeneity. The original model is: $$ \ln(y_{it})=a_i+b_t+\ln(c_{it})+u_{it}, $$ where $y$ is the dependent variable, $a$ and $b$ are the individual and time fixed effects and $c$ is the independent variable of interest. $u$ is the error term. When creating the regression with leads, is it ok to model it in its logarithms form, or should I model it without the transformation? With logarithms it would look like: $$ \ln(y_{it})=a_i+b_i+\ln(c_{it})+\ln(c_{it+1})+u_{it}. $$ Im asking since the lead of the logarithm model is not significant while the lead of $$ y_{it}=a_i+b_i+c_{it}+c_{it+1}+u_{it} $$ is significant.


What is the origin of viruses? How could they get both living and non-living characteristics?

I read that viruses are called intermediate between living and non-living particles. Well, if so, then where did they originate from?  From living or non-living? If they originated from either living or non-living then how could they have both the characteristics of living and non-living?


Show 3 is a primitive root modulo $7^n$ for $n\in \Bbb{N}$.

I tried induction but got stuck. For $n=1$ it is true. Suppose it holds for $n$, i.e, the order of 3 is $\phi(7^n)$. Now I should prove it for $\phi(7^{n+1})=6\cdot 7^n$.  $7^n\mid3^{6\cdot 7^n}-1$. How do I derive that $7^{n+1}\mid 3^{6\cdot 7^{n+1}} - 1$. I would appreciate your help.


Could authors overturn recent community review decisions?

When new users edit a post, the review is posted to a review queue and other reputable users can review the edit and choose to approve or reject it. However, I feel that a lot of people do it pretty quickly.    to . He was fixing broken links in the answer, and as soon as I saw it I knew it would have been a good edit. However, only one reviewer found so, and three others rejected it. I ended up manually doing the edit, and poor Onato didn't get any credit for it (in fact, he got an undeserved 'rejected' for it).  The point I want to bring is that, first and foremost, the person who wrote the answer probably knows best if an edit is acceptable or not. Could there be a time frame where the author of the answer (or question) can overturn a review decision?    EDIT: one more  was rejected by overeager reviewers as well. I absolutely disagree with the notion that the community knows better. The community repeatedly proves that it only wants Internet points.    EDIT: I told a commenter to fix something himself in one of my posts, but . I went back and applied the changes myself. It's not credited to him and his stats got a rejected edit now (which really should be an approved edit). The reason ("This edit is incorrect or an attempt to reply to or comment on the existing post") is blatantly wrong and shows once more that the community has much less insight into edit quality than the people who wrote the answers in the first place. It's true that the UI didn't make it easy for them, but those guys clearly didn't read the comment thread; I did, because as the author, I was notified.    EDIT: This time around, a user fixed a blatant (though small) mistake in one of my accepted answers. One hour later, another, unrelated 10k user , even though it had been approved by the community. I went back to undo his undo.  This goes on again to show that an active user is the best judge for the quality of an edit, and that since I can have the last word on edits on my own posts, I should be allowed to retroactively overturn a community edit vote and accordingly credit the person who proposed the change.    EDIT I wrote a  years ago. Some guy found it and tried to fix it but the community thought that it wasn't worth it. I think that the changes are great and once more I'll integrate them by myself into my post. Unfortunately for this user, he won't be credited for it. I still don't understand why I can't have a binding vote on edits on my posts.


We have two Microsoft Private Clouds: one consists of 8 nodes (each with two processors) and the other consists of 4 nodes (each with two processors). Call them Private Cloud A and Private Cloud B. Each node is currently licensed on our EA with a Windows Server 2012 R2 Datacentre license.  Some production services are hosted on A, with DR instances for those services existing on B (i.e. SQL availability group with primary on A, one secondary on A (for HA) and one secondary on B (for DR), Exchange cross-site DAG). We also have some production services running on B, with DR instances running on A.  Private Cloud A hosts about 70 VM's (95% Windows Server 2012, rest are Linux based) and Private Cloud B hosts about 30 VM's.  We'd like to implement SCCM (more specifically, SCVMM) to help us manage the virtual environment (which is currently done mostly through Powershell scripts and manual intervention on Failover Cluster Manager and Hyper-V console).  How should we license SCCM 2012 R2 in this environment? Would I need to purchase a Datacentre License for each of the 12 hosts (which would be an exorbitant amount)? Or, do I only license one host with a Standard license, and host all my VM's that run SCCM components on that one host? Or should I rather put down a physical machine to host these components, and license with a Standard license?


using Blender with anycubic photon printer

I have designed two parts I wish to print in HO scale.  A drawing of a brick wall in 1:1 scale and exported to .stl comes into Anycubic Photon screen so small it is almost invisable.  Have not been able to change the size no matter what I do. Any help out there?


how to understand regex pattern in the code example in java?

The pattern is from the following Snippet.   private static Pattern specialDoubleRegex = Pattern.compile("((-)?infinityd?)|(nand?)", Pattern.CASE_INSENSITIVE);   I am a beginner. I am starting to use Pattern class to write my own regex. I saw this example in the .I don’t completely understand them. Are we using special construct (?<name>X)? According to  and javase 7 docs, ?infinityd?) is not special construct here. what is (-)?infinityd? about? Can I say that they are the pattern looks like ((X)?XY?)|(X?) pattern?


Linear kernel and non-linear kernel for support vector machine?

When using support vector machine, are there any guidelines on choosing linear kernel vs. nonlinear kernel, like RBF? I once heard that non-linear kernel tends not to perform well once the number of features is large. Are there any references on this issue?


What would be the effect of a Borg assimilating a Q?

In the Voyager episode 'Q2', Q screams at his son "Don't provoke the Borg!". This to me is an indication that even the Q are afraid of them.   Was there ever any canon discussion about the affects of the Borg assimilating a Q? Is there any evidence that a Q can even be assimilated in their 'ascended' form?


How do I find the area for the shaded area?

How do I find the area shaded in red? The difficulty is actually in finding the area in blue.


Is there a way to set app-specific volume?

I'm looking for a way to set the media volume depending on the app being used.  I generally keep my media volume down fairly low so as not to annoy my fellow humans overmuch; while playing Angry Birds, for instance.  When I go into Doggcatcher, though, I generally want to crank the media volume way up, because I'm listening through earbuds or my car speakers and need that volume way up.  Not such a big deal, but if later I go back to Angry Birds and I forgot to turn the volume back down it wakes up the whole house.  This is exacerbated by the fact that the media volume does not follow the "Sound off" setting (accessed by a long-press of the power button).  So, is there a way to do what I want?  (Android 4.0)


How bad is it to use display: none in CSS?

I've heard many times that it's bad to use display: none for SEO reasons, as it could be an attempt to push in irrelevant popular keywords. A few questions:   Is that still received wisdom? Does it make a difference if you're only hiding a single word, or perhaps a single character? If you should avoid any use of it, what are the preferred techniques for hiding (in situations where you need it to become visible again on certain conditions)?   Some references I've found so far:       If you're straight-out using CSS to hide text, don't be surprised if that is called spam. I'm not saying that mouseovers or DHTML text or have-a-logo-but-also-have-text is spam; I answered that last one at a conference when I said "imagine how it would look to a visitor, a competitor, or someone checking out a spam report. If you show your company's name and it's Expo Markers instead of an Expo Markers logo, you should be fine. If the text you decide to show is 'Expo Markers cheap online discount buy online Expo Markers sale ...' then I would be more cautious, because that can look bad."   And  on the same article     We can flag text that appears to be hidden using CSS at Google. To date we have not algorithmically removed sites for doing that. We try hard to avoid throwing babies out with bathwater.   Eric Enge      The legitimate use of this technique is so prevalent that I would rarely expect search engines to penalize a site for using the display: none attribute. It’s just very difficult to implement an algorithm that could truly ferret out whether the particular use of display: none is meant to deceive the search engines or not.


Algebric proof for the identity $n(n-1)2^{n-2}=\sum_{k=1}^n {k(k-1) {n \choose k}}$

Prove the identity:  $$n(n-1)2^{n-2}=\sum_{k=1}^n {k(k-1) {n \choose k}}$$  I tried using the binomial coefficients identity $2^n = \sum_{k=1}^n {n \choose k}$  but got stuck along the way.


How to display same windows side by side on taskbar

How can windows be displayed side by side instead of overlapping on taskbar :     Right clicking &including holding shift key) on taskbar dows not appear to contain this option.


How can I protect my NAS Backup system from ransomware

I'm currently running a Windows 7 Desktop PC, a MacBook Pro and an iPhone. In my homenetwork I am allowed to backup my MacBook to the MacMini Server, which also works as media server. However my father is not comfortable with me backing up my Windows machine on that server. Now I'm facing the question: Should I get myself an external storage to backup my windows on it or should I introduce my own backup system (a synology disk for example) to the homenetwork. The synology disk has multiple advantages:   Integrated Media Server to stream on the MacBook, the PC and the iPhone Backup of all the listed devices User interface to easy configure I could manage a shared git on the server   My only fear now is that if I catch some kind of ransomware on one of these devices, the next sync / backup will also encrypt the data on the synology disk. If one disk would be backup and the other media there would still be affected both.  Is there a possibility to prevent network attached storages / backup services from beeing affected by things like ransomware / realtime encryption? And in the worst case: would my NAS be affected if any of the other devices in the network would catch one of these viruses if they had plex permissions to stream from my server?


Convergence of non increasing and non decreasing sequences to the same limit

If $a_n$ is a non decreasing sequence and $b_n$ is a non increasing sequence, and $a_n \leq b_n$ for all $n$, this is this sufficient condition for concluding that they both converge to the same limit.   If no, what else is needed?


How to generate n points over a circumference and choose label and color

I would like to place n points over a circumference like Figure 3 of this . I'd choose the label to be assigned to each vertex and color and I'd like to have the code in TikZ-pgf.


promised that data.SE would "soon" get live data:     I realize it's a long weekend, but given that data.SE is now over 2 months out of date, it would be nice if this was finally rolled out.


