A coworker just pointed out something odd, and I'm curious what the explanation might be.  On the systems I've tried, cd /', 'cd //', and 'cd ///' all have the effect of changing directory to the file system root. However, 'cd /; pwd' and 'cd ///; pwd' return a response of '/', but 'cd //; pwd' returns '//', even though it's the file system root, as in the other cases.  What gives?

I'm working on a python script that passes file locations to an scp subprocess. That's all fine, but I'm in a situation where I may end up concatenating a path with a filename such that there's a double '/ in the path. I know that bash doesn't care if you have multiple file separators, but I'm wondering how exactly that is rectified. Is it bash that strips extra /s or does it really not matter ever?  I ask because it will save me several lines of code to check for extra /s while concatenating. I know it's not a big deal, but I'm curious as well. I have a bash script that has the line cd //usr (instead of cd /usr), which seems to imply there might be a significance to using multiple /s in a path


I've enabled custom stars in gmail, and can set them for individual emails, e.g. a green checkmark. But I can't figure out how to change all the emails in a folder so they're starred with a custom star, like a green checkmark, when all have been selected. When selecting multiple emails, the only thing I seem to be able to do is star and unstar with the default yellow star.

I have set up a Gmail filter that marks all incoming mail from a certain mailing list with a star. Right now, the filter automatically applies the standard yellow star. How can I set it to use the blue star instead?


I've been given this bike that needs attention.  I have found no information on the web about a Raleigh "The Mission" bicycle that matches this type, though there's lots on the more recent rock hopper.  I'm wondering about its age, make up, market, -any information really.  It looks like it might make a good commuter for a small adult, which I'll have on my hands soon.

This is a canonical question that will hopefully encompass all of the questions we get asking us to determine what year a bicycle was manufactured (how old is my bike, how old is my frame, etc.). Each "answer" should address a different way to determine the manufacturing year of a bicycle. To some extent, these will also help you narrow down the model as well as it will tell you what distinguishing features to look at.  The span of answers would include things such as:      Skiptooth cranks Cartridge bottom brackets (BB30/90 etc) Elliptical chainring Quick releases versus contemporary through-axles How the steerer attaches to the fork (quill vs. threadless)  Braking system (especially with mountain bikes: v-brake, direct pull, etc.)   Shifting ramps and pins on cassettes/sprockets and chainrings (versus flat sprockets) Frame material (e.g., shift from tubular steel to use of CF and hydroformed aluminium)  Frame tubing type (e.g. Reynolds 531 tubing introduced around 1934, still used today; Reynolds 501 tubing introduced around 1983). So a frame with an original 501 decal can't be from the 70', 531 decal doesn't help as much because of the range of years produced. Also, see Decals.   *Decals: style/design, amount, placement, color, etc. can help not only determine models, but also year of manufacture. Many changed decal design for the same model bike often yearly, with special/limited editions even more specific. This applies only if decals are original or have been replaced with the identical design. Tubing decals (Reynolds, Columbus, etc.) also changed designs for same tubing made in different years, although the changes aren't made as often, and manufacturers didn't always put tubing Brand decals on every model. Earlier bikes tended to have less fancy, less colorful, less quantity of decals.   Headbadges: most early bikes had actual "badges", often quite detailed and fancy, made of metal, then plastic, and finally just using decals on the headtube. Most bikes lost their metal badges in the 60's and early 70's, although some brands still have actual badges to this day, but in general a real badge indicates an earlier model bike. Dropout style (including the later inclusion of lawyers lips) Presence or absence of CPSC reflectors (USA only) Manufacturing method (shift from lugs to TIG welding, for example)  Number of gears (shift from 2x5 ten-speed to 3x8, 2x9, 1x11, etc.)  Inspection of lug design: pantographs, cut-out, stampings, custom brazing/filing, chrome, fork crow n sweep, etc. Frame/Fork Braze-ons. Race bikes tended have less braze-ons the earlier the year of manufacture. Most 60's racers and earlier had few or none with cable guides/stops, shifters, bidons, etc. being clamp-on. By the 80's if it was clamp-on, it was a sign of very cheap models and most frames had braze-ons for all cables, with multiple bottle and accessory bosses depending on style and use.   and so forth. Please edit this question if you have an answer that isn't in the index above.   A couple of caveats:   A previous owner could have replaced or upgraded components on a bicycle, so this guide only applies to original equipment There is a delay between the introduction of a technology (such as indexed shifting) and when manufacturers start selling products that use it. Low-end manufacturers may continue using technology that is severely outdated (such as one-piece cranks, freewheels, or quill stems) because it is cheaper to do so. A number of bikes are built in a Retro style, but with modern components.  Dutch bikes, trendy coffee cruisers, and beach cruisers may be modern but appear to be 1950s styling.  These tend to have modern rims and brakes as a giveaway.     Note that bicycles.stackexchange does not do valuations of bicycles. How much your bicycle is worth depends on the location of the buyer and seller, how much the buyer wants the bike, etc. etc. etc.


Since the expected value that minimises the error at each leaf is used for prediction does this mean that the forecasted values can never be smaller than the smallest value in the dataset or bigger than the largest?

I've noticed that when building random forest regression models, at least in R, the predicted value never exceeds the maximum value of the target variable seen in the training data. As an example, see the code below. I'm building a regression model to predict mpg based on the mtcars data. I build OLS and random forest models, and use them to predict mpg for a hypothetical car that should have very good fuel economy. The OLS predicts a high mpg, as expected, but random forest does not. I've noticed this in more complex models too. Why is this?   > library(datasets) > library(randomForest) >  > data(mtcars) > max(mtcars$mpg) [1] 33.9 >  > set.seed(2) > fit1 <- lm(mpg~., data=mtcars) #OLS fit > fit2 <- randomForest(mpg~., data=mtcars) #random forest fit >  > #Hypothetical car that should have very high mpg > hypCar <- data.frame(cyl=4, disp=50, hp=40, drat=5.5, wt=1, qsec=24, vs=1, am=1, gear=4, carb=1) >  > predict(fit1, hypCar) #OLS predicts higher mpg than max(mtcars$mpg)       1  37.2441  > predict(fit2, hypCar) #RF does not predict higher mpg than max(mtcars$mpg)        1  30.78899


Assume that $v_s \sim N(\mu_s,\sigma_s^2)$ and $v_b \sim N(\mu_b,\sigma_b^2)$, denote their correlation by $\rho$, and assume they are jointly normally distributed. How would I assess $E[v_b|v_s\leq c]$ where $c$ is some constant? I figured it would be of the form $$E[v_b|v_s\leq c]=\frac{1}{P(v_s\leq c)}\int_{-\infty}^cE[v_b|v_s]f_{v_s}dv_s$$ however I'm not sure this is right. Not sure how to conceptualize the approach here. Thanks!

Suppose I have  a bivariate normal $(x,y)\sim \mathcal N(0,\Sigma)$ .  Is there an easy formula for the expectation $\mathrm E(x\mid y>0)$ ?


I have an older HP netbook and am looking for a 32-bit version of Ubuntu 18.04 desktop. Can you advise if one is available?

As mentioned in the , Ubuntu 18.04 LTS will not have a 32 bit Desktop Image Installer. But in the  it has  32bit Desktop Images.  This is little off topic, but I'm confused.


Can anyone could help me remember the name of a "journey to mars"-type movie. All I remember is that you see the groups of guys (about 3) chill behind some rocks and they see a group of these short green alien humanoid-shaped beings. There's a trough of water and the aliens are drinking from it. But the one at the end is slightly weak-looking, so then the group attacks it and feasts. Then either this pile of rocks starts to build itself into a organism thing and attacks them, or it attacks the human guys. But it was at least 3 times taller than them and made out of rocks.   I know these if very vague but I've tried and can not find what this is, so if any of you have a clue THANK YOU.

I remember watching a sci-fi movie in the early 00s. It was full of comedy. Here are the details I recalled:   There was a space opera TV show in the movie. It seemed a true copy of Star Trek (they used to pilot a ship and there were captain, first officer, science officer etc on bridge). The name of the TV show was possibly the name of the movie. Once the main crew of the TV show were celebrating some achievement, they were approached by humans having weird behavior (they were actually aliens in disguise; in reality, they looked like octopus). The alien race was innocent. They couldn't comprehend the concept of art, lies etc. So, they believed that the TV show (they got the EM waves) was true historical documentary of mankind. So, they came looking for help from the brave captain of the show. From the TV show details, they had built a starship which really worked. The aliens needed the TV show crew to pilot the ship to defeat another alien race which terrorized them. The TV show crew didn't have any problems piloting the ship as the controls were familiar, only these controls were real.   Can you please identify the movie?


From the Windows 10 console, I type  set GFORTRAN_LIST_SEPARATOR=','   so that   echo %GFORTRAN_LIST_SEPARATOR%   gives  ','   However, compiling and running a program  print*,10,20 end   gives output  10          20   There is no comma. How do I set environment variables such as GFORTRAN_LIST_SEPARATOR on Windows? On Unix, after setting a variable, I export the variable, but Windows does not have an export command.

In a Windows batch file, when you do the following:       set myvar="c:\my music & videos"   the variable myvar is stored with the quotes included. Honestly I find that very stupid. The quotes are just to tell where the string begins and ends, not to be stored as part of the value itself. How can I prevent this from happening?  Thanks.


I am using CSS to style some radio buttons as tabs.  I would like the "selected" tab's font-weight to be bold.  Of course, this causes the size of the tab to increase, as the text takes up more space.  I would like to find a way to have the text go from bold to non-bold without the "tab" changing size      Short of setting a fixed width, is there a crafty and clean way of making the text take up the size of bold text without it actually being bold?  The only method I can think of would be to have the bold text exist (causing the text to exist twice in the HTML), but with visibility: hidden.  Markup:  <input type="radio" name="someTabs" value="someValueA" />Tab 1 <input type="radio" name="someTabs" value="someValueB" />Tab 2 (with longer text)   Relevant CSS as it is now:  .tab {   display: block;   font-size: 1.2em;   height: 2em;   line-height: 2em;   margin-right: 1px;   padding: 0 2em;   position: relative;   text-align: center;   float: left; } .tab.active, .tab:hover {   font-weight: bold; } .tab input[type=radio] {   display: none; }

I created a horizontal menu using a HTML lists and CSS. Everything works as it should except when you hover over the links. You see, I created a bold hover state for the links, and now the menu links shift because of the bold size difference.  I encounter the same problem as . However, the post does not have proper solution. I've searched everywhere for a solution and can't find one. Surely I can't be the only one trying to do this.  Does anyone have any ideas?  P.S: I don't know the width of the text in menu items so I cannot just set the width of the li items.    .nav { margin: 0; padding: 0; } .nav li {      list-style: none;      display: inline;      border-left: #ffffff 1px solid;  } .nav li a:link, .nav li a:visited {      text-decoration: none;      color: #000;      margin-left: 8px;      margin-right: 5px;  } .nav li a:hover{      text-decoration: none;      font-weight: bold;  } .nav li.first { border: none; }

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I want to determine if the following integral converges $$\intop_{1}^{2}\frac{\sin\left(x\right)}{\log\left(x\right)}dx$$ My intuition tells me it diverges. I thought the way to solve that woudln't be by definition but by finding another function that is smaller than that and use integral comparison test. I also know that $$\lim_{x\rightarrow1}\log=0$$ but I don't see how that helps me

I tried to use the absolute convergence test. $$\int_1^2\left|\frac{\sin{x}}{\log{x}}\right| \, dx<\int_1^2\left|\frac{1}{\log{x}}\right| \, dx$$ but I'm not sure whether $\frac{1}{\log{x}}$ converges or not.  Thanks in advance!


