Let $S$ be a closed subspace of $L^1_m[0, 1]$ such that each $f\in S$ belongs to some $L^p_m[0, 1]$ with $p>1$. Prove that there exists a $p_0 > 1$ such that all $S$ is contained in $L^{p_0}_m[0,1]$.  My attempt: Since for finite measure spaces if $1\leq p\leq q<\infty$, $L_q\subseteq L_p$. So we can take the infimum of all such $p$. But I am not sure how to use the closeness or completeness of $S$ to say that the infimum is strictly greater than $1$.  And what is the counterexample when $S$ is not closed?

Let $X \subset L^1(\mathbb{R})$ a closed linear subspace satisfying \begin{align} X\subset \bigcup_{p>1} L^p(\mathbb{R})\end{align}    Show that $X\subset L^{p_0}(\mathbb{R})$ for some $p_0>1.$   I guess the problem is that in infinite measure spaces the inclusion $L^p\subset L^q$ only holds for $p=q$. Is it maybe possbile to apply Baire's Theorem in some way?


I know that color comes from things not absorbing a certain wavelength of light, but what property gives something color? Like what property of copper atoms makes copper as a whole brown, or cobalt blue? Is there a solid states physics explanation for where color arises from microscopically in different materials?

I understand that light (color) is part of the electromagnetic spectrum, and that it depends on what wavelengths are reflected/absorbed. Though what property of an individual atom gives it its color? Do electrons, neutrons, and other subatomic particles have color?  Basically: What intrinsic property causes the differences between how the varying wavelengths of light are reflected at the atomic scale? Also, how do photons factor into this?


I have Ubuntu 16.04. I cannot see any wifi enabling option. I have selected the Broadcom driver in software and update, and the Wi-Fi switch is enabled in the BIOS.  I've looked through the help pages and run the following:  $ sudo lshw -C network   *-network                       description: Network controller        product: BCM4311 802.11b/g WLAN        vendor: Broadcom Corporation        physical id: 0        bus info: pci@0000:0b:00.0        version: 01        width: 32 bits        clock: 33MHz        capabilities: pm msi pciexpress bus_master cap_list        configuration: driver=b43-pci-bridge latency=0        resources: irq:16 memory:efdfc000-efdfffff   *-network        description: Ethernet interface        product: BCM4401-B0 100Base-TX        vendor: Broadcom Corporation        physical id: 0        bus info: pci@0000:03:00.0        logical name: eth0        version: 02        serial: 00:1d:09:b6:10:83        size: 100Mbit/s        capacity: 100Mbit/s        width: 32 bits        clock: 33MHz        capabilities: pm bus_master cap_list ethernet physical mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation        configuration: autonegotiation=on broadcast=yes driver=b44 driverversion=2.0 duplex=full ip=192.168.1.135 latency=64 link=yes multicast=yes port=twisted pair speed=100Mbit/s        resources: irq:17 memory:ef9fe000-ef9fffff*   What should I do?  $ lspci -knn | grep Net -A3; rfkill list 0b:00.0 Network controller [0280]: Broadcom Limited BCM4311 802.11b/g WLAN [14e4:4311] (rev 01)     Subsystem: Dell Wireless 1390 WLAN Mini-Card [1028:0007]     Kernel driver in use: b43-pci-bridge     Kernel modules: ssb, wl

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.


There's this test   The relevant part is:     I have visited so many beautiful places since I (come) to Utah.   Apparently it's more natural to say verb in a Past Simple after "since":  "since i came" = 40,900,000 results  "since i've come" = 8,830,000 results  But is this grammatically incorrect to make it Present Perfect?  The rule says:     We use the Present Perfect to say that an action happened at an unspecified time before now. The exact time is not important. You CANNOT use the Present Perfect with specific time expressions such as: yesterday, one year ago, last week, when I was a child, when I lived in Japan, at that moment, that day, one day, etc. We CAN use the Present Perfect with unspecific expressions such as: ever, never, once, many times, several times, before, so far, already, yet, etc.   Does the word "since" make a time specific?

Sometimes I hear people say something like the example below. Is it correct to use the word since in this manner?     Mosquitoes are surviving on earth since millions of years.


I am working on a requirement to display a PDF that is returned from an external application. I've written the Apex class that will authenticate and then return the PDF document in a HTTP Get response. Given these documents contain sensitive information, we do not want to store the PDF in Salesforce (e.g. create a ContentVersion or File record using the PDF). Also, if viewing from the Salesforce mobile app, we want to avoid users' being able to open the PDF in other apps or downloading them. I've started my approach of using a Lighting Web Component that will call the Apex class to return the PDF. However, I'm not sure this is a viable option to continue to pursue. I've read about the PDF.js library, as well as many examples posted online for LWC or Aura Components. Plenty of them rely on the document being stored in Salesforce, or are Aura Components instead of LWC. We are in Lightning and would need a working approach for Desktop too. Preferably, I'd be able to use the same component for both desktop and mobile, and not have to pursue different frameworks for each device type (i.e. Aura for mobile and LWC for desktop). What approach would be recommended for this? I'm not certain a Lightning Web Component is going to work. Should I double back to Aura Components? Pursue embedding a Visualforce page as PDF? I have limited time so I want to avoid building something then learning I won't be able to meet one of the requirements outlined above. This older question was answered before Lightning Web Components existed:  The answers are limited to using Aura Components. Here is an explanation which highlights differences between Aura and LWC:

I need to view/generate PDF in Lightning component. How can I achieve that?  Do I have to user VF page with "renderAs" attribute inside Lightning Component? Or is there any other way to achieve this?


There was water spilled on my MacBook Air but I replaced the internal speakers. Now the sound is not working at all. No internal speaker or microphone is showing up and also the sound does not work with headphones plugged in. Tried reinstalling software, resetting NVRAM, and SMC. When running system_profiler SPAudioDataType I get Jakes-MacBook-Air:~ jakemacbook$ system_profiler SPAudioDataType  Audio:     Devices:  Does anyone have an idea of how to fix this or what I have to replace?

Sadly, yesterday I've spilled some water on my MacBook Pro (El Capitan). Before you yell at me - it was closed, turned off and it wasn't a lot of water, the laptop was wet only on the top and under - not inside.  Today I've turned him on. At first battery wasn't recharging for some reason, but SMC reset fixed the problem.  At the first booting speaker was like talking to me, hard to explain but it was weird. Also only right speaker was "talking", despite the fact that only left side of the laptop was watered. Then there was no sound at all, not from the speakers, nor from the headphones. Also microphone's not working. USB ports are okay. The water was spilled from the left side of the laptop. I know this is hardware issue, and something's broken, but I want to be 100% sure. No it's not muted. I've also tried NVRAM reset a few times, but it doesn't fix the problem :(  There might be one factor, before spilling, my laptop "died" for the first time (battery energy ran off), but I doubt it's the case. (but hey, every info matters, right?)  It wouldn't be weird for me, if only left speaker wouldn't work, but built-in microphone not working is kinda weird in this case, isn't it?  I just want to ask you guys, what else can I check, before I'll be 100% sure it's dead inside?  I've plugged in external microphone - it's not working too.


I want to know how to secure a php file that has the database connect passwords  (info).   Currently I have just saved the file as connect.php because it is stored locally but now I need to upload the application and make it live.

When a PHP application makes a database connection it of course generally needs to pass a login and password. If I'm using a single, minimum-permission login for my application, then the PHP needs to know that login and password somewhere. What is the best way to secure that password? It seems like just writing it in the PHP code isn't a good idea.


This may be a stupid question, but I want to check the source code of the default Ubuntu installer program . I can't seem to find it, and I assume it is easier if I know the name of the program.

Sorry if somebody has already asked this question, I haven't found anything else.   When you install Ubuntu, some sort of program is run, like where you set different options for your OS installation.  Does anyone know what the software is being run?  Thanks.


Is this possible? I was planning to just import my SD card and import that way, but somehow the files got deleted off my card. I am able to drag the pictures from "Photos" (Mac) onto my desktop and go via that route, but then they are jpegs instead of RAW files.

I recently purchased a new camera to start my photography hobby. I have an SD card that I put into my Macbook Pro, and was able to easily import pictures from it into Lightroom.   This didn't work, however, because the pictures remained on the SD card and upon removing it the photo links were all broken in Lightroom.  I decided to, instead, import them to the new Photos app with the intent to then import them from there to Lightroom, but there seems to be no option to do this and I can't find the pictures from within Lightroom.  The images are visible in the Photos app, however, so they're definitely on the Mac.  I'm new to Lightroom and new to the Macbook, so I'm convinced that this is user error but I don't know what I'm doing wrong. I just want to get the pictures off my SD card, onto the Macbook and editable within Lightroom. How do I do that?  EDIT  I'm using Lightroom CC. I read something once about installing an addon within Lightroom but the option wasn't there because Creative Cloud is apparently slightly different from the older versions?


This question came up in my class. For $X$ and $Y$ path connected, if $X$ and $Y$ are homotopy equivalent, are there base points $x \in X$ and $y \in Y$ such that $(X,x) $ is homotopy equivalent to $(Y,y)$? It is indeed true that if $X$ and $Y$ are homotopy equivalent, then $\pi(X,x) \cong \pi(Y,y)$ for any choice of basepoint $x \in X$ and $y \in Y$. But is it true that we can find basepoints so that $(X,x) \simeq (Y,y)$? Note that if $X$ is not path connected, we can pick a space that is contractible but not pointed-contractible to any of its point. More generally, is it true that if we have a homotopy $f,g \colon X \rightarrow Y$, can we find a based homotopy $f,g \colon (X,x) \rightarrow (Y,y)$? Thanks! EDIT: found a question that answers this question:

Let $(X,x)$ and $(Y,y)$ be path-connected pointed topological spaces.  Is it true that the statement  ''$X$ and $Y$ are homotopy equivalent''  implies  ''$(X,x)$ and $(Y,y)$ are homotopy equivalent as pointed spaces''? How can I prove this?  A pointed homotopy equivalence is a homotopy equivalence where the two involved homotopies are constant on the basepoints at every ''time''.


STATEMENT: Suppose that $≺$ is a partial ordering of $\mathbb{N}$. Use the Compactness Theorem for first order logic to show that there is a total ordering $≺_∗$ of $\mathbb{N}$ such that for all n and m in $\mathbb{N}$,if $n≺m$ then $n≺_∗ m.$  QUESTION: I am unsure of how to proceed with this type of problem. My guess was to create a set of sentences such that $(\forall m,n\in \mathbb{N}(n≺m \rightarrow n≺_∗ m)$ union with another set of sentences $(\forall m,n\in \mathbb{N}((m\not≺ n) \wedge (\forall k\in\mathbb{N}(k≺m\rightarrow k≺n))\rightarrow m≺_*n).$ Then showing that each finite subset is satisfiable means that our set of sentences has a model $(\mathbb{N},≺_*)$.