I never had to deal with sound and I am pretty sure some of you guys have some experience in that kind of application.  My question is more about getting some tips on the different ways to implement an embedded system based on an AVR that plays sounds. More precisely:   What library should I use? Which sound format should I choose? Do I necessarily need a dedicated memory chip aside the MCU? If yes, which one would you recommend? Do you have some code sample to share?   As always, I know that everything depends on the target application. Here are a few precisions:   I want to make a toy for the kids of a friend of mine, the idea is to have a short sound lasting no more than 30[s] I am not interested in high fidelity sound Power consumption matters


In the book "Jurassic Park" does the Lysine Contingency actually get explained?

I was watching the movie recently and noticed that one of the characters (very) briefly mentions a safety they built into the system should any of the dinosaurs escape. They called it the Lysine Contingency saying that all the dinos have been genetically modified to depend heavily on lysine in their diet, so if any of them escape they wouldn't be able to survive without the food supplements that the park gives them.   Why doesn't the story end right there? Does the Michael Crichton book actually explain this in depth?


How does color identity work in Commander?

I recently began playing commander, and have run into a few questions, mainly about color compatibility with a commander. I think I can lump them all together into this one question: What exactly determines color identity in cards? And then just a few specific examples to make sure I'm understanding this correctly:  If my blue commander has an activated ability in non-blue color(s), what colors can I run in the deck? e.g.:   For a mono-blue commander deck, can I have a card with a non-blue color(s) activated ability in the deck? e.g.:   For a mono-blue commander deck, can I include in my deck a card with a hybrid mana cost that can be cast with either blue or non-blue mana? e.g.:   For a mono-blue commander deck, can I have a card that makes non-blue mana? e.g.:


##UserId## parameter is no longer automatically filled on Data Explorer

If I go to e.g.  while logged in at Data.SE, the ##UserId## parameter isn't populated like it usually is. This was originally only happening for some sites, but now it seems to be happening for all of them.


What kind of forces would follow only the second part of shell theorem?

What kind of forces would follow only the second part of ? General expression of a force which would cancel out inside a uniform hollow shell. What about any closed surface?


What do you call someone who always needs to be mentally or physically active?

What do you call a person that can't just relax, someone who always needs to be working or taking a class or working out? Someone who can sit still in one place but only if they are working on something (mentally), and if they aren't working on something mentally then they need to be physically doing something, like running errands or working out etc.. BUT the specific person I have in mind is very calm, and patient but they cannot sit around doing nothing because they feel lazy, like time is wasted.   Maybe it would help to point out that there is not a physical drive to do these things, it isn't a energy level but more of a psychological need to do these things. Often this person is somewhat tired and usually doesn't get a full nights sleep due to over them being so busy with everything they try to do.


If someone claims that God is beyond logic then how do we know he is beyond logic ? (as we lose all the methods to know whether the claim is true or not?) Logic is the use and study of valid reasoning, while reason is the capacity for consciously making sense of things, applying logic, establishing and verifying facts, and changing or justifying practices, institutions, and beliefs based on new or existing information.Logic, scientific reasoning and observations (or experiences) are the methods which can be helpful comprehend God's nature . Without these methods how God can be intelligible? It is often argued by supporters of the claim that     Without God, nothing could have existence. God is the basis of all logic in reality and he is in no way inferior to logic. Logic comes from God, not God from logic. But when it comes to how we know things, logic is the basis of all thought, and it must come before any thought about anything,  God possess infinite knowledge and the knowledge of humans is limited to their observations and their ability and capacity to reason.So, what seems superfluous and flawed may be true .    How these properties can be attributed to God if do not have any method (Logic, scientific reasoning and observations) to know if it is true or not?( I am talking about God of monotheism and henotheism in which God is conceived as the Supreme Being and principal object of faith whose commonly included attributes are omniscience (infinite knowledge), omnipotence (unlimited power), omnipresence (present everywhere), omnibenevolence (perfect goodness), divine simplicity, and eternal and necessary existence.) (The opposition of the above two points) God as supreme being. God governs logic, logic is not governed by God.


In Newtonian pressure, what type of function is force?

This is pressure in Newtonian mechanics:   $$P=\frac {dF}{dA}.$$ What does this mean? (Doesn't it mean that force is a function of area?) What type of function is force?


The pup everyone hates and loves. Dissapears and reapears. After using him to track Kelog, Valentine dismissed him and I have no idea where to. I looled at every settlement, used bells, used dog houses, waited at red rocket, even traced the path from the fort to red rocket, and nothing. Using xbox version so can't use some pc tactic I heard of. Can someone tell me what I can do? I don't wanna have to start over just to have my pup by my side. I got over 72 hours of grinding on this save, and not using mods so I can have achievements.


I know the following libraries for drawing charts in an SWT/Eclipse RCP application:    (Links to an article on how to use it)    Which other libraries are there for drawing pretty charts with SWT? Or charts in Java generally? After all, you can always display an image...


"Through" or "to" for expression of range

16-bit unsigned short integers that range from 0 through 0xFFFF      16-bit unsigned short integers that range from 0 to 0xFFFF   Which expression is better above?


I'm working on a 2D-ish animation (camera above looking straight down to flat objects) for an educational video and am wondering how to create two effects. The first one I'd need is the appearance of something being put on like a sticker. Where it starts out curved or rolled away from the camera and then it lays out flat.


The limit $\lim_\limits{n\to{\infty}}\int_0^{1}\sqrt[n]{x^n+(1-x)^n} dx$

This is  in the American Mathematical  Monthly.     What can we say about the limit $\lim_\limits{n\to{\infty}}\int_0^{1}\sqrt[n]{x^n+(1-x)^n} dx\ ?$   I think we need to use gamma and beta functions here. Again, the result may involve the Euler's constant.


"Resources monitoring" vs "Monitoring of resources"

Please help me understand a difference between phrases "resources monitoring" vs "monitoring of resources", "characteristics of devices" vs "devices characteristics" and the like.


Number of vertices in the Klein bottle triangulation given in "Topology and geometry for physicists" by Nash and Sen

I stumbled upon the following triangulation of the Klein Bottle in page 76 of the book Topology and geometry for physicists by Charles Nash and Siddhartha Sen.    Below the figure, it says "the triangulation $K$ consists of eight $0$-simplexes[...]".  I think this is not an eight-vertex triangulation, but rather a nine-vertex triangulation of the Klein bottle. I also know, thanks to the great comments under  question, that an $8$-vertex triangulation of the Klein bottle is a minimal one, hence the one portrayed in the book isn't minimal.  Am I correct?


I lost my way home on Minecraft. How do I find it?

I was in Minecraft creative mode and built a whole city. Then I decided to explore the world for a bit in survival mode. After a while, I died but it didn't take me back home. It said my bed was not found or obstructed. Please help me, I worked so hard with that world. I don't remember the coordinates.


Is it possible to set up an ordering on a ring compatible with ring structure only if it has no proper zero divisors?

I am trying to rationalise the axiomatic foundation of real numbers, and I am trying to find a minimal way of specifying a totally ordered field. We start with the field axioms for the field $(F, +, \times)$, straightforward enough: $(F, +)$ is an abelian group, $(F_{\ne 0}, \times)$ is an abelian group, $\times$ distributes over $+$, tada, $(F, +, \times)$ is a field. Then we define an ordering compatible with the ring structure of $F$ (as $F$ is a field, then a priori it's a ring): $$\text {OR1}: a < b \implies a + c = b + c$$ $$\text {OR2}: a \ge 0, b \ge 0 \implies a \times b \ge 0$$ This of course presupposes the positivity properties: There exists a propositional function $P: F \to \{T, F\}$ such that $$\text {P1}: P(a) \land P(b) \implies P (a + b)$$ $$\text {P2}: P(a) \land P(b) \implies P (a \times b)$$ $$\text {P3}: (P(a)) \lor (P (-a)) \lor (a = 0)$$ and then in the definition for ordering $0 \le a$ means either $a = 0$ or $P(a)$. It can be proved (I can do this, or at least, I know where to find it) that the ordering given above is in fact a total ordering, as this holds when $F$ is an ordered integral domain. But what about a general ring, or ring with unity, or commutative and unitary ring? I also have that a finite field cannot be ordered compatibly with the ring structure, trivial to prove. And of course the complex numbers, again, no such ordering exists. Because of the fact that this is usually defined on the ordered integral domain, I am assuming that it is because such a structure has no proper zero divisors. That is, it is possible to set up an ordering on a ring $R$ compatible with the ring structure of $R$ only if $R$ has no zero divisors. Does this hold? This question is different from  because that one comes from a different axiomatic basis, and is more specific than what I'm asking.


How to backup all the emails(content) of Postfix? What folders?

I want to backup all the emails (their content) on a server where I run Postfix, so that later on I'll be able to restore the emails, on other server or locally. Among other folders, I have this: $ ls -al /var/spool/  total 16 drwxr-xr-x  4 root    root 4096 May 22  2018 . drwxr-xr-x 16 root    root 4096 Sep  5 18:28 .. drwxrwxrwt  3 root    root 4096 May 23  2018 mail drwxr-xr-x 18 postfix root 4096 Sep 11 20:01 postfix  What precisely do I have to backup, what folders?


Is it possible for unique column to contain multiple null values SQL Server 2008

I want to migrate data contained in an Oracle Table A to SQL Server. The table A contains a column CIN with unique constraint but mutliple null values. The problem is that SQL Server is rejecting the data. Is there any workaround for this ?


