Why is the size of lambda memory not 12?
Why isn't sizeof for a struct equal to the sum of sizeof of each member?
Dual Booting win 10 and Ubuntu 18.04 on two separate physical ssds I have gotten as far as to create the bootable usb, booting into that bootable usb and getting to the install options however i quit because I had some concerns.  I currently have a Samsung 850 evo 1tb that has win 10ninstalled. I want to dual boot with Ubuntu 18.04 by installing it on a brand new unformatted uninitialized Samsung 860bevo 250gb. Should i format the brand new ssd as a new volume in win 10 and then proceed with the Ubuntu install on this volume. What else should i do? Im a first time Ubuntu user and installer.  Any and all help is appreciated. Scenario (Ubuntu 16.04):  I compile and run a C program (with -g, I get the traditional Segmentation Fault (core dumped), and then (of course) there is no mythical "core" file to be found. Some digging says to modify /proc/sys/kernel/core_pattern with a command to the effect of: echo '|tee /home/me/my_core_folder/my_core_file' | sudo tee /proc/sys/kernel/core_pattern, and after doing this, I stop getting (core dumped) and start only getting the plain Segmentation Fault. I try things like gdb ./program_object_file.out core.pid which obviously doesn't exist (I was getting desperate), and of course try the plain gdb ./a.out followed by (gdb) core core.pid and variants of the commands where I spam the tab key desperately trying to get auto-completion to get me to where I need to be.  Question:  Is there a generalized way I can get to core dumps? I recognize that every machine that I touch seems to have a Michael Bay's Transformers-esque ability to reconfigure hardware and software such that no device I own can be expected to work normally out-of-the-box. Is there a simple algorithm/recipe I can follow to locate core dumps on my own machine as well as on other peoples' machines? I always find myself tutoring friends on stuff like this after no small amount of  work to get things working for myself and it would be nice to be able to run a command or something to get core files dumped to the directory which the executable was run from... is there any way to do this that should work on most (I would settle for "some") Linux/Unix machines? I was coding a physics simulation, and noticed that I was using discrete time. That is, there was an update mechanism advancing the simulation for a fixed amount of time repeatedly, emulating a changing system.  I though that was interesting, and now believe the real world must behave just like my program does. It is actually advancing forward in tiny but discrete time intervals? If a Continuous function $f(x)$ satisfies $f(x) = f(2x)$, for all real $x$, then does $f(x)$ necessarily have to be constant function? If so, how do you prove it? If not any counter examples? How to install mods for the new Minecraft launcher I've recently changed to the new Minecraft launcher, and I have noticed a change in the .minecraft folder layout. I can no longer install mods just by copying it over into the versions/1.6.1 jar file, as this file refreshes every time it is launched.  For those who don't know what I am talking about, here is the new layout:    I am specifically trying to install Optifine, which does work with 1.6.1. Where do I drag in the mod files now? I can't seem to find a jar file that is suited to it, except in the version folder, but as I stated above, this refreshes every time.  After copying a recent version and renaming it in the version folder, I get this error in the development console:   Unexpected exception refreshing version list java.lang.IllegalArgumentException: Version '1.6.1' is already tracked     at net.minecraft.launcher.updater.VersionList.addVersion(VersionList.java:91)     at net.minecraft.launcher.updater.LocalVersionList.refreshVersions(LocalVersionList.java:44)     at net.minecraft.launcher.updater.VersionManager.refreshVersions(VersionManager.java:47)     at net.minecraft.launcher.Launcher$2.run(Launcher.java:164)     at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)     at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)     at java.util.concurrent.FutureTask.run(Unknown Source)     at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)     at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)     at java.lang.Thread.run(Unknown Source) I have a WinForms app that I am trying to make full screen (somewhat like what VS does in full screen mode).  Currently I am setting FormBorderStyle to None and WindowState to Maximized which gives me a little more space, but it doesn't cover over the taskbar if it is visible.  What do I need to do to use that space as well?  For bonus points, is there something I can do to make my MenuStrip autohide to give up that space as well? SQL Server - Best way to get identity of inserted row? What is the best way to get IDENTITY of inserted row?  I know about @@IDENTITY and IDENT_CURRENT and SCOPE_IDENTITY but don't understand the pros and cons attached to each.  Can someone please explain the differences and when I should be using each? Ubuntu 12.04 comes with Gimp 2.6, so I installed Gimp 2.8 using the instructions below:   sudo apt-get purge gimp*   sudo add-apt-repository ppa:otto-kesselgulasch/gimp   sudo apt-get update   sudo apt-get install gimp    When try to open help, I get the message below. How do I install and configure the help for 2.8 on Ubuntu? Proving $(P(AB))^2+(P(AB^c))^2+(P(A^cB))^2+(P(A^cB^c))^2\ge\frac{1}{4}$ for any events $A$ and $B$ Show that for any two events $A$ and $B$, $$(P(AB))^2+(P(AB^c))^2+(P(A^cB))^2+(P(A^cB^c))^2\ge\frac{1}{4}$$   Using the Inclusion-Exclusion formula, De Morgan's law and $P(AB^c)=P(A)-P(AB)$, I was able to expand the $\rm{l.h.s.}$ as $$(x+y)(x+y-4z)+2z(2z+1)+x(x-2)+y(y-2)+1\quad...\quad(*),$$ where $x=P(A),y=P(B)$ and $z=P(AB)$.  However I'm not being able to group the terms involved in the $\rm{l.h.s.}$ to form a 'suitable' expression and probably the way I have grouped them is not correct.  