How do I show that every partial order can be extended to a linear ordering?      I think that I manage to prove that claim for finite set, how can I prove it for infinite set?  Thank you.


Today I ran into a irrecoverable problem by accidentally formatting my ubuntu drive, In future I don't want to face these kinda problems, So how can I have a clone of my OS (I mean with all the software I installed) so that if i run into a problem I can just somehow use the clone to get back my OS ? BTW in another post someone mentioned Remastersys , but their website says that the software will no longer be available.  any related tips also might help.

I'm a new Linux user. I've reinstalled my Wubi from scratch at least ten times the last few weeks because while getting the system up and running (drivers, , etc.) I've broken something (X, grub, unknowns) and I can't get it back to work. Especially for a newbie like me, it's easier (and much faster) to just reinstall the whole shebang than try to troubleshoot several layers of failed "fixing" attempts. Coming from Windows, I expect that there is some "disk image" utility that I can run to make a snapshot of my Linux install (and of the boot partition!!) before I meddle with stuff. Then, after I've foobar'ed my machine, I would somehow restore my machine back to that working snapshot. What's the Linux equivalent of Windows disk imagers like  or ?  Note: I found a similar question:


I want to encrypt my WPF code so when I open the EXE file with softwares like 'ILSpy' or 'IL Disassembler' I couldn't see the code.  I don't want to use with any existing software but to write the encryption myself.  Who can give me a simple code which does it? (Do I need to use the 'System.Security.Cryptography' namespace?)  Thanks...

I have an encryption/copy protection question.  I'm writing an application for a company that uses a dongle.  Please don't tell me that software protection is useless, or that I should just let it fly free into the air, or that any time I spend doing this is a waste; this isn't a philosophical question about the validity of software protection, more like a how-to.  As I understand it, the first step in cracking a dongle-protected piece of software is to remove all the calls to the dongle from the code (ie, patch the executable).  Also as I understand it, I can create 'strong names' in .NET in order to protect the application and the assembly, as explained .  Is strong naming enough to ensure that my application can't be easily patched?  Or do I need to use some sort of encryption library?  If I need to use a library, which one, or where can I get information about setting this up?  The next step, of course, is to put important algorithms on the dongle.  I realize that these are just speed bumps to the dedicated cracker, but as our market share grows, the speed bump will help us get to the point where the sting of piracy is not so keenly felt (I hope).  Thanks!


When I am running sudo apt-get -f install, it shows dpkg: error processing. Please find the complete logs below and advise how to solve this. Should I remove the old version?      Reading package lists... Done     Building dependency tree            Reading state information... Done     Correcting dependencies... Done     The following additional packages will be installed:       cuda-cublas-9-1     The following packages will be upgraded:       cuda-cublas-9-1     1 upgraded, 0 newly installed, 0 to remove and 553 not upgraded.     1 not fully installed or removed.     Need to get 50.1 MB of archives.     After this operation, 56.2 MB of additional disk space will be used.     Do you want to continue? [Y/n] y     Get:1 http://developer.download.nvidia.com/compute/cuda/repos/ubuntu1604/x86_64  cuda-cublas-9-1 9.1.85.3-1 [50.1 MB]     Fetched 50.1 MB in 21s (2,313 kB/s)                                                 (Reading database ... 415420 files and directories currently installed.)     Preparing to unpack .../cuda-cublas-9-1_9.1.85.3-1_amd64.deb ...     Unpacking cuda-cublas-9-1 (9.1.85.3-1) over (9.1.85-1) ...     dpkg: error processing archive /var/cache/apt/archives/cuda-cublas-9-1_9.1.85.3-1_amd64.deb (--unpack):      trying to overwrite '/usr/local/cuda-9.1/lib64', which is also in package cuda-cudart-9-1 9.1.85-1     Errors were encountered while processing:      /var/cache/apt/archives/cuda-cublas-9-1_9.1.85.3-1_amd64.deb     E: Sub-process /usr/bin/dpkg returned an error code (1)

For example:  $ sudo apt-get install curl Reading package lists... Done Building dependency tree Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies: bsh : Depends: libjline-java but it is not going to be installed groovy : Depends: libjline-java but it is not going to be installed rhino : Depends: libjline-java but it is not going to be installed E: Unmet dependencies.   Try 'apt-get -f install' with no packages (or specify a solution).   I get the same or similar errors when I attempt to install clojure1.3, leiningen, and several other packages.   When I try the suggestion made in the error message, this is what happens:  $ sudo apt-get -f install  Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following packages were automatically installed and are no longer required:   diffstat linux-headers-3.2.0-26-generic linux-headers-3.2.0-26 dh-apparmor dkms html2text libmail-sendmail-perl libsys-hostname-long-perl Use 'apt-get autoremove' to remove them. The following extra packages will be installed:   libjline-java Suggested packages:   libjline-java-doc The following NEW packages will be installed:   libjline-java 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. 23 not fully installed or removed. Need to get 0 B/72.0 kB of archives. After this operation, 129 kB of additional disk space will be used. Do you want to continue [Y/n]? Y (Reading database ... 226243 files and directories currently installed.) Unpacking libjline-java (from .../libjline-java_1.0-1_all.deb) ... dpkg: error processing /var/cache/apt/archives/libjline-java_1.0-1_all.deb (--unpack):  trying to overwrite '/usr/share/java/jline.jar', which is also in package scala 2.9.2-400 Errors were encountered while processing:  /var/cache/apt/archives/libjline-java_1.0-1_all.deb E: Sub-process /usr/bin/dpkg returned an error code (1)  $ sudo apt-get upgrade Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these. The following packages have unmet dependencies:  bsh : Depends: libjline-java but it is not installed  groovy : Depends: libjline-java but it is not installed  rhino : Depends: libjline-java but it is not installed E: Unmet dependencies. Try using -f.


The question is to show $$ xyz>(-x+y+z)(x-y+z)(x+y-z) $$ where $x$, $y$ and $z$ are distinct and strictly positive. My attempt: Let, $$ \begin{aligned} -x+y+z &= a \\ x-y+z &= b \\ x+y-z &= c \end{aligned} $$ Clearly, $$ x=\frac{b+c}{2} \text{ , } y=\frac{c+a}{2} \text{ , } z=\frac{a+b}{2} $$ Therefore, $$ \begin{aligned} xyz=\frac{(a+b)(b+c)(c+a)}{8} &= \frac{a^2(b+c)+b^2(c+a)+c^2(a+b)+2abc}{8} \\ \implies 8xyz-2abc &= a^2(b+c)+b^2(c+a)+c^2(a+b) \end{aligned} $$ Now, for all $a,b,c>0$, we can easily prove that $$ \begin{aligned} a^2(b+c)+b^2(c+a)+c^2(a+b) &> 6abc \\ \implies 8xyz-2abc &> 6abc \\ \implies 8xyz &> 8abc \end{aligned} $$ But it is also possible that at most one of the $a$, $b$ or $c$ could be negative, in which case, it is quite obvious that $xyz>abc$. My question: Is there a more concise way to prove this?

Let $a,b,c\in\mathbb{R}^*_+$, $abc=1$.  How can i show that $\left(a-1+\frac{1}b\right)\left(b-1+\frac{1}c\right)\left(c-1+\frac{1}a\right)\leq1$ ?  I got $\left(ab-b+1\right)\left(bc-c+1\right)\left(ca-a+1\right)\leq abc=1$, but i can't go any further ...  If i expand it :   $2-ab-\frac{b}a-c-ac-\frac{a}c-b+2a+\frac{2}a-bc-\frac{c}b-a+2b+\frac{2}b+2c+\frac{2}c-4$  Which gives using $c=\frac{1}{ab}$ :   $5ab-\frac{b}a-\frac{1}{ab}-a^2b+\frac{1}a+b+\frac{1}b-2$


When you dual-wield or multiattack somebody who can't see you, are both/all attacks with advantage? We are using facing rules, so attacking silently from behind is a common situation I expect to bring this up.  To clarify, I'm not talking about sneak attack here. I know that you can only sneak once per turn. I'm just wondering if I jump somebody from the shadows and I hit them with multiple attacks, if they are all with advantage. Are they?  If advantage is denied on second attack because the opponent wouldn't be unaware anymore, or would turn and defend, does losing advantage happen even in case the first attack (with advantage) missed?

A hidden ranger with Extra Attack attacks a surprised creature. Do both attacks benefit from Advantage, or just the first one?  If the ranger used Horde Breaker on another creature, would this attack benefit from Advantage?


I copied personal files to ubuntu live home directory usb. with intention of transferring to another pc. but files seem to be lost. how can i recover these files

I have created an Ubuntu16.04 'Persistent Pendrive' which was working perfectly for about a month, but now it seems to be running out of space.  Specifically: I used the information in , see also , to create my Pendrive on a SanDisk 32GbUltra Flair and I've used it to run apache and php as a mini development server on various hardware.  However - I'm now getting 'out of space' errors when I try to run sudu apt-get update.  I was under the impression that any new software or changes would be applied to the persistent partition, not the OS partition.  I'm happy enough to start again, but has anyone else had this, or know how to prevent it?


Recently I started investigating what can I do to protect the app we develop from hacking it. We agreed that we will use local License Server (without internet connection) + Machine HW Lock. I found a lot of tools that are capable of doing this. I'm not searching here for a recommendation for a tool to use, but rather I want to know what kind of features I should expect there.  Our company really worried about guys who tries to crack the software (they had a lot of problems around that in the past), but this is the first .Net app in our company, which has a lot of specifics.  For me to check the license in my app with the tools I investigated so far, I need to insert single call to this library that checks the license in the code. Theoretically this call can be removed. Of course the app will be obfuscated and it will be really hard to do that, but I guess it is still possible. There is also an option for a cracker to substitute the tool with the dummy dll that does nothing.   Should I be worried about that? And what solutions do I have if I should?

Obfuscation is one way, but it can't protect from breaking the piracy protection security of the application. How do I make sure that the application is not tampered with, and how do I make sure that the registration mechanism can't be reverse engineered?  Also it is possible to convert a C# application to native code, and  is too costly.  C# provides lot of features, and is the ideal language for my code, so writing the whole codebase again in C++ is out of the question.  Secure certificates can be easily removed from the signed assemblies in .NET.


Prove that  $(n-r)!(r!)$ divides $ n! $ i know its a factorial formula and it might be easy but i stuck .I tried induction to $n$ or analyzing the factorials but im missing something

Is there a simple way to show that $$n!\over r!(n-r)!$$ is always an integer?