I have a shapefile that I was working on in ArcGIS Desktop 9.3 get corrupted somehow and it gives me the error "Number of shapes does not match the number of table records.". What I would want is to recover this shapefile as it has a lot of edits that other revisions of the file do not have.  Earlier I recovered from this error using  but the tool now just crashes. I have even tried the command line version ogr2ogr but still no luck. This script,  from the ArcScripts website didn't help either.  Any ideas? (except that I stop using shapefiles)    Here is the output from ogr2ogr (based on a a suggestion in the answers):


A search for this question does yield results, but nothing seems to answer my immediate question I'm attempting to create an unrolling paper effect.  (ignore the video quality. no time to locate a decent screen capture program--I can do that later) I've found a couple of tutorials, but the ones I can easily follow don't quite give the effect I need, and the ones that do what I want have no audio or are very tough to understand and move too quickly--one was from 2008. This tutorial is the old one. It does what I want, but I can't get mine to act the same.  This one is a good tutorial and easy enough to follow, but I don't want the wooden handles. It nearly does what I need.  And this guy also does basically what I want, but he moves too fast and doesn't explain anything. Difficult for me to follow at this time. He goes into drivers or something.  I've (hopefully) attached a quick clip (first link above) of what I'm trying to do; I've got the scene set up with an Archimedean spiral, and moving the spiral along the X axis the paper rolls up and unrolls. I set the spiral location for key frame 1 and 100 and when animating the spiral moves accordingly, but the roll of paper either just sits in place, or mysteriously starts crumpling in place. I'm likely missing something. Thanks in advance. I'm running Blender version 2.81.16, Windows 10 64 bit Please be simple with your answers, I'm still learning. Yes, I'm a noob ~ but hey, we all start at the bottom. ;)


What novel has people exploring a spaceship with cubbies that duplicated anything, including a hand?

A group of people are exploring a huge spaceship. They are worried about supplies until they find cubbies that duplicate anything put into them. They discover this by someone placing their hand inside one of the cubbies and it duplicates their hand. Specifically, once something is placed in the cubby, whenever it is removed it is immediately replaced. So there's now always a hand in the cubby.  Definitely True   Everything in the above paragraph Read it more than 10 years ago.   I think...   I read it approximately 15 years ago. I have no idea how old it was when I read it. The ship was discovered in a glacier, or the arctic or something, which was reflected on the cover. It may have not been a spaceship exactly. I think there may have been interdimensional/tranporting doors and they were unable to go back the way they came.   I did not finish the book and would like to now, so I will not be able to answer clarification questions about later plot points and would prefer to avoid spoilers.


How can we share a pricebook record to a group using apex code

I want to share record of Pricebook to a group. Their is no object called PricebookShare, how can we share if there is no object PricebookShare to share? Is there any way? Please guide me.


Tipping in the US when paying in advance

On a couple of occasions during a recent trip to the US, I paid in a restaurant when I ordered (at a walk-up counter), and was invited to add a tip to the CC slip. The food and drink is then brought to my table (waiter service).  What is the protocol for tipping in this situation? – I'm being asked for a gratuity before the service that I am to receive.  I accept the tipping culture in the US, but how do I gauge what percentage to give? Just the usual 15-20%? A bit less because they don't have to bring me the check? Or should I tip in cash at the end? Will I cause offence if I don't add a tip when I pay?


Why is my 3 month old waking up 10+ times a night?

My 3 month old went from starting on a good sleep trajectory (a five hour and 3 hour stretch at 8 weeks regularly) to waking between every 15 minutes and every 2 hours. What I'm trying to figure out is what causes the frequent night wakings. She was fighting her arms out of her swaddle and getting the fabric over her face in the process, so for her safety we taught her to sleep without it.  Plus she started sleep crying for gas pain or some other cause in the very early morning nearly every morning that we rushed to comfort.  With all that her sleep habits deteriorated.  They have been getting worse and worse since 9 weeks and at 14 weeks I am at my wits end with the double digit number of night wakings.  Reading that some people consider 4 bad was hardly comforting.  I've seen Marc Weissbluth's  in .  I've tried his solution, too, which is invariably to move bedtime earlier.  Well Her bedtime has consistently been earlier than 6:30 for well over a week with no changes.  I'm sure the completely fragmented sleep is making her overtired, but earlier bedtimes are doing nothing to help.   Her naps are not yet organized (I'm despairing that they ever will be at this rate) and so she takes 4 to 5 30-45 minute naps - if she'll take them - that I offer whenever she starts yawning, looking glazed-eyed, or rubbing her eyes.   suggests hunger as one possible cause.  My little girl is skyrocketing up the growth chart and eats every 1-2 hours during the day on demand.  I feed her 2-3 times at night, but not at every waking.  I sincerely doubt she's hungry, but I'm open to being wrong.  Baby does have a pacifier, and popping it back in often soothes her back to sleep.  Would trying to wean her off of it at this early age perhaps help her learn to self-soothe, or would it just make sleep worse?  I am totally fine if she wants to suck on her fingers or thumb and get us all a little sleep, but so far every time she finds her thumb it does nothing to help her go back to sleep.  She's not really coordinated enough to keep it in her mouth.  Could it be the  come to call early?  An early start of ?  Is there any solution other than to soldier through?  Is there an age-appropriate form of sleep training worth trying?


I had problem with a spamming domain and I am asked to delete files in some folders in var/qmail/queue but I accidentally deleted whole folders.  Now any domain can either get or send email, getting   554 mail server permanently rejected message (#5.3.0)   Is there any way to fix this beside using a backup?  Thanks in advance


Having trouble in solving second-order linear ordinary differential equation

$(2x^2+1)y''-4xy'+4y=0$  $y_1(x) = x$ is given and I have to find $y_2(x)$ and solve equation. thanks.


Unable to open spreadsheets downloaded from reports

This could be a Salesforce problem or an Office problem although I am leaning toward the former rather than the latter.  When we Export Details from reports, there are a number of users who're struggling to open these files. Excel opens, albeit blank like below:    What's odd is that if we e-mail the exact same file to ourselves, the document will then open.  If the file is exported as a .csv file, it opens as expected.  Has anyone else experienced this bug? Is this likely to even be a Salesforce bug or something to do with Office instead?  Edit   This happens regardless of the user opening directly from the browser or directly accessing the file from folders It happens regardless of Excel being open at the time or not, with or without Spreadsheets being open This is happening on multiple PCs with multiple users with various profiles (including System Administrator) on Salesforce


I'm fairly new to the Stack Exchange network, and I really like the Q&A format used here, which is very clear to read and to use.  I started exploring all the sites, and I found there's a Code Golf site (), but it doesn't seem to be a Q&A site, but rather a contest site, which seems to go against what the Stack Exchange sites represent.  So, why does this site exist in the network? Wouldn't it be more suitable in a different kind of site?  Please note that I do enjoy the site (I read the challenges every day although I've never sent an answer), but I'm curious about the issue.


iMac only show flashing folder with question mark after formatting OS X partition drive

Today i format my "OS X El capitan" partition for installing "Yosemite". But due an error in bootable yosemite usb it didn't install on this partition. After some hours when i turned on iMac and hold down "option" key for boot into usb but just blank screen and mouse show. And every time when i turend on iMac it only show flashing folder with question mark. I've tried to resolve it by reseting "NVRAM". But after restarting problem still same.  Also I've tried many "Startup key combinations for Mac" but didn't work any combination on startup.  Also i have important data in my other one partition. Please can anyone tell me what i do for resolving that issue Without loosing my data?


I created a class Person and a HashSet. If I add the same person to the HashSet, it is not aware the Person is already present and it will add the same person multiple times. What function do I need to overwrite to have only unique elements in the HashSet?  public class Person {     public Person(int age, string name)     {         this.age = age;         this.name = name;     }      int age;     string name;      public int Age {         get { return age; }         set { age = value; }     }      public string Name {         get { return name; }         set { name = value; }     }      public override bool Equals(object obj)     {          var other = obj as Person;         if (other == null) {             return false;         }          return age == other.age && name == other.name;     } }  void Button1Click(object sender, EventArgs e) {     List<Person> allPeople = new List<Person>();     Person p = new Person(15, "John");     allPeople.Add(p);     p = new Person(22, "Michael");     allPeople.Add(p);     p = new Person(16, "Alex");     allPeople.Add(p);     p = new Person(22, "Michael");     allPeople.Add(p);     p = new Person(15, "John");     allPeople.Add(p);      HashSet<Person> hashset = new HashSet<Person>();      foreach(Person pers in allPeople) {         hashset.Add(pers);     }      foreach(Person pers in hashset) {         listBox1.Items.Add(pers.Name + ", " + pers.Age);     } }


Have option conditionally require package

I want to declare an option in my package that, if provided, will require another package. However, just doing \DeclareOption{requiresomething}{     \RequirePackage{somepackage} }  does not work, as you can't mix package requiring with the Option Section. Is there any simple solution to this? Am I doing something wrong?


On my Samsung Galaxy Tab, I have contacts stored on the Device Contacts and Google Account Contacts. Since only the latter get synced, I want to change the former in Google Contacts format.   I read to achieve this I have to export device contacts to the SD card. Delete all device contacts. Import back contacts on the SD card, specifying to import them to the Google Account.   The problem is the option Export to SD card is greyed-out.   I am on Honeycomb.


I am using a bossbar to show the money value . This is the repeating command  execute store result bossbar money:bar value run scoreboard players get @p money   If playerA has 10 money and playerB has 20 money will playerB's bar show 20 and playerA's money bar show 10 ? And the money bars should be separate for each player and I do not want a different bossbar for each player.


Sample of drawing of the Computer Processes with TikZ

i need this as a Tikz drawing but im no able to do the back and forward arrows (1)&(2) and in total im not sure what im doing at all.:  May somebody show me as an starter how to do Tikz drawings correctly?


What recourse do I have if I believe a moderator has abused their privileges?

One or more of the following things happened to me on a Stack Exchange site:   My post(s) were wrongly deleted or locked by a moderator A moderator posted a wrong comment on one of my posts I was suspended, but did not do anything wrong I asked a meta question, but the question was closed and/or deleted A moderator discredited me in public ...   I think a moderator has abused their power, but I feel powerless against them.  What recourse do I have now? What can I do when I feel that a moderator has abused their power, and has been repeatedly unfair in their dealings with me?


How does light speed up after coming out of a glass slab?

As I learned today in school, my teacher told me that when light enters a glass slab it slows down due to the change in density and it speeds up as it goes out of the glass slab. This causes a lateral shift and the light emerges out from the point different than that from where it should have actually emerged from.  Okay so what I mean to ask is, when light enters point A on glass slab and emerges from point C why does the light speed up? Where does it get the energy it has lost when it entered the glass slab?  P.S.: Also, if I place a very very very large glass slab and make a beam of light pass through it will the light never come out as all the energy was lost in place of heat?