The expression $(*)$ is subject to the condition   $\max\{0,x+y-1\}\le z\le \min\{x,y\}$ and obviously $0\le x,y,z\le 1$, but I am unable to use this.      Is there an elegant/slick way to show the inequality? It probably can be shown without a lot of work and it's possible I'm missing something trivial here. Please help me  to evaluate combinatorially the following sum: $$\sum_{k=0}^n \binom{n}{k}$$   Thank you. Maximum and Minimum values for ints Selecting a database in mysql with spaces in its name I want to select my particular database in mysql console, but the problem is that my database name has a space in between and mysql ignores the part after the space. For instance, when i give the command:  use 'student registration'   I get the message:  cannot find database 'student' sum numbers in different lines in shell i have 8000 lines similar to this   &lt;Flow flowId="1" timeFirstTxPacket="+0.0ns" timeFirstRxPacket="+924100.0ns" timeLastTxPacket="+199984927558.0ns" timeLastRxPacket="+199675473275.0ns" delaySum="+2287566662167.0ns" jitterSum="+65280162191.0ns" lastDelay="+3511349483.0ns" txBytes="161956" rxBytes="116536" txPackets="3125" rxPackets="2251" lostPackets="640" timesForwarded="0"&gt;   and what i need to do is summing rxPackets in each line together and txPackets too   i mean total sum of them in 8000 lines  thanks in advance  &lt;Flow flowId="1" timeFirstTxPacket="+0.0ns" timeFirstRxPacket="+924100.0ns" timeLastTxPacket="+199984927558.0ns" timeLastRxPacket="+199675473275.0ns" delaySum="+2287566662167.0ns" jitterSum="+65280162191.0ns" lastDelay="+3511349483.0ns" txBytes="161956" rxBytes="116536" txPackets="3125" rxPackets="2251" lostPackets="640" timesForwarded="0"&gt;  &lt;Flow flowId="2" timeFirstTxPacket="+3000000.0ns" timeFirstRxPacket="+3254190.0ns" timeLastTxPacket="+199988489445.0ns" timeLastRxPacket="+199631899307.0ns" delaySum="+12081144328484.0ns" jitterSum="+105606015634.0ns" lastDelay="+9407845452.0ns" txBytes="251896" rxBytes="124840" txPackets="4867" rxPackets="2413" lostPackets="1757" timesForwarded="0"&gt;  &lt;Flow flowId="3" timeFirstTxPacket="+4000000.0ns" timeFirstRxPacket="+4254098.0ns" timeLastTxPacket="+199971756470.0ns" timeLastRxPacket="+198959480315.0ns" delaySum="+5150205600987.0ns" jitterSum="+74009967633.0ns" lastDelay="+9862217799.0ns" txBytes="163044" rxBytes="90532" txPackets="3150" rxPackets="1751" lostPackets="1013" timesForwarded="0"&gt; Massive 404 attack with non existent URLs. How to prevent this? The problem is a whole load of 404 errors, as reported by Google Webmaster Tools, with pages and queries that have never been there. One of them is viewtopic.php, and I've also noticed a scary number of attempts to check if the site is a WordPress site (wp_admin) and for the cPanel login. I block TRACE already, and the server is equipped with some defense against scanning/hacking. However, this doesn't seem to stop. The referrer is, according to Google Webmaster, totally.me.  I have looked for a solution to stop this, because it isn't certainly good for the poor real actual users, let alone the SEO concerns.  I am using the Perishable Press mini black list (), a standard referrer blocker (for porn, herbal, casino sites), and even some software to protect the site (XSS blocking, SQL injection, etc). The server is using other measures as well, so one would assume that the site is safe (hopefully), but it isn't ending.  Does anybody else have the same problem, or am I the only one seeing this? Is it what I think, i.e., some sort of attack? Is there a way to fix it, or better, prevent this useless resource waste?  EDIT I've never used the question to thank for the answers, and hope this can be done. Thank you all for your insightful replies, which helped me to find my way out of this. I have followed everyone's suggestions and implemented the following:   a honeypot a script that listens to suspect urls in the 404 page and sends me an email with user agent/ip, while returning a standard 404 header a script that rewards legitimate users, in the same 404 custom page,  in case they end up clicking on one of those urls. In less than 24 hours I have been able to isolate some suspect IPs, all listed in Spamhaus. All the IPs logged so far belong to spam VPS hosting companies.   Thank you all again, I would have accepted all answers if I could. For a lot of questions here on TeX.SE and on other fora regarding MiKTeX, it turns out that the underlying problem actually lies in the not understood distinction between administrative and user modes. So let me ask these questions:  What’s the difference between administrative and user mode in MiKTeX, and in which situation should I use either one of these modes? Can the effects of a person's mass upon the local gravitational field be detected and measured remotely? Not sure how to make tables, but:  For a binary operation $*$, and set $\{e,a,b,c\}$, in the Cayley table, $a*a$ can be filled with either the identity or an element different from both $e$ and $a$. If in the table the place for $a*a$ is filled with $e$, then the rest of the table can be filled out in two different ways.  What are the two different ways?  Thanks Can I use my laptop as a second monitor? Is it possible to make my laptop's screen act as a second monitor for my desktop computer? Editing a starred post in chat breaks display for user who starred it Steps to reproduce:   User A posts a message User B stars it, the star next to the post appears yellow User A edits the post The display of the star in User B's view becomes black, as if they haven't starred it   This is the worst bug ever in the history of StackExchange and makes the entire network completely unusable for me. I'm going to Yahoo! Answers until this is fixed. Is $v=\ (r_i)^{-1}\cdot z $, a uniformly random value of a field? We consider a finite field $\mathbb{F}_q$ where $q=2p+1$ and $q$ and $p$ are prime numbers.  Let $r_i$ be a value picked uniformly at random from the field such that $r_i&gt;\frac{q}{2}$. Let $z$ be a fixed field element.   Question: Is $v=(\ (r_i)^{-1}\cdot z) \bmod q$, a uniformly random value of the field?