There was an episode of a Sci-fi/horror anthology. Either a TV series, or a series of movies. It was about a man whose wife is starved for affection, and overly attentive, trying to win his love. He buys a clone/robot to replace him so he can have some free time. On down time, the clone is kept in cold storage in the basement. The clone ends up being super romantic and treating the wife better than the husband did. They fight for her at the end of the episode.   Where is this story from?

I read a short story about four years ago and can't remember the title or author. The only thing I know is that it is relatively old -- like Huxley or Asimov era. Can anyone help me?   The basic synopsis is this: a man clones himself and has his clone do the parts of his life that he doesn't enjoy. He deceives his wife about this; she doesn't know he has a clone. Whenever the man and the clone are both home, the clone is locked in the "toolbox" in the basement. The clone starts to treat the man's wife better than he had previously. His wife starts to fall in love the clone, and the man decides he needs to get rid of the clone. When he tries to do so, the clone overpowers the man and locks him in the toolbox in the basement!  I'm hoping to share this story with my English class this school year. Any help is appreciated!


I made a leaf texture in photoshop and exported it as png and I hope to use it in a tree model I'm making in blender. However after I import it using the add-on "Import Images as Planes", this is the result. Does anyone know why this is happening?

I must be missing something here.  I'm doing an extremely simple Import Image as Plane using the AddOn and the imported image has an alpha background but it renders (and even previews in the material preview) as black where the alpha background should be.  When I import, I select Emission & Transparent so the material setup is automatic.  I've read similar issues but people are typically missing the transparent node and connecting the Alpha channel from the image into the Mix Node factor.  But this is all here.  I must be missing something really stupid but I've wasted so much time trying to fix this thing.  Any help would be greatly appreciated.  Not sure if it matters but I'm using 2.74 RC2.  Many thanks!  I created this dummy blend file to test outside my project but problem still exists.  Here is the simple .blend file:


I have 2 servers.    Server A is behind a router, to which I have no admin access.    It has a user: userA   Server B (example.com) is a cloud server with a public ip.   It has a user: userB     I am running the following command on Server A, to forward any connections made to Server B on Port 8022 back to Server A on port 22: ssh -R *:8022:localhost:22 userB@example.com  This creates a ssh connection and I have a session open for userB@example.com  If I then open another terminal (on another computer) and ssh into userB@example.com and once connected run ssh userA@localhost -p 8022 I have an active ssh connection to Server A  This is new to me but all seems to make sense.  I would like to ensure that the inital remote forwarding connection ssh -R is always active. This means if the connection drops I need it to reconnect. If Server A reboots I need it to connect on startup.   How would I go about doing this?   Is there a better approach?

I use an SSH tunnel from work to go around various idotic firewalls (it's ok with my boss :)). The problem is, after a while the ssh connection usually hangs, and the tunnel is broken.  If I could at least monitor the tunnel automatically, I could restart the tunnel when it hangs, but I haven't even figured a way of doing that.  Bonus points for the one who can tell me how to prevent my ssh connection from hanging, of course!


To save space, I often use "&" instead of "and". I noticed many B2B websites,brochures and reports don't use "&". Is it wrong, or considered shabby if you use the short form?

Are there rules of usage when using the ampersand "&" instead of "and"?  Are they completely interchangeable?   The ampersand seems more casual, but I'm not sure.


Sound argument is an argument which is both valid and it's premises are true. But my question is, why do we mention in the definition of the sound argument that "it's premises are true" when we've already said it's valid? Is not that true that when we say an argument is valid, we've already accepted it's premises are assumed to be true?so when the premises are true the conclusion must be true for the argument to be valid, thus, when we say an argument is valid, we've already confirmed the premises correctness.So I again say, why do we mention that "premises are true" in the definition of the sound argument?   thanks in advance

My text book gives the definition of validity as "An argument is valid IFF if the premises are true, then the conclusion must be true". Using a conditional elimination on the RHS of the IFF yields "An argument is valid IFF the premises are false or the conclusion is true".   Yet, this seems strange to me. Am I doing something incorrect with my manipulation or is this definition actually true? Surely the criteria for a valid argument goes beyond a false set of premises or a true conclusion.


I'm pretty sure I couldn't earn 200 rep recently, moreover I'm an inactive user for years, just occasionally returning here to have a look

With the recalculation of reputation due to the update to rep gained from questions, there are a few stacks where I hit the daily reputation cap, where I didn't before.  Take for example  In the progress bar for the Epic badge, this is shown:    Mortarboard, however, has not been awarded.   Is this a bug? Or was retroactively checking for that badge deemed not worth the effort?


Let $f : [1,\infty) \to \mathbb R$ be uniformly continuous. Show that there exists a number $C > 0$ such that $$|f(x)|\le  Cx$$ for all $x \ge 1$.

$f$ defined on $[1,\infty )$ is uniformly continuous. Then $\exists M>0$ s.t. $\frac{|f(x)|}{x}\le M$ for $x\ge 1$.  I know f uniformly continuous $\implies \forall\varepsilon > 0s.t.\forall x,y\in [1,\infty)$, $$|f(x)-f(y)|<\varepsilon \space\space\forall |x-y|<\delta$$  By Mean value theorem, $\exists c\in (x,y)\forall x,y\in [1,\infty)$ such that   $$\frac{f(x)-f(y)}{x-y}=f'(c)$$  $$\frac{|f(x)-f(y)|}{|x-y|}=|f'(c)|<M$$ for some $M>0$  $$|f(x)-f(y)|<M|x-y|<M\delta $$  How can I get an expression for $|f(x)|/x$?


Tell me please why the speaker left out the preposition about in the following sentences.     The connective tissue we are going to  discuss in this episode is essential in maintaining homeostasis, so today we are talking blood.   I aware of the idiomatic phrases like talk money, talk shop or talk business, but the example I have given is not only one that does not seem idiomatic. Another similar phrase I have heard is talk clothes, that is why I wonder if there any difference between talk about something and talk something or the preposition about has got redundant in modern English.

Let's talk money.   It's from an American show: Friends(Season02 Episode03), Usually, I would say "Let's talk about money, but why did she omit the word "about"?


How do I produce the output >> in a LaTeX Beamer presentation?  When I write >> or \textgreater\textgreater, I get this symbol, which I believe to be the guillemet(»):    I do not want this symbol. I want literally two greater-than symbols, in the context of     Use >> to append to a file, as in date >> dates

I need the characters «» in my LaTeX document.  I'm writing in English though, and I don't want to use Babel.  I have the following hack but I'd like a better way:  \newcommand{\q}[1]{{% \font\larm = larm1000% \larm% \char 190}{#1}{% \font\larm = larm1000% \larm% \char 191}}


I need to know how to correctly capitalize this title. I usually go with the Chicago Manual of Style for rules, but wasn't able to find anything regarding something like this:        This Is How He Finally Got the Hell Out Of Mexico!   This Is How He Finally Got the Hell Out of Mexico!   This Is How He Finally Got the Hell out of Mexico!      I know that prepositions should not be capitalized as long as they are shorter than five letters. So is "out of" a single preposition consisting of two words, or does "out" act as a part of the phrasal verb "get out"?

Are there any concrete rules that say which words (parts of speech) in a title should start with a capital letter? What would be a correct capitalization for the title of this question?


Im learning how to use scripting in blender. I would like to know how could I make a certain object to appear only in a certain frame. I have been searching this for a long time and I still can´t manage to do it... Initially I have two primitive_cubes moving around. At the frame x, a third cube starts to move. The problem is, the third cube is all the time visible, and I want him to appear only in the frame he starts moving...

I've been trying to create an animation where an object blinks on and off.   For example, I have a Cube and I set a keyframe on it's Restrict Visibility icon (the "eye" icon) with I, then I toggle off that "eye" so my cube doesn't show in the Viewport and again I press I to record that keyframe. Then, when I preview the animation in the Viewport, I see my cube appears and then disappears like I want, but when I render it, the cube does not disappear at all.  What am I doing wrong?


Can't use PDO.  I have read many questions here, this is my first time trying to do something for people outside my office, so I need to sanitize data input, researching about it found this function.  function clean_data($input){ $input = trim(htmlentities(strip_tags($input,","))); if (get_magic_quotes_gpc()) $input = stripslashes($input); $input = mysql_real_escape_string($input); return $input; }   example:  $vartodb = clean_data($_POST['yourformfieldhere']);   Its ok this function to sanitize data?

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


I read a series of books 20+ years ago in which the players of an RPG were transported to inhabit their characters while in the campaign they were playing.    There was a paraplegic or quadriplegic who was a mighty dwarf fighter, an abused teen girl who was a healer, a wizard named Andrea, a thief who only had one hand and was killed off early.   The handicapped guy who was the dwarf and the healer liked being in the player's universe because they had abilities they otherwise could not have.   I remember the series was at least 5 books geared toward the Young Adult reader.

I read a book as a teenager and I am searching for it. (from around the 90's)  Things I remember:   I remember that one of the players was in a wheelchair and he played a dwarf, Also remember when the wizard woke up in the game world, he set off a lightning bolt and exploded most of their gear.    I wish I could give you more, I read it and it inspired me to start playing D&D. Want to revisit it.


I believe I have finally found my biological father.  I was recently contacted by a possible cousin.    Amount of Shared DNA in Ancestry is 548 centimorgans shared across 31 DNA segments.  In GEDMATCH the Largest segment = 75.3 cM Total of segments > 7 cM = 625.0 cM 25 matching segments  Estimated number of generations to MRCA = 2.3  Is this a good chance that I have found my long lost family?

Given two tests that share some cM of autosomal DNA, how can I easily find the predicted relationships that such shared cM would suggest? For example, a 2,200 cM match suggests it could be either: grandparent, half-sibling, or grandchild.


