I want to cite references within a subfile and have the subfile correctly compile, but I seem not to be able to access my .bib from the subfiles, since it always gives me an error message when I try to do so.  An MWE is as follows:   \documentclass[12pt,a4paper,twoside,final]{memoir}  \usepackage[T1]{fontenc}  \usepackage[utf8]{inputenc}  \usepackage[english]{babel}  \usepackage{subfiles}  \usepackage[   backend=biber,   style=authoryear-icomp,   sorting=nyt   ]{biblatex}     \addbibresource{/bib/ref.bib}   %End of Preamble   \begin{document}   \subfile{chap/chapter1/ch1.tex}   \printbibliography   \end{document}   And in my ch1.tex file I have the following set:   \documentclass[../../thesis.tex]{subfiles}  \begin{document}  \chapter*{1}  Testing a citation \cite{Aigner2014}.  \end{document}   Where the cited entry is to be found in the ref.bib inside the bib-subdirectory of my main-directory. However, when I try to compile the document, biber gives the following error:     INFO - This is Biber 1.9 INFO - Logfile is 'ch1.blg' INFO - Reading 'ch1.bcf' INFO - Found 1 citekeys in bib section 0 INFO - Processing section 0 INFO - Looking for bibtex format file '/bib/ref.bib' for section 0 ERROR - Cannot find '/bib/ref.bib'! INFO - ERRORS: 1 Process exited with error(s)   Is there any possible way to make the ch1.tex file able to find my ref.bib file?  I have tried the workaround provided in the answer , but it doesn't seem to help me anyway. I can't make much sense of the code there however.  Any help is much appreciated!

I am having some trouble getting a modular document to work.  This is what my files look like at the moment     ./rootdoc.tex      ./tex/childdoc.tex      ./bib/bibliography.bib   the files look like...     ./rootdoc   \documentclass{book}     %some packages     \usepackage{subfiles}     \usepackage[colorlinks=true]{hyperref}     \usepackage[backend=biber,style=numeric]{biblatex}         \addbibresource{bib/bibliography.bib}  \begin{document}         \subfile{tex/childdoc.tex}         \printbibliography[heading=bibintoc]     \end{document}      ./tex/childdoc   \documentclass[../rootdoc.tex]{subfiles} \begin{document} \chapter{Sample Chapter} some text that i have to cite\cite{ross} \printbibliography \end{document}   When compiling the root document everything works fine and I get the following    But when I compile .\tex.childdoc I get    Any help will be greatly appreciated.


I wrote a little . When I tried to run a.out, I got "command not found".  When I ran ./a.out, it worked fine.  Where can I learn about why that was?

While executing a C program, a.out, using the Ubuntu terminal, why do I always need to type ./ before a.out, instead of just writing a.out? Is there solution for this?


Let f be an entire function. Suppose $\exists$ $M>0$ such that   $\mid$$f(z)$$\mid$ $\leq$ $M$$\mid$$z$$\mid$ $\forall$   $z$$\in$$\Bbb{C}$. Show that $\exists$$\lambda$$\in$$\Bbb{C}$ such   that f(z)=$\lambda$$z$ $\forall$ $z$$\in$$\Bbb{C}$.   This problem is related to Liouville's theorem (which is a corollary of the cauchy inequalities) and someone told me use function g(z)=f(z)/z. But since g(z) is not 'entire' function, I don't really know how to use this function to solve this problem. How can I solve this matter?

Let $f:\mathbb{C} \rightarrow \mathbb{C}$ be a entire function. Suppose that there are $M$, $r>0$ and $n\in \mathbb{N}$ such that $\left|f(z)\right|<M\left|z\right|^n$ for all $z \in \mathbb{C}$ with $\left|z\right|\geq r$.  Show that $f$  polynomial of degree at most $n$.  Remark: I tried to follow the proof of Liuville's Theorem but I have complications with the condition  $\left|z\right|\geq r$..


First, the guy accidentally gets wounded and a strange thing gets implanted in his arm. The thing causes his arm to swell but he visits a doctor who tries to keep it in check by bandaging him and giving some medication to him. But, one fine day it gets out of control and the thing takes over his body leading to his transformation.  I described a clipping I saw a long time ago probably on Facebook. Can anyone recall an anime like that?

Typical Japanese style anime art, it was a series.   It has been around for more than 6 years. I think it mixed fantasy and sci-fi. It was certainly not Isekai and it has no magic, it feels more like revered science. A boy gets a gem embedded into his arm after a terrorist attack and transforms into a white and orange humanoid being. There are more people able to transform into these beings. There is also a red flying ship with a dark yellow underbelly that throws boxes with parachutes. There is also this top-secret laboratory where the scientists study how to battle against the beings. There are some other flying ships of varying colors. If I remember correctly, the protagonist gets amnesia near the end of the plot.


Difference between linear regression with or without intercept? Why and when to use which one?

I am running linear regression models and wondering what the conditions are for removing the intercept term.   In comparing results from two different regressions where one has the intercept and the other does not, I notice that the $R^2$ of the function without the intercept is much higher. Are there certain conditions or assumptions I should be following to make sure the removal of the intercept term is valid?


Having more gold in Dungeons and Dragons allows a player to add things to their character sheet, and effects the actions they can take in a combat round.  But what is gold in terms of game mechanics in Dungeons and Dragons games? (I am leaving it broad regarding editions, as there isn't a huge difference--that much I know).  It is codified in the rules how XP is distributed equally among the party.     When adventurers defeat one or more monsters-typically by killing,   routing, or capturing them-they divide the total XP value of the   monsters evenly among themselves.  -5e DMG   This is not the case for gold.       Over the course of a typical campaign, a party finds treasure   It is clear a PC can do things with gold that effect their character sheet and available actions in a combat round.  Being able to cast Forcecage, increasing armor class, having more spells.  Note that even in 5e, regardless of intention, the DMG provides options to buy magic items, which many DM's allow, and lists suggested prices--using that rule, gold directly affects your character sheet like XP.    There doesn't seem to be any mechanic in any edition that allows stealing of XP or abilities from other characters, so whats up with gold?  Where exactly is the delineation from mechanic and in-game economy?  (Well, there was Psychic Drain psionic power from 2e, but not a lot in this arena.)  So are there two types of gold in the game world:  one is more like "mana," and disassociated, while the other can be used to buy bushels of apples, and is useless to the PC's, so who cares?   There are implications to questions like "should gold be distributed like XP, in a manner that PC's get so much each, and can't possibly 'steal' it?" depending on what gold is in the game.

I am a DM for a small group. One of the players has a very sneaky dwarf from a criminal background and chaotic neutral alignment. The problem is he keeps pick pocketing his Elvish teammates, saying that he hates elves and how his criminal background means he did the same back home. He rolls very well, and his Elvish counterparts have low Wisdom (Perception). Since he is a dwarf, chaotic neutral and a criminal, it seems perfect.   He doesn't steal much, just about 10 gold out of 1000 gold. But I don't want this to continue because the players know that he has the gold but they can't catch him without metagaming. How do I stop this?


I am looking for simple games that I should develop to learn the basics of how different game mechanics work. I have read in many places that it is good to make Pong.  Is there a recommended list of basic games to try recreate when starting with game development?

I believe that in order to become a good game developer, you need to make games.   From a programmer's perspective, what are some good entry level games to get your hands dirty? What skills and challenges do each of these games teach you?


Is it obvious that $\mathbb Q(\sqrt 3+\sqrt 5)=\mathbb Q(\sqrt 3,\sqrt 5)$ ? If not how can I show it ?

Is $\mathbf{Q}(\sqrt{2}, \sqrt{3}) = \mathbf{Q}(\sqrt{2}+\sqrt{3})$ ?    $$\mathbf{Q}(\sqrt{2},\sqrt{3})=\{a+b\sqrt{2}+c\sqrt{3}+d\sqrt{6} \mid a,b,c,d\in\mathbf{Q}\}$$   $$\mathbf{Q}(\sqrt{2}+\sqrt{3}) = \lbrace a+b(\sqrt{2}+\sqrt{3}) \mid a,b \in \mathbf{Q} \rbrace  $$  So if an element is in $\mathbf Q(\sqrt{2},\sqrt{3})$, then it is in $\mathbf{Q}(\sqrt{2}+\sqrt{3})$, because $\sqrt{6} = \sqrt{2}\sqrt{3}$.  How to conclude from there?


When restoring a database, is there a way to restore the plan cache so it doesn't have to be re-created during production use?  Similar question: is there a way to pro-actively restore the buffer cache during or after a database restore?,…. other than to create and run select statements on the tables previously in the buffer cache, a solution which would be time-consuming to create, and inevitably inaccurate.    This is a followup to this question:  "".  edit:  This question is a follow-up because I want to know if there is a workaround to get the plan cache and buffer pool back to their source state.

on our development server, we refresh database (restore from production backup) every week. my question is does restore db clear its buffer cache/stored procedure cache from sql memory? Does it have the same/similar effect of  DBCC FREEPROCCACHE and DBCC DROPCLEANBUFFERS  Thanks.


We know that accelerating charged particles emit electromagnetic radiation. We also know that electrons around nucleus have an angular momentum which means that electrons are revolving around the nucleus, therefore, they are subjected to acceleration due to their orbital motion. However, atoms do not constantly emit light. Isn’t this a contradiction?

According to electrodynamics, accelerating charged particles emit electromagnetic radiation.  I'm asking myself if the electron in an hydrogen atom emits such radiation. In , Murod Abdukhakimov says the total momentum of the electron is zero, hence it does not emit radiation. Could someone prove this statement ?  It may be an obvious question, but I can't figure out why the total momentum of the electron should always be zero, in any energy state.


How to prove that $(n!)^{1/n}$ tends to infinity as $n$ tends to infinity ?

I am trying to prove that the sequence $$a_n = (n!)^{\frac2n}$$ tends to infinity as $ n \to \infty $.  I've tried different methods but I haven't really got anywhere. Any solutions/hints?


If $0<a<b$, prove that $a<\sqrt{ab}<\frac{a+b}{2}<b$  So far I've got:  $a<b$  $a^2<ba$  $a<\sqrt{ab}$  And:  $a<b$  $a+b<2b$  $\frac{a+b}{2}<b$  So I need to prove that $\sqrt{ab}<\frac{a+b}{2}$  How can I do it?

I am having trouble with this problem from my latest homework.  Prove the arithmetic-geometric mean inequality. That is, for two positive real numbers $x,y$, we have $$ \sqrt{xy}≤ \frac{x+y}{2} .$$ Furthermore, equality occurs if and only if $x = y$.  Any and all help would be appreciated.


I want to move my computer into another room for the summer, the destination is 10m away in terms of cable length. I had no problem finding a 10m HDMI 2.0 cable but USB 3.0 seems to be a different story.  Trying to do this as cheaply as possible, the current plan is to get a 5m active cable and attach another 5m passive cable to it to reach the hub on my desk. The reasoning being that the active cable is only active at one point - the female end of the cable which theoretically would be the same as a passive cable + hub at the end, right?  If the manufacturers of the active cable feel comfortable stretching the 3m specification to 5m then it.. might work?