The propositions are given as below.  P: Grizzly bears have been seen in the area. Q:Hiking is safe on the trail. R:Berries are ripe along the trail.   Now tell me, what will be the logical expression of this, and why:  "If berries are ripe along the trail, hiking is safe if and  only if grizzly bears have not been seen in the area."  The problem is from the book "discrete mathematics and its application" by Keeneth H.Rosen page no.17 in its sixth edition.   Now I had tried to do myself. And I finished with $((R\rightarrow Q)\leftrightarrow(\neg P))$. But in my book the ans was  $(R\rightarrow(Q\leftrightarrow(\neg P)))$, but I can't understand why this is the answer. I think the answer should be $((R\rightarrow Q)\leftrightarrow(\neg P))$ because $\rightarrow$ has precedence over $\leftrightarrow$.  Could anyone please tell me what is the right answer is and why.

I came across this question:  Let p, q, and r be the propositions  p : Grizzly bears have been seen in the area. q : Hiking is safe on the trail. r : Berries are ripe along the trail. Write these propositions using p, q, and r and logical connectives (including negations).     If berries are ripe along the trail, hiking is safe if and   only if grizzly bears have not been seen in the area.   I see an If r,q iff ~p where If r,q is the part "If berries are ripe along the trail, hiking is safe" and ~p is "grizzly bears have not been seen in the area"  and I came up with (r -> q) <-> ~p  But the answer given is: r -> (q <-> ~p)  Can someone please explain the difference in precedence?


I have following code, I am not able to understand the difference between use of fit_transform() and transform() method in this case.  In the following code, when I am using fit_transform(X_valid) instead of transform(X_valid) it gives me different outputs.   from sklearn.impute import SimpleImputer  # Imputation my_imputer = SimpleImputer() imputed_X_train = pd.DataFrame(my_imputer.fit_transform(X_train)) imputed_X_valid = pd.DataFrame(my_imputer.transform(X_valid))

I'm a newbie to data science, and I do not understand the difference between the fit and fit_transform methods in scikit-learn. Can anybody explain simply why we might need to transform data? What does it mean, fitting a model on training data and transforming to test data? Does it mean, for example, converting categorical variables into numbers in training and transforming the new feature set onto test data?


We are given four positive real numbers $a,b,c,d$. I would like to prove that $$\frac ab+\frac bc+\frac cd+\frac da\ge4$$ To start solving this I assumed $$a\ge b\ge c\ge d$$ Therefore $$\frac ab,\frac bc,\frac cd\ge 1,\ \frac da\le 1$$ and the last one is causing the problem.

Prove that, $\dfrac{a}{b}+\dfrac{b}{c}+\dfrac{c}{d}+\dfrac{d}{a}\ge 4$ where we do not use AM-GM inequality on the given statement to prove it. Typically, I am actually looking for a little advanced and elegant solution.    EDIT: $a,b,c,d>0$


Some friends and I were having a discussion about the death of characters. What happens to effects when a character dies? I searched but haven't found anything really concrete except for attunement is broken upon death. Physical things that affect the body such as poisons would persist, but what about magical effects. What about a curse placed on a person, or the invisibility spell, or even insanity and other conditions?  This is with the idea of the different resurrections as well, as the more powerful versions restore and cure more.

In a , I mentioned the possibility of killing a character and restoring them to life as a possible method of removing conditions from them. On reflection, I have no idea whether this works or not, and I can't find anything in my books to prove or disprove it.  Are some or all conditions removed when a character dies? If the answer is some, which ones?


Suppose I am writing to a friend, asking if he remembers a certain question I asked him.  Do any of the following sentences correctly use the question mark?  Do you remember when I asked you "do you know the time"? Do you remember when I asked you "do you know the time?" Do you remember when I asked you "do you know the time?"?  Less specifically, what is the general rule that can be applied to such a situation?

If my sentence is a question and ends with a quote of a question, where exactly do I put a question mark?   Did she ask, "Is it raining"?  Did she ask, "Is it raining?"?  Did she ask, "Is it raining?"


A scenario of this would be something like a domain called domain.com has a mailserver set up that forwards all email sent to info@domain.com to person@gmail.com. If someone sends a lot of spam to info@domain.com, is my mailserver at domain.com at risk of being blacklisted?  Note: I do not intend to spam, I just want to know if my server would be at risk.

I've installed Postfix on Ubuntu 14.04 with the defaults. I then configured some virtual aliases to forward email from a few addresses to various personal (mostly Gmail) accounts. This is just to make these addresses all connect cosmetically to the domain on the website we are hosting.   Unfortunately, in a short amount of time Gmail has started rate blocking the forwarded emails due to spam. Apparently, Postfix is rewriting the headers in a way that makes Gmail think all the spam is originating with our server. Google  for information on how to best forward to them.  In it, they say:     We recommend that you do not change the envelope sender when   forwarding email to Gmail. Sometimes, when forwarding email, the   envelope sender gets changed to your domain. When this happens, Gmail   may learn that your domain is sending spam, and will treat other   emails from this domain as spam as well.   This make sense, but it would still seem that Gmail would have to see the IP and hostname of our mail server and register it as a source of spam. But this is what they say and I've found nothing on point anywhere.   I even tried using Mailgun to filter the forwards as they provide spam blocking, but within a day they deactivated the domain and are being rather slow to respond to my inquiries. Any help is appreciated. I would like to avoid a full fledged mail server setup just to handle a few rarely used forwards.  Update: My original assumption was incorrect in that Postfix is not rewriting the headers, however the original issue remains. Gmail is rate limiting forwards due to excessive spam. It would be understandable if they limited the servers that are actually sending the email, and these are listed in the headers as part of the delivery chain.


This question stems from .   Does a shield count as "armor" with regard to the proficiency requirements listed under Armor Proficieny?

PHB describes the downsides of wearing an armor you are not proficient with:     Armor Proficiency.   Your class gives you proficiency with certain types of armor. If you wear armor that you lack proficiency with, you have disadvantage on any ability check, saving throw, or attack roll that involves Strength or Dexterity, and you can’t cast spells.   However, .   The Spellcasting chapter says about armor explicitly, and not shields:     Casting in Armor   Because of the mental focus and precise gestures required   for spellcasting, you must be proficient with the armor you   are wearing to cast a spell. You are otherwise too distracted   and physically hampered by your armor for spellcasting.   It seems . What exactly are the downsides of not being proficient with shields?


Why do radio waves, X-ray and gamma rays penetrate through matter? Can anyone explain me this in terms of incident energy or wavelength of the photon and the effective cross-section that these photons face while interacting with matter. I want to understand the physical process by which this cross section is low for X rays and gamma rays.  Also why is the probability of knocking an electron out of K shell by X rays is high?

and they are on opposite ends of the electromagnetic spectrum, then why can't light travel through walls which is right in the middle of the spectrum?    This question has already been asked . However, I am not entirely satisfied by the answer given on that page which relies on fanciful analogies and metaphors of ants, elephants etc. I am looking for a better explanation.    I think the crux of the matter, and my dilemma, relates to formula for . This is a well known formula used to explain the fact that low frequency waves have more penetration than high frequency waves.     But then how come gamma waves have such high penetration?     Are there some assumptions behind derivation of this formula which break when we consider very high frequency waves?    Or, are there some new factors that need to be taken into account as we move into the high frequency regime?     If given a radio source and a gamma source of equal intensity, then will the radio source have more penetrability than the gamma source per formula for ? If not, why not?  Thanks for all those who posted answers to this question. The answer being proposed is that light waves have the right energy to interact with atoms and electrons in the matter and thus get absorbed. This is a quantum mechanical explanation. The skin depth, on the other hand, is derived purely on basis of classical electrodynamics. So I see there are two mechanisms at work here? Does anyone agree with this? If so, the net absorption will be the sum of absorption due to skin effect + absorption due to atomic physics. Now if we take gamma rays - agreed there will be no absorption due to atomic physics but there should be absorption in accordance with skin effect. And so I come back to original problem.


grub shows that there is Windows, but when I click on it, it showing me a black screen with a dash at top-left; and then sending me back to grub what can I do? please help !!!

I did dual boot with Windows 7 & Ubuntu 14.04. I get both in boot menu but can't boot into Windows 7. The primary drive where Windows 7 was configured now shows to be logical drive with all files in it. How to resolve it ?  This is what it shows:  irshad@irshad-desktop:~$ lsblk NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT sda      8:0    0 465.8G  0 disk      ├─sda1   8:1    0  58.6G  0 part /media/irshad/B2E08E69E08E339F     ├─sda2   8:2    0     1K  0 part      ├─sda5   8:5    0 195.3G  0 part /media/irshad/8E90A6A690A6946D     ├─sda6   8:6    0 182.8G  0 part /media/irshad/7650B08250B04B1F    ├─sda7   8:7    0    25G  0 part /    └─sda8   8:8    0     4G  0 part      sr0     11:0    1  1024M  0 rom     I tried to run update-grub but I get the following result.  $ sudo update-grub  Generating grub configuration file ...  /etc/grub.d/06_custom: 31: /etc/grub.d/06_custom: function: not found  /etc/grub.d/06_custom: 34: /etc/grub.d/06_custom: save_env: not found  /etc/grub.d/06_custom: 36: /etc/grub.d/06_custom: Syntax error: "}" unexpected


I've been researching how to find the owner phone number of a iOS device, but with no luck. There are post all around showing thirdparty frameworks that allow to do that, but are rejected from Apple.   In my app I'm accessing to the AddressBook Contact and getting all phone contacts, with Name and Phone. In my case (with my iPhone, I didn't test in other iPhones) I can see my own number listed with the rest of contacts. Is there a way to find out/flag or recognize a contact as owner of the iPhone?  Here my Code:  ABAddressBookRef addressBookRef = ABAddressBookCreateWithOptions(NULL, NULL);      if (ABAddressBookGetAuthorizationStatus() == kABAuthorizationStatusNotDetermined) {         ABAddressBookRequestAccessWithCompletion(addressBookRef, ^(bool granted, CFErrorRef error) {             ABAddressBookRef addressBook = ABAddressBookCreate( );         });     }     else if (ABAddressBookGetAuthorizationStatus() == kABAuthorizationStatusAuthorized) {   CFErrorRef *error = NULL;         ABAddressBookRef addressBook = ABAddressBookCreateWithOptions(NULL, error);         CFArrayRef allPeople = ABAddressBookCopyArrayOfAllPeople(addressBook);         CFIndex numberOfPeople = ABAddressBookGetPersonCount(addressBook);          for(int i = 0; i < numberOfPeople; i++) {              ABRecordRef person = CFArrayGetValueAtIndex( allPeople, i );               NSString *firstName = (__bridge NSString *)(ABRecordCopyValue(person, kABPersonFirstNameProperty));              NSString *lastName = (__bridge NSString *)(ABRecordCopyValue(person, kABPersonLastNameProperty));                NSLog(@"Name:%@ Surname: %@", firstName, lastName);               ABMultiValueRef phones = ABRecordCopyValue(person, kABPersonPhoneProperty);              for(CFIndex j = 0; j < ABMultiValueGetCount(phones); j++)             {                 CFStringRef phoneNumberRef = ABMultiValueCopyValueAtIndex(phones, j);                 CFStringRef locLabel = ABMultiValueCopyLabelAtIndex(phones, j);                 NSString *phoneLabel =(__bridge NSString*) ABAddressBookCopyLocalizedLabel(locLabel);                  NSString *phoneNumber = (__bridge NSString *)phoneNumberRef;                 CFRelease(phoneNumberRef);                 CFRelease(locLabel);                 NSLog(@" - %@ (%@)", phoneNumber, phoneLabel);              }          }

Is there any way to get own phone number by standard APIs from iPhone SDK?