I have one kernel installed currently, 3.10.0-327.28.3.  In my /boot directly, I have what looks like a lot of stuff that package-cleanup perhaps missed:       -rw-r--r--  1 root root  17M Aug 28 18:00 initramfs-3.10.0-327.10.1.el7.x86_64.img     -rw-r--r--  1 root root  17M Aug 28 18:00 initramfs-3.10.0-327.28.2.el7.x86_64.img     -rw-r--r--  1 root root  20M Aug 29 00:46 initramfs-3.10.0-327.28.3.el7.x86_64.img     -rw-r--r--  1 root root  17M Aug 28 17:00 initramfs-3.10.0-327.28.3.el7.x86_64kdump.img     -rw-r--r--  1 root root  17M Aug 28 18:01 initramfs-3.10.0-327.4.5.el7.x86_64.img   Can I remove those 3 files safely?   They look like they belong to older kernels.

I might be encountering odd symptoms resulting from competing kernels in CentOS 7.  So how do I safely delete the old kernels?  And how do I know which kernel is the newest one?    Below is the terminal output I get at the moment when researching this on the server in question.  Note that I tried package-cleanup but it leaves the same 2 kernels:     say that the output of the following two commands should match, but you can see that they do not match, even after a reboot:    [root@localhost ~]# rpm -qa kernel |sort -V |tail -n 1 kernel-3.10.0-229.el7.x86_64 [root@localhost ~]# uname -r 3.10.0-229.14.1.el7.x86_64   The remaining commands confirm that there are two kernels, and illustrate attempts to delete the old one.    [root@localhost ~]# cd /usr/src/kernels [root@localhost kernels]# ls -al total 16 drwxr-xr-x.  4 root root 4096 Oct  2 12:55 . drwxr-xr-x.  4 root root 4096 Oct  2 13:15 .. drwxr-xr-x. 22 root root 4096 Oct  2 12:55 3.10.0-229.14.1.el7.x86_64 drwxr-xr-x. 22 root root 4096 Oct  2 12:35 3.10.0-229.el7.x86_64 [root@localhost kernels]# rpm -q kernel kernel-3.10.0-229.el7.x86_64 kernel-3.10.0-229.14.1.el7.x86_64 [root@localhost kernels]# package-cleanup --oldkernels=1 Loaded plugins: fastestmirror Usage:      package-cleanup: helps find problems in the rpmdb of system and correct them      usage: package-cleanup --problems or --leaves or --orphans or --oldkernels Command line error: --oldkernels option does not take a value [root@localhost kernels]# package-cleanup --oldkernels Loaded plugins: fastestmirror No old kernels to remove [root@localhost kernels]# rpm -q kernel kernel-3.10.0-229.el7.x86_64 kernel-3.10.0-229.14.1.el7.x86_64 [root@localhost kernels]#    I also opened up /etc/yum.conf and set installonly_limit=1, but this resulted in an error from a subsequent yum update command saying that 1 is outside the range of acceptable values for installonly_limit.    I assume that 3.10.0-229.14.1.el7.x86_64 is the newest, but how can I know this?  Also, the boot options seem to offer multiple kernels to choose from.  And the opportunities for confusion get worse when the system auto-boots from the first kernel on the list of options.    Can someone please explain how this works, and in specific, how to safely delete old kernels so that kernel version can be eliminated as a possible cause of odd symptoms?  I want to make sure that the most recent kernel is the only kernel that can ever run, no matter how the system is restarted.


In my game called Void Wars, when a player dies they are sent to the lobby (they can't spectate). I need a command block to recognize when a winner is claimed aka after one person is left. Does anyone know a vanilla or Bukkit command to do this? Thanks in advance!

I want to run a command when there are only 10 entities left. I know you can use /execute unless entity to detect when all matching mobs have died, but it doesn't work if you want to run a command when there are for example 10 entities left.  A command like /execute if entity @e[limit=10] does not work, it also triggers if there is only one entity.  Such a counting system could also be used to determine once there is only one player left in an arena, meaning they have won a battle or similar.


Not only that, the object is no longer manifold, and I haven't been able to fix it.

Alright so I've seen some postings about loop cuts and done some research. I am very new to blender and modeling overall. I am trying to loop cut this concrete barrier. Now I'm following a tutorial and kind of did my own thing in some areas. I cleaned it up following some instructions in another answer here on stack exchange.  I can't for the life of me figure out why I can loop cut around the whole bottom:   ...but not the whole middle:   I see this marked as answered by another question. That question refers to ngons and inside faces. Now once again I'm totally new to this. I looked on the inside. I don't believe I have inside faces or any ngons by the terms I've read online in my research.  Here is a wireframe picture and the inside view:     Maybe I'm missing something the answers on other posts are saying. If so and you know what it is I'd be very appreciative of what it is.


$$\sum_{k=1}^{∞}\frac{1}{(2^k-1)}$$  I need to show that the series is convergent.  If there is a method that can be used to solve this (not the comparison test), what test would that be, and how would I go about solving it using that test?

Calculate $$\sum_{k=1}^{\infty}\frac{1}{2^{k+1}-1}.$$    I used Wolfram|Alpha to compute it and got it to be approximately equal to $0.6$. How to compute it? Can someone give me a hint or a suggestion to do it?


A windows application requires to return different error codes when there has been a problem while being called from Command Line. I am trying to find an appropiate way to define the error codes. So far I have only found standards related to Operative Systems or HTTP.  For example in Windows:

What is the correct (most efficient) way to define the main() function in C and C++ — int main() or void main() — and why? And how about the arguments? If int main() then return 1 or return 0?  There are numerous duplicates of this question, including:       — For C++, with a very good answer indeed.     Related:


Find: $$\lim_{n\to\infty} \sqrt[n]{n}$$  How does one not having any intuition able to do this?

I've spent the better part of this day trying to show from first principles that this sequence tends to 1. Could anyone give me an idea of how I can approach this problem?  $$ \lim_{n \to +\infty} n^{\frac{1}{n}} $$


In a nutshell, I'm wondering just how this can be done, since there doesn't (As far as I know) seem to be a way to do this with PHP's SimpleXMLObject setup.   Here's my xml:  <main> <item><field>1</field></item> <item><field>2</field></item> <item><field>2</field></item> <item><field>4</field></item> </main>   I'm trying to have it so that only enteries that match the field value of 2 would be returned in a new xml object. The problem is being able to filter out what doesn't match. I've tried using unset, but it only seems to return an object with t and e as enteries. Is there a better solution for what seems to be a simple request?

I have several identical elements with different attributes that I'm accessing with SimpleXML:  <data>     <seg id="A1"/>     <seg id="A5"/>     <seg id="A12"/>     <seg id="A29"/>     <seg id="A30"/> </data>   I need to remove a specific seg element, with an id of "A12", how can I do this?  I've tried looping through the seg elements and unsetting the specific one, but this doesn't work, the elements remain.  foreach($doc->seg as $seg) {     if($seg['id'] == 'A12')     {         unset($seg);     } }


three weeks ago I've installed macOS High Sierra on my MacBook Pro 13" (Early 2015). I've an internal SSD with about 120 GB (Apple Logic) disk space. Before the update I had about 30 GB of space lost. But after the update it seems that some of the disk space is "lost" or got filled with some random crap. This is a screenshot that shows the information about my Macintosh HD (the text is in german):  As you can see the overview tells me, that there are about 28.38 GB free space with the information, that 21.36 GB can be deleted. So my first question is what can be deleted? After some googling I found out, that these are files that were not really needed because they can be downloaded or found somewhere in the cloud. But at the moment it's not clear to me which files are really meant. I first recognized the problem when I wanted to download the latest version of Xcode and the AppStore.app told me that there is not enough disk space and I've to clean up my disk. I've then also checked the complete usage of my disk:  As you also can see, the app shows me that the system requires about 88.14 GB disk space, which cuts me really off. For what is this disk space needed? I've checked my personal data and as you can see I've only a few programs installed and the needed disk space of my personal data is also really low:   The most space is taken by all the developer tools. My personal data like images, etc. were stored on a SD card. When I run df -h in iTerm2 it tells me that in fact only 6.4 GB are left on my disk and it also shows me that there are many TimeMachine backup snapshots left on my disk. Normally TimeMachine stores the backups on an external usb hard drive:  So my question is, how can I get my disk space back and why is the system using so much space?

Every few days I get notices on my MacBook that it's running or run out of hard drive space. Curiously, restarting the computer will enable me to recover gigabytes of space (this past time, it was able to recover about 2.2GB). However, I can't identify anything in my personal activity that consumed that space.  It's possible that it's a rogue iTunes podcast or a huge software update that my Mac is automatically downloading - would either of these reclaim the space upon a restart?  One possibility that I can think of is that FileVault has some sort of disk leak, allocating but not freeing files. Does this make sense? Is there a tool that I can run to determine where this space is going? Assuming it is FileVault, should I try to disable it? What's the best way to turn of FileVault on a nearly full computer?


Show $\frac{d^3\underline{k}}{2\omega_{k}(2\pi)^3}$ is Lorentz   invariant.      Hint: try to evaluate $\int dk_0\delta(k_0^2 - M^2)\theta(k_0)$ where $M^2 = \underline{k} + m^2$   My attempt is as follows,  $$ I = \int d^4k \delta(k_0^2 - M^2)\theta(k_0) = \int dk_0 \int d^3\vec{k}\ \delta(k_0^2 - (|k|^2 + m^2))\theta(k_0)\\ = \int dk_0 \int d^3\vec{k} \delta(k_0^2 - (|k|^2 + m^2))\theta(k_0) $$  then using $M^2 = m^2 + |k|^2 = \omega_k^2$ and $\delta(a^2-b^2) = \frac{1}{2|\omega_k|}\delta(a-b) + \frac{1}{2|\omega_k|}\delta(a+b)$ we get  $$ I = \int dk_0 \int d^3\vec{k} \Big( \delta(k_0 - \omega_k) + \delta(k_0 + \omega_k) \Big) \frac{\theta(k_0)}{2\omega_k} $$ using the property of the theta function, we get, $$ I = \int_{0}^{\infty} dk_0 \int d^3\vec{k} \Big( \delta(k_0 - \omega_k) + \delta(k_0 + \omega_k) \Big) \frac{1}{2\omega_k} $$ integrating over $dk_0$ and using the fact that $\theta(\omega_k) + \theta(-\omega_k) = 1$ $$ I = \int \frac{d^3\vec{k}}{2\omega_k(2\pi)^3} \Big( \theta(\omega_k) + \theta(-\omega_k) \Big) = \int \frac{d^3\vec{k}}{2\omega_k(2\pi)^3} $$ however, I still have an integral for $\int d^3\vec{k}$ I don't know how to loose this integral without loosing the $d^3\vec{k}$!