Recently I've been thinking of upgrading my computer with some USB 3.0 ports. However, the problem is my computer is some ways away from my desk so that would mean I would need a long cable, approximately 10ft or so.  My question is how badly does a long cable (10ft for example) impact the transfer rates of USB 3.0? At what point will the USB controller revert back to say, high speed mode as opposed to super speed mode? What have you guys experienced?  Thanks


Let $f:[0,1]\to \mathbb{R}$ be continuous and $g:[0,1]\to \mathbb{R}$ with $g(x):=\int_{0}^{x}(x-t)f(t)dt$. I have to show that $g''=f$ on $[0,1]$.    How can I get the derivative of an integral?

Let $f:\mathbb R\to \mathbb R$ be a continuous function and $\Phi(x)=\int_0^x (x-t)f(t)\,dt$. Justify that $\Phi(x)$ is twice differentiable and calculate $\Phi''(x)$.   I'm having a hard time finding the first derivative of $\Phi(x)$. Here's what I tried so far:  Since $f$ is a continuous function and $x-t$ is a polynomial function, thus continuous, $f(t)(x-t)$ is the product of two continuous functions and is also continuous. Since $x$ and $0$ are differentiable functions, by the Fundamental Theorem of Calculus   $\Phi'(x)= (x-x)f(x)x' - (x-0)f(0)0'=0$  I checked the solution and this is wrong, the solution goes like this: $\Phi'(x) = (x\int_0^xf(t)dt - \int_0^xtf(t)dt)' = \int_0^xf(t)dt + xf(x) - xf(x) = \int_0^xf(t)dt$  So I tried to do it their way, expanding $(x-t)f(t) to xf(t) - tf(t)$ and I got this:  $\Phi'(x) = (\int_0^x (x-t)f(t)dt)' = (\int_0^x xf(t) - tf(t)dt)' = (x\int_0^xf(t)dt - \int_0^xtf(t)dt)' = xf(x)x' - xf(0)0' - (xf(x)x' - 0f(0)0') = xf(x) - xf(x) = 0$  $0$ again.  Another thing I didn't understand is why they put the $x$ outside the integral, I thought we were only supposed to do that with constants. As in, why is $\int_0^x xf(t)dt = x\int_0^x f(t)\,dt$  I understand the rest of the exercise, I just can't get this derivative right with the Fundamental Theorem of Calculus. The version I'm using says  Let $f$ be a continuous function and $a(x)$ and $b(x)$ be differentiable functions. If $$F(x) = \int_{a(x)}^{b(x)} f(t) \,dt$$ then $F'(x) = f(b(x))b'(x) - f(a(x))a'(x)$  Is this correct? Because if so I don't understand how the derivative of this exercise works.


when I insert data into mysql database Serbian letter like č looks like Ä and ć looks like Ä‡. In header I have:  <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge">   and encoding is set to utf8_unicode_ci so I don't know where is the problem...  When I put   mysqli_set_charset($connection, "utf8");   before insert, then in mysql is looking good, but in my app ć is appear as symbol ?  Where am I wrong?

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


I am unable to post Chinese text symbols here but basically I just want to remove all the lines that do not contain at least one Chinese symbol.    How can I extract that so it looks like

I am working on a text written in Italian and Chinese and I need to extract only Chinese characters using AWK. How can I do this?  I tried:  [The range of Chinese Unicode chars is 4E00 thru 9FFF (344 270 200 thru 351 277 277) so the test should be >"\343" and <"\352" (to avoid picking up any 4 char UTF-8 codes)]:  { f=0; for ( i=1; i<=length; i++) if(substr($0, i, 1)>"\343" &&substr($0, i, 1)<"\352") f = 1   print $f }   But there is an error or more errors. I can't find it / them


I have a problem using lstlisting environment with utf8 encoding. I got this error    Package inputenc Error: Unicode char \u8:�\expandafter not set up for use wit     MWE  \documentclass{article} \usepackage[frenchb]{babel} \usepackage[utf8]{inputenc} \usepackage{listings} \begin{document} \begin{lstlisting}   {entête}.{informations}.{signature}  \end{lstlisting} \end{document}

I'm having some problems with listings and UTF-8 in my document. Maybe someone can help me? Some characters work, like é and ó, but á and others appear at the beginning of words...  \documentclass[12pt,a4paper]{scrbook} \KOMAoptions{twoside=false,open=any,chapterprefix=on,parskip=full,fontsize=14pt}  \usepackage[portuguese]{babel} \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{listingsutf8}  \usepackage{inconsolata} \lstset{     language=bash, %% Troque para PHP, C, Java, etc... bash é o padrão     basicstyle=\ttfamily\small,     numberstyle=\footnotesize,     numbers=left,     backgroundcolor=\color{gray!10},     frame=single,     tabsize=2,     rulecolor=\color{black!30},     title=\lstname,     escapeinside={\%*}{*)},     breaklines=true,     breakatwhitespace=true,     framextopmargin=2pt,     framexbottommargin=2pt,     extendedchars=false,     inputencoding=utf8 }  \begin{document} \begin{lstlisting} <?php  echo 'Olá mundo!'; print 'Olá mundo!'; \end{lstlisting}  \end{document} \end{lstlisting}


Well, here is the situation. I have four students. They did a test. Suppose that the regulation is a student getting a score below 40 gets the remark "study hard" which is written at the bottom of the work instead of a numerical score. When I want to confirm this, may I say:  They get study hard if their SCORE IS (instead of SCORES ARE) below 40, right?

After the therapy, eight children (43%) became able to crawl/move on their back.   Or should I use "on their backs"?   Singular because each child only has one back, or plural because we're dealing with eight backs?


We had some performance issues with our ERP system. Somewhere around 06:00 the problem started. Long story short; one of my colleagues executed a DBCC FREEPROCCACHE (I know that this is not a preferred action, but that is not the point here). After that, he restarted the whole ERP application, not the database engine. That didn't seem to help. I looked into the Query Store and saw that the query plan was changed somewhere around 06:05. I tried forcing the older plan and the performance issues were gone.   I compared the 2 plan XMLs and I saw that both were based on the same statistics (updated date was exactly the same). The number of changes on the indexes was different, but that did not trigger an update statistics, because else the new query plan would have had a new date for the used statistics. I checked all the statistics of the involved tables, but they were not updated since the last maintenance job. The last maintenance job ran this weekend, which was also the update date of the statistics used in both query plans.  The query is a parameterized query, so why the query plan changed suddenly is a little unclear to me. I would think just the opposite, that a query suddenly runs slow, because the same plan is used for different parameters. This did not seem to be the case here, because I forced the old query plan.  The query comes from some bespoke work that retrieves orders. Now, I suspect that someone issued the parameterized query which would have returned a very large dataset and that slowed down the ERP system. Then, my colleague ran a DBCC FREEPROCCACHE and that triggered the re-compile of the query plan, based on the new statistics from this weekend. The current query just kept running and that is were he decided to restart the ERP application. Now with the new query plan all new queries slowed down until I forced the old query plan.   Could this be the explanation? I am a little skeptical, because SQL Server would trigger a re-compile when statistics have changed, so the plan should already have been re-compiled after the index maintenance job.   I think I am missing something here, but I am not exactly sure what. It is SQL Server 2016 Standard and is a dedicated server for the ERP system.  Edit 15-4-2020 12:17: Now that I write this... I think the issue is just that after the DBCC FREEPROCCACHE the parameters of the first execution of the parameterized query in question used different parameters, which caused SQL Server to recompile the (bad) plan. Or is there still something I am missing?

[Salutations]  (check one)  [ ] Well trained professional, [ ] Casual reader, [ ] Hapless wanderer,   I have a (check all that apply)  [ ] query [ ] stored procedure [ ] database thing maybe     that was running fine (if applicable)   [ ] yesterday [ ] in recent memory [ ] at some point    but is suddenly slower now.  I've already checked to make sure it's not being blocked, and that it's not the victim of some long running maintenance task, report, or other out of band process.  What is the problem, what should I do, and what information can I provide to get some help?  [*Insert appropriate closing remarks*]


This month, I have number of postdocs interviews planned. I just passed the first one and I did really good, the PI just send me an informal email telling me that I did really good and I should expect a decision tomorrow (I just got interviewed the day before). So, I'm expecting good news. Here's the issue, I still have an interview by the end of the month that I am looking for, and another one at a another university 4 weeks from now. For this last interview, I really like the research project they're working on and my strong skills are the essential skills they're looking for. So, I'm confident about this last interview. I don't want to decide anything until I pass these 3 interviews, but the committee in the first interview is moving way too quickly for me. So, I don't know what to do. On the scenario where I received an offer from the first interview tomorrow or early next week. Should I cancel the interviews that I am actually looking for? Is it acceptable to accept the offer and still have the other interviews? (You know where I'm going with this)

I will graduate soon from the doctoral program. I will apply for multiple postdoc positions. The results of the one that I really think is great for my career will be probably announced later than the others. If I accept an earlier offer, and later learn that I could also get the one I desire the most, then I will really regret. However, I don't want to risk by refusing an early offer, since at the end I may get nothing.  Do you have any recommendations for such situations? Have you ever experienced this dilemma? How did you manage it?


After trying many different way to express the following program, I wasn't able to get pass a value from an activity to another. It seems that the bundle keeps being null for some reason. I don't think it could be a permission problem.  MainActivity :  public class MainActivity extends AppCompatActivity {      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);     }      public void ButtonRAWclick(View view)     {         Intent intent = new Intent(MainActivity.this                 , RestClient.class);         intent.putExtra("type", "RAW_TYPE");         startActivity(intent);     }      public void ButtonHTTPclick(View view)     {         Intent intent = new Intent(MainActivity.this                 , RestClient.class);         intent.putExtra("type", "HTTP_TYPE");         startActivity(intent);     }      public void ButtonJSONclick(View view)     {         Intent intent = new Intent(MainActivity.this                 , RestClient.class);         intent.putExtra("type", "JSON_TYPE");         startActivity(intent);     }  }   RestClient :  public class RestClient extends AppCompatActivity implements SensorListener {     RawHttpSensor rhs1;     TextSensor rhs2;     TextView temperature;     String output;     String type;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_rest_client);          Bundle bundle = getIntent().getExtras();         if (bundle != null) {             type = bundle.getString("type");         }          if (type == "RAW_TYPE") {             rhs1 = new RawHttpSensor();             temperature = (TextView) findViewById(R.id.temperature);             rhs1.registerListener(this);             rhs1.getTemperature();         }          if (type == "HTTP_TYPE")         {             rhs2 = new TextSensor();             temperature = (TextView) findViewById(R.id.temperature);             rhs2.registerListener(this);             rhs2.getTemperature();         }          if (type == "JSON_TYPE")         {            ...         }        ...     }   Can someone help me spot the bug ?