Hello fellow users of this forum:  Show that for any orthogonal matrix Q, either det(Q)=1 or -1.  Thanks

Looking for elementary proof for $\rm~det(\textbf{P})$ = $\pm 1$ if $P$ is an orthogonal matrix.  I prefer a proof without using determinant of transpose matrix. My First Proof, with $\det(\textbf{P}^{t}) = \det(\textbf{P})$ If $P$ is orthogonal matrix,  $\textbf{P}^{t}=\textbf{P}^{-1}$. So, $$\det(\textbf{P}^{t}\textbf{P})=\det(\textbf{I}) \implies \det(\textbf{P}^{t}\textbf{P}) = 1 \implies \det(\textbf{P}^{t}) \det(\textbf{P}) = 1$$ because $ \det(\textbf{P}^{t}) = \det(\textbf{P})$. Therefore, $\det(\textbf{P}^{t})=\det(\textbf{P}) = \pm 1$. My Second Proof,  without $\det(\textbf{P}^{t}) = \det(\textbf{P})$ Let $\lambda$ be an eigenvalue for orthogonal matrix $\textbf{P}$. $$\textbf{P}\vec{v}=\lambda\vec{v},\quad\vec{v} \neq \vec{0}$$ $$\implies \rVert \textbf{P}\vec{v}\lVert = \lVert \lambda\vec{v} \lVert \implies \rVert \textbf{P}\vec{v} \lVert = \rvert \lambda \ \lvert \lVert \vec{v} \rVert = 1$$ because $\lVert \vec{v} \rVert = 1$ Therefore $\lvert \lambda \rvert = 1$ because $\textbf{P}$   is orthonormal matrix. $$\textbf{P} = \textbf{P}^{t}$$ Therefore $\textbf{P} = \textbf{U}^{t}\Lambda\textbf{U} $ $$\det(\textbf{U}^{t}\Lambda\textbf{U}) = \det(\textbf{U}^{t})\det(\Lambda)\det(\textbf{U})$$ $$\det(\textbf{U}^{t}\Lambda\textbf{U}) = \det(\textbf{U}^{t})\det(\textbf{U})\det(\Lambda)$$ $$\det(\textbf{U}^{t})\det(\textbf{U}) = 1 $$ (because $\textbf{U}$ is orthogonal matrix}) $$\det(\textbf{P}) = \det(\textbf{U}^{t}\Lambda\textbf{U}) = \det(\Lambda) = \prod_{i=1}^{n}\lambda_i = \pm 1 $$ $$\implies \det(\textbf{P}) = \pm 1$$


A friend, after attending a talk recently discussing relativistic and other time-like notions, pondered on this question:  "Given the fact that much of the talks I attended discussed at length how there is no "universal now" and that, potentially, describing time as a line is functionally inaccurate - what does the quoted figure of 13.8 billion years (for the age of the universe) represent?"  This seems to me to be an extremely interesting question - he hypothesised that their figure was, in a sense, an upper-bound for all objects' world-lines, i.e. that there exists no object that has percieved the passing of more than 13.8 billion years.   How do we resolve the question? Is his hypothesis correct?  Remark: While there may have been similar questions before, I do not consider them duplicates as these issues - i.e. explicitly giving explanations as to the meaning behind the "13.8 billion" figure - were not discussed thoroughly or in any meaningful way, such as , where almost nothing is discussed beyond the statement of an unexplained equation which almost certainly resolved nothing for the OP.

Many times I have read statements like, "the age of the universe is 14 billion years" . For example this wikipedia page .   Now, my question is, which observers' are these time intervals? According to whom 14 billion years?


I have the following result:  The set $\{\mathbf{v}_1,...,\mathbf{v}_n\}$ is linearly dependent if and only if some $\mathbf{v}_i$ is a linear combination of its predecessors. That is, $\mathbf{v}_i \in$ span$\{\mathbf{v}_1,...,\mathbf{v}_{i-1}\}$ for some $i \in \{1,...,n\}$  I was curious what happens in the case where $\mathbf{v}_1$ is the zero vector and $\mathbf{v}_2,...,\mathbf{v}_n$ are linearly independent. This set is linearly dependent and I think you can say the second sentence in the above statement is true since the predecessors of $\mathbf{v}_1$ is the empty set and the span of the empty set is the zero vector. But I'm unsure about the first sentence. Can you have a linear combination of the empty set?

Why is the span of the empty set defined to be $\{0\}$? It is known that the span of any nonempty set of vectors in a vector space $V$, gives a subspace of $V$, and it is stated in “Linear Algebra Done Right” by Axler, that to be consistent with this, the span of the empty set is defined to be $\{0\}$? Is this the only reason or does this definition prove useful in other ways later on?


I want to implement setLocationSource() to handle the battery High of use, i tried from the  and search for samples , but i get NullPointerException on   mMap.setLocationSource(this);   what am i missing..  I have long code..this is just related code i display..not all code.  public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,         GoogleApiClient.ConnectionCallbacks,         GoogleApiClient.OnConnectionFailedListener,         LocationSource,         LocationListener { and so on...   ..  private OnLocationChangedListener mMapLocationListener; private GoogleMap mMap;   ...      @Override         public void onMapReady(final GoogleMap googleMap) {             if (mGoogleApiClient == null) {                 buildGoogleApiClient();             }             mMap.setLocationSource(this);             mMap = googleMap; and so on....   ...  private static final LocationRequest REQUEST = LocationRequest.create()             .setInterval(INTERVAL)             .setFastestInterval(8000)             .setSmallestDisplacement(SMALLEST_DISPLACEMENT)             .setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);   ...  @Override     public void activate(OnLocationChangedListener onLocationChangedListener) {         mMapLocationListener = onLocationChangedListener;     }      @Override     public void deactivate() {         mMapLocationListener = null;     }   ...  @Override     public void onConnected(@Nullable Bundle bundle) {         isOnline();         if (mGoogleApiClient == null) {             buildGoogleApiClient();         }         if (mGoogleApiClient.isConnected()) {             if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {                 return;             }             LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, REQUEST, this);         }else{             Toast.makeText(this, "Koneksi ke Google API Terganggu, Coba lagi.", Toast.LENGTH_SHORT).show();         }         Toast.makeText(this, "Terhubung dari Google Play Services.", Toast.LENGTH_SHORT).show();     }   ...  @Override     public void onLocationChanged(Location location) {         if (mGoogleApiClient == null) {             buildGoogleApiClient();         }         if (mMapLocationListener != null) {             mMapLocationListener.onLocationChanged(location);         }         latLng = new LatLng(location.getLatitude(), location.getLongitude()); and so on...

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?


My old PhD adviser and I had a falling out. We wrote a paper together, it is done at this point in my eyes. He "disagrees". Near the end of revisions the edits became more and more banal and even flip flopping. "Do it this way, no change it back, no change it back, no change it back etc" endlessly. I have shown the paper to other faculty and they think it looks fine.   We got into an argument about this, the paper has been done for well over a year at this point. I have a new adviser. At this point the old adviser flat out refuses to submit the paper, he refuses to make any edits to the paper, he refuses to even talk to me.   The grad head has been notified, other professors have been notified. My current adviser is really pissed off about the whole situation and is planning on talking to the old one.   Can he just not submit the paper? Do I have any recourse? I wrote the paper, I did the majority of the work (other than his idea etc). Can I just submit it myself? I feel like he would email the journal and complain about it. But I don't see any other choice.

I did my PhD four years back. I was funded from my home country and I have done all the work. I started writing papers before submitting my thesis.  I am sending my supervisor drafts every year until now. Altogether I have now done 32 drafts. Since last year alone, I have rewritten my paper 12 times but he still is not happy to submit it and not willing to make any changes by himself. He is even not letting me to show it to the reviewers.  My supervisor is a lecturer and I was his first PhD student. I acquired the opinion of two professors (one of them is my 2nd supervisor and is a co-author) recently about the quaility of paper and they recommended to send it to a good journal (impact factor of 10 and above). After many years of struggle my supervisor wished to publish it in a journal with an impact factor less than 1. Above all he is not willing to pay publication costs and he is not allowing me to try for good journal. I am the one who did all the work, who paid for work, who wrote paper and who is paying for publication costs and i am not allowed to try any good journal.  One thing about his recomened changes: He did not ask repeating any experiments, redoing any analysis or revisiting any conclusions. It’s only text style that is being changed over last four years.  I contacted the university services and they told me that I don’t qualify for university help as they only cover two years post PhD duration.   What can I do now? Can I publish my work without him as co author. Can I just acknowlege him for hosting me and remove his name from the author list?


Prove that ${n \choose k} + {n \choose k+1} = {n+1 \choose k+1}$.  I can prove it using numeric examples, but i need a broader proof. I think it might have to do with Pascal's Triangle.

I'm trying to prove that ${n \choose r}$ is equal to ${{n-1} \choose {r-1}}+{{n-1} \choose r}$ when $1\leq r\leq n$.  I suppose I could use the counting rules in probability, perhaps combination= ${{n} \choose {r}}=\frac{n!}{r!(n-r!)}$.  I want to see an actual proof behind this equation.  Does anyone have any ideas?