When we canonically quantize the scalar field in QFT, we use a Lorentz invariant integration measure given by $$\widetilde{dk} \equiv \frac{d^3k}{(2\pi)^3 2\omega(\textbf{k})}.$$  How can I show that it is Lorentz invariant?


Heres the error that I'm getting:  Execution of AfterUpdate caused by: System.QueryException: List has no rows for assignment to SObject ()  I believe the issue is with the following lines, which aims to retain the current account owner when a lead is converted automatically by the trigger:  Account a = [SELECT OwnerId FROM Account WHERE Id=:accountId LIMIT 1];  lc.setOwnerId(a.OwnerId);  trigger autoconversion on Lead (after update) {   Lead ld=Trigger.new[0];    if( ld.Ready_to_Convert__c == TRUE && ld.IsConverted == FALSE) {       Database.LeadConvert lc = new database.LeadConvert();       lc.setLeadId(ld.id);       lc.setAccountId(ld.Linked_AccountId__c);       lc.setDoNotCreateOpportunity(TRUE);       String accountId = ld.Linked_AccountId__c;        //Account a = [SELECT OwnerId FROM Account WHERE Id=:accountId LIMIT 1];        List<Account> accs = [SELECT OwnerId FROM Account WHERE Id=:accountId LIMIT 1];       Account a = null;        if (!accs.isEmpty()) {           a = accs[0];           lc.setOwnerId(a.OwnerId);       }else {           a = null;           }        LeadStatus convertStatus = [SELECT Id, MasterLabel FROM LeadStatus WHERE IsConverted=true LIMIT 1];       lc.setConvertedStatus(convertStatus.MasterLabel);       Database.LeadConvertResult lcr = Database.convertLead(lc);   } }

I am getting FATAL_ERROR|System.QueryException: List has no rows for assignment to SObject. I know that it is because it is not returning any rows in the SOQL query but what I want is that if it returns any row, it should update ALO field on contact object, if it is null then ALO field should be set to null.  Here is my code:  ziptoLOD = [SELECT Id, Name, LOD__c             FROM Zip_3_to_LOD__c             WHERE Name =: contact.Extract_Zipcode__c ];  Zip_3_to_LOD__c ziptoLOD2 = (ziptoLOD != null) ? ziptoLOD : null;  if (ziptoLOD2 == null) {     contact.ALO__c = ' ';    } else {     System.debug(System.LoggingLevel.ERROR, 'Zip to LOD' + ziptoLOD2);     contact.ALO__c = ziptoLOD2.LOD__c; }   My code gets stuck at the SOQL query and gives me the list has no rows error.


Let $k$ Be an infinite field.  Show that for any $n>3$ there exists a degree $n$ hypersurface $f(x_0, x_1, x_2, x_3)$, so deg$f = n$, that contains no lines.  I’ve been trying to figure this out / have been looking for a proof of this statement for a week now but no luck. Does anyone have a proof for this?

Let $d \geq 4$. I'm interested by know if there is a surface $S$ of degree $d$ in $\mathbb P^3_{\mathbb C}$ such that $S$ does not contains a line. I know  I have no idea how to do it.


What is the use of interface if it should be defined in the subclass implementing it? Also, to access an interface we need to create an object of that class.  import java.io.*;  Interface area {    compute(); }  Class rectangle implements area {   compute()   {     x*y;   } }  Class circle implements area {   compute()   {     x*y;   } }  Class test {   public static void main(String args[])   {    rectangle r=new rectangle();    area ar;    ar=r;    ar.compute();   } }

I have seen this mentioned a few times and I am not clear on what it means. When and why would you do this?   I know what interfaces do, but the fact I am not clear on this makes me think I am missing out on using them correctly.   Is it just so if you were to do:  IInterface classRef = new ObjectWhatever()   You could use any class that implements IInterface? When would you need to do that? The only thing I can think of is if you have a method and you are unsure of what object will be passed except for it implementing IInterface. I cannot think how often you would need to do that.   Also, how could you write a method that takes in an object that implements an interface? Is that possible?


Given be a program that has many functions, how can I find out how much time spends in every functions?  For example it is very simple to track the execution time of one funtion, 27 possible solutions are laid out in this post, .  However what would be a sensible extension to an already exisiting project to keep track on the times of all its functions during one execution? The total run time might be a few hours, thus it might be very interesting/revealing to know, if there are spots, that need improvements.

and other coding contests often have a maximum time to run or people boast of how fast their particular solution runs. With Python, sometimes the approaches are somewhat kludgey - i.e., adding timing code to __main__.  What is a good way to profile how long a Python program takes to run?


The word 'explain' has an 'i'.  Why does that 'i' disappear when we write it as 'explanation'.

I often catch myself trying to write ?explaination, phonetically spelling the word in my head. To my chagrin I get part way through and have to stop myself.  So I’m wondering why is the i dropped? I can’t think of other words ending ‑ain that take the ‑ation suffix for comparison.


I have a category of items lets say :   Sold In shop Coming soon   Every items are record in database as follow :   item.category = 0 for sold item.category = 1 for shop item.category = 2 for coming soon   Today I do as follow :  <% if item.category = 0 %>Sold<% end %> <% if item.category = 1 %>in shop<% end %> <% if item.category = 2 %>coming soon<% end %>   Is there a way to centralize an enum for all my application so it will be available in any pages like this :  <% if SOLD %>Sold<% end %>

What's the best way to implement the enum idiom in Ruby? I'm looking for something which I can use (almost) like the Java/C# enums.


I remember reading this word or expression in a book that describes the feeling you have when you think about a reply that you could've given to someone, but you do it too late.

or l'esprit d'escalier (literally, staircase wit) is a French term that describes the predicament of thinking of the perfect comeback too late.  Merriam-Webster dictionary defines it as follows:     Definition:      A witty remark thought of too late, on the way home; the clever   comment you wish you had delivered      Example:      "When he bragged about sleeping like a baby, I should have added the   bit about waking up crying every two hours, but that's just esprit de   l'escalier. At the time I just nodded and said nothing."   Is there an English term for that?


Using Kubuntu 16.04, I'm trying to use Google Hangouts via Chrome. Webcam works fine, however no one can hear me.   Using Blue's Snowball which works fine in Skype and Audacity.   Someone suggested I need to disable the linein, not sure how to do that.  Any help would be much appreciated.

I have a DELL inspiron 5537 i5 laptop with Ubuntu 14.04. When I use Google Hangouts on Google Chrome, my mic just doesn't work. When I open the secure info setting it shows that the mic is allowed.  Works in Windows.  I have tried to add the Hangouts plugin and it also doesn't work.  Is there any to solve the problem?


Edited to clarify the issue: New install of Ubuntu 16.04, and I recognized the wireless network option never showed up. Clicking on the Networking icon at the top, I'm given a greyed-out line saying "No network devices available". According to Pilot6 below, the drivers have been installed properly, so I can't say exactly what the real problem is.  Under my first assumption that the driver installation was the problem, I did a lot of searching around, mostly returning to this forum specifically, trying to find an answer. Most of what I've been doing has been trying to follow this:   So far, no luck. I followed the top answer, to the best of my abilities, and nothing seems to have worked. So I ran the install again, this time tethered to an internet connection. Next, I found a Linux driver on the Broadcom website; after some searching around to figure out how to properly use a tarbell, I've been continually returned an error following any make commands.  I'm not sure where to go next, or even what information to supply here. I'm a new user with little understanding of what exactly I'm doing, so patience is appreciated. Working between two computers, to prevent burning through data, but I will do my best to edit in any requested information as quickly as possible.  It is entirely possible that I've simply completely missed something basic. Here's what I've gathered that seems relevant or important:  lspci gives me: 01:00.0 Network controller: Broadcom COrporation BCM 43142 802.11b/g/n (rev 01)  Using lspci -nn -d 14e4: I gather the PCI ID is [14e4:4365] (rev 01)  rfkill list all only gives me information on the Bluetooth connection, which isn't blocked.  UEFI boot mode was brought up during installation, turned off Safe Boot.  Nothing else has been run during this install, except the attempt at installing the driver directly out of the tarbell that Broadcom offered.  Thank you in advance, any help or advice is greatly appreciated.    Edits: Output of lspci -knn | grep Net -A3:              01:00.0 Network controller [0280]: Broadcom Corporation BCM43142 802.11b/g/n [14e4:4365] (rev 01)                 Subsystem: Hewlett-Packard Company BCM43142 802.11b/g/n [103c:2230]                 Kernel modules: wl   /etc/network/interfaces text file contains the following:              # interfaces(5) file used by ifup(8) and ifdown(8)             auto lo             iface lo inet loopback

I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible.   What are the steps to install Broadcom wireless drivers for a BCM43xx card?  I'm a user with no advance knowledge in Linux, so I would need clear explanations on how to make, compile, etc.    lspci -vnn | grep Network showed:   Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller [14e4:432b]      iwconfig showed:  lo        no wireless extensions. eth0      no wireless extensions.   NOTE: Answer below is updated every time new information is added and confirmed working.


I have a list in one sub-site, now I want to add/show that list on a page in its  main site.  It should be with edit menu of the list content.  Any suggestion !

I've got a list setup on a HR subsite that keeps tracks of Scheduled Vacations for employees. I'd like a way to display a certain view from this list as a web part on the Parent of this site. I figured just copying the list items to a list located on the parent site would be the easiest way, but the workflow that populates the subsite list can't 'see' anything located on the parent site.


I started learning english.   Often we hear "Got it?" sentence.   So I'm confusing following two sentences. When should we use one over the other?      1) Got it?      2) Get it?   Thank you.

What the heck are you doing? Stop that nonsense. Get it?     What the heck are you doing? Stop that nonsense. Got it?    Which one of the above is correct? Is it okay to use just "Get it?" or "Got it?" instead of "Did you get it?" or "Have you got it?" in informal spoken English?


I was reading about $A_4$ and $S_4$ groups and I got curious about some of the subgroups. And if we have $H:= \{(),(12)(34),(13)(24),(14)(23)\}$, how would I determine and how would the structure look like of the quotient group $A_4/H$ and is $A_4$ a simple group?