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


The description of the  cantrip reads:  A flickering flame appears in your hand. The flame remains there for the duration and harms neither you nor your equipment. The flame sheds bright light in a 10-foot radius and dim light for an additional 10 feet. The spell ends if you dismiss it as an action or if you cast it again. You can also attack with the flame, although doing so ends the spell. When you cast this spell, or as an action on a later turn, you can hurl the flame at a creature within 30 feet of you. Make a ranged spell attack. On a hit, the target takes 1d8 fire damage.  If I have one hand occupied with a shield and another hand occupied with an arcane focus, can I cast produce flame into one of my occupied hands? If I have the War Caster feat, can I then use the flame as an opportunity attack while my hands are occupied? I'm getting ready for a one-shot battle-royale and want to be able to have a free damage cantrip.  This question is different from the question . The previous question is about casting produce flame with an open hand and then equipping an item. I am specifically talking about having both hands equipped with items and then choosing to cast produce flame.

The text of the  spell reads:      A flickering flame appears in your hand. The flame remains there for the duration and harms neither you nor your equipment. The flame sheds bright light in a 10-foot radius and dim light for an additional 10 feet. The spell ends if you dismiss it as an action or if you cast it again.   Emphasis mine. The druid in our party asked our DM if he is able to cast produce flame in a dark cave, then opt not to attack with it, and wield a shield and sword. The goal is to continue emitting light, since he doesn't have the light spell. He claims that since the flame does not harm his equipment, he is able to hold a shield or sword with the fiery hand with no problem.  Is this okay to do RAW, or are we missing something?  This is specifically not asking about casting spells with a sword in hand. He wants to draw his weapon after casting and holding the flames.  Related, but not the same question: , , .


I have .pages document which have been damaged. I tried different methods like  and  one on internet but no success. My last hope is to read data from .iwa files but I cannot find a way to decompress .iwa files in order to read contents. Is there any way to get my data back through these files?

Pages has crashed, my file is now corrupted and I'm trying to get the text from this file.  if I Right click on the file > Show package content > open index.zip , I can see a bunch of .iwa files which seems to contains my original text, especially "Document.iwa".  If I "$ nano Document.iwa" (because "$ file" only returns "data") I can see some of my text, but the overall seems crypted.  Does anyone know how to decode/read this kind of .iwa file or recover corrupted files?


I read this short story at least thirty years ago, an anthology in the UK but the story was set in the US.  A grandmother is struggling to raise her grandson, I think the parents are dead. There is an ongoing war with (I think) Russia. Nothing atomic is mentioned IIRC, instead some futuristic weapons are being deployed.   The problems are caused because a weapon used a while ago  has rendered the population deaf. The woman is continually waving a sign saying NO at this kid to try and get him to behave, she gets him to school. There are despairing teachers trying to instil some learning into these kids , a real problem with both sides being deaf.  Mention is made in the newsheets of another enemy weapon that can cause the body's molecules to separate, causing rapid death, this is characterized by people suddenly growing to giant size and doing a parody of a dance as the weapon destroys them.  I think the downbeat short story ends with her and the kid in the street outside her house, they are suddenly dancing and getting rapidly bigger, surrounded by their neighbours doing the same.

A long time ago, I read a story about a future war.  Everything is in ruins.  An old lady is trying to raise a boy.  But one weapon has made everyone deaf.  When the boy does something bad, all she can do is hold up a card which says "No!".  They can tell when the air raid siren goes off by the vibrations of the sirens causing beans to jump about in a tube.  TV shows lots of old silent movies.  It may have been in an anthology.


My friend gives me Gentoo [installed yet]. I virtualized it on virtual box but my friend doesn't remember User and Password and he says me there is a method to remove user and password but he doesn't remember what this method is.  How can I do this?  In alternative, is there a method to create another account without touch that one?

I forgot my root password...actually I think I know what it is because it is the same password I have for pretty much everything but in the Terminal in tell me "Sorry, try again." Is there a way to reset the password? If so how?


How do I change the equation numbering to appear in the right, instead of the left default side in Lyx?

I am new to TeX and am using  to write a maths paper. When I put the followng code, the equation number is automatically displayed on the left, instead of in the right as is usually done. What is the problem and how do I fix it?  \documentclass[12pt,oneside]{amsart} \usepackage{amssymb} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \begin{document} Let us consider a spherical symmetric metric in curvature coordinates: \begin{equation}  \label{metric} ds^2=-e^\lambda dr^2-r^2(d\theta^2+\sin^2\theta d\phi^2)+e^\nu dt^2 \end{equation} \end{document}   The output I get is


Is there a way to echo output that being piped to the next command? For example lets say that I can reading filenames from a text file and then running a command on that file:  cat files.txt | xargs -I{} -d"\n" command    The command runs and the output is displayed in the terminal, is there a way to print out the filename as well?   Lets say the input file contains:  file1.txt file2.txt   Intended output:  file1.txt [output of command with file1.txt as input] file2.txt [output of command with file2.txt as input]   Is there a way to get file1.txt and file2.txt in stdout as well?

I have a script that outputs text to stdout. I want to see all this output in my terminal, and at the same time I want to filter some lines and save them in a file. Example:  $ myscript Line A Line B Line C  $ myscript | grep -P 'A|C' > out.file  $ cat out.file Line A Line C   I want to see output of first command in terminal, and save the output of the second command in a file. At the same time. I tried using tee, but with no result, or better, with .


I've got a class named tmc, which now contains (among other things, which are not relevant here) a private constructor, a static factory method, and an instance method named ReadLoop (void*):  extern "C" { #include <pigpiod_if2.h> }  class tmc { public:   static tmc* Initialize ();   static int  main ();  private:   void *ReadLoop (void *params);   tmc ();   pthread_t *tmc_receiver_reader; };  tmc::tmc () : tmc_receiver_reader (start_thread (tmc::ReadLoop, NULL)) { }  void* tmc::ReadLoop (void *params) {   return params; }  tmc* tmc::Initialize () {   tmc* instance = new tmc ();   return instance; }  int tmc::main () {   return (tmc::Initialize ()) == NULL ? 0 : 1; }   The issue is now the following: How shall I use the ReadLoop as a function pointer for use with the  function contained in pigpiod_if2? The code shown here doesn't compile because of the following error:  error: invalid use of non-static member function ‘void* tmc::ReadLoop(void*)’    tmc_receiver_reader  (start_thread (tmc::ReadLoop, NULL))   I've seen several questions here at SO with the same error message, but none of them was about a pointer to a non-static member method given to a C function. Please note that even if the object created here is a singleton, I can't make ReadLoop () static. I'm using the g++ 6.5.0 on Raspbian Buster. Thank you.

I'm using an API that requires me to pass a function pointer as a callback. I'm trying to use this API from my class but I'm getting compilation errors.   Here is what I did from my constructor:  m_cRedundencyManager->Init(this->RedundencyManagerCallBack);   This doesn't compile - I get the following error:      Error  8 error C3867: 'CLoggersInfra::RedundencyManagerCallBack': function call missing argument list; use '&CLoggersInfra::RedundencyManagerCallBack' to create a pointer to member   I tried the suggestion to use &CLoggersInfra::RedundencyManagerCallBack - didn't work for me.   Any suggestions/explanation for this??  I'm using VS2008.  Thanks!!


I clarified my question, by editing the title. Using the comments  and links below, I have answered it myself:  The answer to my question is: The similarity is between 98.4%-99.9%, depending on which type of differences you include. The numbers relate to writing my and the other person's DNA as a long string, and compare differences (change of letter, missing/inserted letter). The most important differences seem to be SNPs (=difference in a letter in a gene-coding sequence) and account for 0.1% of difference between our 2 DNA's:       I have striked out the original question text, because it includes some motivation and interpretation, which seems false.  edit: It was suggested that the question is a duplicate to  but this might seem not to be the case, as this question just concerns the used metric (compare answer below).    99.9% vs 88%:  2 person's DNA is 99.9% the same (which goes down to 99% in some sources), e.g.   Does this number include differences in copy-number variations and maybe other ?  On the other hand  says that there may be up to 12% of some other differences (I am not sure what those differences mean).  Question:  I have been pouring through the internet and books, but have not yet understood to which metric this 99.9% number refers to? (I am a pure mathematician)  My hypothesis what it means:  If we look at a 1000 base-pair long snippet of the DNA of person A, then we will find this same snippet somewhere also in person B's DNA, with just one difference in one of the 1000 base pairs.  Now, if the latter is true, then this means that my DNA may still be significantly different than my neighbours, e.g. by containing a different number of repetitions in the non-coding DNA.   Ultimately, my DNA could be only, say, 2% similar instead of 99.9% (depending on the number of different repetitions), if we used as a metric the number of single base changes (including single deletions/insertions), we need to do to go from the DNA of person A to the DNA of person B (assuming we wrote down each other's DNA in one long string). Question 2: In fact, I would be quite interested to know how much the DNA of two people is similar using this last metric?

It is often cited that humans share 99% (or 98%) of their DNA with chimpanzees.  On the other hand it is stated that siblings share only half of their genes.  What (if any) is the difference between DNA and genes; or, how can the above two claims be reconciled? (I am assuming of course that chimps and humans are more different from each other than two siblings are from each other.)   (I am asking this question as a layperson, who had a little biology in school but not much more.)  June 2015 Addendum: Here is a nice  just released by MinuteEarth; I do not know how accurate this video is, but as a layperson I found it insightful.


I would like to prove the following:  Let $p$ and $q$ different prime numbers and let $a$ be an integer such that $a < p$ and $a < q$.  I want to prove that  $$pq \; | \; a^{pq} - a^p - a^q + a$$  i.e. I would like to prove: $$ \frac{a^{pq} - a^p - a^q + a}{pq} \in \mathbb{Z}$$.  Can any body help me to prove this?

If $p$ and $q$ are distinct primes and $a$ be any integer then $a^{pq} -a^q -a^p +a$ is divisible by $pq$.  Factorising we get $a^{pq} -a^q -a^p +a =a^p(a^q -1) - a(a^{q-1}-1)$ and we know $p \mid a^{p-1}-1$ and $q \mid a^{q-1}-1$.  I can't proceed further with the proof. Please Help!


How rare are magic items in D&D5e? How often do a bandit drop a +1 sword or how often can the party find a bag of holding? After reading though the DMG, I cannot find anything about how many items a party of four should have at lvX and so on.  I have previously played (as a player, not DM) D&D4e, where Magic items feels a lot more common.

What is the baseline distribution of magical treasure and at what level should a given character expect to have received or have a potential of getting a specific rarity of item?  Example: Rare lvl 10+  Also Does this take into account general non-combat magic items?


