JTree and CellEditor not working correctly when using two different objects in the same JTree
What is a NullPointerException, and how do I fix it?
Convert HTML entities to Unicode and vice versa Can someone please verify my proof?     Is the collection $\tau_\infty = \{U:X-U$ is infinite or empty or all of $X\}$ a topology on $X$?   No. Let $X = \mathbb{R}$.  Clearly, $\{x\} \in \tau_\infty$ for all $x \in X$.  Set $\displaystyle{B = \cup_{x \neq 0} \{x\}}$. Clearly, $X - B = \{0\}$, but $\{0\} \notin \tau_\infty$. Since $\tau_\infty$ is not closed under arbitrary unions, it does not define a topology on $X$. In CSS what is the difference between "." and "#" when declaring a set of styles? What is the difference between # and . when declaring a set of styles for an element and what are the semantics that come into play when deciding which one to use? Ever since upgrading to Windows 10 1903 the other day, my CPUs have all been pegged at 100%.  "Antimalware Service Executable" is using 60%, and "Microsoft OneDrive (32 bit)" is using 35% (with the other 5% being spread amongst everything else running).  After running like this for a day or so my computer case (Surface Tablet) is smoking hot.  How can I find out what's causing this problem?  Is there logging I can review for those services?  Known issues with 1903 that I just can't find on Google? move file by list in file (with leading whitespace) Do you "gain" your 1st level? How can I repair the Windows 8 EFI Bootloader? What is the limit of $\lim\limits_{x→∞}\frac{\sin x}{x}$ A positive integer is divisible by $3$ iff 3 divides the sum of its digits I am having trouble proving the two following questions:    If $p|N$, $q|N$ and gcd(p,q)=1, then prove that $pq|N$ If $x$ is non zero positive integer number, then prove that $3|x$ if and only if 3 divides the sum of all digits of $x$.   For both questions I tried to use theorems of discrete mathematics, but I could not find the way to solve them. How do I create a D&D character correctly as a total newbie? The current process for self-deletion of a user account has several problematic aspects, both in the process itself and in the end result. Some of these issues are:   The process requires manual intervention of a mod or SE employee, leading to delays and sometimes mistakes. It is more complicated than it has to be, which can lead to the impression that SE is imposing some rather arbitrary-looking restrictions and steps one has to take. This can give the impression that the user isn't really in control of his private data at SE. It is irreversible once the account is deleted, although an account can be partially reconstructed with a lot of manual effort from an SE developer. There is no real protection against mod/SE employee errors, if an account is deleted in error, there is no easy way to undo the damage. Because it is manual, it consumes the time of SE employees that have to deal with it  (unless  is used), removing useful voting information and annoying users that lose reputation that way.   I'm proposing an alternative way of handling self-deletion that would be automated, and also reversible to some extent, while still being pretty much a hard-delete (and not a soft-delete that would be problematic with respect to user privacy). The process would work roughly like this:   The user clicks a "delete profile" button in his profile. There should be a way to indicate if you want to delete all profiles on all SE sites, only on this site and a way to select multiple sites from a list where the profile should be deleted. It is verified that the user has true access to the account in some way (confirmation mail?) and not just someone that found the unlocked computer of the user. A countdown until deletion is started (I'd go with 48h, but that could be different). The timer shouldn't be too long, but long enough to correct mistakes and leave users a bit of time to reconsider. Alternative options would be to enable users to override the countdown if they really want to nuke their account immediately. Another option would be to soft-delete the account immediately, and make the countdown only for hard-deletion of the user data. Upon deletion, the posts of the user and his votes are transferred to a newly created blank account, the original account itself is hard-deleted with all the remaining data it contains. The dummy account that holds the user's data should be flagged in some way as deleted, so that the profile links will be disabled, the profile won't be accessible and it won't appear in any user lists.  