Let K={(1),(12)(34),(13)(24),(14)(23)} show that K is a normal subgroup of the alternating group of degree A4 and find all the members of A4/K and write down the group table for A4/K.   i know that K is the Klein four group and i have already proven it is a normal subgroup but i need a start on approaching the A4/K part of this question no direct answers are necessary,just ideas thank you! :)


I'm trying to set up an array of certain PoseBones by scanning all the bones in the blender. But attempt to loop through all the objects via  for ob in bpy.data.objects:     print(ob.name)   I get this error  AttributeError: '_RestrictData' object has no attribute 'objects'   Here's the source code:   I put the piece of code at the end of weld_op.py

I got this error message when I try to enable my addon.  dataBrush = bpy.context.blend_data.brushes  AttributeError:'_RestrictContext' object has no attribute 'blend_data'   Please some help    I am working on an dynamic palette for sculpt brushes


If I am in the middle of using the terminal, say to apt-get something;   If I click the x / close button, does the Terminal continue to run in the background?    To afraid to try it, cause I don't want to have to start the process all over again...  Has anyone accidentally done it?

How do I run a program in the background of a shell, with the ability to close the shell while leaving the program running? Lets say my UI is having problems or for some reason, I need to boot up a program from the terminal window, say, nm-applet:  nm-applet   When it's started, it occupies the foreground of the terminal window.  Is there any simple way to run the program in the background without needing to leave the terminal open or have it occupy the whole terminal?  On that note, I did find a way to run programs from the terminal and have it allow for other inputs, by appending an ampersand (&) to the command as such:  nm-applet &   But this isn't much use as any processes started in the terminal are killed once the terminal is closed.


I've been playing the steam Monster game and it tells me that I have received 4 cards from playing yet I have no cards in my Steam inventory? Does anyone know what's going on?

The cards that it says I've unlocked aren't in my inventory. Do you just get them after the whole event? I have two from just buying games actually in my inventory, but the cards I've 'unlocked' aren't around. I'm Steam Level 7, so I know they should be dropping...


This is a binary model that my colleagues and I developed that regards a connection between the satisfaction with air (dependent variable) and overall satisfaction with public transport (covariate). I don't know how to interpret the results shown below.

I'm quite new on this with binomial data tests, but needed to do one and now I´m not sure how to interpret the outcome. The y-variable, the response variable, is binomial and the explanatory factors are continuous. This is what I got when summarizing the outcome:  glm(formula = leaves.presence ~ Area, family = binomial, data = n)  Deviance Residuals:  Min      1Q  Median      3Q     Max   -1.213  -1.044  -1.023   1.312   1.344    Coefficients:                         Estimate Std. Error z value Pr(>|z|)  (Intercept)           -0.3877697  0.0282178 -13.742  < 2e-16 *** leaves.presence        0.0008166  0.0002472   3.303 0.000956 *** --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1  (Dispersion parameter for binomial family taken to be 1)  Null deviance: 16662  on 12237  degrees of freedom Residual deviance: 16651  on 12236  degrees of freedom (314 observations deleted due to missingness) AIC: 16655 Number of Fisher Scoring iterations: 4   There's a number of things I don't get here, what does this really say:                          Estimate Std. Error z value Pr(>|z|)  (Intercept)           -0.3877697  0.0282178 -13.742  < 2e-16 *** leaves.presence        0.0008166  0.0002472   3.303 0.000956 ***   And what does AIC and Number of Fisher Scoring iterations mean?  > fit Call:  glm(formula = Lövförekomst ~ Areal, family = binomial, data = n)  Coefficients: (Intercept)        Areal   -0.3877697    0.0008166    Degrees of Freedom: 12237 Total (i.e. Null);  12236 Residual (314 observations deleted due to missingness) Null Deviance:      16660  Residual Deviance: 16650        AIC: 16650   And here what does this mean:  Coefficients: (Intercept)        Areal   -0.3877697    0.0008166


We are a web hosting company. We have 4 Servers which are running OpenVZ on top of CentOS. Each of the server has around 50 containers running on top of it.   We are planning to provide ssh root access to some of the customers (around 50). All of these 50 users will be developing and hosting modules of a single website. For eg. there is a website xyz.com Now there will be a module xyz.com/module1 This module1 will be hosted by different developers and hosted on different containers. Similarly there will be other modules developed by different developers and hosted on other containers. The problem is that these containers are running behind a NAT firewall. There is a public I.P for xyz.com.  We do not want to do port forwarding as it will open unnecessary ports in the Firewall.  We were thinking of forwarding all the ssh requests to xyz.com to a single container (ssh-temp) and then allowing ssh to other containers from ssh-temp container only. But this approach is not feasible as the users will be having root access to their containers and can modify the firewall rules.  Is there any better approach to perform this task. I was thinking of having a scheme where a user could run a command such as:  ssh user@module1.xyz.com   The user would then be redirected to that particular module. How can I achieve such a scheme?  Thanks  Edit: I do realize that providing root access to containers within a network is a bad idea but for now this is a compulsion and not a choice.

I've grown quite fond of HTTP reverse proxies in our development environment and found the DNS based virtual host reverse proxy quite useful. Having only one port (and the standard one) open on the firewall makes it much easier for management.  I'd like to find something similar to do SSH connections but haven't had much luck. I'd prefer not to simply use SSH tunneling since that requires opening port ranges other than the standard. Is there anything out there that can do this?  Could HAProxy do this?


Does there always exists an injective homomorphism from $G$ into $S_m$ for some $m<n$ where $|G|=n$   I know that for $|G|=n$ there is always an injective homomorphism from $G$ into $S_n$

Let $G$ be a finite group of order $n\ge2$. Which of the following statements are true? a. There always exists an injective homomorphism from $G$ into $S_n$. b. There always exists an injective homomorphism from $G$ into $S_m$ for some $m\lt n$. c. There always exists an injective homomorphism from $G$ into $GL_n(R)$.  I think b. is right (don't know how to prove though). I also think that c. is false. But not sure.


In the campaign I run, it is frequently the case that one player will make an attack against an unsurprised enemy to start combat. For example:     DM: "At the end of the long hall, you see a large door, flanked by two   hobgoblins. They are alerted to your presence but do not move."      Ranger: "I shoot at the one on the left with my longbow."   In these situations, no one is surprised, and a party member has specifically stated that they will perform the action that brings us into combat and cues initiative order. But does this affect initiative order?  If everyone just rolls for initiative, then there is a very good chance that someone, maybe even an enemy, will have a higher initiative than the inciting adventurer. But that doesn't make a whole lot of sense when the combat wouldn't happen at all (not yet, anyway) if that adventurer didn't make an attack. And then the player who is playing the ranger feels like his cool idea was ignored when he rolls a crappy initiative.  I realize that those who roll a higher initiative than the inciting adventurer could take a non-combat option, such as Dodge, Help, or Dash, but I don't think the party would be a big fan of reducing the party's attack quantity for the first round..  I was thinking about making a house rule that gives such a player a +5 bonus on their initiative roll or that allows players to choose their initiative as long as it isn't higher than what they rolled or something like that, but is there already a mechanic in place for this kind of situation?

This example is a somewhat simplified version of what happened during the last game I DMed for a bunch of friends. A party of PCs was trudging through the woods when they happened upon a very small outpost in a clearing containing hostile elves. The rogue goes and checks it out, and sees two hostiles patrolling, one near the northern edge of woods (Elf1), one on a stone platform about 15 ft from the southern edge of the forest (Elf2).   The rogue goes back and relays the information. If the warrior of the party would simply trudge into the middle of the clearing, all enemies would be aware of a threat and the enemy wouldn't be surprised. They want to start combat with an edge, so they formulate a plan that would cause the enemies to be surprised: the rogue will go stealth up to the northern edge of the clearing, wait for Elf1 to get close, and sneak attack him. When that happens (it's a small clearing, so it's within his vision) the warrior in the party, who will attempt to sneak up to the southern edge of the forest, will run for Elf2 and beat him up. They both roll great stealth checks and head to their positions. So far so good.   The rogue waits for Elf1 to get close and attacks with his short sword. Time for combat, and this is where things got confusing, and where a discussion broke out between players:  According to page 189 of the PHB:   Determine surprise — Both Elf1 and Elf2 are surprised, because they didn't notice any threat. Establish positions — Should be clear from the description of the situation above. Roll Initiative — The warrior gets a 20, Elf2 a 15, the rogue a 5, and Elf1 a 1. Take Turns — The warrior can go first. However, as the party discussed before, he was supposed wait until he sees the rogue hit Elf1. The rogue's attack is what started the combat encounter, yet the attack hasn't been resolved yet due to his poor initiative roll. And .   Option 1: Some people at the table argue that he can't yet run into the clearing because that would pose a clear and noticeable threat and the elves would not be surprised. He should wait for the rogue to hit Elf1 and use the Ready action on his first turn. This option seems to punish the warrior for rolling well on his initiative.  Option 2: As determining surprise occurs before the initiative roll according to page 189 of the PHB, I would argue that the rules support that the warrior should be able to run up to Elf2 and hit him, without breaking surprise. The fact that the attack that caused the surprise hasn't yet been resolved and that this goes somewhat counter against their agreed plan of waiting for the rogue to hit Elf1, makes this option incredibly unintuitive though.  Which of these options is the correct one? Or is there a hidden option 3?


I want to try old versions of UNIX for fun, but I don't know where to get them. Is there a way to download them?

Where can I get the original Unix (from the year 1969)? I would like to look at the source code of the original Unix.


I have this problem with footnotes on every section.  i have two sections in one page and each of them has a footnote in it and the footnotes reset after the first section ends  it somehow seems section dependent although i have used the package :  \usepackage[perpage]{footmisc}   the problem is it is not working as it should be just resetting at every page.

I would like the footnote counter to automatically restart from '1' for each page of my document.


I've only played a lot of Bedrock edition, but I just came up with Minecraft Java Edition and I have no clue here.  I made a bit of research and found out that these ones are around the best:   Guardian farms (Highly efficient, but highly resources friendly) Enderman farms (Efficient and resources friendly) Witch farms (Didn't found a result about its efficiency)   Also, I saw a video where furnaces can store XP since earlier versions of Java and someone build a cactus based farm where you can get to level 30 by just taking out one cactus after letting the farm working by almost an hour.  What are the best strategies to obtain XP for enchanting with higher levels in Java Edition?

Now that experience does something besides render regions of a server uninhabitable due to  orb lag, what's the most efficient and safe way to get those excellent enchants?  A mob farmer may rank highly, but what about without tons of setup?


In an article I met this table.  How can one design such a table?

I'm trying to mimic the design of this table:    Any advice?