Let $f: \Bbb R \to \Bbb R$ be a differentiable function with $m=sup${$|f'(x)||x \in \Bbb R$} $<1$.  Let $a_0 \in \Bbb R$ and define $a_{n+1} =f(a_n)$ for $n=0,1,2...$. Prove the sequence $(a_n)_{n \geq 0}$ is a Cauchy sequence.  So we have to prove that $\forall \epsilon >0 ,\exists N \in \Bbb N$ such that when $n,m >N$ then $d(a_n,a_m) < \epsilon$, but I don't really know how to continue from here.

Let $f$ be a real function such that $f$ is differentiable and $|f'(c)| \leq M<1$. Let $a_1$ a real number and define $a_{n+1} = f(a_n)$. Then $(a_n)$ converges.   My attempt:   By the mean theorem, we have that $|a_{n+1} - a_n| = |f(a_n) - f(a_{n-1})| \leq M|a_n - a_{n-1}|$.  Then, $|a_{n+1} - a_n| \leq M^{n-1}|a_2 - a_1|$.  As $M < 1$, we know that $M^{n-1}$ converges to $0$.


In the story, the time traveler travels to the sixties, I believe, and posts an ad somewhere along the lines of:  "Remember Reaganomics? VCRs? Perestroika? Call me at KL-123."  Obviously, only another time traveler who'd experienced the eighties would recognize those terms ('VCRs' may be misremembered, but you get the point). I'm pretty sure about the "Reaganomics" term, which will date its writing to most likely in the eighties, certainly no earlier than 1981.

This novel is about a character who jumps back in time to relive his life.  It's called “replayer” or something like that but Google didn’t help with the variations I tried.  He’s in his office talking on his phone to his wife, and she is saying “We have to…” and he feels like he has a heart attack, and wakes up in a “very messy room” which he quickly discovers is his young self.  Each time his life ends at the exact same date and time, but each jump is not as far back.  He meets another replayer and they have a love spanning many lifetimes. He (as a rich hermit) first notices her because of a movie she made.  to try and find others, they posted a newpaper ad with the “remember when” theme, listing slogans from the future.  A few replied with wrong ideas about what the ad was concerning.  One replied with proof of his own, adding Tylonol Scare and Princess Di to the list.  They knew which stocks to but for long-term investment, simply from remembering brand names in the future.  Investment consultants were the cover they used when visiting the other guy they had found (who was in an institution for the criminally insane, BTW).  What novel is this?


Is Carnot engine the only form of reversible engine? Is it possible to have a different form of reversible engine that goes through different processes?  For a standard Otto cycle working with ideal gas, theoretically the two processes involving isochoric pressure change can be reversible processes. Does it mean that the Otto cycle can also have same efficiency as Carnot cycle? Since temperature of the working fluid is changing during isochoric pressure change, does it mean there are infinite number of heat reservoirs being used at different temperatures so that there is no finite temperature difference at every point of the isochoric process?

I have this homework question:  "Show that any reversible engine operating between T1 and T2 is a carnot engine."  I think I have a solution, but it feels very hand-wavy. We know that any process that can be represented as a loop in the PV plane is reversible as the net entropy change will be zero. We must operate between two specifice temperatures, so the loop must comprise of two isotherms a T1 and T2. So the question is what curves join the isotherms. As a heat engine comprises of energy input at constant temperature, there will be no energy change between the isotherms. So the curves connecting the isotherms must be adiabatic curves. So we have a carnot cycle.   Is this sufficient? I don't know why, but I doubt it.


Do I have to commit to participate in the beta or will I be able to do it regardless?  I don't want to commit to some proposals but I'd like to participate in them (with no strings attached).

There's this proposal for a new S.E. site which is about to enter the beta phase. It reads  This proposal is in: Commitment A successful site needs people to commit to use it. This proposal is 100% complete. Committed users will be invited to the private beta soon.  I'd like to participate in the beta but I don't want to commit (due to a full name being required). Will I be unable to participate in the beta if I don't commit?


In Data Explorer, looking through some SO data, I noticed that some comments have 0 for Score, while others are null. Why is this? Is there a difference between 0 and null comment scores?

While researching my theory that , I noticed that there are surprisingly few posts with zero comments.  Here's what the  looks like:  That graph was generated using the following SQL: select CommentCount, count(*)  from Posts  where CommentCount < 30 group by CommentCount order by CommentCount  The huge distribution disconnect makes me think comments are not being counted correctly.


I'm starting to learn Java Swing, so I have many low-quality questions. But I don't know where to post low-quality (or newbie) questions? And I have some wrong tags (tag indexing) because I'm a newbie at Stack OverFlow and Java Swing. My account don't have the right to ask anymore...

If you are reading this, you may have been affected by one of our post quality bans. If so, it is important that you  to understand what has happened and how to regain the permissions that you lost. While trying to ask a question, one could see:  We are no longer accepting questions from this account. See  to learn more.  Likewise, for answers:  We are no longer accepting answers from this account. See  to learn more.   Why am I getting this message? Are deleted posts taken into account too? Is a question/answer ban the same as a suspension? How do I avoid getting a question ban? How long do I have to wait before I can post again? What can I do to release the ban? How can I reactivate my account? Can I simply create a new account? I'll just ask somewhere else on the SE network, and they'll migrate my question to the correct site! Will a ban on one Stack Exchange site affect my standing on other sites in the network? Does this apply to meta sites too? My account is in good standing. Why am I still blocked?


When we tried  to run the following program then it successfully runs.  class with {     public static void main(String args[]) {         System.out.println("With static");     } }   but even if we tried to run the following program it did't ran successfully.  class without {     public void main(String args[]) {         System.out.println("With static");     } }   we know becuase in this program we have't use static in main() method. So, we want to ask that the : - is it possible to run java program without static ? if is it possible then how can i do this.

The method signature of a Java main() method is:  public static void main(String[] args){     ... }   Is there a reason for this method to be static?


Does anyone knows how many records can an object have in a lookup relationship?   I've found in the documentation that as a best practice, don't exceed 10,000 child records for a master-detail relationship.But how about for a normal lookup relationship? If I have an object called "Warehouse" could it be referenced more than 10000 times on "Item" object?

Typically, each record in Salesforce will be 2kb large: .   However, let's say in an extreme example, the Opportunity object is related to 40 custom objects, each which has 100,000 records. The page would load much slower, especially in an older browser version.   1) Is there a 'rule of thumb' as to what the upper limit of how many related records an object should have?   2) Also, , there's an indication that there's some sort of tier-tuning per org based on the volume of data it has. Is that correct? And if so, are the volume ranges and respective tier-tuning capacity available?


So this is an exercice given by my teacher. We're creating a SkipList, aka a "LinkedList" with shortcuts. He gave us a class diagram with one interface (AbstractLink) and three class (StartLink and EndLink implement AbstractLink while Link extends StartLink). He also gave us a huge part of the code but i find it surprising that the interface is empty, i dont really understand why it is and he doesn't look like we need to fill it. Anyhow, in the StartLink, he told us to write the constructor.  So i tried to initialize nexts, which is an array of AbstractLink (???), with the parameter n. As far as I searched, it's impossible to do it because the type of the AbstractLink is not defined. But it leaves me clueless with what i have to change ...  public interface AbstractLink<T extends Comparable<T>> extends Comparable<AbstractLink<T>> {  }   public class StartLink<T extends Comparable<T>> implements AbstractLink<T> {      final AbstractLink<T>[] nexts;      public StartLink(int n){         this.nexts = new AbstractLink<T>[n];    //my line     }    And Eclipse gives me this : Cannot create a generic array of ChainonAbstrait  Thanks in advance

Due to the implementation of Java generics, you can't have code like this:   public class GenSet<E> {     private E a[];      public GenSet() {         a = new E[INITIAL_ARRAY_LENGTH]; // error: generic array creation     } }   How can I implement this while maintaining type safety?  I saw a solution on the Java forums that goes like this:  import java.lang.reflect.Array;  class Stack<T> {     public Stack(Class<T> clazz, int capacity) {         array = (T[])Array.newInstance(clazz, capacity);     }      private final T[] array; }   But I really don't get what's going on.


I've always seen spacetime shown with a ball on top of some cloth that curves around it, and I don't really understand it, since it really only has 2 dimensions and there's some sort of external gravity causing gravity? I was wondering what it would look like if that ball had more balls inside of it (like Earth contains humans, gases, etc.). Is there a way to visualize that? Does the fabric of spacetime go through everything or does it wrap around individual elementary particles? Is it even actually a fabric?  Apologies if this question is too broad.

I've seen many science popularisation documentaries and read few books (obviously not being scientist myself). I am able to process and understand basic ideas behind most of these. However for general relativity there is this one illustration, which is being used over and over (image from Wikipedia):    I always thought that general relativity gives another way how you can describe gravity. However for this illustration to work, there needs to be another force, pulling the object down (referring to a direction in the attached image). If I put two non-moving objects in the image, what force will pull them together?  So where is my understanding incorrect? Or is general relativity not about explaining gravity and just describes how heavy objects bends spacetime (in that case the analogy is being used not correctly in my opinion)?    UPDATE Thank you for the answers and comments. Namely the XKCD comics is a spot on. I understand that the analogy with bent sheet of fabric pretty bad, but it seems that it can be fixed if you don't bent the fabric, but just distort the drawn grid.   Would you be so kind and answer the second part of the question as well - whether general relativity is explaining gravitational force. To me it seems that it is not (bending of spacetime simply can not affect two non-moving objects). However most of the time it is being presented that it does.


Please how can l reinstall google playstore on my Huawei G700-T00. i have tried to install it three time

I have a rooted Huawei G700-U10 with android 4.2.1. I removed the Android Play Store and Services, but now I need it. How do I reinstall them?


I am studying on websites manual test. I haven't any idea about making a bug report for developer by MS word, excel, powerpoint, PDF, video, screenshot etc. That they can understand easily my report & absence of me they fixed bugs. How to create a report, specially bugs report for developer. Developers need clean & easy report for understanding & also fixing those bugs. Which report will be clean & that report will have details about bugs. Step by step every bug & their fixing issue.  I need some idea with examples that I can understand & created by myself. If anybody know about any tools & websites about manual bugs reporting so please details information to me.

Nothing can ruin your day like a poorly-written bug report.  I've seen several sets of guidelines for bug reporting in different organizations. In your opinion, what guidelines/steps are most essential for good bug reporting?  Feel free to share complete guideline recommendations from prior/current projects/organizations.


On page 9 of Linear Regression Analysis 2nd Edition of Seber and Lee there is a proof for the expected value of a quadratic form that I don't understand.  Let  $X = (X_i)$ be an $n \times 1 $ random vector and let $A$ be an $ n \times n$ symmetric matrix. If $\mathbb{E}[X] = \mu$ and $\operatorname{Var}[X] = \Sigma = (\sigma_{ij})$ then $\mathbb{E}[X^T AX] = \operatorname{tr}(A\Sigma) + \mu^T A\mu$  The problem I have is almost right out the gate, I can't see how $\mathbb{E}[X^T AX] = \operatorname{tr}(\mathbb{E}[X^T AX])$ I think I get the rest of the proof, but if someone here can't point me in the right direction on this part, I'd be forever grateful!