This code is returning a memory address of an array being returned by the rgb2hsv function. I am not sure as to why this is, or if it is even a memory address that it is returning as I am familiar with memory addresses looking something along the lines of "0x038987086" but the code is returning something that looks more like this : "[F@12bb4df8", I am not sure as to why this is, if you could answer why and what it exactly what it is returning that would be extremely beneficial. Here is the code:    public class HelloWorld{      public static float max(float[] nums) {         if (nums[0] > nums [1] && nums[0] > nums[2]) {             return nums[0];         }         if (nums[1] > nums [0] && nums[1] > nums[2]) {             return nums[1];         }         if (nums[2] > nums[0] && nums[2] > nums[1]) {             return nums[2];         }         return 0;         }      public static float min(float[] nums) {         if (nums[0] < nums [1] && nums[0] < nums[2]) {         return nums[0];         }         if (nums[1] < nums [0] && nums[1]  < nums[2]) {         return nums[1];         }         if (nums[2] < nums[0] && nums[2] < nums[1]) {             return nums[2];         }         return 0;       }      public static float[] rgb2hsv(float r,float g, float b) {          float h;          //Initializes h          h=0;          float s;          float v;          // Floats added to avoid operator precedence          float x;          float a;          float hue;          //Divides by 255           r=r/255;          g=g/255;          b=b/255;          float[] rgbArray = {r,g,b};          float mx= max(rgbArray);          float mn= min(rgbArray);          float df= mx-mn;          if (mx == mn) {             h=0;           }          if (mx==r) {             x=g-b;             a=x/df+360;             hue=a % 360;             h=hue;          }          if (mx==g) {         x=b-r;         a=x/df+120;         hue=a % 360;         h=hue;      }      if (mx==b) {         x=r-g;         a=x/df+240;         hue=a % 360;         h=hue;      }       if(mx==0) {          s=0;      }      else {          s=df/mx;      }      v=mx;      float[] hsvArray = {h,s,v};      return hsvArray;  }  public static void main(String []args){  float[] x=rgb2hsv(255, 255, 0);  System.out.println(x);  }   }  This should of outputted something along the lines of 3 distinct numbers telling me hue, value, and saturation. Instead it returns something similar to "[F@12bb4df8"

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 am implementing a card view on  a map fragment so on implementing  it, i used two sub classes that extends view holder class.so when i am calling .setText() method for the text View of one of the sub classes from the constructor of the main class its returning null i know its due to the scope which it cannot access but how to solve this .This is the code     public class Adap1 extends RecyclerView.Adapter<Adap1.ViewHolder> {      String a121[] = new String[10];     RecyclerView recyclerView;     RecyclerView.LayoutManager layoutManager;     RecyclerView.Adapter adapter;     FloatingActionButton a1s, a2s, a3s;     TextView ajk;      public static final int WeatherVe = 0;     public static final int ChronoVe = 1;     int jh=0,moj=0;     double lat1,lat2,lon1,lon2,degree,s1,speed,l1,l2,lat,lon;       public Adap1(String a121[])     {         this.a121 = a121;     }       public Adap1(double l1,double l2,double lat1,double lat2)     {         this.l1=l1;         this.lat1=lat1;         this.l2=l2;         this.lat2=lat2;         s1 = getDistanceFromLatLonInKm(l1, l2, lat1, lat2);         System.out.println(l1+" "+l2);         System.out.println(lat1+""+lat2);         speed=s1%(0.0019);         ajk.setText(d);//error is coming here when i am accesing text view of clima class        }     public static class ViewHolder extends RecyclerView.ViewHolder     {         public ViewHolder(View v)         {             super(v);         }     }     public class WeatherVe extends ViewHolder {         public TextView itemTitle;         ImageView acv;         public TextView itemg;         public WeatherVe(View v)         {             super(v);             itemTitle = (TextView) v.findViewById(R.id.ass);             itemg = (TextView) v.findViewById(R.id.ass1);         }     }     public class Clima extends ViewHolder     {         public Clima(View v)         {             super(v);             a1s = (FloatingActionButton) v.findViewById(R.id.as);             a2s = (FloatingActionButton) v.findViewById(R.id.as1);            ajk=(TextView)v.findViewById(R.id.olx);             System.out.println(ajk);             System.out.println("Initialization");         }     }     @Override     public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)     {         View v;         if (viewType == WeatherVe) {             v = LayoutInflater.from(parent.getContext())                     .inflate(R.layout.card_lay12, parent, false);             return new WeatherVe(v);         }         else         {             v = LayoutInflater.from(parent.getContext())                     .inflate(R.layout.card123, parent, false);             return new Clima(v);         }     }     @Override     public void onBindViewHolder(ViewHolder holder, int position)     {         if (holder.getItemViewType() == WeatherVe) {             WeatherVe hsolder = (WeatherVe) holder;             hsolder.itemTitle.setText(a121[position]);             avd = hsolder.itemTitle.getContext();             hsolder.itemg.setText(a121[position + 1]);         } else if(holder.getItemViewType()==ChronoVe)         {             Clima hags = (Clima) holder;         }         else         {         }     }     }   In the logcat it is showing     Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence) on a null   object` reference   please tell me how to acces that text view from that constructor.Thanks in advance!!


In not-magic world (especially in movies), spies and cops often carry a backup gun in case they are disarmed during combat (the famous gun in the sock).  There are many examples in the books where a wizard or witch is disarmed during combat. All it takes is a simple expelliarmus spell. So it probably would be wise to carry a backup, wouldn't it?  Is there any canon example of a wizard or witch carrying a backup wand?

Is there any canon information in Harry Potter that proves one way or another whether a wizard always owns only one wand as a matter of routine?  What I am talking about is a wizard buying and owning one wand and also a second wand (for backup, or simultaneous use, or separate purpose, or ceremonial+work wand), akin to people buying more than one pair of boots, guns or hammers.  A proof would be either canon info showing someone owning 2 wands simultaneously; or a statement showing why that does not happen except in rare exceptions (see below).    NOTE: I am discounting special situations such as winning an extra wand in a duel ala Harry (e.g. the second wand's obtainment wasn't intended/planned), or someone winning a Death Stick from prior owner (in which case it was intended as a replacement wand and not an extra one); or taking another's wand for a time being, ala Voldemort and Lucius Malfoy (since it was more of a "temporary replacement because main wand was useless for the purpose due to paired cores" - far from a normal situation).  Also, I meant wands intended for use - e.g. if Malfoy would have a (imagined by me) collection of rare antique wands, that's as irrelevant as someone having flintlocks in a display case.


This  and I wanted to check how things have changed in the past 2 years. My problem:    I run a site with most of the content distributed to subdomains that’s are user based. E.g:  Joe.example.com John.example.com Jil.example.com    So all of these subdomains have the content and the main site example.com becomes a mere dummy listing all the subdomains. Now the question is, as of 2012, how is google treating domain authority and page rank in this case? I understand the notion of page rank as page per se but when it comes to domain authority will the parent domain have the cumulative effect of the domain authority or will it be spread out?

If I have example.com, and blog.example.com, do search engines see those as one site or two? Will using subdomains hurt SEO? I have some technical reasons why I can't use example.com/blog.


I'm trying to understand how method overrides work when the to-be-overridden method is called from a constructor.  (Using VS2012)  Given the test program:  #include <string> #include <iostream>  using namespace std;  struct Foo {     Foo()     {         cout << "\tFoo::Foo()" << endl;         Initialize();     }      virtual void Initialize()     {         cout << "\tFoo::Initialize()" << endl;     }  };  struct Bar : public Foo {     Bar()  {          cout << "\tBar::Bar()" << endl;      }       void Initialize() override     {         cout << "\tBar::Initialize()" << endl;     } };   int main(int argc, char *argv[]) {     cout << "Creating Foo" << endl;      Foo foo;      cout << endl;      cout << "Creating Bar" << endl;      Bar bar;      std::getchar();      return 0; }   I get the following output:  Creating Foo         Foo::Foo()         Foo::Initialize()  Creating Bar         Foo::Foo()         Foo::Initialize()         Bar::Bar()   I would expect the second section to be:  Creating Bar     Foo::Foo()     Foo::Initialize()     Bar::Initialize()   <---- Not called.     Bar::Bar()   I'd expect that, when the Foo ctor is called, and it calls ::Initialize(), that the override Bar::Initialize() is actually called.  Now, I can guess why this is happening: When Foo::Foo() is called, before the body of Bar::Bar() is executed, there's no guarantee that items needed by Bar::Initialize() have been allocated, much less initialized.  The Question  Can I override a method that is called by a base constructor, and have that override execute when instantiating a derived class? That is, is there any way to modify the above code so that Bar::Initialize() will be called?  The alternative I'm using at the moment is to remove the ::Initialize() from the Foo constructor, and do something like this:  Bar bar; bar.Initialize();   and modify Bar::Initialize() to  void Bar::Initialize() override { Foo::Initialize(); ///... bar-specific initialization here }   Is this the best or only way to do this?

Why the following example prints "0" and what must change for it to print "1" as I expected ?  #include <iostream> struct base {    virtual const int value() const {       return 0;    }    base() {       std::cout << value() << std::endl;    }    virtual ~base() {} };  struct derived : public base {    virtual const int value() const {       return 1;    } };  int main(void) {    derived example; }


I have Ubuntu 18.04 64-bit installed on my Lenovo Ideapad 700-15 isk. Which has integrated video card Intel HD Graphics and NVIDIA Geforce 950M. So, I can say that now it doesn't feel so good as I thought it will be. It's like a little bit laggy and feels slow.  Should I switch to an NVIDIA driver, and if so, then how?

I just ordered the Nvidia GTX card. I have a dilemma, though. Should I keep using the driver which is available in "additional drivers" in Ubuntu, or should I install the driver from the Nvidia site?  So which driver is the best for me?


In the following sentence, how do you understand the en dash?     Our findings are very interesting from an international viewpoint – business tourism.   Is the use of the en dash appropriate here?  Spoiler  By using an en dash, the author of this sentence said he wanted to give just a hint or a summary of what the findings were without having to write too much.

I generally know how to use a hyphen, but when should I use an en-dash (–) instead of an em-dash, or when should I use a hyphen (-) instead of an em-dash (—)?


Does anybody know the keyboard shortcuts or menu commands to fill a formula down without dragging? I'm using Excel for Mac 2011 on a MacBook.  I've got a spreadsheet like this pattern but for like 5000 rows:  A, B, C, D 5, 1, 3   =SUM(A1:C1) 3, 2, 4 ...   I know how to hover over D1 and get the handle and drag down, but there must be an easier way.  There are a billion tips online but I'm not finding any that work.  FWIW, Macbook has some exceptions to shortcut key rules, so that's probably why, I guess.  But anyhow, anyone know how to do this?  PS: I would have thought "fill series" would be a choice but no. Here's a picture.

Typically, in Excel, one can autofill a column by drag a cell down. However, with a lot of cells to fill up, manually dragging and scrolling the spreadsheet is time consuming.  Is there a much better way to fill up a column with formulas?  Edit: I tried to input the $F$1:$F$20000 at the highlighted place, but the values inside column F is not populated.


My version of Firefox has a runaway process/thread that makes it use 100% cpu on my MacBook Pro (OSX 10.7.4) after a few minutes. I've tried to use about:memory and about:addons-memory to try to figure out what is causing the issue, but it doesn't seem to be related to memory usage at all. Is there instead a way to see CPU usage by tab or add-on?