The question is not about the real photons bursted out of an atom and their size (I call them real photons) but about the quantized modes in a box and that they are called photons (I call them QED photons). I wonder what common has the real photon and the QED  photon with each other.  According to QED quantization procedure of the EM field as known Debye decomposed EM field in a box in Fourier components, then Born, Jordan and Heisenberg quantized the amplitude of the standing waves (SW) so the energy was devided into pieces hv and hence the amplitude of the SW is multiple of n (integer). So it turns out that the photon in QED is a standing wave with energy = hv whereas its length seems = length of the box. There are some questions about this notion of photon (as pictured in QED) I want to find answers.   The standing wave fills the whole box at once – so a photon appears on top of the existing standing wave like dropping above immediately, whereas the atom in the walls should have delivered the energy hv and this seems not relativistic (there should be some moment that energy left the wall, so at that moment there can not be EM amplitude near the other wall or in the center of the box). As the length of box can be varied it turns out that the length of the photon depends on the length of the box, which is unknown to the atom. For distant objects this seems extremely unbelievable as for item 1 so for item 2. (but QED says that one easily stretches the box to infinity and all is the same.) In order to insure the release of proper frequency an instantaneous process is needed which to measure the distance of the box and to deliver the info to the emitting atom.   I think some answers maybe based on Heisenberg uncertainty principle though I haven’t seen these questions ever asked anywhere and nonetheless some answers. I hope someone knows a paper or book where they are posed and cleared and will be so kind to share this knowledge.

What's the smallest aperture a photon can pass through? I mean with no transmission at all.  I'm pretty sure I saw long ago an experiment when they were reducing the size of a hole in a gold film and at about a quarter or a third of the wavelength there was no transmission.   If so, can we say that the size of the aperture can be associated with the dimension of the photon?


Here is my whole bib file Refs.bib  @book{Shalev, author = {Shalev-Shwartz, Shai and Ben-David, Shai}, title={Understanding Machine Learning}, year={2014}, publisher ={Cambridge University Press, NY}, }   I am trying to run BibTex on it.  The Texmaker outputs an error:  "I couldn't open file name `Refs.aux' Process exited normally"   The TexWorks does not output anything: it just hangs indefinitely.   What is going on?

I've browsed the forums and found a number of posts that have addressed this issue, but none of the solutions seem to work for me. I have the following script that I just copied from the bibtex home page to get familiar with it. Instead of the citation number I get a question mark. I compile using Latex+Bibtex+Latex+Latex+PDFLatex+ViewPDF just as has been previously suggested and the problem persists.   \documentclass[11pt]{article} \usepackage{cite}  \begin{document}  \title{My Article} \author{Nobody Jr.} \date{Today} \maketitle  Blablabla said Nobody ~\cite{Nobody06}.  \bibliography{mybib} \bibliographystyle{plain} \end{document}   My bibliography (Bib.bbl)  @misc{ Nobody06, author = "Nobody Jr", title = "My Article", year = "2006" }    Looking at previous posts one thing that is concerning is that my .bbl looks empty as shown below. Further, I don't have a .blg  \begin{thebibliography}{}  \end{thebibliography}


\documentclass[tikz,border=3.14mm]{standalone} \usepackage{tikz} \begin{document} \begin{tikzpicture}  \node[rectangle, draw, minimum height=1.5em, minimum width=1.5em] (I) {X};  \end{tikzpicture} \end{document}   Is there a way to personalize the thickness of the lines conforming a rectangle node?

Suppose I have a node in the shape of a circle. How can I make its border thicker?   \node[circle, draw=blue!80, inner sep=0pt, minimum size=12pt] (1) at (0,0) {1};


but it shows how to comment with //  since I'm using notepad ++ to view Python scrips the comment needs to be # and not //  How can i comment multiple rows with # ?

In Eclipse it is possible to comment out multiple lines at once by selecting them and executing CTRL + /:  // helloworld  Is this possible in  as well instead of typing /+/ in front of each individual line?


I applied for sweden last June 2018 unfortunately I denied. Coz of insufficient fund. After 4 mos I applied again but this time for Malta since Sweden is not my lack, but then I denied due to unreliable source of documents with no further explanation unlike in Sweden. This time I'm planning to reapply again as tourist in Europe. What are the preparation should I have to do? And can I change again my destination?thank you!

Schengen refusal formulae can be difficult to understand sometimes.  Sometimes an applicant receives a refusal with:       Justification for the purpose and conditions of the intended stay was not reliable.     often accompanied by:       Your intention to leave the territory of the Member States before the expiry of the visa applied for could not be ascertained.   What is meant by this refusal reason?  What are they trying to say?


I'm having significant server issues at the moment, and am worried the server will go at any moment. I need to backup my SQL databases immediately.   Could I please get a command just to dump all my databases (different domains) into their own sql backup files?  I'd like to work with this cron syntax, since it already works fine for backing up individual SQL files.   mysqldump -uadmin2 -p$(cat /etc/psa/psa.my/.psa.myshadow) MyActualDB > /var/www2/backup/mybackup1.sql   The above syntax is just for one SQL file. But I need to add:  all-databases   syntax in there somewhere. Also, for each backup, to backup to their own SQL file (preferably using their already established database name).

I want to copy a live production database into my local development database.  Is there a way to do this without locking the production database?  I'm currently using:  mysqldump -u root --password=xxx -h xxx my_db1 | mysql -u root --password=xxx -h localhost my_db1   But it's locking each table as it runs.


I have read that boolean doesn't take any memory size from java 5 & above.Why Boolean do not take any size in memory (not even single bit) from Java 1.5 and above? for e.g.   boolean flag=true;   it should only take 1 bit because you can use 1 to represent the value true, right?  so what is the core concept behind it?

Can any one tell the bit size of boolean in Java?


This question was asked in complex analysis end term of previous year and I am trying to solve it to gain some experience. I need help with following question:  If f and g are entire functions with no common zeroes and if h is an entire function show that h can  be always written as h=fF+gG.with some entire functions F and G.  I am completely stumped on which theorem should I use to solve it as this question seems very hard for me and I am unable to get any intuition. Also, not much assignments  were given to us by course instructor due to Covid-19 and so it's a problem as I am often blank on how to approach some questions. Entire functions are functions which are holomorohic on all of $\mathbb{C} $ . Kindly shed some light on solution of this problem.

I have found this exercise.  Let $f, g$ be entire functions.  a) Show that there exists entire $f_{1}, g_{1}$ and $h$ such that $f=hf_{1}$, $g = hg_{1}$ and $f_{1}$ and $g_{1}$ have no common zeros.  b) For $f$, $g$, and $h$ as above, show that there exists entire functions $A$ and $B$ such that $Af+Bg = h$.  Any idea ? How to manage the case ord($f$) = $\infty$ and ord($g$) = $\infty$ ?


I have learned that, in Java,  is a SortedMap that sorts according to its keys or by using a Comparator<? extends K> of the keys.  Are there some other SortedMap like TreeMap<K,V> but can sort using a Comparator<? extends V> of the values instead of the keys?

I am relatively new to Java, and often find that I need to sort a Map<Key, Value> on the values.  Since the values are not unique, I find myself converting the keySet into an array, and sorting that array through array sort with a custom comparator that sorts on the value associated with the key.  Is there an easier way?


I'm trying to figure out why I am getting this error, but so far no results.  Exception in thread "Thread-2" java.lang.NullPointerException     at Help.render(Help.java:22)     at Game.render(Game.java:246)     at Game.run(Game.java:123)     at java.lang.Thread.run(Unknown Source)   I'm trying to run a method from another class which always results in this kind of error.  public void centerText ( String m , Graphics g,  int y){          FontMetrics fm = g.getFontMetrics ( g.getFont() );         int sw = fm.stringWidth ( m );         g.drawString ( m , ( Game.WIDTH * Game.SCALE + sw ) / 2 - sw , y + sw /2);     }   That's the method from the Menu class, which is a game state.  Now, I try to execute this method from another class called Help, which is another game state.  import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Rectangle;  public class Help {      Menu menu;      public void render(Graphics g) {          Graphics2D g2d = (Graphics2D) g;          g.setColor(Color.white);         Rectangle test = new Rectangle(Game.WIDTH * Game.SCALE / 2 - 50, 350, 100, 50);         g2d.draw(test);          menu.centerText("Hello WOrld", g, 100);      }      public void tick() {      } }   Am I missing something, if so, what ? Thanks.

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 have a road bike with tyres that aren't that great I want to upgrade for more wider and gripper tyres any recommendations?I desperately need it.The old tyres are Triban Protect 700 x 28 tyres. Tyre weight: 440g Anti-puncture protection Supple carcass for light weight Max pressure: 8 bar /116 psi. 48mm Triban inner tube with Presta valve

We often get questions on bicycles.stackexchange about fitting wider or narrower tires to bicycles. We have a large number of these with answers suiting the specific bike or style of bicycle in question, but I have been unable to find one that provides a generic answer covering off all things that need to be considered. For most bicycles, the answer is the same regardless of the specific style and sizes of tires in question.   This is intended as a canonical question that we can point closed questions to.


What does energy being quantised have to do with the decrease in intensity as it approaches zero wavelength?  Furthermore, how does quantised energy link with the avoidance of the UV catastrophe.

I understand how classical physics leads to the . But I cannot understand how quantization solves it.    How can quantization prevent the body from radiating a lot of energy?   I know this question is similar to many other questions but I need a layman's explanation (without too much mathematical details).    Finally why does the peak reach zero intensity after a certain frequency?     Image source:- Wikipedia


I have Ubuntu 20.04.2 LTS. Wi-Fi is connect but I have no internet connection. There’s a question mark on top of the wifi sign on the desktop. When I go to wifi settings, wifi is on but still no internet. I tried the following possible solutions with the following results ping -c4 www.google.com Result: ... I disabled automatic DNS and set it to IP 8.8.8.8 Result: ...

I installed Ubuntu 18.04 right now and after connecting to the internet instead of a network icon there is a question mark. There is no network issues, but that question mark is annoying.


I am trying to find abstract all occurrences of a function call in a full project in Webstorm. The issue is that the function call may be broken into multiple lines for readability, hence I am trying to use regex for this. foobar(a,b c,d);  foobar(e,f,g,h);  I am trying to use regex foobar[\S\s]*\);? to get both the calls as separate occurrences but I keep getting one match only with the entire text highlighted(greedy result). What am I doing wrong with respect to the non greedy reg ex?

I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully  I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}:  The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}?


A friend of mine received a letter stating the following: "The committee has issued orders to suspend John Doe for 30 days from the 20th of April 2018 until the 19th of May 2018." So, does the suspension end on the day of the 19th of May, or the 20th of May? Thanks.

What does until mean in the following?     You need to deliver this product within 2 days (until August 18, 2011)   to meet your deadline and get paid.   Does this mean that I have to deliver the product by 23:59 on 17 August 2011 or 23:59 on 18 August 2011? The order time is 21:04 on August 16 2011.