For random variables $X \in \mathbb{R}^h$, and a positive semi-definite matrix $A$: Is there a simplified expression for the expected value, $\mathop {\mathbb E}[Tr(X^TAX)]$ and variance, $Var[Tr(X^TAX)]$? Please note that $A$ is not a random variable.


I've tried to use find to change all file permissions in a file tree to be owned by my user, but accidentally ran on all files on my system. This is causing  me many assorted problems and strange behavior.  Version and info:  lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description:    Ubuntu 18.10 Release:    18.10 Codename:   cosmic   uname -a Linux hostname 4.18.0-25-generic #26-Ubuntu SMP Mon Jun 24 09:32:08 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux   Is it better to just reinstall? or there is any other viable solution?

I accidently ran  sudo chmod 755 -R /   instead of  sudo chmod 755 -R ./   I stopped it after few seconds, but now there is some problems such as  sudo: must be setuid root   How can I revert permissions back?


I will move to the USA from Azerbaijan (I am an Azerbaijani citizen with a Green Card). I am planning to buy tickets with 3 stops: Sofia (Bulgaria), Athens (Greece) and Barcelona (Spain). The transits are within these airports: I will not leave them. Do I need to obtain a Transit Schengen visa?  Here are the details:   [May 22 08:30] Baku GYD - 10:55 Sofia SOF | Azerbaijan Airlines 3h 25m Layover in Sofia for 3h. 13:55 Sofia SOF - 15:10 Athens | ATH Aegean 1h 15m Layover in Athens for 17h 35m. [Wed 23 May 08:45] Athens ATH 11:00 Barcelona BCN | Aegean 3h 15m Layover in Barcelona for 5h. 16:00 Barcelona BCN - 18:15 Boston BOS

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


Prove the given identity.  $$\left(\sin\frac {9\pi}{70}+ \sin\frac {29\pi}{70} - \sin\frac {31\pi}{70}\right) \left(\sin\frac {\pi}{70}-\sin\frac {11\pi}{70} - \sin\frac {19\pi}{70}\right) =\frac {\sqrt {5} -4}{4}$$  I though of many ideas but could not start even.I know there is an answer for this . I saw the answer but it is inefficient and out of my mind. A shorter answer is expected. Thanks.

Prove the given identity.  $$\left(\sin\frac {9\pi}{70}+ \sin\frac {29\pi}{70} - \sin\frac {31\pi}{70}\right) \left(\sin\frac {\pi}{70}-\sin\frac {11\pi}{70} - \sin\frac {19\pi}{70}\right) =\frac {\sqrt {5} -4}{4}$$  Please help, I could not gather enough ideas, even on how to get to the first step. I thought of using the transformation formula (from sum to product) but did not find a fruitful result.   UPDATE 1.:  $\left(-\frac{1 +\sqrt{5}}{8} + \frac{1}{8} \sqrt{14\left(5 - \sqrt{5} \right)}\right)\left(-\frac{ 1+ \sqrt{5}}{8} -\frac{1}{8} \sqrt{14 \left(5 -\sqrt{5} \right)}\right) $,    I noticed that Alexis had got to this point.  Can anyone explain me how did he get here, with calculations. Please help.  Thanks in Advance.


How do you prove that the only integer solutions of $2^m+1=3^n$ are at $m=1, n=1$ and $m=3, n=2$? I have observed the following:  $9\equiv1$ (mod $4$), so any $n>1$ that is part of an integer solution must be even.  $3^n-1=2^m$, so $2^{m-1}=\sum_{k=0}^{n-1}3^k$.  $8\equiv-1$ (mod $9$), so any $m>1$ that is part of an integer solution must be odd divisible by 3.  However, none of these observations have gotten me anywhere.  I have no idea how to continue and would appreciate any help you can give. It would also be interesting to know if there are ways to solve more generalized versions of these kinds of problems (such as finding integer solutions to $2^m+1=k^n$, $2^m+k=3^n$, etc.).

Consider the equation $$|2^x-3^y|=1$$ in the unknowns $x \in \mathbb{N}$ and $y \in \mathbb{N}$. Is it possible to prove that the only solutions are $(1,1)$, $(2,1)$ and $(3,2)$?


I want to use Ubuntu based computer (2 machines) in organization  1) to run some learning initiative 2) Some production small projects.  Please let me know if there is any licensing fee if I don't expect any support (from community or professionals) in both these situations. Regards, Sumit

I really like Ubuntu desktop.  My company has some computers. I'm thinking on install Ubuntu on our computers. So, I need to know how much the operative system cost? If not, how much is the cost for future system maintenance?


I'm trying to understand how notify & notifyAll are different.  Lets consider a case in which thread t1 is using a resource R. And now two threads t2 & t3 are waiting on the same resource. If t1 invokes notify method on R, which one of t2 & t3 will start? If t1 invokes notifyAll method on R, both t2 & t3 will be notified but as they are still competing for same resource only one of them should be able to start. And which one will be able to do so?

If one Googles for "difference between notify() and notifyAll()" then a lot of explanations will pop up (leaving apart the javadoc paragraphs). It all boils down to the number of waiting threads being waken up: one in notify() and all in notifyAll().  However (if I do understand the difference between these methods right), only one thread is always selected for further monitor acquisition; in the first case the one selected by the VM, in the second case the one selected by the system thread scheduler. The exact selection procedures for both of them (in the general case) are not known to the programmer.  What's the useful difference between  and  then? Am I missing something?


Let $f : \left[0,\infty\right]\to \mathbb R$ be uniformly continuous.   If $\displaystyle\lim_{n \to \infty} f(n+x)=0$ where $x$ is in $[0,1]$  then $\displaystyle\lim_{x \to \infty}f(x)=0$  Furthermore if $f$ is just continuous , what happens to the result?

$f\colon [0,\infty) \to \mathbb{R}$ is uniformly continuous.  If $\lim_{n\to \infty}f(n+x)=0$ where $x\in [0,1]$, then $\lim_{x\to\infty} f(x)=0$.  every my trying to solve this is wrong :(  how can i prove this?  and if $f$ is just continuous, what happens to the results


I have two date pickers (arrival date and depart date) the user selects an arrival date and then, when the user selects a depart date it must disable (or grey out) all previous dates from which the arrival date has been chosen, i.e if arrival date is 4th July 2013, user can only select a depart date from 4th July 2013 and onwards.  I have used the following code to no success:  <script> jQuery(function($){ $( "#input_2_5" ).datepicker({   onClose: function( selectedDate ) {     $( "#input_2_6" ).datepicker( "option", "minDate", selectedDate );   } }); $( "#input_2_6" ).datepicker({    onClose: function( selectedDate ) {     $( "#input_2_5" ).datepicker( "option", "maxDate", selectedDate );    } }); </script>

I am using the jQuery Datepicker widget with two input boxes, one for the "From" date and the second with the "To" date. I am using the  as a basis for getting the two input boxes to work with each other, but I need to be able to add these additional restrictions:   Date range can be no earlier than 01 December 2008  "To" date can be no     later than today Once a "From" date     is selected, the "To" date can only     be within a range of 7 days after     the "From" date If a "To" date is     selected first, then the "From" date     can only be within the range of 7     days before the "To" date (with the     limit of 01 December being the first     selectable date)   I can't seem to get all of the above working together.  In summary, I would like to be able to select a range of up to 7 days between 01 December and today (I realise I am posting this on 1st December so will only get today for the moment).  My code so far  $(function () {  $('#txtStartDate, #txtEndDate').datepicker(             {             showOn: "both",             beforeShow: customRange,             dateFormat: "dd M yy",             firstDay: 1,              changeFirstDay: false             }); });  function customRange(input)  {   return {          minDate: (input.id == "txtStartDate" ? new Date(2008, 12 - 1, 1) : null),          minDate: (input.id == "txtEndDate" ? $("#txtStartDate").datepicker("getDate") : null),           maxDate: (input.id == "txtStartDate" ? $("#txtEndDate").datepicker("getDate") : null)        };  }   I'm missing the 7 day range restriction and also preventing a "To" date selection before 01 December 2008 or after today. Any help would be much appreciated, Thanks.


Find $$\lim_{n \rightarrow \infty} \int_0 ^{\infty} \left(1+ \frac{x}{n}\right)^n e^{-ex} dx.$$ I know that $\lim_{n \rightarrow \infty}  \left(1+ \frac{x}{n}\right)^n = e^x.$ Also, I showed that $ \left(1+ \frac{x}{n}\right)^n \leq e^x$ for all $x \geq -n$. So I'm thinking about the Lebesgue Dominated Convergence Theorem. But I'm not sure how to deal with the $e^{-ex}$ part.

Establish the following limits:  $\lim_{n\to \infty}\int_{[0,1]}\dfrac{n^2x^2}{\exp(nx)}=0$ $\lim_{n\to \infty}\int_{[0,1]}\dfrac{1+nx}{(1+x)^n}=0$ $\lim_{n\to     \infty}\int_{[0,\infty]}\left(1+\dfrac{x}{n}\right)^n\exp(-ax)=\dfrac{1}{a-1}$ (In the last part, assume $a>1$.)  The first two were relatively simple to do. Just do tabular integration for each and then take the limit and you are done. However the third one is giving me a hard time to show that the statement is true. I first integrated and found this large complex expansion. But this seems too complicated. Can I get some suggestions?


I was wondering if $AB=E$ ($E$ is identity) is enough to claim $A^{-1} = B$ or if we also need $BA=E$. All my textbooks define the inverse $B$ of $A$ such that $AB=BA=E$. But I can't see why $AB=E$ isn't enough. I can't come up with an example for which $AB = E$ holds but $BA\ne E$. I tried some stuff but I can only proof that $BA = (BA)^2$.  Edit: For $A,B \in \mathbb{R}^{n \times n}$ and $n \in \mathbb{N}$.

If $A$ and $B$ are square matrices such that $AB = I$, where $I$ is the identity matrix, show that $BA = I$.    I do not understand anything more than the following.   Elementary row operations. Linear dependence. Row reduced forms and their relations with the original matrix.   If the entries of the matrix are not from a mathematical structure which supports commutativity, what can we say about this problem?  P.S.: Please avoid using the transpose and/or inverse of a matrix.


Is pronouncing "ate" and "eight" differently wrong? When I say "ate" it sounds like "ate" itself and when I say "eight" it sounds like "ey-ht" is that a wrong pronunciation?  I understand pronunciation may differ from one person to another depending on the accent spoken by the person. But one of my friends told me that ate and eight must be pronounced exactly alike and if you're pronouncing them differently you are pronouncing one of the two words wrong.

I was talking to some friends and I said "I ate (/et/) chocolate yesterday...". Then my friend corrected me: "you ate (/eit/) chocolate...". I repeated my sentence with the /eit/ pronunciation and we moved on.   But later at home I checked some dictionaries and online debates on the subject, and now I'd like to know if it's possible or not to pronounce ate as /et/ rather than /eit/.