Disable shape detection in Preview's annotation tools

When I try to draw a line on an image using Preview's annotation tools, it doesn't remain as I drew it but instead the line is drawn linear. How can I set it to be preset as nonlinear?  So looking to the images, I don't want it to be set like this:    Instead I want it to be preset in this way, instead of clicking the actual function everytime to make it nonlinear.


Existence of subgroups in group of order $2n$

Let $G$ be a finite group with order $2n$. Let's assume $G$ has $2$ distinct subgroups $G_1$ and $G_2$ both of order $n$. I want to prove that there exists another subgroup $G_3$ of order $n$ with $G_3\neq G_1$ and $G_3 \neq G_2$. Both $G_1$ and $G_2$ are normal since they have index 2. When I'm asked to prove the existence of a subgroup I immediately think of Sylow theorems, but I don't know if they are helpful here since by conjugating $G_1$ we would still obtain $G_1$. Hence $n$ cannot be prime. Any hints?


Where did the “&” character come from, and why is it here?

I’m sorry if this was asked a million times before, but neither Google nor the ELU site has helped me out.  I’m wondering:   What’s the reason behind introducing this character?  What’s the difference between it and and?


I know this is a shot in the dark, but I had a phone call yesterday that I really want to retrieve it.  Can I phone up my provider (Vodafone) and ask for the recording? How do I go about doing this? Or is the conversation stored locally on my Galaxy S3?


Too Many SOQL Queries 101 though limit 100

I am getting this error though limit 100 is provided in SOQL statement.Can someone please suggest a way out here? Apex code:  public  class Attachments_11{ public List<attachmentCaseWrapper> caseWrapper= new List<attachmentCaseWrapper>(); public void Attachments_11(){}  public List<Attachment> getattachedFiles() {         List<Attachment> attachedFiles = [select ParentId,ID,Parent.Name from Attachment limit 10];        return attachedFiles ;      }  public List<attachmentCaseWrapper> getcaseWrapper(){ LIST <ID> K=new List<Id>(); for(attachment a :[SELECT PARENTID FRom attachment where Parent.recordtype.sobjecttype='Account']) {k.add(a.parentid);}  //List<Call2_vod__c> listCases = new List<Call2_vod__c>([select Account_vod__c,name,Account_vod__r.Name,id from Call2_vod__c where signature_date_vod__c!=Null and account_vod__C in :k limit 10 ]);  //List<Id> hcp=new List<Id>();  list<list<Call2_vod__c>> listOfLists = new list<list<Call2_vod__c>>(); list<Call2_vod__c> listOfContacts = new list<Call2_vod__c>(); for (Call2_vod__c c : [select Account_vod__c,name,Account_vod__r.Name,id from Call2_vod__c where signature_date_vod__c!=Null and account_vod__C in :k limit 100] ) {     if (listOfContacts.size() > 999)     {         listOfContacts = new list<Call2_vod__c>();         listOfLists.add(listOfContacts);     }     listOfContacts.add(c);  }  //and the last set... listOfLists.add(listOfContacts);  system.debug(listOfLists.size()); for (list<Call2_vod__c> cons : listOfLists) {     system.debug(cons.size());     for (Call2_vod__c con : cons)     {         system.debug(con.Name);   for (Attachment atf : [Select Id,Name,ParentId from attachment where parentId =:con.Account_vod__c AND Parent.recordtype.sobjecttype='Account' limit 1]) {       map<id,Attachment> mapCaseAttachments = new map<id,attachment>();          mapCaseAttachments.put(atf.ParentId,atf);          System.debug('keys in the map: ' + mapCaseAttachments.keySet());             System.debug('list of values in the map : ' + mapCaseAttachments.values());        }      } } /*for(Call2_vod__C c : listCases ) { hcp.add(c.account_vod__C); }*/        //for1      map<id,Attachment> mapCaseAttachments = new map<id,attachment>();         for (List<Call2_vod__c> cs : listOfLists) {                for (Call2_vod__c c : cs)    {       attachment atf = mapCaseAttachments.get(c.Account_vod__C);            attachmentCaseWrapper cw = new attachmentCaseWrapper(c,atf);            caseWrapper.add(cw);           }         }     // for2       return caseWrapper;    }    public class attachmentCaseWrapper {     public string Call_Name     {get; set;}     public string accountName    {get; set;}     public string attachmentId   {get; set;}      public attachmentCaseWrapper (Call2_vod__c cse, Attachment atf) {       Call_Name = cse.Name;       accountName = cse.Account_vod__r.Name;       if (atf != null) {         attachmentId = atf.id;         System.debug('***************************************************attachmentId : ' + atf.id);       }      }   }  }   Apex Page:  <apex:page controller="Attachments_11" renderas="pdf" >   <apex:form id="theForm"> <apex:pageBlock id="details">  <apex:pageBlockTable value="{!caseWrapper}" var="j">                  <apex:column value="{!j.accountName}"/>                   <apex:column >          <img src="/servlet/servlet.FileDownload?file={!j.attachmentId}"/>          <!--apex:image url="/servlet/servlet.FileDownload?file={!j.attachmentId}"/-->          </apex:column>       </apex:pageBlockTable>                    </apex:pageBlock>   </apex:form>   </apex:page>   Error: Too many SOQL Queries 101


You have two dogs which are black and white, two white dogs, and two black dogs. Have the following sentences correctly distinghsed them?   There are white and black dogs (two white and two black only) There are white and black dogs (two white and black dogs only)


Too much review time and the related actions

We have submitted an article in a finance journal ( ABDC rank A) more than one year ago. After around 6 months they sent us the review of two reviewers where one reviewer reject the paper with few correction suggestions and another gave relatively good comments with additional correction suggestions. Hence the editor asked for revise and resubmission and also mention that if we comply with the reviewer's comments, he will personally read that article. Accordingly, we revise and resubmit that paper. It has been 7 months since our resubmission and they still do not give any feedback. Since I am a Ph.D. student, such a long review process is hurting my Ph.D. process. Can anyone suggest me what should be my action in this regard? Should I send the editor an email? If the editor does not respond even after that email, should I withdraw that paper from that journal?


I just bought a new MTB and am planning to change my previous MTB into a Road Bike.   How do I do it? What kind of parts do I need to change or add or remove?  I am not looking to for a full conversion into specialised road bike. But like the answers are suggesting, I am looking for a bridge between commuter or road bike. My majors concerns to be met are:   Should be fast enough to compete with road racers over short distance Should be light as a road  Should be as close as possible in as cheap as possible.


What is Electromotive force (EMF)? How is it related to potential difference?

What is  (EMF)? How is it related to the potential difference? Is it created by the potential difference in any conductor? Is it a process? Why is it called force?  Does writing EMF instead of voltage make any difference in AC circuits? (Studying alternating current I found some books using EMF while others used voltage.)


I was motion tracking a scene, after I clicked on setup tracking scene, I went to my previous saved file, which was before I clicked and on setup tracking scene, but when I came back my scene was gone, but markers remained.. and I could still play the video, but no image was showing. Also, you can see at the bottom that the video is here "scene 16-.mp4", but dunno it just disappeared.  Do you guys know what happened, or how it could be fixed?  Thanks


Installing Unity3d in Ubuntu 16.04 from terminal

How to Install  from the terminal in Ubuntu 16.04?


Referencing other points(rows) in field calculator

I'm trying to calculate an angle between points using a field calculator.  Is it possible to reference the previous or next FID with reference to the current one using the field calc?   Eventually I'd like to have an angle between the next and previous point be input into a field for the current point - like shown below


Is $\langle x^2-x-1 \rangle$ a maximal ideal of $\mathbb{Z}[x]$?

I have to prove that      $$\langle x^2-x-1 \rangle \text{ is not a maximal ideal of } \mathbb{Z}[x].$$   My attempt: I am not that much familiar with field theory but i know that an ideal $I$ is maximal over a commutative ring $R$ iff $\displaystyle\frac{R}{I}$ is a field ,but here $\mathbb{Z[x]}$ is a UFD and given ideal is  irreduicble over $\mathbb{Z[x]}$ so it is prime and thus $\displaystyle\frac{\mathbb{Z[x]}}{\langle x^2-x-1 \rangle }$ is an integral domain ,but don't know about is it field or not?


How many k-dimensional subspaces there are in n-dimensional vector space over $\mathbb F_p$?

I am asked to find how many there are $k$-dimensional subspaces in vector space $V$ over $\mathbb F_p$, $\dim V = n$.  My attempt: 1) Let's find a total number of elements in $V$: assume that $\{v_1, v_2, \cdots, v_n\}$ is a basis in $V$. Then, for every $v \in V$ we can write down $$ v = a_1 v_1 + a_2 v_2 + \cdots + a_n v_n $$ and since the coordinates ($a_1, \cdots, a_n$) are from $\mathbb F_p$ there are $p^n$ vectors in $V$;  $p-1$ without the zero vector.  2) Let's look at a situation where $k=1$. Let's call this 1-dimensional space $V'$. $$\forall v' \in V'. v' = a_1 v_1$$ where $v_1$ is a basis in $V'$. We know that if there are two non-zero vectors $u \in V'_1$ and $v \in V'_2$,  they are not linear dependant. So, every 1-dimensional subspace has $(p-1)$ basises. Therefore, there are $\frac{p^n - 1}{p-1}$ possible 1-dimensional subspaces in $V$  3) k-dimensional subspace is defined by the set of it's basises. Since basis can not contain zero vectors we can write down the formula for selecting $k$ linear independent vectors: $C^k_m (p-1)^k$, where $m = \frac{p^n - 1}{p-1}$. Here we first choose $k$ 1-dimentioanl subspaces and then we choose one of $(p-1)$ non-zero vectors from each of the subspaces.  4) .. unfortunately, this is where I am stuck. My intuition says that the answer may be  $\frac{p^n - 1}{(p-1)^k}$, but this might be completely wrong and I don't know how to go about finishing the problem.  Thanks in advance.