Is there anything in the current Firefox similar to the Task Manager in Google Chrome? (Shift + Esc)  There is something that occasionally takes up enough CPU to make Firefox unresponsive - but with multiple windows, each with a dozen or so tabs open, trial & error is going to take a while.


Normally you would not be allowed to cast  targeting a non-Creature, because of its "Enchant creature" ability. But it could end up enchanting a card that is not normally a creature, due to an effect that makes it temporarily a creature, such as a a manland (). Or because it was enchanting a flip-walker () that has now transformed.  So you turn Inkmoth into a creature, then enchant it with Metamorphic Alteration, making it a copy of . At the end of the turn, Inkmoth's ability wears off, so now you have Metamorphic Alteration enchanting just a land.  However, that land isn't a land, it is a creature still, because it is copying Grizzly Bears.  So does 704.5m apply here? Is this an Aura attached to an illegal object, thus causing the Aura to go to the graveyard? Or, is the object actually legal, because it is being made a creature?     704.5m If an Aura is attached to an illegal object or player, or is not attached to an object or player, that Aura is put into its owner’s graveyard.

This happened this weekend, and we were unsure how to resolve it.    Opponent casts . On my turn, I cast . Then I cast,  targeting the .   Normally, I could not target the Progenitus because it has Protection from Everything, but since it lost all abilities and became a frog, it was a valid target (We thought so anyway). It was at the end of this turn that we were unsure. Polymorphist's Jest effect ended, but the Darksteel Mutation was still enchanting the creature. This is what we thought:   Progentius has Protection from Everything and the Enchantment "falls off" as it is no longer a valid target.  The Insect has no abilities apart from Indestructible, and the Enchantment stays. Something Else???   I'm really hoping this is #2 since this combo would allow for targeting of things with shroud and hexproof, etc. on the turn I cast Polymorphist's Jest.


I have a time series of monthly data points with a corresponding cost. Within these months, if you strip out the trend, I believe the cost to be highly correlated to the number of trading (or business days). What I don't understand is how exactly to strip this out? If the month's trading days can vary (example - January has 21 days one year and 22 another), I don't think I can rely on a typical method of averaging the historical monthly seasonalities. Is there a better way to go about doing this?

So for the last few months I've been doing a lot of forecasting for my company and specifically I've been looking at monthly forecasts of total weight of different categories of products output's each month.  I've been using time series models such as Arima, ETS, and tslm() within R to do my forecasting, as well as using cross validation to select a model. Over the last two days I've been presenting my results and discussing implementation of my forecasts.  But, I've been asked the same question multiple times and I don't know the answer to it, so let me ask you guys.  If this has been asked before, I apologize.  I'll write out a few questions that hopefully will make clear what I'm trying to understand.  Also, I'd like to keep technical answers about the models in the context of R, since that's what I'm using.   Do time series models take into account the number of days in a month? Particularly, do time series models consider the number of business days in a month? (or is there a way to incorporate this?) Do we even need to worry about this when forecasting using a time series model or does the model account for this?   For instance, lets say in October of 2014 a certain category sold 35,000 lbs of a product, and that there were 31 days, 23 of which were business days.  Well for this year, 2015, there are still 31 days, but now there are only 22 business days.  Just some background on the data, I have monthly data that starts in August of 2008.    So would it possibly be better to average the weight per month with the number of business days and forecast out this way since the # of business days change month to month and year to year?


I came across a statement which said that if we have a function $f:X\rightarrow Y$ where $A\subset X$ and $B\subset X$, then its true that $f(A\cup B)=f(A)\cup f(B)$, however its false that $f(A\cap B)=f(A)\cap f(B)$. I do not understand how this is so. Any help?

I am struggling to prove this map statement on sets.   The statement is:   Let $f:X \rightarrow Y$ be a map.   i) $\forall_{A,B \subset X}: f(A \cup B)=f(A) \cup f(B)$ ii) $\forall_{A,B \subset X}: f(A \cap B) \subset f(A) \cap f(B)$ iii) $f$ is injective $ \Longleftrightarrow$ $\forall_{A,B \subset X}: f(A \cap B)=f(A) \cap f(B)$  My problem is: I know how to operate on sets, I know how to operate on sets, but I don't know how and where to start the proof,  the biggest problem in mathematics, I think.   Thanks for help!


I have interface called RestClientInterface which is implemented by abstract RestClient class, those class is extended by SearchRestClient and IndexRestClient. Both of those classes are singletons. I would like to be able implement in the interface static method getInstance. I decided to use Guava library like suggested here: .  I have implemented two statics methods in interface:  public interface RestClientInterface {      ClassToInstanceMap<RestClientInterface> classToInstanceMap = MutableClassToInstanceMap.create();      static <T extends RestClientInterface> T getInstance(Class<T> type) {         return classToInstanceMap.getInstance(type);     }      static <T extends RestClientInterface> void registerInstance(Class<T> type, T identity) {         classToInstanceMap.putIfAbsent(type, identity);     } }   And next registered instances in both extending classes:  public class IndexRestClient extends RestClient {      static {         RestClientInterface.registerInstance(IndexRestClient.class, getInstance());     }      /**      * IndexRestClient singleton.      */     private static IndexRestClient instance = null;      private IndexRestClient() {}      /**      * Return singleton variable of type IndexRestClient.      *      * @return unique instance of IndexRestClient      */     private static IndexRestClient getInstance() {         if (Objects.equals(instance, null)) {             synchronized (IndexRestClient.class) {                 if (Objects.equals(instance, null)) {                     instance = new IndexRestClient();                     instance.initiateClient();                 }             }         }         return instance;    }  }   Next I call this like that:  IndexRestClient restClient = RestClientInterface.getInstance(IndexRestClient.class);   But every time I get null. Static registration of the instances doesn't work as the array of registered instances is empty. How can I correctly instantiate those both classes?

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?


For any $a \in \mathbb{N}$, $4^a \equiv (3a+1) \mod 9$. How do I prove this?  I have attempted to do so by induction(which I think should be sufficient).  For the base case: $4^0 = 1 \equiv (3(0)+1) \mod 9$.  I have tried assuming the inductive hypothesis $4^a \equiv (3a+1) \mod 9$ to try and get the result to be true for say $a+1$ but I can't get past that point and don't know whether this is the correct route. Any help would be appreciated.

I'm trying to prove the above result for all $n\geq1$ but after substituting in the inductive hypothesis, I end up with a result that is not quite obviously divisible by 9.   Usually with these divisibility induction problems, it falls apart nicely and we can easily factorise say a 9 if the question required us to prove that the expression is divisible by 9. However in this case, I do not end up with such a thing.  My work so far below:  Inductive Hypothesis: $7^k(3k+1)-1=9N$ where $N\in\mathbb{N}$  Inductive Step:  $7^{k+1}(3k+4)-1 \\ =7\times 7^k(3k+1+3)-1 \\ =7\times \left [ 7^k(3k+1)+3\times 7^k \right ] -1 \\ = 7 \times \left [ 9N+1 + 3 \times 7^k \right ] -1 \\ = 63N+21\times 7^k+6 \\ = 3 \left [ 21N+7^{k+1}+2 \right ]$   So now I need to somehow prove that $21N+7^{k+1}+2$ is divisible by 3, but I'm not quite sure how to proceed from here...


I am not a beginner to calculus. Till know I have learned about: 1. Functions - Domain,range,odd/even,periodic,compositemapping, etc. 2. Graphical transformations. 3. Evalution of limits, checking continuity differentiability and their theorems. 4. Derivative of functions, their theorems and application like monotonicity etc. 5. Definite and Indefinite Integration. 6. Differential Equations.  I need a textbook for much more advanced calculus according to my level, as I look forward to maths as career choice. Right now I need a book that have little bit of what I have already learned, so that I can practise it + more advanced and challenging calculus for deeper understanding.

I've already taken my calculus sequence and I'm interested in brushing up and staying sharp on the basics. So far, my calculus background is limited to single-variable calculus, which I applied in my physics sequence and engineering statistics. I learned a little bit of vector math in physics as well, but I'm not strong in it. My mathematical strengths lie in the discrete mathematics.  I'm particularly interested in studying for my IEEE Certified Software Development Associate exam - 10% of the exam is mathematics (calculus, differential equations, and statistics). Calculus is one of the mathematics knowledge areas that a software engineer should be competent in, so I'm looking for not only solidifying the courses that I've already taken, but moving forward with slightly more advanced topics, at an undergraduate mathematics level.  I'm currently using the textbook from my calculus sequence, but I'm interested to know what books other people used to learn calculus and if the book is potentially worth checking out.  What books are available to help me?


Show that the set of real numbers has no nontrivial clopen set without using connectedness of $\mathbb R$.    I tried to show this by showing that an open set in $\mathbb{R}$ is strictly contained in its closure.   My attempt:      Let $U$ is open in $\mathbb{R}$. Then $U$ can be written as union of disjoint open intervals. $U =  \bigcup_{n=1}^{\infty}A_n$ , where $A_n = (a_n, b_n)$. Now Closure of $U, Cl(U) = Cl( \bigcup_{n=1}^{\infty}A_n) =  \bigcup_{n=1}^{\infty}Cl(A_n)$ [ not true in general ] = $ \bigcup_{n=1}^{\infty}[a_n, b_n] \supsetneq U$. So the problem thus reduces to the problem, whether $Cl(\bigcup_{n=1}^{\infty}A_n) =  \bigcup_{n=1}^{\infty}Cl(A_n)$ holds for countably infinite intervals in $\mathbb{R}$. This surely holds for finitely many sets, but doesn't hold for countably infinitely many sets in general. Is this true? or there's another proof of this?