Which is the best?  Single column:   or...  Two column:

Don't look at me like that, I actually like the way to call both login and registration forms together a logistration form, well it's convenient. I've designed a logistration form, but the problem is that I want to know which approach do you think you're more comfortable with, a single column or two column approach? By the way I've read  I'd actually like to know your own opinion, which one is better?  Two column approach?     And one column approach:


I'm trying to show that given a compact Hausdorff space $X$ and given a continuous function $f:X\to X$, there exists a compact subset $K\subseteq X$ such that $f_{\big|K}:K \rightarrow X$ maps $K$ onto $K$.  I'm not sure how to approach this.

Let $X$ be a compact Hausdorff space and let $f:X\to X$ be continuous. Prove that there exists a non-empty closed set $C$ such that $f(C) = C$.    Proving by contradiction seems hard to me, since if $f(C)\neq C$ for all closed sets $C$, then we can have either $f(C)\subset C$, $f(C)\cap C\neq\varnothing$ or $f(C)\cap C = \varnothing$. The only thing I might have thought about is to set $C = f(X)$. Since $X$ is compact, $f(X)$ is compact and since $X$ is Hausdorff, $f(X)$ is closed. Then we have that $f(C)\subseteq C$ by definition. I was not able to prove that $C\subseteq f(C)$, namely that $f(X) \subseteq f(f(X))$. It is not obvious for me that in general it is even true, so maybe the choice $C = f(X)$ does not help.


Imagine a spherical ball with radius r that equally coated into two hemisphere P(grey) and S(white) is thrown at the pool. Consider the ball can float (up-down) and rotate. There is an interface separate two different fluid A(air) and B(water). Assume that the interface is flat. α defines the position of the ball and β defines the orientation of the ball. So α larger means ball is more in zone A and vice versa. Range of β and α is $[0,360^0]$ and $[0,180^0]$. The Schematic representation of this is below.   To calculate the surface area of P(grey) coated portion of the ball into A(air) is given by following equation,  $\mathrm{Area}_{P@A}=  r^2\int_{\theta=\frac{\pi}{2}-\beta}^\alpha  \int_{\phi=\arcsin(1/(\tan\theta \tan \beta))} ^{\pi -\arcsin(1/(\tan\theta \tan \beta)} \sin\theta\; d\theta d\phi.$  After solving this equation, we can get the following solution.  $\textrm{Area}_{P@A}= 2 r^2 \left\{ \cos (\alpha) \sin ^{-1}(\cot (\alpha) \cot (\beta)) -\tan ^{-1}\left(\frac{\cos (\beta)}{\sqrt{\sin ^2(\beta)-\cos ^2(\alpha)}}\right)\right\}+\pi  r^2 (1-\cos (\alpha)).$  Note that the solution is defined as a function of α and β. If we change the value of α and β, the area of P coated portion into A(air) will change eventually. Thus we can calculate the area for all valid condition of $\alpha$ and $\beta$.  Now consider a different situation where P and S are not equally coated rather S>P. To show that I have introduced another angle γ also $r1$ the radius of the base of the cap.   Now how can i write $z$ as an increased angle? what will be the limits of integration for a spherical cap? Is there any particular analytical solution exists to calculate the area P(grey) into A(air) as a function of $α,γ,β$?

Given a sphere of radius $r$ with two spherical caps on it defined by the radii ($a_1$ and $a_2$) of the bases of the spherical caps, given a separation of the two spherical caps by angle $\theta$, how do you calculate the surface area of that intersection?   To clarify, the area is that of the curved surface on the sphere defined by the intersection. At the extreme where both $a_1,a_2 = r$, we would be describing a spherical lune.   Alternatively define the spherical caps by the angles  $\Phi_1 = \arcsin(a_1/r)$ and $\Phi_2 = \arcsin(a_2/r)$.


I am going to apply soon for a US visa while currently being in the Schengen Zone (Germany). I am not a EU citizen but currently here on a work permit. I want to travel to US to continue my employment in the US. Currently, there is a ban on travel to US from Schengen countries. Assuming that I get my visa soon (it is not under the banned categories), what are the ways for me to fly back to US? For example, I am thinking to travelling to Croatia or Serbia, staying for 14 days in a quarantine there and then flying to US because I think I can travel to these countries with my National D Visa/Work Permit while these countries are not in the Schengen zone. What would be your advice? I am also a bit afraid of getting stuck in the e country and not being able to go back to Germany if there are some unknown rules prohibiting me from flying back to US.

I'm a European citizen living in the US on a work visa. Due to some unfortunate circumstances, I need to urgently visit my home country. However I would like to get back to the US after my visit is complete. Flying from the US to Europe is not a problem as there are still daily flights between some city pairs. However going back could be tricky, as  anyone who has been in the Schengen area in the past 14 days from re-entering the country.   Is there a flight route that would let me from Europe to some country, stay there for 14 days and then fly to the US? Canada is out, as they've banned international visitors. Mexico seems to keep their border open, but I  any direct European flights from their airports. Almost every other country either suspended flights or doesn't allow foreign nationals to enter.


I have seen this salutation written to me in an email, " Hi, -" Is this correct grammar  ?

Sometimes I see a comma after the proper name:     Hello Mr. Black,      In order to give you....   But my native language is not English and I think that the comma in this phrase should be placed before the proper name:      Hello, Mr. Black.      In order to give you....   What is the correct punctuation in English?


I’m kind of new to the game and I want to make a wizard, but I can’t understand the part of the hero’s handbook (pg.29) where it says: “Pick a number of spells from this page equal to 3 + INT”  I have 17 + 3 INT, so what do I do?

How do I determine what spells are in my spellbook when creating a character? Do I simply have a spellbook with all Pathfinder spells? Or if I'm creating a level 6 wizard, do I start knowing all level 6 spells, and then have to learn the rest as I play the game?


I need to know whether ntrights.exe 64 bit version exists?  If not, which is the 64 bit equivalent of ntrights.exe?  Thanks in advance.

What is an equivalent for ntrights.exe on Windows 7?   I need it to be able to be run from the command line.


Here's my code  public static int[] parseInt(char[] myChar) {           int[] myInt = new int[myChar.length];     for(int x = 0; x < myChar.length; x++)     {                 myInt[x] = (int)myChar[x];     }     return myInt; }   When I System.out.println(object.parseInt(myChar)); with values {'1','2','3'} I would expect it to print myInt with the corresponding unicode values for {'1','2','3'}.  Instead I get [I@15db9742  Any ideas on what I'm doing wrong?

In Java, arrays don't override toString(), so if you try to print one directly, you get the className + '@' + the hex of the  of the array, as defined by Object.toString():  int[] intArray = new int[] {1, 2, 3, 4, 5}; System.out.println(intArray);     // prints something like '[I@3343c8b3'   But usually, we'd actually want something more like [1, 2, 3, 4, 5]. What's the simplest way of doing that? Here are some example inputs and outputs:  // Array of primitives: int[] intArray = new int[] {1, 2, 3, 4, 5}; //output: [1, 2, 3, 4, 5]  // Array of object references: String[] strArray = new String[] {"John", "Mary", "Bob"}; //output: [John, Mary, Bob]


I need to track changes in network drive (Z:) using FileSystemWatcher in C#.   When I try to set the Path property of FileSystemWatcher in Wndows form application everything OK.   But when I try to do the same action in my Windows Service application I recieve an Error message in journal   "Unable to start the service. System.ArgumentException: The folder Z:\ is not allowed in System.IO.FileSystemWatcher.set_Path(String value)".    How can I fix this?

Suppose some Windows service uses code that wants mapped network drives and no UNC paths. How can I make the drive mapping available to the service's session when the service is started? Logging in as the service user and creating a persistent mapping will not establish the mapping in the context of the actual service.


I am missing a vertical line in this multirow & multicolumn table.  \begin{table}[] \centering     \caption{Example} \begin{tabular}{l||ccccc|c|c}%hier zwischen dann die breite in {\textwidth}     \hline      & \multicolumn{5}{c}{Text} & \multirow{2}{*}{Text} & \multirow{2}{*}{Text} \\      & Text & Text & Text & Text & Text & & \\     \hline     Text & 1 & 0 & 3 & - & 2 & 5 & 5 \\     \hline \end{tabular} \end{table}

I am new to Latex and I have tried to create a table but it seems not to work correctly - the vertical line is missed. Here is the code:  \begin{table*}[t]   \centering   \begin{center}    \begin{tabular}{|r|l|c|c|c|}     \hline &&\multicolumn{3}{c}{\bf Results}\\     \hline\bf Nr.& \bf Features&\bf Strict &\bf Outer &\bf Inner\\ \hline     1&Morphological F.&100.00&100.00&100.00\\     2&1 + Bla &100.00&100.00&100.00\\     3&2 + Blabla&100.00&100.00&100.00\\     4&3 + blablabla&100.00&100.00&100.00\\     5&4 + blablablabla&100.00&100.00&100.00\\     \hline    \end{tabular}   \end{center}   \caption{\label{font-table} Results. }   \label{tab:1} \end{table*}   Here is the output that I become :(    I think that something is wrong with the 5 line, but it seems I have tried everything :(


I accidentally made many queries at  (forked and generated permalinks for same query many times..) and now they are listed in "my queries" history.   How do I delete any of my made queries? There seems to be no button for that...

Is it possible to delete or at least hide your own data explorer query when you know you've only been testing something and don't want it to show?


Suppose that the series $\sum_{n=1}^{\infty} a_n$ of real terms converges absolutely and $\sum _{n=1}^\infty a_{kn}=0  ,\forall k \in \mathbb N $ , then how to prove that $a_n=0 , \forall n \in \mathbb N $ ?

Let $\sum a_{n}$ be an absolutely convergent series such that $$\sum a_{kn}=0$$ for all $k\geq 1$.   Help me prove that $a_{n}=0$ for all $n$.  Thank you!


I was playing mental maths in which we solve problems without pen and pencil.  Then I came across a problem  $$\sqrt {6 \sqrt{6 \sqrt{6\sqrt\cdots}}}.$$ I asked my teacher and he told me that the answer is $6$  I was amazed and asked how but didn't get satisfying reply.  Kindly tell me what was the reason behind my teacher's saying...      If this question is asked somewhere else, please send the link in comments  I am still amazed!!!!

Is there any trick to evaluate this or this is an approximation, I mean I am not allowed to use calculator.     $$\sqrt{7\sqrt{7\sqrt{7\sqrt{7\sqrt{7\cdots}}}}}$$


How do we we write in latex a phrase directly under another symbol. I want to get the r going to infinity directly beneath the Tilda as shown below . However am unable to do so  I tried using \sim_{\r \rightarrow \infty} but this does not work.

I have to write some equations in latex, but I'm having trouble finishing them.    My Latex equation for image 1:  \widehat{f}(x,y)=median \left\{g(s,t)\right\}     My Latex equation for image 2:  A\oplus B = U A_{b}   How can I make a subscript below the formulas?