Show that $E(X)=\int_{0}^{\infty}P(X\ge x)\,dx$ for non-negative random variable $X$

Show that for a non-negative random variable $X$,   $$\mathbb E(X)=\int_0^\infty \mathbb P(X\ge x) \, dx.$$   I started with  $$\mathbb E(X)=\int_0^\infty x \, dF(x)=\int_0^\infty \int_0^x dt\,dF(x).$$ This is my try.


Ultimately, I want to make mirrored ribbons, wider at the bottom/furthest from the bow-knot. I created one mirrored bezier curve and rotated its duplicate (with the 3D cursor) at one end of the curve; I then made another curve (random shape for demonstration purposes) spanning the maximum width between what will be the sides of each ribbon. Is there a way to bridge the side-of-ribbon edge loops with the third curve, rather than the shortest path between points? Or is there a way to vary the extrusion width of ribbons generated using  prior to converting to mesh (after which I know I could use proportional scaling)? Thanks!


"help someone do" vs. "help someone to do"

Which sentence is correct and why?         Could you help the carnivore cut his meat?   Could you help the carnivore to cut his meat?


80's-90's TV show or movie about life clocks

It's from the late 80's early 90's I saw it on PBS I think. Everyone had a life clock installed at birth.   Everything bought and sold was with time increments. No one went to prison, time was just subtracted. When you ran out you died. I remember an addict begging for time before they died.  I have been looking for this one for years.


How can I force bibliography items not to be split across pages?

Possible Duplicate:          \documentclass{mwrep} \usepackage[nodisplayskipstretch]{setspace} \setstretch{1.9} \begin{document}  Dummy  \begin{thebibliography}{999}  \bibitem{1}John Doe, Jane Doe, Captain America, Superman: \emph{Bibliography item with a very long title: part one}, Some title of a magazine with a very long title, 2009, pages 1234--4321  \bibitem{2}John Doe, Jane Doe, Captain America, Superman: \emph{Bibliography item with a very long title: part one}, Some title of a magazine with a very long title, 2009, pages 1234--4321  \bibitem{3}John Doe, Jane Doe, Captain America, Superman: \emph{Bibliography item with a very long title: part one}, Some title of a magazine with a very long title, 2009, pages 1234--4321  \bibitem{4}John Doe, Jane Doe, Captain America, Superman: \emph{Bibliography item with a very long title: part one}, Some title of a magazine with a very long title, 2009, pages 1234--4321  \bibitem{5}John Doe, Jane Doe, Captain America, Superman: \emph{Bibliography item with a very long title: part one}, Some title of a magazine with a very long title, 2009, pages 1234--4321  \bibitem{6}John Doe, Jane Doe, Captain America, Superman: \emph{Bibliography item with a very long title: part one}, Some title of a magazine with a very long title, 2009, pages 1234--4321  \bibitem{7}John Doe, Jane Doe, Captain America, Superman: \emph{Bibliography item with a very long title: part one}, Some title of a magazine with a very long title, 2009, pages 1234--4321  \bibitem{8}John Doe, Jane Doe, Captain America, Superman: \emph{Bibliography item with a very long title: part one}, Some title of a magazine with a very long title, 2009, pages 1234--4321  \bibitem{9}John Doe, Jane Doe, Captain America, Superman: \emph{Bibliography item with a very long title: part one}, Some title of a magazine with a very long title, 2009, pages 1234--4321  \bibitem{10}John Doe, Jane Doe, Captain America, Superman: \emph{Bibliography item with a very long title: part one}, Some title of a magazine with a very long title, 2009, pages 1234--4321   \end{thebibliography} \end{document}   As you can see, item 10 is split between two pages. How can I prevent that and force a bibitem to appear on single page?    Don't understand me wrong. My goal is not to fit everything on single page. I just don't like broken entities in my bibliography.


How can I switch back to Nvidia card from Intel with Nvidia-prime

So I updated to Ubuntu 14.04 and found that the primusrun command no longer works, so ditched bumblebee in favour of nvidia-prime. This lets you switch video card from nvidia-settings rather than running through the command line (I prefer the old method, but want the primus performance).  The problem is that after switching to Intel from nvidia-settings, I can no longer open it up again to switch back to the nvidia card. When I open nvidia-settings I get a segmentation fault (according to the terminal).  Is there any way to open nvidia-settings switch back? I would like the ability to be able to switch between the two since having the nvidia card on all the time kills my battery and heats up the laptop a lot.


Missing date & time applet from top Unity panel

I like Unity very much. Recently, I installed Compiz manager and Nautilus Elementary also then tried to Play. During some of my playing around, Unity's clock applet has vanished.  I want to make it show the time again. How can I do this?


It is possible to have Steam Family Sharing set up so me and my child can both play the same game at the same time? As of now it says:     An error occurred while updating Red Faction Guerilla Steam Edition (shared library locked)   Is there a possible fix or am I stuck with it?


Integer to string conversion of fixed length

Is there an elegant solution to do this?  I have a counter running from nmin to nmax. I want to convert these numbers to strings of a fixed length.  Let me illustrate it with an example:  for j in range(nmin,nmax):     if j<10:         testval='0000'+str(j)     elif j>9 and j<100:         testval='000'+str(j)     elif .....:         testval=.....     else:         testval='00000'   Although it does the job, I found it rather inelegant. Is there a neater and elegant solution to convert the integer to string of a fixed length?


How to assign values to a property whose name is in a string?

I want to assign value to the property of the object of class. I have taken the list of property names using GetProperties();         PropertyInfo [] props;       props=typeof(Import_Column).GetProperties();   I have created an object         Import_Column myobj=new Import_Column();   I want to do something like         myobj.props[2]=value; //giving me error   How can i do it? is there any different approach?


Can someone explain this nutrition label to me?

The math on the carbohydrates section doesn’t seem to add up... how to decipher this section of the label?


How to use PC internet on Android mobile via Bluetooth

How to use my PC internet on Android mobile via Bluetooth. I'm having a bluetooth dongle connected to my PC. My phone and the PC are paired.  DETAILS    OS: Windows XP INTERNET CONNECTION MECHANISM : ADSL modem (connected to PC via Ethernet cable) Phone: Sony Xperia (Android Ice Cream Sandwitch)   Any help will be greatly appreciated.


Let a be an integer greater than or equal to 2. If a | mn, then a | m or a | n. Show that a is a prime.

I understand that this is part of Euclid's Lemma but how do I prove that a must be prime?


Explicit isomorphism between the four dimensional orthogonal Lie algebra and the direct sum of special linear Lie algebras of dimension 3.

I have read in Integrable Hamiltonian Systems on Complex Lie Groups by Velimir Jurdjevic p. 61 that the complex orthogonal Lie algebra of dimension 4, $\mathfrak o_4(\mathbb C)$ or $\mathfrak{so}_4(\mathbb C)$, (by which I mean the space of skew-symmetric matrices of size 4) is isomorphic to the Cartesian product of two copies of the special linear Lie algebra of size 2, $\mathfrak{sl}_2(\mathbb C)\times\mathfrak{sl}_2(\mathbb C)$, but I cannot come up with an explicit isomorphism. Can someone please help me find one?


Why the purple and red light entering the prism is broken at different angles?

Lights entering the prism with different wavelengths at the same angle. why go to different directions? what happens step to step between the protons&electrons in glass and the photons? what is the wavelength of interest in the direction the light goes? please don't tell they have different index of refraction.


"Reputation & Moderation" page still says "Stack Exchange the company"

The "Reputation & Moderation" page on any site (/help/site-moderators) still refers to the company behind Stack Exchange as Stack Exchange and not Stack Overflow.     Moderators act as a liaison between the community and Stack Exchange the company.   Seeing as how the name change was recent, I'm not surprised this hasn't been caught yet, and I'm sure there are other instances of this around somewhere.


Simple solution for escaping the QGIS locked into fullscreen mode on Ubuntu 12.04

"  No crash in this case, but I made the mistake of toggling to fullscreen mode on my netbook running Ubuntu 12.04. It's now impossible to escape this "No Menus" view, and it seems to have disabled the popout unity launcher as well. Steps I've already taken:  Alt-Tab to move to a different program, then back - QGIS remains in fullscreen Alt-V, Ctrl-F and F11 get no response I've unistalled QGIS, deleted the /.qgis/ profile data folder, and reinstalled. Still launches fullscreen   To add to the weirdness, it now launches - still in fullscreen - into a different workspace than the active one.  I realize this has the sound of a Unity problem, but it's just this program that has a malfunctioning UI.  Thanks to all the crew; this in no way changes my opinion of QGIS as an essential tool. qgis ubuntu shareedit  asked Sep 13 '12 at 17:28 Bill Morris 1179 "  ***I got the same problem mentioned above and also found a simple solution. I could't post any answer due to lack of reputation in this forum (I am a newbie here). The solution for escaping the Full Screen trap of QGIS on Ubuntu 12.04 is  (1) - press Alt + F4  (2) - QGIS will ask you about Close without saving, cancel or save, however, when you move your mouse arrow to the top of the screen the menu will appear again, then you go to "view" and click the last option "toggle full screen".  That's all!*


Google Maps API 2 gives NullPointer in Singleton

I have a very simple example of an instance for creating a IconGenerator and make it visible on the map.   The problem is that it gives me a NullPointerException each time it wants to create the IconGenerator iconita = new IconGenerator(getContext());  public class Controller { GoogleMap mMap; Context context; private static Controller instance;  private Controller() { }  public static Controller getInstance() {     if (instance == null) {         instance = new Controller();     }     return instance; }  public void setContext() {     this.context = context; }  public Context getContext() {     return context; }  public Map<String, List<Marker>> adaugaRuta(ShowTheRute theRoute) {     Map<String, List<Marker>> objectMap = new HashMap<>();      IconGenerator iconita = new IconGenerator(getContext()); <-- HERE it gives NullPointerException     iconita.setContentPadding(5, -5, 5, -5);     iconita.setRotation(-270);     iconita.setContentRotation(270);      Bitmap iconbit = iconita.makeIcon("Marker 1.");     final Marker mae = mMap.addMarker(new MarkerOptions().icon(BitmapDescriptorFactory.fromBitmap(iconbit)).position(new LatLng(46.762035, 23.597659)).anchor(0f, 0.5f));     mae.isVisible();      List<Marker> marker1 = new ArrayList<>();     marker1.add(mae);      objectMap.put("marker1", marker1);      theRoute.getTheRute(objectMap);     return objectMap; }   }


Proof of Nesbitt's Inequality: $\frac{a}{b+c}+\frac{b}{c+a}+\frac{c}{a+b}\ge \frac{3}{2}$?