We are using oracle > 10.0 here and our software creates different types of reports for evaluation of the stored data. Because of the amount of data it is possible that such a report takes a couple of minutes to create and the customers would like to stop the queries.  Is there a way to say the DMBS that it should stop a query? It would also be great to get state information like a count of rows allready read.

I would like to be able to kill a user's query in Oracle 10.2.0.4 without killing their entire session.  This would allow the query to end, but not log that user out of their session, so they can continue making other queries.  Is this possible at all?  Or is the blunt hammer of killing the session the only way to go about ending a query's execution?


So on the , I see:   Yet, I was unable to find the normal review button, so I clicked on , it says that:     Note: These two queues do not exist on per-site Metas.   So, my question is why is this even listed as an achievement?

When I visit Stack Overflow, I see the review option in the bar at the top of the screen.    However when on MSO, I don't see it. I assumed this was because I didn't have enough reputation to access the queue. I was curious what the requirement was on meta, so I moseyed on over to the privileges page. To my surprise, I saw that the privilege is listed as only requiring 500 rep and informs me I already have it:    Confused, I manually typed in meta.stackoverflow.com/review to see what would happen. The page did in fact load, but as you can see meta has no "First Posts" or "Late Answers" queue.    Seeing on that page that a minimum of 2k reputation is required to access any queues on MSO, I report the following bug:  1) On the privileges list on MSO, the 500 rep privilege of "Access first posts and late answers review queues" should not appear.  I also have the following feature request:  2) On the privileges list on MSO, it would be useful if instead there was a 2k privilege that informed you that you have access to the "Suggested Edits" and "Low Quality Posts" queues.


Show that $\sum\limits_{n=0}^\infty \dbinom{n+2}{2}x^n$ converges for $|x|<1$ and calculate its sum.  My attempt: $$\sum\limits_{n=0}^\infty \dbinom{n+2}{2}x^n=\sum\limits_{n=0}^\infty \frac{(n+2)(n+1)}{2!}x^n=\frac{1}{2}\sum\limits_{n=0}^\infty (n^2+3n+2)x^n$$ We look for absolute convergence of the power series: $$\lim\limits_{n\longrightarrow\infty}\left|\frac{((n+1)^2+3(n+1)+2)x^{n+1}}{(n^2+3n+2)x^n}\right|<1$$ $$|x|\lim\limits_{n\longrightarrow\infty}\left|\frac{n^2+5n+6}{n^2+3n+2}\right|<1$$ $$|x|*1<1\Longleftrightarrow|x|<1$$ The power series converges $\forall x \in \mathbb{C}:|x|<1$ $\Box$ Now we calculate its sum: $\frac{1}{2}\sum\limits_{n=0}^\infty (n+1)(n+2)x^n$ First of all, we know (for $|x|<1$): $$\sum\limits_{k=0}^\infty x^k=\frac{1}{1-x}$$ Since the power series converges in a radius of $\rho=1$ we can differenciate elementwise: $$\sum\limits_{k=0}^\infty \frac{d}{dx}x^k=\sum\limits_{k=0}^\infty kx^{k-1}=\frac{1}{(1-x)^2}$$ Differenciating another time gives us: $$\sum\limits_{k=0}^\infty \frac{d}{dx}kx^{k-1}=\sum\limits_{k=0}^\infty k(k-1)x^{k-2}=\frac{2}{(1-x)^3}=\sum\limits_{k=-2}^\infty (k+2)(k+1)x^{k}$$ This gives us: $$\frac{1}{2}\sum\limits_{n=0}^\infty (n+1)(n+2)x^n=\frac{1}{2}\left(\frac{2}{(1-x)^3}\right)=\frac{1}{(1-x)^3}=\sum\limits_{n=0}^\infty \dbinom{n+2}{2}x^n$$  It would be great if someone could look over it and check if my work is correct :) thank you

$$\frac1{(1-x)^3} = \sum_{n=0}^\infty \binom{n+2}2x^n$$  I am not sure how to begin. $$\begin{aligned}\frac1{1-x}&= \sum_{n=0}^{\infty} x^n\\\frac1{(1-x)^2}&=\sum_{n=0}^{\infty} nx^{n-1}\end{aligned}$$ Then you would get: $$\frac{1}{(1-x)^3} = \sum_{n=0}^{\infty} nx^{2n - 1}$$ Which is nowhere near the same...?


I am trying to understand how to derive the following formula:  $\frac{dP(r)}{dr}=-\frac{GM(r_<)\rho(r)}{r^2}$  The notes are as follow:  Consider a star with COM and a shell:  $P_1 - P_2 = -{\large\frac{dP}{dr}}\,dr$  ${\large\frac{dP}{dr}} + g\rho = 0$ ( My main issue with the derivation is unsure where this comes from.)  Then if we take $g = {\large\frac{Gm}{r^2}}$ and substitute into the above equation, we get the expected result.  If anyone could explain this derivation to me or an alternative one, it would be much appreciated.

First and foremost I am sorry for this; in order to make the questions clear I must first upload the lecture notes from my institution $^\zeta$ for the derivation of Hydrostatic Equilibrium:          $^\zeta$ Lecture notes courtesy of Imperial College London, Astrophysics dept, 2017-2018 edition.    Firstly, in equation $(3.1)$ why is there no negative sign for $F_g$? Last time I checked, Newton's law of gravitation told us that   $$F=-\frac{GMm}{r^2}$$  Nextly, I have a conceptual problem with equation $(3.2)$; when they use the term 'pressure' I am going to assume that they are referring to the radiation pressure that is released due to nuclear fusion reactions taking place in the sun. In that formula it must be the case that $P(r) \gt P(r+\delta r)$ if this is the case then $(3.2)$ should read $$F_p=-\left(\frac{dP}{dr}\right)\delta r\,\delta A $$   Correct me if I'm wrong but Hydrogen nuclei are fused together to generate the more stable Helium and hence lots of radiation pressure acting outwards from the centre of the star. If this is correct then $P(r+\delta r)=0$, since the outside face of that cylindrical volume element in Figure $3.1$ will not 'feel' any of this radiation pressure because this pressure only acts on the inner face. What am I not understanding here?  Moving on to equation $(3.3)$, let's suppose the sign of the gravitational force in $(3.1)$ really is neglected. Does this mean that the negative sign in $(3.3)$ is due to $P(r+\delta r) \lt P(r)$ and hence $$\frac{GM(r)\rho(r)}{r^2}=-\left(\frac{dP}{dr}\right)\,?$$ I know this is the same equation as in $(3.3)$ but I have written it with the negative sign next to the pressure differential as I would like to know where this minus sign originates from. Does anyone know?  My final concern is the sign in $(3.4)$ as last time I checked $$g=-\frac{GM}{r^2}$$ and not $$g=\frac{GM}{r^2}$$  Hence, equation $(3.4)$ should read  $$\left(\frac{dP}{dr}\right)=\rho(r)\,g\,?$$     I forgot to mention that I have done some research and  is the closest derivation I could find, which, needless to say is no less helpful than the notes I have.


How can I configure postgresql to use multiple cores in a single machine , is it automatically uses it ?

In recent versions of PostgreSQL (as of Dec 2013), can we share a query between two or more cores to get a performance boost? Or should we get faster cores?


I am studying for an exam and going through various earlier tutorial sheet questions. For the question below, I have tried and just can't figure out how to prove that $x$n$ $ < $ 3$ by mathematical induction. Does anyone know how to prove this?     The question is:     Let $x$1 = 1, and for each $n \in  \mathbb{N}$ let $x$n+1 = $\frac{2}{3}x$n$ $ + $ 1$. Then $x$n$ $ < $ 3$ for all $n \in \mathbb{N}$.

This one should be pretty easy as its only a first year math problem. it s proof by induction that Im having trouble with.  $$let\;x_{1}=1; for\;each\;n\in \mathbb{N}\;let\;x_{n+1}=\frac{2}{3}x_{n}+1; prove\; x_{n}< 3\;for\;all\;n$$  If anyone is willing to spell it out really obviously step by step and explain how they got from one step to the next I would appreciate it a lot. Thanks.


I've heard many times that black holes have infinite density at their center, but I've also heard astronomers quote mass estimates for black holes. How could the singularity have infinite density if it has a finite mass?  EDIT: Also, if the singularity has a size above zero, what is it?

I mean besides the obvious "it has to have finite mass or it would suck up the universe." A singularity is a dimensionless point in space with infinite density, if I'm not mistaken. If something is infinitely dense, must it not also be infinitely massive? How does a black hole grow if everything that falls into it merges into the same singularity, which is already infinitely dense?


I tried to post the question below on Stack Overflow, then on Cross Validated, then on Server Fault but my question has been stated as off-topic each time. I'm a bit fed up because I have posted far more answers than questions on Stack Overflow and the day I need some help: no way. I always asked how could I make this question not off-topic or where would it be better to post then, but no answer. Just a downvote or on-hold response. I know it is not a programming issue but there are many very, very similar questions on Stack Overflow so I am really surprised. It seems a bit more picky when it relates to questions on R.     R web-service for real-time prediction with online learning      What free framework or R packages should I use to deploy R as a web   service handling many models for real-time prediction (with online   learning) ?      It should be able to address those key points:         allow parallel processing/requests while handling a memory/cpu policy preventing reaching memory/cpu limits.   update many models in parallel safely (ie. prevent concurrent updates). able to quickly load/unload many models on a single machine   because not all models (ie. >1000) could fit in memory.   handle large streams with low footprint (out-of-core).   able to use VowpalWabbit and StreamMOA R packages.   web service could be Http or Thrift based.         Thanks a lot for any help!   FYI, the different versions of my question:   1st try on SO:  CV:  2nd try on SO:  Server Fault:

I have a list of requirements for a program, but I don't know what program meets these criteria. That's about general-purpose software, for example, not a programming IDE or statistical workbench, questions about which would certainly go to respective sites.  Is this question appropriate on Stack Overflow? Where should I ask about it? On Super User or elsewhere?


I have added a lightning:dataTable within  like this  <lightning:card title="My Table" iconName="standard:contact">      <p class="slds-p-horizontal_small">             <lightning:datatable                   aura:id="sparesTable"                   columns="{! v.columns }"                   data="{!v.stipulationsSpares}"                   keyField="Id"                   hideCheckboxColumn="true"                   showRowNumberColumn="false"               />      </p>  </lightning:card>   I am creating columns like this in the controller  var actions = [             { label: 'Show details', name: 'show_details' },             { label: 'Delete', name: 'delete' }         ];  component.set('v.columns', [     {label: 'Start Date', fieldName: 'Start_Date__c',type: 'date'},     {label: 'End Date', fieldName: 'End_Date__c', type: 'date'},            { type: 'action', typeAttributes: { rowActions: actions } }  ]);   When I click on the down arrow on the action column the dropdown menu of actions appears but I need to scroll down to view    This looks bad particularly if there is just one row in the table . Its hard for users to understand that a menu is there if they don't scroll.  Is there any way this menu gets visible without scrolling ?