Find all rational solutions to $x^3 - y^2 = 2$.  The only integers solutions are $(3,\pm5)$:

Reading the book by Diophantus, one may be led to consider the curves like: $y^2=x^3+1$, $y^2=x^3-1$, $y^2=x^3-2$, the first two of which are easy (after calculating some eight curves to be solved under some certain conditions, one can directly derive the ranks) to be solved, while the last , although simple enough to be solved by some elementary consideration of factorization of algebraic integers, is at present beyond my ability, as my knowledge about the topic is so far limited to some reading of the book Rational Points On Elliptic Curves, by Silverman and Tate, where he did not investigate the case where the polynomial has no visible rational points. By the theorem of Mordell, one can determine its structure of rational points, if the rank is at hand. So, according to my imagination, if some hints about how to compute ranks of elliptic curves of this kind were offered, it would certainly be appreciated. Thanks in advance.


Dementors seemed to have had some distance effects on humans - the feeling of coldness, moral depression, darkness.  Is there canon evidence that these area effects were targeted at specific individuals (or that Dementors excluded individuals from such effects)?  Or was the effect 100% determined by distance of Dementor and the individual's personal "Dementor resistance"?

Quoting from  and : From a :  Samantha: Was snape the only death eater who could produce a full patronus J.K. Rowling: Yes, because a Patronus is used against things that the Death Eaters generally generate, or fight alongside. They would not need Patronuses.  I always had the impression that just the presence of a dementor should have an effect on any human around, DE or otherwise. However, this quote makes it sound like DE's are exempt from the effect of the dementors. However, from Sirius's description in book 3, we know every prisoner in Azkaban was affected by dementors, which can further be corroborated by the fact of how much Barty Crouch, Jr. was scared of being thrown into Azkaban. Moreover, if the dementors didn't affect the DE's at all, throwing them in Azkaban wouldn't be much of a punishment either. So, Can dementors decide who to affect or not?


Not using --shell-escape sandboxes pdflatex to some degree. Still, it is perfectly possible for it to, for instance, open and read files, e.g. through \input or Tex primitives such as \read.   Is there a list of Tex primitives and LaTeX macros which, if blacklisted, will prevent pdflatex from reading or writing to files, and more generally will effectively sandbox it? I am especially interested in the case that the tikz or xymatrix packages are used.  Things like \def should presumably be blacklisted, as well as use of packages, and programming constructs like \if and \loop.  On a related note, even if one does not prevent file reading, if one blacklists ../, ~/, /etc/, /home/, and so on, is it possible to prevent pdflatex from leaving the working directory on a linux machine?

I'm building a webapp that takes latex code from users, which is then compiled serverside. Now latex creates a huge system vulnerability since it is turing complete and you can basically hack the entire system by using commands like \openin, \read, \readline or \write.  I've read the articles tagged with security, but I'm not sure yet what is necessary to make the system entirely safe. E.g. it says change the texmf.cnf file. But then in one of the comments it says:     Be aware that a malicious loop could spike the CPU indefinitely. (Dave Jarvis)   A solution for this is not presented. What can be done about this? But so my concrete question is:  Which measures are necessary to make my web page secure, when compiling user latex?


Given  public class A {  public B First { get; set; } }        public class B {  public C Second { get; set;} } public class C  {   public D Third { get; set; }   }   And somewhere in the class you have this  var testClass = new A(); //All the properties have values in it and the class D has a property value that it is holding in to the memory //testClass.B = new B(); //etc..   What happens if you did testClass = null? What does testClass's reference now to the heap? And what about D that is holding to a value that it can't collect?  EDIT: Just to clarify, given D has an event that hasn't been unsubscribed and has 10,000 handlers. What happens to testClass = null?

Is it necessary to set large objects to null when implementing a Dispose() method?


(X_train, X_test) = X[50:], X[:50]   How does the split happens here? Please provide the inner explanation.

I need a good explanation (references are a plus) on Python's slice notation.   To me, this notation needs a bit of picking up.   It looks extremely powerful, but I haven't quite got my head around it.


Ultimately I want to prove that for two random variables with cdfs F and G, with inverses $F^{-1}(t)=\inf\{x:F(x)\ge t\}$, we have $\int_{\mathbb{R}}|F(x)-G(x)|dx = \int_0^1 |F^{-1}(t)-G^{-1}(t)|dt$.  This fact seems kind of obvious to me, since we are talking about the area between the graphs.  So firstly I tried to prove that the area between bijections $f$, $g$ is the same as the area between the inverses, provided that the area is finite, and then generalise it to my problem.  I thought of doing some substitution in the integral, but I am stuck. Probably there is an easy way of showing this fact and I would appreciate any help.

Let's $X$ and $Y$ have CDF functions admitting moment of order $1$. Let's be $F$ cdf of $X$ and $G$ cdf of $Y$.  I want to show that $$\int_{\mathbb R} \mid F(x)-G(x)\mid dx = \int_{0}^{1} \mid F^{-1}(u)-G^{-1}(u)\mid du\,.$$


Give an example for a linear ordered set $\langle A, ≺_A\rangle$, such that $\langle {^2}A,≺\rangle$ is not well ordered where $$f ≺ g ↔ (∃a ∈ A)[(∀b ∈ A)(b <_A a ⇒ f(b) = g(b)) \text{ and } f(a) < g(a)].$$ My attempt: We know that $\langle A, ≤_A\rangle$ is well ordered if for every nonempty $b$ in $A$, $b$ has a minimal element with regard to $≤_A$. Hence we have to show the contrary for $\langle A2,≤\rangle$. This $A2$ (if I am not mistaking the notation) is actually $P(A)$. However I am not sure whether I should check for another element in $P(A)$, so I am stuck on this problem. Any Help is welcome.

So, to explain the title, I'm referring to the necessity of the axiom of choice in the existence of a well ordering on reals, or any uncountable set.  Now, while tweaking some sets, I came across this :  We start with the natural numbers, $N$. We take the power set of the naturals, $P(N)$.  Then we remove all the finite subsets of $N$ from $P(N)$. Let us call this new set $S$. This set is the set of all infinite subsets of $N$.  It is easy to show that $S$ has uncountable cardinality, same as that of real numbers. This is because the removal of finite subsets only removes a countable number of elements. (Haven't posted this deduction, for it is very easy, but I may post it if it is not so evident)  Now, we seek to find an ordering on the set $S$. Every set in this set is an infinite subset of natural numbers, so each of these sets are well ordered by the natural ordering of $N$.  Taking any two sets in $S$, say $A$, and $B$, we seek to order them by checking their elements lexicographically. We compare the first two elements in $A$, and $B$. Let them be $a_1$, and $b_1$ respectively. If $a_1 = b_1$, then we move on to the second elements in the sets, $a_2$, and $b_2$, and so on. If, at any point, $a_n < b_n$, then $A < B$, or if $b_n < a_n$, then $B < A$.  This order seems to be a well ordering of the uncountable infinity of reals. I don't seem to have invoked the axiom of choice anywhere in the construction of this set $S$.  So, why isn't this a well ordering on the uncountable of reals?


just to clarify.  If i wipe my ubuntu budgie hard disk, the bootloader will be removed and replaced, right?  thanks

I accidentally issued some commands I thought were safe in the terminal, and I ended up with no System Settings and lots of other missing functionality, but the OS still boots normally. I've decided I want to install Lubuntu instead of fixing Ubuntu for a fresh start and since my laptop is running on a 1GHz dual core AMD CPU.  I created a bootable USB as I usually do and placed Lubuntu 17.10 amd64 using Rufus 2.14.1086. I have GRUB that was installed with Ubuntu upon first install I still have Win8.1 which I still want to keep.  PS: I also tried creating a startup disk from Ubuntu  The question is: How can I boot from USB with GRUB2 so I can overwrite Ubuntu?


I have tried all the methods I can find on the web but nothing seems to work. I still get a 404 page. I already modified $config['index_page'] = ''; and add the lines to .htaccess as suggested by the ci documentation site. Please help. I am stressed with this for a whole day now!  these are what I put in .htaccess. I am using LAMP  RewriteEngine on RewriteCond $1 !^(index\.php|images|robots\.txt) RewriteRule ^(.*)$ /index.php/$1 [L]

This is a  about Apache's mod_rewrite.   Changing a request URL or redirecting users to a different URL than the one they originally requested is done using mod_rewrite. This includes such things as:   Changing HTTP to HTTPS (or the other way around) Changing a request to a page which no longer exist to a new replacement. Modifying a URL format (such as ?id=3433 to /id/3433 ) Presenting a different page based on the browser, based on the referrer, based on anything possible under the moon and sun. Anything you want to mess around with URL   Everything You Ever Wanted to Know about Mod_Rewrite Rules but Were Afraid to Ask!  How can I become an expert at writing mod_rewrite rules?   What is the fundamental format and structure of mod_rewrite rules? What form/flavor of regular expressions do I need to have a solid grasp of? What are the most common mistakes/pitfalls when writing rewrite rules? What is a good method for testing and verifying mod_rewrite rules? Are there SEO or performance implications of mod_rewrite rules I should be aware of? Are there common situations where mod_rewrite might seem like the right tool for the job but isn't? What are some common examples?   A place to test your rules  The  web site is a great place to play around with your rules and test them. It even shows the debug output so you can see what matched and what did not.


Is there a way to make the colors into the UV/image editor I'm not using a texture But I want to be able to export the image with the colors because I can't change them where I'm exporting it.

I have a sphere having a planet material MADE WITH NODES, and I want to convert this material into an image texture; because this material is made with nodes and only works in Blender, but I want to use in another software. This is my sphere material :   For Example : This is Jupiter :  And this is the texture :  In this case I used a downloaded image for Jupiter to be the material but I want the opposite, I want to change the material to image texture Like The shape of Jupiter texture. Is there anyway in Blender that can achieve my goal ? This is the file with my sphere material .  Textures Needed :  Albedo / Color / Diffuse Normal Map Roughness Glossines  I am using normal nodes and I am not useing the new Principled-shader


I'm not sure the above sentence is true, but I read it ,  and  that quantile loss function percentile 0.5 is MAE(mean absolute error), Is it true(Yes or No)? and How?

From the , specifically :     A forecast method that minimizes the MAE will lead to forecasts of the   median, while minimizing the RMSE will lead to forecasts of the mean   Can someone give an intuitive explanation of why minimizing the MAE leads to the forecasting the median and not the mean? And what does this means in practice?  I have asked a customer: "what is more important for you to make mean forecasts more accurate or to avoid very inaccurate forecasts?". He said that to made mean forecasts more accurate have higher priority. So, in this case, should I use MAE or RMSE? Before I read this citation I believed that MAE will be better for such condition. And now I doubt.