I just thought of this proof but I can't seem to get it to work.  Let $a,b,c>0$, prove that $$\frac{a}{b+c}+\frac{b}{c+a}+\frac{c}{a+b}\ge \frac{3}{2}$$  Proof: Since the inequality is homogeneous, WLOG $a+b+c=1$. So $b+c=1-a$, and similarly for $b,c$. Hence it suffices to prove that $$\frac{a}{1-a}+\frac{b}{1-b}+\frac{c}{1-c}\ge \frac{3}{2}$$. From $a+b+c=1$ and $a,b,c>0$ we have $0<a,b,c<1$, so we have $$\frac{a}{1-a}=a+a^2+a^3+...$$ and similarly for $b,c$, so it suffices to prove that $$\sum_{cyc} a+\sum_{cyc} a^2+\sum_{cyc} a^3+...\ge \frac{3}{2}$$, or equivalently (by $a+b+c=1$) $$\sum_{cyc} a^2+\sum_{cyc} a^3+...\ge \frac{1}{2}$$, where $\sum_{cyc} a=a+b+c$ similarly for $\sum_{cyc}a^n=a^n+b^n+c^n$. Here I get stuck. For example, doing the stuff below yields a weak inequality, because of too many applications of the $a^2+b^2+c^2\ge (a+b+c)^2/3$ inequality.  "stuff below": Now, from $0<a<1$ we have $a^3>a^4$, $a^5>a^8$, $a^7>a^8$, $a^9>a^{16}$, and so on, so it suffices to prove that $$\sum_{cyc} a^2+2\sum_{cyc} a^4+4\sum_{cyc} a^8+8\sum_{cyc} a^{16}+...\ge \frac{1}{2}$$, or, multiplying by 2, $$2\sum_{cyc} a^2+4\sum_{cyc} a^4+8\sum_{cyc} a^8+...\ge 1$$, which by a simple inequality (i.e. recursively using $a^{2^n}+b^{2^n}+c^{2^n}\ge \frac{(a^{2^{n-1}}+b^{2^{n-1}}+c^{2^{n-1}})^2}{3}$) is equivalent to $$2(1/3)+4(1/3)^3+8(1/3)^7+...+2^n(1/3)^{2^n-1}+...\ge 1$$. But then *%281%2F3%29%5E%282%5Ei-1%29 and so we're screwed.


Why are this do/while loop and if statement not working?

Scanner s = new Scanner(System.in);   String x;    do {      x = s.next();      System.out.println(x);      if (x == "1") {         System.out.println("working");      }   } while (x != "2");   This code prints the correct value of String x, but will never print "working" and does not end the do/while loop when x == 2. What is wrong with this code?


Cannot find Background Images feature in Blender 2.8

Cannot find Background Images feature to add in a photo in Blender 2.8  Where is it?


Can I travel to France with Fiktionsbescheinigung (Fiction Certificate) of Germany

I am planning to travel to Germany from India and would want to stay in Paris in between for a week. I have Fiktionsbescheinigung from the German Government.


Who do you want to talk to?  Whom do you want to talk to?  Which one is correct sentence?


Effect of interchanging response and predictor in linear regression

I'm trying to run linear regression models using the R data "Auto.csv", which has the data for miles per gallon and the displacement. Now I'm trying to run two different linear regression models fit <- lm(mpg ~ displacement)  For this model, I get the result (intercept)     displacement 35.12            -0.06  Then, I interchange the response and predictor fit <- lm(displacement ~ mpg)  For this model, I get the result (intercept)     displacement 447.50          -10.79  For both these models, I'm getting the same results for p-value, r^2 values. Which of these models if better and what metric do we use to ascertain that? Any explanation would really be helpful


How degenerate time independent perturbation theory works?

Let's consider the usual setup for time independent perturbation theory: $$H=H_0+\varepsilon H'$$ and we can then set up the usual expansion: $$(H_0+\varepsilon H')[|n_0\rangle+\varepsilon |n_1\rangle+\varepsilon ^2 |n_2\rangle+...]=(E_n^{(0)}+\varepsilon E_n^{(1)}+\varepsilon ^2 E_n^{(2)}+...)[n_0\rangle+\varepsilon |n_1\rangle+\varepsilon ^2 |n_2\rangle+...]$$ Long story short: when we have to solve a problem using perturbation theory the only thing we are interested about is how to calculate the corrections to the eigenstates and the eigenvalues. If we are in the case of time independent non degenerate perturbation theory then this task is preatty straight forward once you know the formulas for the corrections: $$E^{(k)}_n=\langle n_0|H'|n_{k-1}\rangle$$ $$|n_k\rangle=\frac{1}{H_0+E^{(0)}_n}|_{|n_0\rangle}[(E_n^{(1)}-H')|n_{k-1}\rangle+E_n^{(2)}|n_{k-2}\rangle+.....+E_n^{(k)}|n_0\rangle]$$ Done! Wonderful! But of course what if our Hamiltonian is degenerate? On textbooks I have found reasons why the old formulas do not work. I also understood that in some cases the perturbation cancels the degeneracy and in some other cases it doesn't. And there are also talks about the need to diagonalize the matrix in the degenerate space (this last point is not clear to me at the moment). Ok. But in practice: How can I set up and solve the perturbative expansion in the degenerate case? What are the formulas for the correction? (Knowing why the formulas work would also be nice but it is not the main point of this question) Those are simple questions but I cannot seem to find any direct answer in my books or lecture notes. I would like a nice and concise answer. This topic seems really complicated to me as a beginner and I would like a summary of what is going on here. Especially from a practical point of view, on how can we solve exercises and expansions in the degenerate case.


Will I get in trouble for sending money to an account specified by my sugar daddy?

I met a guy on an app and we talked for about a couple of weeks. Then, he asked if he could help me with my bills and I said yes. However, he wanted information on my bank account, so I gave him my , as it would be more convenient. He told me to take $300 and send the rest to an account that he had. Will I get in trouble for that? I only did what he told me to do.


This may be an old question but I'm really curious about the nature of copying objects by reference as an assignment in javascript.   Meaning that if   var a = {};  var b = a; a.name = "Renato"; console.log(b);  Object {name: "renato"}   I'm kind of new to javascript and this really caught my attention to have a shallow copy as a default for Object assignment. I searched that in order to create a hard copy, you have to create a mixin. I was wondering why was this chosen as the default since it's transformation seems to be very implicit. Thanks!


If   (10) instanceof Number   returns false, then why does  (10).constructor   return [Function : Number]?  Update: I see now what happens, but this behaviour was obviously designed into the language. I can understand the benefit of, say, allowing implicit conversion of "4" to 4, but is there a tangible advantage to implicitly converting primitives into objects?


How many ways you can make change for an amount

I am looking for a formula or at least something to use when trying to compute how many ways I can make change for an amount.       Example: there are $3$ ways to give change for $4$ if you have coins with denomination $1$ and $2$: $1+1+1+1, 1+1+2, 2+2$.    What formula should I use?


Given $a_2 = 2$ and $a_{mn}=a_m a_n$ for $m$, $n$ coprime, show $a_n=n$ for all natural numbers

I'm a bit stuck on this... my only thought was to use second induction on $n$, which works well enough for the case where $n$ is composite and has two or more distinct prime factors, but if $n$ is prime or a prime power the induction hypothesis does nothing, so I'm thinking there must be another way.  Any ideas?


Can I globally change the cmd-Q shortcut to require holding for two seconds, like the option in Chrome?

Many, many times, I accidentally press ⌘+Q when I meant to close a tab or window, or switch applications. When I saw the option in Google Chrome to require the shortcut to be held, I was overjoyed. Problem is, I use Safari.  So, in short: How can I make the "hold command-Q" shortcut universal across all of my applications (or at least Safari)?


Vertical filaments during Atomic bomb explosion

What are those vertical filaments that form in the air whenever an atomic bomb is detonated? They are clearly visible in  at .