I'm having troubles with rendering my datatable correctly. There are actions added but it seems the datatable is not high enough to view it correctly. Is it something I'm doing wrong? Or is it a bug?    This is the code for the datatable
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 <lightning:datatable data="{! v.persondata }"                      columns="{! v.personcolumns }"                      keyField="id"                     onrowselection="{! c.getSelectedPerson }"                     hideCheckboxColumn="true"  />   Here is the code for initializing the columns  //init datatable component.set('v.personcolumns', [             {label: 'Last Name', fieldName: 'LastName', type: 'text'},             {label: 'First Name', fieldName: 'FirstName', type: 'text'},             {label: 'Mailing Zip/ Postal Code', fieldName: 'PersonMailingPostalCode', type: 'text'},             {label: 'Mailing City', fieldName: 'PersonMailingCity', type: 'text'},             {label: 'Billing Street', fieldName: 'PersonMailingStreet', type: 'text'},             {label: 'Email', fieldName: 'PersonEmail', type: 'text'},             {label: 'Primary Phone', fieldName: 'PersonHomePhone', type: 'text'},             {label: 'Secondary Phone', fieldName: 'PersonOtherPhone', type: 'text'},             {type: 'action', typeAttributes: { rowActions: actions}}         ]);   And the code for adding data (the response is a list of Accounts)  component.set('v.persondata',response.getReturnValue());


Let there be an imaginary digital lock that verifies a simple 4-digit passcode (in base 10 numbers, like 4281 or 3349, etc.)  BUT unlike other locks, it does not reset after a failed trial. That means if you enter 1823917 consecutively, you have in effect tried 1823, 8239, 2391, and 3917 (if it were a traditional lock) i.e. If the passcode was 8239, it would open after you enter 18239. Since it requires fewer guesses, I suppose it's not so good of a lock in terms of security, but as a question out of pure curiosity:  What would be the most efficient method to opening this lock (the pattern of entering the numbers)  and how many numbers would you have to input in order to guarantee success?

Suppose you have a computer with a password of length $k$ in an alphabet of $n$ letters.  You can write an arbitrarly long word and the computer will try all the subwords of $k$ consecutive letters. What is the smallest word that contains all combinations of $k$ letters as subword? (i.e. the fastest way to hack the computer :) )  The smallest word that contains $n^k$ subwords of size $k$ has length $k-1+n^k$ and based on some easy cases, we would like to prove that it is in fact possible to find a word of such length that contains all possible passwords. The problem can be translated into a problem in graph theory, by taking as vertices all words of length $k$.  We tried $k=2$, where you can prove the conjecture by induction. For $n=2$ and small $k$ it also works.


As a beginner of bash script, I wrote a simple script to change the directory. Here it is my source code:  #!/bin/bash  set -x echo "---------------------START-----------" cd /home/cocadas/Workspace/carnd/CarND-Behavioral-Cloning-P3   I save it as "start" in the /root folder. I change the property of the file to be executable, and then run it as below. The problem is that the execution command cd doesn't work. What did I miss?  cocadas@cocadas-ThinkPad-W540:~$ ./start + echo ---------------------START----------- ---------------------START----------- + cd /home/cocadas/Workspace/carnd/CarND-Behavioral-Cloning-P3 cocadas@cocadas-ThinkPad-W540:~$ cd /home/cocadas/Workspace/carnd/CarND-Behavioral-Cloning-P3 cocadas@cocadas-ThinkPad-W540:~/Workspace/carnd/CarND-Behavioral-Cloning-P3$

I'm trying to write a small script to change the current directory to my project directory:  #!/bin/bash cd /home/tree/projects/java   I saved this file as proj, added execute permission with chmod, and copied it to /usr/bin. When I call it by: proj, it does nothing. What am I doing wrong?


so, I have a drive that is NTFS. it has thousands of graphics/video files that totals to about 6TB. I wanted to compress and send this info to someone.  What is my best option for compressing? I've also noticed that the drive has compression set on file explorer: "compress this drive to save disk space"  When I start to use 7zip on the data, the total is larger than what I anticipated, like 8TB or 9TB which I'm guessing is because drive compression is on.  I've tried Keka on mac but it's going slow as hell. What are my options here to ensure the recipient doesn't get corrupted data? Currently, I'm trying using 7zip format and 'store' for compression. Thanks!

A 398MB directory was only compressed to 393MB using 7Z and Normal ZIP compression. Is this normal? If so, why do people continue to use ZIP on Windows?


trying to a sum dropdown sum. I have an error somewhere, but cannot figure it out. Can anyone assist? I have attached a picture with the error. Thanks a million! Jose

I would like to make a sum of all dropdown values into a label text box. I am using following formula, but I do not understand where am I going wrong. Can anyone assist? I have also added a screenshot if that helps anyhow. Note: scores is the table name the dropdown values feed from. Sum(scores, Dropdown3.Selected.Value + Dropdown3_1.Selected.Value + Dropdown3_2.Selected.Value)


I use Ubuntu on a netbook and am looking for a way to run reasonably basic android apps. The only ways to do that I've seen are to either run the emulator from the SDK or a VM, but those aren't really great options for people like me on underpowered computers.  What I was wondering is if anyone here knew of an alternative to this setup. All I really need is something capable of interpreting android apps in desktop linux and spoofing any information like location or accelerometer data (so no playing games or even 3D work). It could be in development (just so long as I can follow along), I'm just hoping it exists.

Is it possible to run Android apps on Ubuntu? And I don't mean inside an emulator, but natively, as you would with any other application installed using the Ubuntu Software Center.


Where can I see the  file format of my SD card on Android?  I use a Samsung Galaxy s9 with Android 9.    Note a dupe because here we're talking about SD cards.

How can I find the file system type of USB drive without using computer? Drive is attached to Android phone and I can see the files in it. I want to know if it is extFAT etc.


I'm using windows 7 pro and do not want to upgrade to windows 10. To prevent the permanent notifications i've removed update KB3035583. Also the reservation of the upgrade is canceled so Windows Update should not download 10.  But when to execute Windows Update to perform updates it looks like it will download windows 10 but instead it downloads the updates.  It looks that there is some UI issue

I am running Windows 8.1 Single Language for about a year now and although Windows 10 is due to release tomorrow, I've decided to put things on hold for a while and stick to Windows 8.1.  So I canceled my reservation for Windows 10 through the "Get Windows 10" app but something unusual happened today. I've noticed some network activity that consumed quite a bit of bandwidth. I narrowed it down to a Windows Update which has failed to install. Turns out it was named "Upgrade to Windows 10 Home Single Language". Here is a screenshot from the reliability monitor:    This download consumed almost 2.5GB before it failed to install. But now it has started downloading again. What do i do?


I know that (I might be wrong):   Symbol for empty or null set :  {Ø} or {} Null or empty set is 'subset of all sets' as well as 'empty or null set' set So, { {} } is same as { Ø }   I just want to know { {} } or { Ø } is an empty set or not ? And if yes then we can conclude that if a set contains a only null set which is by definition always true then it must be a null or empty set.  (Here I am assuming empty and null are same, because I've read that they sometimes taken as different.)

Herbert in his book "Elements of set theory" on page no 3 says that      we can form the set $ \{ \emptyset \} $ whose only member is $\emptyset $. Note that $ \{ \emptyset \} \neq  \emptyset $, because $ \emptyset \in \{ \emptyset \} $ but $\underline{ \emptyset \notin \emptyset} $·   By the last argument $\emptyset \notin \emptyset$, is he saying that empty set is not a member of or does not belong to empty set  OR  it is a typo and he wanted it to be $ \{\emptyset \} \notin \emptyset $, that set containing empty set is not a member of empty set


From what I know, boolean operators are the likes of AND, OR, XOR, NOT, NAND and NOR. So does this mean that there are actually 6 distinct boolean operators that can take three inputs?

In short, this is an assignment question for a course I am taking - the exact wording is this:  "Given n Boolean variables, how many 'semantically' different Boolean functions can you construct?"  Now, I had a crack at this myself - and got pretty stuck. The question doesnt state how many boolean operators there are (and, or, xor, nand, nor, iff, implies, not) nor does it state whether brackets should be used, i.e. a ^ (b v c) is different from (a ^ b) v c.  So, my question for you is - is this question possible given the limited information available?   Is it going to be something like ${n^x}$ where x is the number of boolean operators.  Any direction here would be greatly appreciated.


It's glad to see the .  But, the top bar still indicating the items count to be reviewed after completing daily limit(20 for suggested edit).  I requested not to show the review indicator after limit reached.

Once a user has exhausted their (currently) 30 edit suggestion approval/rejections, the pending edit box in the top bar can still show up:    You click through and see some edits suggested to vote yay or nay on.   But when trying to approve/reject you get the warning:      Out of votes - you may only vote 30 times a day.   Don't tease me, bro!


let $f$ be a continuous function.  I want to show that $\exists$ continuous non-negative functions $g$ and $h$ such that $f = g - h$.  My attempt: define  $$g(x) =  \begin{cases} f(x), & \text{for $x$ such that $f(x)>0$} \\ 0, & \text{for $x$ such that $f(x)\leq 0$} \end{cases}$$ and  $$h(x) =  \begin{cases} 0, & \text{for $x$ such that $f(x)\geq0$} \\ -f(x), & \text{for $x$ such that $f(x)<0$} \end{cases}$$ The trouble I was having was in showing that $g$ is in fact continuous.  This was what I tried:  let $a \in \mathbb{R}$.  Suppose $a$ is such that $f(a)>0$.  Then since $f$ is continuous, $\exists \delta_0 >0$ such that $\forall x: |x-a|<\delta_0 \implies f(x)>0$.  Then within this delta interval, $g(x)=f(x)$ and so it can be shown that $\lim_{x\to a}g(x)=f(a)=g(a)$. Hence $g$ is continuous for $a$ such that $f(a)>0$  How do I finish off?  I think I'm most confused about showing continuity for piecewise functions like these.

Prove that every continuous function $f$ can be written $f = g−h$, where   $g$ and $h$ are nonnegative and continuous.   If I define $g=\max\{f,0\}$ and $h=\max\{0,-f\}$, do I need to prove that $g$ and $h$ are still continuous and if so how do I do that?


The exercise is to redo the game Breakthrough in Python; it's a Draughts-like game, with a board of n lines and p row.  I initiate my game board with this function:   def NewBoard(n,p):     board = [["."] * p for i in range(n)]      for i in range(0, 2):         for j in range(0, p):             board[i][j] = 'o'      for k in range(n - 2, n):         for l in range(0, p):             board[k][l] = 'x'      return board   But this always reset the board, because this function is the initial state of the game.   When I try to do the main game function, every time the player changes, the board is reseting itself:  def Breaktrough(n, p):     DisplayBoard(NewBoard(n,p))     DisplayBoard(Where(NewBoard(n, p), 1, *SelectPawn(1)))     DisplayBoard(Where(NewBoard(n, p), 2, *SelectPawn(2)))   I tried some solutions that I thought were good but weren't.