The user receives a private code that can be used to claim ownership of the account. Other ways are not possible as all private information is removed about the account. This allows for an automatic way of reclaiming most of the important parts of a deleted account. The ability to restore a deleted account might have to be somewhat restricted to avoid misusing it to get rid of the account history. It is more meant as an additional safeguard so that account reconstruction is more easily possible in rare cases. Such additional safeguards might be necessary as the deletion itself would be automatic and without oversight from SE or moderators.   I personally think that the information which posts and votes were connected to a (now anonymized) account is not sensitive enough that it would have to be removed on account deletion. My idea is that this would be close enough to a hard-delete that it satisfies any privacy concerns, but still allow reassociation of posts with a recovered account. The partial reversibility would alleviate concerns about removing the manual oversight by mods and SE employees over the account deletion process. Username and Password not recognized when logging into Minecraft Limit involving the exponential of an expression plus a small-o I'm trying to formalize the following limit:  $$\lim_{x \to \infty} \left[1+\frac{a}{x}+o\left(\frac{1}{x}\right) \right]^x= e^a$$ however I can't see how to rigorously show this identity.  Any suggestions? Sum of indepedent random variables and a constant Let $X_1$ and $X_2$ be independent Normal random variables with mean $\mu_1$ and $\mu_2$, and variances $\sigma_1$ and $\sigma_2$. Let $Y = X_2-X_1 + c$, where $c$ is a constant. For notational simplicity, let $Y = X' + c$, where $X' = X_2-X_1$ The moment generating function of a Normal random variable $X_n\sim N(μ_n,σ_n^2)$ is $$M_{X_n } (t)=\text{exp}\Big(μ_n t+\frac{σ_n^2 t^2}{2}\Big)$$ Then, $$M_{X'} (t)=\text{exp}\Big[t(\mu_1+\mu_2)+\frac{t^2}{2}(\sigma^2_1+\sigma^2_2)\Big]$$ Thus, by the uniqueness property of moment generating function, $X'$ is said to follow a Normal distribution with mean $(\mu_1+\mu_2)$ and variance $(\sigma^2_1+\sigma^2_2)$. How do I proceed from here to derive the following:  First, I want to establish that $Y$ is also a Normal random variable using the moment generating function. The constant $c$ bugs me, but I cannot ignore it. As per my understanding, $Y\sim N\big(c+\mu_1+\mu_2,\sigma^2_1+\sigma^2_2\big)$ (and I could be completely wrong). But I don't understand how to apply the moment generating function to prove that.  Secondly, I want to derive $P(Y \leq a)$, where $a$ is a constant. If I am not mistaken, $P(Y \leq a)$ can be written as $$P(Y \leq a)=\Phi\Bigg(\frac{a-X_2-X_1 + c}{\sqrt{2(\sigma^2_1+\sigma^2_2)}}\Bigg).$$ But how do I arrive at that.   Any help is high solicited and appreciated. How to upgrade from 18.10 to 19.10, using the command line? I'm trying to upgrade from 18.10 to 19.10, using sudo do-release-upgrade however I only get an error: An upgrade from 'cosmic' to 'eoan' is not supported with this tool. I performed the steps to update my sources.list to point to old-release server, as suggested here:  This did not help. I get the same error. lsusb relevant output Bus 001 Device 006: ID 0bda:8812 Realtek Semiconductor Corp. RTL8812AU 802.11a/b/g/n/ac WLAN Adapter  Upon plugging the device it is recognized by lsusb, however when I go to wireless settings no adapter is recognized. The driver is installed (by going to software and updates -> addition drivers and selecting the open source driver). Find the limit of $\sum\limits_{k=1}^n\left(\sqrt{1+\frac{k}{n^2}}-1\right)$ What is the use of a persistence layer in any application? How a module can override theme suggestion? Basically it was  but I'll reword it, as I don't want to define a new theme (reason was already given).  What I want to do: in my module I have a file node--attach.tpl.php which is a modifed version of node.tpl.php. Now I want that, if view_mode = 'attach' then this file is used. Also, theme should be allowed to override it with its own node--attach.tpl.php in theme folder. My floating point number has extra digits when I print it