How to give a direct proof of the following result?     Let $A$ be a subset of $\mathbb{R}$ such that $A$ is both open and closed. Then $A$ is either empty or all of $\mathbb{R}$?   My work:   If $A$ is not empty, let $u \in A$. Then there is some open interval $(a,b)$ such that $$u \in (a,b) \subset A.$$  Now if $\mathbb{R} - A$ is not empty either, then let $v \in \mathbb{R} - A$. Then there is some open interval $(c,d)$ such that  $$v \in (c,d) \subset \mathbb{R} - A.$$  Suppose that $u < v$.   Since $$\emptyset \subset (a,b) \cap (c,d) \subset A \cap (\mathbb{R} - A) = \emptyset,$$ we must have $$(a,b) \cap (c,d) = \emptyset.$$ So we can conlclude that $$b \leq c.$$ But $b \in A$ and $c \in \mathbb{R} - A$. So we must have $$b < c.$$  What next? Can anybody here please help complete the proof from here on?  An edit based on a comment by Marc Paul:   Let us assume that the set $A$ is a non-trivial clopen set in $\mathbb{R}$. Let us define a function $f \colon \mathbb{R} \to \mathbb{R}$ as follows:  $$f(x) \colon= \begin{cases} 1 \ \mbox{ for } \ x \in A; \\ 0 \ \mbox{ for } \ x \in \mathbb{R} - A. \end{cases}$$   Let $V$ be an open set in the range space $\mathbb{R}$. We show that the inverse image set $f^{-1}(V)$ is open in the domain space $\mathbb{R}$.   The following cases arise:   If $0, 1 \in V$, then $f^{-1}(V) = \mathbb{R}$.   If $0 \in V$ but $1 \not\in V$, then $f^{-1}(V) = \mathbb{R} - A$.   If $1 \in V$ but $0 \not\in V$, then $f^{-1}(V) = A$.   And, if $0 \not\in V$ and $1 \not\in V$, then $f^{-1}(V) = \emptyset$.   Thus, $f^{-1}(V)$ is open in the domain space $\mathbb{R}$.   Hence the function $f$ is continuous.   What next? How does this lead to our desired conclusion?   [Yet another edit, again based on valuable comments from Marc Paul: ]  So if both $A$ and $\mathbb{R} - A$ were non-empty, then let's suppose $a \in A$ and $b \in \mathbb{R} - A$, and we can assume without any loss of generality that $a < b$.   Then $f(a) = 1$ and $f(b) = 0$. So by the intermediate value theorem there is a real number $c \in (a,b)$ such that $f(c) = 1/2$, which is a contradiction because the image set of $f$ does not contain $1/2$.


For any non empty set $X$; $A,B \in \mathcal{P}(X)$, the power set, define $A\sim B \iff $ both $A$ and $B$ have same cardinality and let $\tilde{X}$ denote the equivalence classes. For $\tilde{A}, \tilde{B}\in\tilde{X}$, define $\tilde{A} \preccurlyeq\tilde{B} \iff |\tilde{A}| \leq |\tilde{B}|$  where $|\tilde{A}|$ denotes the cardinality of $\tilde{A}$. Now, we know that the axiom of choice implies that $\preccurlyeq$ is a total order.  What I wish to know is whether it is a well-order.

I'm looking for a proof that the class of cardinal numbers is well ordered under the order relation $|A|\leq |B| \Leftrightarrow$ exists an injection $f:A \to B$.  In fact, I've found a very beautiful proof in an article, but I think it's not the standard one.


I open the app Enter Stack Overflow Click Show tags See list of tags Search a tag Select a tag See the list of posts for that tag Open a post and read it Kick BACK-BUTTON   I am now back to step 4 and have to redo 5-7 every time. I would expect to get back to step 7.     App Version: 1.0.89 Device Manufacturer: samsung Device Model: SM-G900F   OS Version: 6.0.1 (G900FXXU1CPFH)

This looks a little bit like a variation on  but specific to the tags view.  Reproduction (app version 1.0.71):   Select any site (say Meta) from the sidebar Switch to the tags view using the top bar Choose a tag, any tag ( is nice)   optionaly refine your search with more terms  Go to any question found, go back   you end on the unfiltered tags view  Go back again   lucky you, your search is here


Let $(X,\tau)$ a topological space  If $A \subset X$ is a compact set, does this imply that $\overline{A}$ is a compact set?

Can anyone gives me an example of a compact subset such that its closure is not compact please? Thank you.


I'm drawing the following cylinder which represents a water flowing and cooling down  \documentclass[a4paper,10pt]{article} \usepackage{pstricks} \usepackage{auto-pst-pdf} \usepackage{pst-solides3d} \usepackage{xcolor} \usepackage{epstopdf} \usepackage[english]{babel} %change language if necessary \usepackage[english,verbose]{layout}%change language if necessary  \begin{document}  \begin{pspicture}(-3,-4)(3,4)  \psset{viewpoint=50 50 20 rtp2xyz,Decran=50,lightsrc=viewpoint  }   \psset{color1=cyan,color2=red}   \psSolid[h=8,r=0.5, object=cylindre, ngrid=50 15, RotZ=30, hue =1 0 0 0 0 1,linewidth=0.01pt ](0,0,-2.5)  \end{pspicture}  \end{document}   I would like the black lines to disappear, or atleast partially merge with the image. Is there anyway to perform this ?

\documentclass[pstricks,border=12pt,12pt]{standalone} \usepackage{pst-solides3d} \begin{document}  \begin{pspicture}[viewpoint=5 30 45 rtp2xyz,Decran=5](-6,-6)(6,6)     \psSolid[object=cylindrecreux,h=2,r=1,fillcolor=cyan,ngrid=30 30]     \axesIIID(1,1,1)(3,3,3) \end{pspicture} \end{document}     What option do I have to set to remove the mesh from the cylinder such that the cylinder looks clean, smooth with gradient color?  Edit:  When I set linewidth=0 I got the following, but I am not sure that linewidth=0 is the recommended solution.


I'm curious as to what the difference between the Interest Rate and Annual Percentage Yield is.  For example: This Bank I was looking at offers 0.45% interest rate on savings account balances over $100,000. It also has an APY of 0.45% on balances >$100,000.  I'm not interested in opening a savings account with $100,000+ for 0.45% so I'm not looking for feedback on whether that's a good idea or not, I'm just curious as to when they numbers are different, and why. I know they can be different with government bonds, but I would like a simplified example.

What is the difference between Interest Rate and APY on savings accounts, CDs, etc?  Is there a simple formula to convert the two?


How does one find out if a given number is a rational number or irrational number?

How is it possible to prove a number is irrational?  First part of that question: How it possible to know that a number will go on infinitely?  Second part: How is it possible to know that no repetition will occur during the infinite sequence of digits?  Any examples of proofs of irrationality?


First, it is observed that sound travels faster in denser mediums, therefore a sound wave will travel the fastest through solids. But again it is observed that because hot air is less dense sound passes through it faster than in cold air? It is totally opposite of the first case, how?

Its an established fact that increase in the temperature causes increase in speed of sound waves but what is the property which is changed by changing temperature ? Does frequency and wavelength get affected by temperature?


I recently installed Windows 7 on my desktop computer and found that even after going to Display settings and setting it to the highest setting that there's still black space between the edge of the display and the edge of the monitor. Also, that resolution isn't as high as my monitor's native resolution (it's telling me I can go as high as 1400 x 1050, and I think mine goes as high as something close to 1920 x 1280).  I believe that my monitor is an .  When I try to detect my monitor/graphics card with  it tells me that they are named "Standard VGA Graphics Adapter" and "Generic PnP Monitor".

Native resolution of my monitor is 1920 x 1200; however, when I connect it via a D-Sub cable, I can't choose this resolution. Only 1920 x 1080 and 2048 x 1152 are available. How can I make my native resolution available?  UPS I'm using Windows 8.1 x64. Monitor is detected as Generic Non-PnP. My monitor drivers installation says that the monitor is not found (I guess because it's connected via an analog cable)  UPD2 I've installed Dell monitor drivers forcibly, but the native resolution still is not available in the resolution selector.


CommentAppend() {     # Comment line and append line below commented line      local comment="$1"      # search this line and comment it      local append="$2"       # Append this line below commented line      local InputFile="$3"          sed -i "s/${comment}/#${comment}/g ; s/#${comment}/& \n${append}/" $InputFile }   This function working fine for non escape character but when escape character available then it fail..   So We can build function, for escap character ?

I'm a relative Linux novice.  Suppose that I have a text file a.txt that contains the following text:  A B C   Now, if I want to change the text on line 2 (which contains B), I can use the following sed command:  sed -i '2s/^.*$/X/' a.txt   to change the B to X, for example.  But now suppose that I want to write an sed command that changes the text on line 2 to something that includes a bash string variable.  I want to change the text on line 2 to fname="myaddress", where the quotation marks are included explicitly, and where myaddress is a bash string variable (defined somewhere else).  To try to do this, I have created a bash shell script called mytest.sh and containing the following:  #!/bin/bash  myaddress="/home/" echo fname=\"$myaddress\"  head a.txt sed -i '2s/^.*$/fname=\"$myaddress\"/' a.txt head a.txt   Now, echo fname=\"$myaddress\" prints fname="/home/", which is the text that I want to be on line 2 of a.txt.  However, sed instead prints fname="$myaddress" to line 2 of a.txt, probably because it is inside the surrounding apostrophes.  In other words, the output of the above bash shell script is:   fname="/home/" A B C  A fname="$myaddress" C   My question is, how can I get sed to actually print the value stored in myaddress and referenced by $myaddress?


My issue:  On this answer I dig in a comment and stated that the poster should add more than just a bare-bones code answer, then we got into a little chat about Impatience and editing, as should be exampled by the link.  What this brings up to me is it would be very, very helpful to have a small note on a post that when I load a question (and answers) on a page that I can see a flag marker that the Q or A is currently being edited.   Who by and the details of the edit are not needed, simply the fact that someone has the question open as an edit and that I can wait a few minutes to see the additions before posting my comments or scoring based on the pre-edit condition of the post.  This is not the same as  where the answer  is a good answer, but the answers core reasoning only applys if the information is given in the context of a parallel edit.     All the topics on META that I've found about this seem to be based on parallel edits and on people editing posts at the same time needing to know if someone else is, I think that bare if at all croses over to this where I think a comment or a vote on a question/answer can be better saved/posted if they knew that the question/anwser was currently being edited.      This is not a duplicate post of     That post is all about parallel editing this is about informing readers that a post is being edited. There is a crucial difference here.

Sometimes (eg. ) more than one user will simultaneously attempt to edit a post, particularly to fix poor formatting by the OP. It looks like in that case, I finished 30 seconds sooner than @marcog, but I don't know who might have clicked "edit" first.  Anyway, a useful usability enhancement would be to keep track of who is (or might be) editing a post at any given time. With this enhancement, the second user to click "edit" might see something like:     The following users may currently be editing this post:         marcog (21 seconds ago)      If a message like that were available, I would immediately choose not to edit at that time, and maybe come back later if the formatting still needed fixing. This saves effort, frustration, and duplicate "hey I fixed your formatting" comments.  It is important to note that this feature would not attempt to prevent multiple editors, everything else would work just the same as it does now.  Implementation idea  This feature could be implemented by adding a new table, say "editors", with the columns (post_id, edit_start, user_id). When a user clicks "edit" on a post:   Check the editors table for old entries for this post, say > 5 minutes. Delete them. If there are any current editors, show the list as above. Insert a row for the current post and the current user with the current time.   When a user submits changes to a post:   Delete the user's record from the editors table for that post.   Periodically:   Scrub old entries from this table (if a user clicked "edit" but never submitted a change for that post).   Optionally:   Provide a "Cancel" button on the edit page. Cancelling would remove the current user's record for the current post, but obviously not submit any changes.     Update: After saying in the comments that I've never seen the edit notification, I actually did just get it today editing . However, it showed the orange bar at the top (1 other users edited!) for a brief time just after I pressed "Save". What good is that?