WIfi Issues with Macbook Pro Retina Early 2015 (12,2) on Ubuntu 15.04

Part 1  I upgraded 2012 MBA to 2015 MBPr (I loved Mint 17.1 Rebecca on the MBA but graphics/kernel issues means I need to wait till 17.2 to use Mint again)  I've managed to install Ubuntu on an SDcard. It boots and works. Great tutorial on this is .  I cannot get the Wi-Fi to work.  Used Terminal to determine the chipset:   $ lspci -nn | grep 0280 03:00.0 Network controller [0280]: Broadcom Corporation BCM43602 802.11ac Wireless LAN SoC [14e4:43ba] (rev 01)   I tried enabling the driver in Software & Updates → Additional Drivers. Ubuntu freezes so that's a no go.  I used terminal to install the following blobs/drivers (not sure what you call them) offline:  sudo dpkg -i bcmwl-kernel-source_6.30.223.248+bdcom-0ubuntu2_amd64.deb dkms_2.2.0.3-2ubuntu3_all.deb   This caused the system to freeze at:  DKMS: install complete   I rebooted and tried reinstalling using Ubuntu Software Installer which caused it to hang.  I've not messed with anything else. Can someone please explain what I am doing wrong?  Okay, here's part 2:  I tried installing bcmwl-kernel-source_6.30.223.30+bdcom-0ubuntu3_amd64.deb.  This is the error message:  Selecting previously unselected package bcmwl-kernel-source. (Reading database ... 170952 files and directories currently installed.) Preparing to unpack bcmwl-kernel-source_6.30.223.30+bdcom-0ubuntu3_amd64.deb ... Unpacking bcmwl-kernel-source (6.30.223.30+bdcom-0ubuntu3) ... Selecting previously unselected package dkms. Preparing to unpack dkms_2.2.0.3-2ubuntu3_all.deb ... Unpacking dkms (2.2.0.3-2ubuntu3) ... Setting up dkms (2.2.0.3-2ubuntu3) ... Setting up bcmwl-kernel-source (6.30.223.30+bdcom-0ubuntu3) ... Loading new bcmwl-6.30.223.30+bdcom DKMS files... First Installation: checking all kernels... Building only for 3.19.0-15-generic Building for architecture x86_64 Building initial module for 3.19.0-15-generic ERROR (dkms apport): kernel package linux-headers-3.19.0-15-generic is not supported Error! Bad return status for module build on kernel: 3.19.0-15-generic (x86_64) Consult /var/lib/dkms/bcmwl/6.30.223.30+bdcom/build/make.log for more information. modprobe: FATAL: Module wl not found. update-initramfs: deferring update (trigger activated) Processing triggers for man-db (2.7.0.2-5) ... Processing triggers for initramfs-tools (0.103ubuntu15) ... update-initramfs: Generating /boot/initrd.img-3.19.0-15-generic   I then tried:  $ sudo modprob wl sudo: modprobe: command not found   I checked and apparently the driver is recognized as installed:  ~$ sudo lshw -C Network *-network UNCLAIMED         description: Network controller    product: BCM43602 802.11ac Wireless LAN SoC    vendor: Broadcom Corporation    physical id: 0    bus info: pci@0000:03:00.0    version: 01    width: 64 bits    clock: 33MHz    capabilities: pm msi pciexpress bus_master cap_list    configuration: latency=0    resources: memory:c1400000-c1407fff memory:c1000000-c13fffff   So here I am, no Wi-Fi, not seeing any network ID...  I've Googled and found a few other people who've managed to get Wi-Fi working using the same blobs/drivers.  Can someone please shed light on why this is not working?  Also, why is the Apple Thunderbolt Ethernet Adapter not recognized, that thing came out years ago and it would make this processes a lot easier if I could at least get online to look up fixes, etc.


How to enable Account History Tracking in Scratch Org?

I have a project with existing metadata that requires Account History Tracking to be enabled. I can't figure out how to spin up a scratch org with this enabled (or to have it automatically turned on when I force:source:push the metadata into org).  The Account.object-meta.xml file does contain <enableHistory>true</enableHistory> but that alone isn't preventing errors like: The entity: Account does not have history tracking enabled (348:13)  I don't see any scratch org preferences that would seem to control history tracking for anything except contract (IsContractHistoryEnabled). I tried IsAccountHistoryEnabled, just in case, but it complains because that's not a valid flag.  Thanks,


I installed Ubuntu 18.04 yesterday. Today I tried to install micro editor through snap, but it doesn't work. Any command like this sudo snap install hello-world freezes for a minute and I receive  error: unable to contact snap store  Is there some problem with the snap store or is it because I couldn't connect to it from my network? How could I check that?


store part of an executable string as a variable using t-sql

Instead of  WHERE foo = 'one' and bar = 'two'   I would like to store parts of it in a variable to allow changing WHERE clause easily  DECLARE @var VARCHAR(50) SET @var = "foo = 'one' and bar = 'two'" ... ... WHERE @var   This notation doesn't work but I think it indicates what I am trying to do. Does anyone have any ideas?


Create an alias for a SQL Server named instance pointing to sql default instance

I have an installation of SQL Server 2012 Std Ed on Windows 2012 R2 running in a default instance, and an app that wants to connect to it using a named instance (can't be changed)  E.g.   ServerName - mySQLServer Alias required by app - mySQLServer\CrazyApp   I've tried to create an alias as follows:     Alias Name - .\crazyapp Port No - 1433 Protocol - TCP/IP Server .   I've:   checked TCP/IP protocol is enabled have started SQL browser (not needed, I believe) restarted SQL (several times) tried with the machine name instead of "." tried with no port number instead of 1433. banged head against wall   ...all to no avail.  Is it possible to do this, if so, would some kind person tell me what I'm doing wrong.  Thanks!


Although farmers appear to be able to tell their cows apart, cows look very much alike to me. And this similarity in appearance seems to be a general trait across the animal kingdom: one individual of one animal species looks much like another.  Why do human facial and body shapes vary so much?  I understand that human beings live in many different environments (e.g. hot and cold) and have adapted to these (e.g. through lighter or darker skin color), but there seems to be much variation that has no apparent evolutionary purpose. So does the difference have a purpose in itself? That is, did we evlove to vary in appearance, and what is the purpose of this variation?


C: Printing a separate letter of a string to the screen

Hi I'm new to C and I'm having trouble finding a way of printing only the 4th, 5th or 10th letter of a String.   I've got this little code:   char firstWord[100]; char secondWord[100];  printf("Please type in: Hello World\n"); fgets(firstWord, sizeof(firstWord), stdin);  printf("Please type in: How are you?\n"); fgets(secondWord, sizeof(secondWord), stdin);  printf("You typed: %s,%s", firstWord, secondWord);  strcat(firstWord, secondWord);  printf("together it looks like this: %s", firstWord);   Now how would I print for instance the 4th or the 6th character only of the concatenated string?


tail -f all files in a "living directory"

I am working with a directory where logs are constantly created. I use tail -f * in bash to view all the log entrys in the dir. However, when new files are created while the tail is running, the new files are not utilized by the tail. Is there a simple solution for that? Thank you!  EDIT: OS: SLES4SAP 12 SP2 3.0.101-63-default


I would please like some recommendations for an introductory level book on combinatorial group theory, by which I mean a group theory book which places emphasis on generators and relations and free groups, and then discusses common concepts such as quotient groups in terms of these. Thank you.


I administer a PostGIS server that was originally intended for internal use. Then, along the way, we open up access to external institutions. Internally, I therefore created views according to the needs and users. Then for internal webmapping, mapserver allowed me to produce WFS and WMS flows. Now that we're opening up to the outside world, without much thought, we've started to share mostly WFS streams. Data is visualized using, mostly, GIS clients like QGis and Arcgis. Before continuing this deployment, I'll try to give you an update on the subject:  Apart from the technological question, what is better to distribute: views or WFS streams? Are some better than others? In which case? In short, I am interested in feedback or reflections more accomplished than mine.


How do I get a  TP-Link TN-WN727N usb wireless stick working?

Just bought a new TP-LINK tl-wn727n usb thumb drive.  I'm running Ubuntu 12.04 32-bit. When I plug the stick in, nothing happens.  This may be normal for Linux veterans but as a new Linux user coming from Windows it seems weird.   I used the lsusb command and the device appears in the terminal as:  Bus 002 Device 007: ID 148f:5370 Ralink Technology, Corp. RT5370 Wireless Adapter  It is not showing up in the network connections list and I have no idea where to go from here.


Can a question be restored if the owner deletes it?

There was  by  (no, another Jon) that had an incorrect accepted answer with 0 votes. I pointed out in the comments that the accepted answer is wrong and started writing my own answer (a workaround, but anyway!). As I finished my answer and pressed Post Your Answer, I realized the question has just been deleted. This kind of bugs me because I really wanted to share my solution. Should I:  repost the question; wait for someone to revert it if possible?  Update I reposted the question (along with my answer) .


Wrong error message when suggesting an edit on a per-site-meta when not logged in

It is probably very unlikely for anybody to encounter this bug, but just for completeness’ sake:  If you try to access the edit link to a post on a per-site-meta, e.g.,   without being logged in (e.g., in a private browser window), you get the following error message:     There is a pending suggested edit in the queue, try again in a few minutes.   This happens always – even if there is no suggested edit.


Citation style error - Mendeley and LaTex

I have some citation errors using mendeley and latex (texmaker). I do not know how to explain the errors so I attached the code. Please run it and help if you can.  How to make that: in text - all the articles to appear "last name et al year" ??? in bibliography - all the authors to appear and the order of the names to be "first - last" ???  \documentclass[12pt,a4paper,twoside,openright]{book} \usepackage[  backend=biber, style=authoryear, %sorting=none, maxcitenames=1, citestyle=authoryear]{biblatex}  \addbibresource{bibliography.bib} \begin{document} \textbf{ERROR In text}:\\  This is good: \cite{Chapman1964}\\  This is not good: \cite{Nie2007}, neither this: \cite{Nie2003}\\ Why do I have more than one name? \textit{\textbf{(1. I want all to be "last name et al." - how to do it?)}}\\  For bibliography errors:\\ \cite{Arrayago2015}\\ \cite{Bursi2005}\\  \textbf{ERROR In bibliography?\\}  1. Why some articles have all the authors and others just the first and "et. al" - see first two. \textit{\textbf{(2. How to modify this to be make all the authors appear in the bibliography?)}}\\  2. Why the first author is "last name - first name" and the others "first name last name"? \textit{\textbf{(3. What should I do make all the articles be "last - first name".)}}  \printbibheading \printbibliography[type=article, heading=subbibliography,title={Articles}]  \end{document}   the bibliography.bib file contains:  @article{Chapman1964, author = {Chapman, JC and Balakrishnan, S}, journal = {The Structural Engineer}, number = {1}, pages = {369--383}, title = {{Experiments on composite beams}}, volume = {42}, year = {1964} }  @article{Arrayago2015, author = {Arrayago, I and Picci, F and Mirambell, E and Real, E}, doi = {10.1016/j.tws.2015.02.012}, journal = {Thin-Walled Structures}, pages = {96--107}, title = {{Interaction of bending and axial load for ferritic stainless steel RHS columns}}, volume = {91}, year = {2015} }  @article{Bursi2005, author = {Bursi, OS and Sun, FF and Postal, S}, doi = {10.1016/j.jcsr.2004.06.002}, journal = {Journal of Constructional Steel Research}, number = {1}, pages = {67--92}, title = {{Nonlinear analysis of steel concrete composite frames with full and partial shear connection subjected to seismic loads}}, volume = {61}, year = {2005} }  @article{Nie2007, author = {Nie, J and Cai, CS and Zhou, TR and Li, Y}, doi = {10.1061/(ASCE)0733-9445(2007)133:4(530)}, journal = {Journal of Structural Engineering}, number = {4}, pages = {530--540}, title = {{Experimental and Analytical Study of Prestressed Steel Concrete Composite Beams Considering Slip Effect}}, volume = {133}, year = {2007} }  @article{Nie2003, author = {Nie, J and Cai, CS}, doi = {10.1061/(ASCE)0733-9445(2003)129:4(495)}, journal = {Journal of Structural Engineering}, number = {April}, pages = {495--506}, title = {{Steel Concrete Composite Beams Considering Shear Slip Effects}}, volume = {129}, year = {2003} }   Any help would be appreciated. Thank You!