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


If $A+B+C=\pi$ then what is the minimal value of  $$\tan^{2}A/2+\tan^{2}B/2+\tan^{2}C/2$$

$A, B, C$ are the angles of a  triangle  then  $tan^2(A/2)+tan^2(B/2)+tan^2(C/2)$ is  always greater than what integral value.


I'm trying to understand why the function "connect" is called with two inputs in the last line of the following snippet that uses React and Redux:  import {connect} from 'react-redux';   class SharedGraphScreen extends Component {...}  const mapStateToProps = (store) => ({   user: store.userState.user,   theme: store.userState.theme,   relations: store.core.relations,   knowClosure: store.core.knowClosure, });  export default connect(mapStateToProps)(SharedGraphScreen);  Here's the part I'm not understanding what the code is supposed to do: connect(mapStateToProps)(SharedGraphScreen)  I'm guessing that  connect(mapStateToProps) returns a function that is called with SharedGraphScreen as its parameter, but I'm not sure about this. Is that correct ? If that's the case, how can I know the name of the returned function ? I have searched for it on the redux documentation, but couldn't figure out which of all the functions described in the documentation was the one used in the code I'm presenting (). I understand that the final result of the code is the connection of the component 'SharedGraphScreen ' to the redux store, but I would like to know more details about the inner returned function.

I've seen references to curried functions in several articles and blogs but I can't find a good explanation (or at least one that makes sense!)


I've been trying to download and install Ubuntu on my Dell Inspiron 6000 laptop computer with no luck. It's an old computer about 9 years old. It has intel 1.6g processor and 2 gigs of memory. I had tried to install one of the Ubuntu but I got a message that says I need an x86-64.  I have a 32bit laptop.  I have only one hard drive with windows XP on it,  How can I purchase a Ubuntu O.S. or download the correct Ubuntu for my particular computer but a current system where I can get support.

What is the difference between 32-bit and 64-bit Ubuntu? I've heard the 64-bit platform performs better and can detect more than 4GB of RAM. Also, while some apps haven't ported to 64-bit yet, ia32-libs lets a 64-bit machine run them.  If so, why not promote 64-bit over 32-bit?


I want to make car with a friend who is much more experienced than I am and it would help a lot if I could work and he could correct me and help within the same blender file. Thank you in advance.

Me and my team are new to blender, we are now planning for a small project. What I want to ask here are some questions regarding the team work:   We use git for version control in web projects, Is there any special version control for blender project. Creating object of each file and integrating in the project is one way we saw to complete the project. But is there any good way to work in the group?   Please tell us from your experience what might be the best way to work together in a group blender project.


I am attempting to use Kinect V2 for motion capture in blender. After playing around with locations and rotations of bones I finally found out what was causing the unintended contortions in my mesh, but one problem still remains. The character's hip region is deformed but the rest of the character is fine, so I'm not sure what is causing this. Pictures are below:    Here is the link to the blender file:  .

I follow this  which uses rigify and I have run into some issues.    Not every vertex moves along the rig. Any idea what could cause this? I applied the location and rotation for every object.  The entire head is weight painted with blue.


I am trying to reverse a string literal with the use of pointers, though my code received SEGSIGV signal on *head=*tail line   char* reverse(char* input, int n) {     char temp;     char* head= input;     char* tail= &input[n-1];     while(head<tail){         temp=*head;         *head=*tail;         *tail=temp;         head++;         tail--;     }     return input; }   int main(void){     char* sentence= "All work and no play makes jack a dull boy";     reverse(sentence, strlen(sentence));     printf("%s", sentence);     return 0; }   I don't know if I am trying to access restricted memory segment.

The following code receives seg fault on line 2:  char *str = "string"; str[0] = 'z';  // could be also written as *str = 'z' printf("%s\n", str);   While this works perfectly well:  char str[] = "string"; str[0] = 'z'; printf("%s\n", str);   Tested with MSVC and GCC.


The context Consider the following directory $ tree -a $(pwd) | sed "s,$HOME,~,g" ~/mytest ├── 1 │   ├── 1.txt │   └── 2 │       └── 1_2.txt └── 2     └── 2.txt  3 directories, 3 files  and the following files $ find $(pwd) -type f \ | while read l; do echo "File: $l"; cat $l; done \ | sed "s,$HOME,~,g" File: ~/mytest/1/2/1_2.txt 1 File: ~/mytest/1/1.txt 1 File: ~/mytest/2/2.txt 1  As can be seen above, all files contains the pattern 1. What I want to do is to search a pattern in all directories but the ~/mytest/2 directory. That is, I do want grep to include the ~/mytest/1/2 directory when searching. The problem I first tried executing the following command  grep --exclude-dir=2 -R '1' . but it excludes the ~/mytest/1/2 directory.  According to the manual page of the grep command in my system, the --exclude-dir flag waits for a pattern $ man grep ... --exclude-dir=GLOB     Skip any command-line directory with a name suffix that matches the pattern GLOB.    When searching recursively, skip any subdirectory whose base name matches GLOB.  Ignore any redundant trailing slashes in GLOB. ...  Because of this, I've tried with the following commands but none of them worked.  grep --exclude-dir="./2" -R '1'  but tt doesn't exclude the ~/mytest/2 directory. grep --exclude-dir="./2/*" -R '1' . but it doesn't exclude the ~/mytest/2 directory. grep --exclude-dir="$(pwd)/2" -R '1' .: but it doesn't exclude the ~/mytest/2 directory. grep --exclude-dir="$(pwd)/2/*" -R '1' .: but it doesn't exclude the ~/mytest/2 directory.  The question Which are the flags that would need to be used to make grep exclude an specific directory (A) without making it exclude those directories that have the same name as (A)? Note that in the minimal working example, the answer must output the following $ grep {options} ./1/2/1_2.txt:1 ./1/1.txt:1  Additional context I can accomplish that by running the following command (see code below). However, I'm interested in understanding how to do it just by using grep. I do want to understand why the arguments (which I've tried and which are patterns) passed to the --exclude-dir flag does not cause grep to exclude that specific directory. At the end, they were patterns which only match the ~/mytest/2/ directory. $ find . ! -ipath "./2/*" -type f -exec grep '1' {} + ./1/2/1_2.txt:1 ./1/1.txt:1

Or I have to use ack or find for this?  Here's what I want. Say I have this dir structure:  dir/nesteddir/match.txt otherdir/nesteddir/match.txt   How do I exclude first nesteddir only? Is it even possible using grep?  Most obvious answer $ grep -r --exclude-dir="dir/nesteddir" "stringToFind" . doesn't seem to work, nor do any of my experiments with various --exclude-dir paths using globbing, leading ./, etc.   Reading man page and googling didn't help, the only mention of this usecase I found is this question:   It was concluded that this is bug introduced in grep 2.12, but I'm using latest version (2.16) and grep's bugtracker () doesn't mention anything related to --exclude-dir, so I guess either it was fixed or it's an intended behaviour.   Would be really nice to get some clarification.


How to turn off the iSight indicator of my Mac's camera (without putting black tape on it)?

Recently a the Dutch government advised to put a tape on your webcam to prevent hackers from taking pictures and video using your device ().  The build in iSight camera in Apple laptops have a green light next to the camera, this light turns green when you use the camera.  Is it possible to use the camera without the activation of the green light? Personally I think the green light turns on when the sensor requires power and this is hardwired in the hardware. Am I wrong?  I have found similar questions on stackexchange, but I found non that answer this specific question.


What's the rule about sentences that end in something that already has a period in it?  Like a sentence that ends in: Washington D.C. -or- etc.  Personally, and I realise this is wrong, I would love to have two periods - the first being, of course, the mark for the abbreviation and the second being the period/full-stop of the sentence.  I'm guessing that it is just treated as a stone that kills two birds, but I've never heard a definite answer as to how to deal with these.

Example:     It's all about apples, oranges, bananas, etc.   VS.     It's all about apples, oranges, bananas, etc..   Update  What happens if the abbreviation is inside parentheses, do you place a dot after and before the closing parenthesis?     It's all about fruit (apples, bananas, etc.).


I have a get_pages() function. I all works great but I only want all the post_id's in my variable. Is that possible?  Thanks in advance.  $countries = get_pages(array(     "hierarchical" => 0,      "sort_column" => "menu_order",      "sort_order" => "desc",      "meta_key" => "page_type",      "meta_value" => 2, ));

I am looking for a way to output all page IDs from the following menu:   <?php wp_list_pages('depth=1&exclude='3,5,11')); ?>   Only top level pages needed, therefore the 'depth=1'.  Any help appreciated.


the code is trying to read a comma delimited text file  this is the code that is giving the error     while((PlaceHold = in.readLine())!=null){             PlaceHold = in.readLine();             String[]Split = PlaceHold.split(Delimit);             db.Restaurant1.setFoodName(Split[0]);             db.Restaurant1.setCarbs(Split[1]);             db.Restaurant1.setServingSize(Split[2]);             db.addRestaurant(new DBLocationHelp.Restaurant(Split[0], Split[1], Split[2]));         }   and this is the error it gives  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.diabeticdiner/com.example.diabeticdiner.Arby}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String[] java.lang.String.split(java.lang.String)' on a null object reference

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


I'm running a Python program, condensed below, from the command line, and it gives me an error (name 'cursor' is not defined) and points to the cursor.fetchmany() row near the bottom. However, the program runs as desired if I move the first two rows of main(), the conn and cursor assignments, above and outside of main() into the body of the program. Why doesn't this work when I assign cursor inside main()? I'd love to understand whether this is just a quirk of the pyodbc library, or there is a better way to get it to work from inside main(), or it's actually okay to leave the assignments in the body of the program.  import pyodbc import csv #   ...other modules...  def main():     conn = pyodbc.connect(DSN=abcxyz, autocommit=True)     cursor = conn.cursor() #   ...sys.argv assignments and validation...     pull_data(query_file, start_date, end_date, out_file)  def pull_data(query_file, start_date, end_date, out_file): #   ...prepare query as string, date range as list...     for date in list_dates:         cursor.execute(query, date)         append_rows(out_file)  def append_rows(out_file):     with open(out_file, 'a', newline='') as file:         writer = csv.writer(file)         while True:             results = cursor.fetchmany(chunk_size)             if not results:                 break             for result in results:                 writer.writerow(result)  if __name__ == '__main__':     main()

What exactly are the Python scoping rules?  If I have some code:  code1 class Foo:    code2    def spam.....       code3       for code4..:        code5        x()   Where is x found?  Some possible choices include the list below:   In the enclosing source file In the class namespace In the function definition In the for loop index variable Inside the for loop   Also there is the context during execution, when the function spam is passed somewhere else. And maybe  pass a bit differently?  There must be a simple reference or algorithm somewhere.  It's a confusing world for intermediate Python programmers.