Phone:  Samsung Galaxy S3 Carrier:  AT&T (US) Upgrade Path:  v4.2 to v4.4.2  Is anyone else noticing SD card file deleting issues after the upgrade to Android v4.4.2?  I use CoolReader to view files stored to  my SD card and continually delete them and add new ones.  After the updgrade, CoolReader and Astro File Manager are unable to delete files.  In fact, with Astro, the system popup appears with "Deleting..." and stays up until I cancel it.  Only connecting to a PC with USB and opening the folders there has allowed me to delete files.  Any suggestions on settings or anything else to correct this?  Thanks! Bill

On a Samsung Galaxy S4 Google Play Edition running 4.4 and non-rooted (I'd prefer not to root a device used for professional development purposes)  Having stored some ebooks on my external SDcard, I decided that I wanted to add some audio as well (as my internal device storage is quite full.)  As far as I can tell not one app (nor adb) can perform any write operations to the external SDcard's root directory.  The one exception that I've found is that my ubuntu computer, can create and rename directories inside /storage/extSdCard/Android/data/ even though none of my apps can.  Is there a workaround for this that doesn't involve rooting the device?


I'm trying to grab a random value from this array. When I run the program it just prints 0 for x. Why isn't it printing the updated value that is returned from the function?  import java.util.*; public class randomArray {     public static void main(String[] args)     {         int[] myArray = new int[]{1,2,3};         int x = 0;         getRandom(myArray, x);         System.out.println(x);     }     public static int getRandom(int[] array, int h)      {         int rnd = new Random().nextInt(array.length);         return h;        } }

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


Is 'e.g.,' or 'e.g.' correct?. In some published papers, I either see 'e.g.,' or 'e.g.' used in some sentences or phrases. Can someone justify and comment?

It seems that "e.g." is always followed by a comma but "i.e." is not. Why is that?


The PDG  lists the  as an observable particle (measurements).  Is this an accepted fact? All other information says it is just hypothetical i.e. Wiki etc.  see

Wikipedia lists the  as a hypothetical particle. I wonder whether graviton is indeed hypothetical or does its existence directly follow from modern physics? Does observation of gravitational waves amount to the discovery of graviton or could there be gravitational waves not composed of gravitons?


Have any of you used online bank statements (i.e. print outs of the pdf documents from your online banking) to apply for a UK Visitor Visa?  If so, were they accepted or rejected?  Please only reply if you have actually applied using the documents stated. I am specifically looking for real experience rather than opinions.  Not a duplicate as this specifically asks for people with experience. I am very aware of the guidance stating the need for originals only, however, it is not black and white on whether online statements constitute originals. As stated - PLEASE ONLY REPLY IF YOU HAVE EXPERIENCE OF USING ONLINE STATEMENTS

I'm applying for a UK visit visa. I have an account in a UK bank. Should this bank statement be stamped by the bank? And is it accepted as an online paper? Because it takes time to deliver to my country.


I am in the process of recovering from a catastrophic hard disk failure on a completely new machine. I am fortunate to have both a database backup and a backup of the folder with the D7 code that was running on the original machine.  After restoring everything to the original state the site at first appeared to be running well. All nodes that I clicked on worked perfectly and showed the data I expected. The problems began when I tried to login. It looks as if submitting any form whatsoever (including the login form) does not have any effect. I couldn't even login until I generated a one time login link with drush uli. Using that link I was at last able to login with the admin user, but whenever I try to change something in the admin area I simply can't do it - the page is reloaded after I submit the form and my changes disappear. There are no error messages 1) in the web UI, 2) in the Apache log files, or 3) in the watchdog database table.  Things that I tried without any effect:   Clean the cache tables. All of them, both with drush and with phpMyAdmin Set up a completely new site using the same codebase (Drupal 7.14). The new site works perfectly, after the setup I can login and create content without problems. The original site still doesn't work. This shows me that neither the Drupal code I am using is the problem, nor the Apache setup (the vhost for the new site is practically identical to the vhost for the problematic site). Upgrade to Drupal 7.44 Disable all modules (only disable, not uninstall) Enable tracing using the xdebug PHP module, but the result gave me information overload. I'm no PHP hacker.   I am now pretty desperate. I must overlook something essential, but for the life of me I can't find what it is. I am aware that this is all pretty vague, but I hope that someone with more experience than me can offer me a hint what I am doing wrong.  Info on my environment   Server   Debian jessie Apache 2.4.10-10+deb8 php5 5.6.20+dfsg-0+deb8u1 MySQL 5.5.49-0+deb8u1  Client   Mac OS X 10.11.4 Firefox 46.0.1 and Safari 9.1 on Mac  Configuration   Drupal 7.14 and 7.44 SSL-enabled vhost

I just recently copied a Drupal 7 site from one server to another, everything looks like it works fine except that I cannot save any settings.  Here are some other symptoms:   I can't disable or enable modules Overlay doesn't work Once I log out, I can't log back in When trying to log back in with the wrong criteria, I don't get a message about the user/pass being wrong admin_toolbar doesn't work (except immediately after clearing cache via drush) Status report doesn't show anything being wrong   I've got varnish running on the server and I'm not quite sure if that would have anything to do with it.


Without using Lagrange's Theorem or permutations, why must the order of an element in a cyclic group divide the order of the group?  I think it has something to do with the fact that every element in a cyclic group can be written as a form of the generator.

This is a very easy fact we use in Group Theory,  But somehow, I wondered that whether there may be another way (other than Lagrange's Theorem) to prove that the order of an element divides the order of Group.  I attempted to go on the term "exponent" of the Group (just assume that G is a Finite Group), which we may define the least common multiple of orders of elements in G. But this exponent divides $|G|$, since the order of each element divides $|G|$. So it became a little paradox.   Shall I think that; before teaching this fact in a Course, one should teach about Lagrange's first?


An airplane wing creates a faster air flow on the upper side and slower air flow on the lower side. Pressure of a gas and the speed of the gas molecules are directly related. If the speed of molecules increases, pressure will also increase.   Are these assumptions correct? If not can you correct it? If they are not wrong: can you please help me understand how an higher speed of air flow creates a lower air pressure? A higher speed of airflow does not mean a higher average molecule speed as well?  Another question, that might be related with this: Suppose we have a sealed room that no molecules and heat can escape or enter. We started to run a fan which has a motor that do not produce any heat. So the air start to flow inside the room.  Will the room temperature and pressure increase?  I hope these questions are not too stupid. I don't have Physics or Math education (but I have a great admire on them), and its really hard for me to understand the equations. Explanations that would help me visualize how things are happening is very appreciated.  Edit: My question was set as "duplicate" to a question to which I cannot see-understand how it is same with my question. My aim is just to understand, please help. Thank you.  Edit2: My actual question here is not to understand how a wing creates a lift, but to understand how this is possible:

What aerodynamic effects actually contribute to producing the lift on an airplane?  I know there's a common belief that lift comes from the Bernoulli effect, where air moving over the wings is at reduced pressure because it's forced to travel further than air flowing under the wings. But I also know that this is wrong, or at best a minor contribution to the actual lift. The thing is, none of the many sources I've seen that discredit the Bernoulli effect explain what's actually going on, so I'm left wondering. Why do airplanes actually fly? Is this something that can be explained or summarized at a level appropriate for someone who isn't trained in fluid dynamics?  (Links to further reading for more detail would also be much appreciated)


I have an application that needs to manage a priority queue of some items, where the priorities themselves can actually be fractional quantities (like 2.4 or 0.3). Smaller is better, as with usual integer priorities. The following one-liner generates a DoubleStream with DEFAULT_CAPACITY - many doubles pseudo-uniformly distributed between 0 and SCALE:  DoubleStream priorities = IntStream.range(0, DEFAULT_CAPACITY).map(_ -> r.nextDouble() * SCALE);   My question is: how can I avoid the unnamed parameter _ in the lambda that is given as an argument to map? Unfortunately, Random::nextDouble() is not static, so a method reference is not possible.   This question generalizes, of course: lacking a static method and given a known number of iterations, how can we avoid an unnecessary unnamed lambda parameter? Effectively, the generation of an intermediate Stream (the result of calling IntStream::range()), should really not be necessary.  // Edit: After looking at my IDE a bit closer, I am noting that the syntax above is actually NOT compilable since Java 9! The compiler says: As of Java 9, '_' is a keyword, and may not be used as an identifier. So this question is even more important to me now :)

How do I generate a random int value in a specific range? I have tried the following, but those do not work: Attempt 1: randomNum = minimum + (int)(Math.random() * maximum);  Bug: randomNum can be bigger than maximum. Attempt 2: Random rn = new Random(); int n = maximum - minimum + 1; int i = rn.nextInt() % n; randomNum =  minimum + i;  Bug: randomNum can be smaller than minimum.


synchronized(queueClientList){     Iterator<Client> iterator = queueClientList.iterator();     while (iterator.hasNext()){         Client client = new Client();         client = iterator.next();         try {             Thread.sleep(client.serviceTime);         } catch (InterruptedException e) {             Thread.currentThread().interrupt();         }         System.out.println(client.ID+ " it`s out");         queueClientList.remove(client);     } }   This code should iterate through queueClientList and sleep the Thread for client.serviceTime milliseconds. After waking up, it should delete the current client from the queueClientList.   It gives me the ConcurrentModificationException at client = iterator.next() line  The declaration of queueClientList is:  public List<Client> queueClientList = Collections.synchronizedList(new ArrayList<Client>());   Why does it throw that error if this whole method is synchronized?

We all know you can't do the following because of ConcurrentModificationException:  for (Object i : l) {     if (condition(i)) {         l.remove(i);     } }   But this apparently works sometimes, but not always. Here's some specific code:  public static void main(String[] args) {     Collection<Integer> l = new ArrayList<>();      for (int i = 0; i < 10; ++i) {         l.add(4);         l.add(5);         l.add(6);     }      for (int i : l) {         if (i == 5) {             l.remove(i);         }     }      System.out.println(l); }   This, of course, results in:  Exception in thread "main" java.util.ConcurrentModificationException   Even though multiple threads aren't doing it. Anyway.  What's the best solution to this problem? How can I remove an item from the collection in a loop without throwing this exception?  I'm also using an arbitrary Collection here, not necessarily an ArrayList, so you can't rely on get.


I know:   Single Double Triple Quadruple   But what comes next? Up to 10 would be fine.

I'm not sure what these are called, but how can I form a word like "quadruple" for any number I want? Like 5× as much is quintuple, what is 31× as much or 147× as much? I want to know how they are formed so I can make my own.  Similarly, how do I construct the prefixes, such as unicycle, bicycle, tricycle, quadricycle? I figured out 12 is duodeci-, but how can I form any prefix like this?