Converse of Lagrange's theorem for abelian groups

I'm trying to prove that the converse of Lagrange's theorem is true for finite abelian groups (i.e. "given an abelian group $G$ of order $m$, for all positive divisors $n$ of $m$, $G$ has a subgroup of order $n$"). This is an exercise from a book, and it is in the section on finite abelian groups, so I know I have to use the fundamental theorem of finite abelian groups. I have come up with a proof, but it seems a bit messy, and I'm not entirely sure if it's correct. It is given below.     Let the order of $G$ be $m$ = $p_1^{\alpha_1} \ldots p_k^{\alpha_k}$. It is known that $G$ is a direct product of $p$-groups, say:      $$G = G_1 \times \ldots \times G_k$$      where each $G_i$ is a $p_i$-group. By the fundamental theorem of finite abelian groups, each $G_i$ is isomorphic to a direct product of cyclic groups of the form      $$\mathbb{Z}_{{p_i}^{\beta_1}} \times \ldots \times \mathbb{Z}_{{p_i}^{\beta_l}},$$      where $\beta_1, \ldots, \beta_l$ are positive integers such that $\sum_{j=1}^l \beta_j = \alpha_i$. Now if $n$ divides $m$, then we must have      $$n = p_1^{\gamma_1} \ldots p_k^{\gamma_k}$$      for some $\gamma_1, \ldots, \gamma_k$ with $0 \leq \gamma_i \leq \alpha_i$.      Claim: Each $G_i$ has a subgroup of order $p_i^{\gamma_i}$      Proof: As above, we have that       $$ G_i \cong \mathbb{Z}_{{p_i}^{\beta_1}} \times \ldots \times \mathbb{Z}_{{p_i}^{\beta_l}} $$      where $\beta_1, \ldots, \beta_l$ are positive integers such that $\sum_{j=1}^l \beta_j = \alpha_i$.      Now since $0 \leq \gamma_i \leq \alpha_i$, we can find   $l$ numbers $\delta_1, \ldots , \delta_l$ such that $\gamma_i = \sum_{j=1}^l \delta_j$, and $0 \leq \delta_j \leq \beta_j$. (This choice of numbers is not necessarily unique).      Then $p_i^{\delta_j} | p_i^{\beta_j}$ for each $j = 1, \ldots , l$. Hence, for each factor $\mathbb{Z}_{{p_i}^{\beta_j}}$, there exists a subgroup of order $p_i^{\delta_j}$, namely $\mathbb{Z}_{{p_i}^{\delta_j}}$ (using the fact that the converse of Lagrange's theorem is true for finite cyclic groups). Taking the direct product of each of these subgroups, we get a new subgroup $G_i'$ of $G_i$:      $$G_i' \cong \mathbb{Z}_{{p_i}^{\delta_1}} \times \ldots \times \mathbb{Z}_{{p_i}^{\delta_l}}$$      The order of this subgroup is $p_i^{\delta_1} \times \ldots \times p_i^{\delta_l} = p_i^{\delta_1 + \ldots + \delta_l} = p_i^{\gamma_i} $. So we have found a subgroup of $G_i$ of order $p_i^{\gamma_i}$, as required.      So each factor $G_i$ in the product $G = G_1 \times \ldots \times G_k$ has a subgroup $G_i'$ of order $p_i^{\gamma_i}$.       Therefore, $G$ has a subgroup   $$G_1' \times G_2' \times \ldots \times G_k'$$       of order $p_1^{\gamma_i}...p_k^{\gamma_k} = n$, which completes the proof.   I have two questions about this: firstly, does this proof seem to work? Secondly, is there a way to make the proof more concise (e.g. a way to prove the statement without using all these indices)?


How to fix insufficient access rights on cross-reference id?

I am getting the error:     INSUFFICIENT_ACCESS_ON_CROSS_REFERENCE_ENTITY, insufficient access rights on cross-reference id: []   Scenario is, I am inserting an Opportunity and then Opportunity Line Item from a VisualForce page using controller. When I am doing this I am logged in as user whose profile license is "Authenticated Website".  Strange thing is, when on another org logged in as user whose user profile license is Customer Portal Manager the same code work fine. Both orgs have Opportunity OWD "Read Only" and Opportunity line item "Controlled By Parent".  To resolve this problem I've used "without sharing" on class which executes the insertion code, and it works fine from "Authenticated Website" user. As this may be a security issue when we try to list the app on AppExchange, is there any other way to resolve this problem?


Hi I have to apply dark theme flair but it is not updated (Reputation) from last 2 days.  Show image Below:


Word/phrase for a task that must be done in the current sprint

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I have looked everywhere on google, bing, yahoo, and so far found nothing. Can anyone tell me where the longest D&D game was held?


I recently got in a road accident and my laptop fell (HP Pavilion p045TX, Win 10 and Ubuntu dual boot). I booted it up and it started showing the automatic repair screen. I booted it in Ubuntu and It started fine. I restarted it again and I got the "Hard Disk not detected error". After that it never detected the hard disk and only made clicking sounds.   Is there any hope of repairing it or recovering the data? Is there something wrong with the head? I guess if the platters were broken, It would have never booted in the first place. Any help would be appreciated.


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I've been reading Wald's book on General Relativity and in appendix $E_{2}$ it discusses the Hamiltonian formalism of General Relativity.I would like to understand it more, can you recommend me a textbook about ADM formalism? P.S. I have already read Eric Poisson book too.


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In Star Wars Episode 3, Revenge of the Sith, there's a scene where Anakin and Yoda are sitting in that little meditation room (with the horizontal shades over the windows) and discussing the meaning of Anakin's recent premonitions of "someone" (Padme) dying. Yoda gives Anakin a piece of advice that starts out quite wise, but then, for me, skews off into nonsense.  Yoda: "These visions you have ..." Anakin: "They are of pain, suffering ... death." ... Yoda: "Careful you must be when sensing the future, Anakin! The fear of loss is a path to the Dark Side." Anakin: "I won't let my visions come true, Master Yoda." Yoda: "Rejoice for those around us who transform into the Force. Mourn them, do not. Miss them, do not. Attachment leads to jealousy, the shadow of greed, that is." Anakin: "What must I do, Master Yoda?" Yoda: "Train yourself to let go of everything you fear to lose."  The bold words are the parts that I find to make little sense or have little relevance to the problem Anakin is trying to seek help for. Now, I understand that certain George-Lucas-isms have been injected into this speech, but maybe I'm the one who just fails to understand the meaning? First of all, how is fearing for a loved one a path to evil? Isn't that precisely what makes a tragic hero tragic? It may be harkening back to the Phantom Menace's "Fear leads to anger, anger leads to hate, hate leads to suffering" line, but even that is gibberish. My biggest problem is the "attachment leads to jealousy" line. Now, I've put a LOT of thought into trying to understand this, but I've come up empty each time. According to Lucas, the Jedi are similar to Buddhist monks, so I looked up "attachment in Buddhism" and discovered that it means something very different to the Western world's definition of attachment. We Westerners see 'attachment' as synonymous to a bond, a relationship or even love. Buddhism defines it as ... well, something confusing to me. One definition is that it is "clinging", another, that it is "craving" and then another that says something about "becoming" ... I have no good idea what any of this means or how it relates to Anakin Skywalker, or greed, or jealousy. Then there's the "letting go of what you fear to lose" part. This sounds, a lot, like Yoda is saying, "Well, Anakin, to spare yourself the pain of grief, you should just cut this person out of your life and forget them. Let them go before he/she dies!" I would assume that he means to learn to let Padme go after she dies, but the wording of "train yourself to let go of everything you fear to lose" is so darn vague and sounds like Yoda is talking about "letting go" while Padme is still alive. Isn't that a little cold? Does anyone know what is going on in this scene? :P


How many times can I repeat a keyword without looking spammy to Google?

I have an eCommerce based on Opencart, but I have some doubts about how many times I can repeat the same word.  For example, the keyword is present in the title, description, h1, h2 and is repeated several times in the text:   Page Title: Shop Iphone other keyword Page description: Shop Iphone other keyword   (and they continue appearing below)   H1: Shop Iphone other keyword H2: Shop Iphone other keyword 10 more times in the text: Shop iPhone   I mean, if Googlebot sees the same WORD 30 times, can it be considered SPAM? Can I lose something or can I use keywords a lot?  In WOORANK I saw my review and I noticed that I need to improve my keywords, and a lot. I have some keywords like: payment, description, promotion, sales... keywords really "empty"  [ UPDATE ]  Can repeating keywords make them lose importance?


Should binary files be stored in the database?

What is the best place for storing binary files that are related to data in your database? Should you:   Store in the database with a blob Store on the filesystem with a link in the database Store in the filesystem but rename to a hash of the contents and store the hash on the database Something I've not thought of   The advantages of (1) are (among others) that atomicity of transactions is preserved. The cost is that you might dramatically increase storage (and associated streaming/backup) requirements  The goal of (3) is to preserve atomicity to some degree - if you can enforce that the filesystem you are writing to does not allow files to be changed or deleted, and always has the correct hash as filename. The idea would be to write the file to the filesystem before permitting the insert/update referencing the hash - if this transaction fails after the filesystem write but before the database DML, that is fine because the filesystem is 'faking' being the repository of all possible files and hashes - it doesn't matter if there are some files in there that are not being pointed to (and you could clean them up periodically if you are careful)  EDIT:  It looks like some RDBMSs have this covered in their individual ways - I'd be interested to know how others do it - and particularly in a solution for postgres


I tried apt-get update and upgrade together and this is what I got.  E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?   What should I do?