(Just a theoretical question, I don't see a direct practical use)  Is there a way to do something like:  super.super.someMethod()   In Java?  super.someMethod()   exists, why not be able to invoke the super class of a super class?  (of course you can create a method:  protected void someSuperMethod(){     super.someMethod(); }   In the super class and invoke that in the child class having the same effect, but is there a direct way of doing that and, if not, why?)  S.
I read  and thought that would easily be solved (not that it isn't solvable without) if one could write:   @Override public String toString() {     return super.super.toString(); }   I'm not sure if it is useful in many cases, but I wonder why it isn't and if something like this exists in other languages.  What do you guys think?  EDIT: To clarify: yes I know, that's impossible in Java and I don't really miss it. This is nothing I expected to work and was surprised getting a compiler error. I just had the idea and like to discuss it.
Relation between intensity of light and refractive index Bevel specific edges Is there a video that explains how Stack Overflow works and can be used? Is there a video that explains how Stack Overflow works and can be used? I.e. a short tutorial to get new users started. If there isn't, then the people behind this site or others who know how it works should make one, because it's overwhelmingly different from other sites and thus difficult for beginners. I am trying to compute this integral/limit, I don't feel like I have any good insight...   $$\lim_{n \to \infty} \int_0^{n^2} e^{-x^2}n\sin\frac{x}{n} \, dx.$$  I have tried to make a change of variable to get rid of the $n^2$, I changed to $X=\frac{x}{n^2}$ but got something even worse, I've tried to reach a situation where I could use a convergence theorem for Lebesgue Integrals,... I'm not sure I'm even on the right track!  Could you give me a hint on how to start this?  Thank you very much! What is the point of Sauron making the One Ring? Why would Sauron make himself a ring that he invested most of his power in? Wouldn't it be better to keep the power in his physical form and not risk leaving his power in a physical form that could be stolen (which did happen when Isildur took it). Because of its being in the form of a ring, its power could be abused by someone else to attack him. Not that it's a very good idea to change it, but for fun. According to  post, there are still some problems even after changing entries in /etc/passwd, /etc/shadow, and /etc/sudoers. Any suggestions? Defaults to true.  If set to true replaces all instances of known swear words with replacements (comical or * based). If false renders the content as originally presented.  Benefits:    Reduces moderation requirements necessary to ensure that people behind corporate firewalls are not blocked by an errent swear word.   Stops idiots like me complaining about it. Show that $S$ is compact. Let $A \in M_n(\bf C)$ and let   $S=\{ A \in M_n(\bf C) : A=A ^*$ and  $\rho (A) \leq 1 \}$, $\rho(A)$ denotes spectral radius of $A$.     Show that $S$ is compact subset of $M_n(\bf C) \cong \bf C^{n^2} $ with usual topology.    $S$ is subset of $\bf O_n(C)$ which is compact so I think its enough to show that $S$ is closed.Please help. Expected Number of coin flips for 2 consecutive heads for first time. I was working on problems on expectation and found this one as a question from a well-known exam  Assume that you are flipping a fair coin, i.e. probability of heads or tails is equal. Then the expected number of coin flips required to obtain two consecutive heads for the first time is.  (A)4  (B)3  (C)6  (D)10  (E)5  I worked up like Let N be the number of tosses required untill 2 consecutive heads are obtained for the first time.  Let the probability of obtaining heads be p and tails be q and for a coin p=q=1-p=1-q.  For N=2, the probability will be $p^2$  For N=3, the probability will be $p^2.q$  For N=4, the probability will be $q^2.p^2$  For N=5, the probability will be $q^3.p^2$  and so on...  Now, $E[N]=2(p^2)+3(p^2.q)+4(q^2.p^2)+5(q^3.p^2)+......$  and this comes out to be $\frac{3}{2}$ but it matches with none of the options.  Please tell me where I am wrong and what should I do to reach the correct solution? How do I select an object in the 3D viewport? Boolean and Texts I have used Hexagon for years but find that it sometimes crashes when trying to do Boolean operations with texts.  I have been trying to make the two tables of the Ten Commandments and have been trying to use Blender.  I did it about two years ago in Blender and lost everything on my computer so I am trying again with the latest version of Blender and am having difficulty.  I start with a cube and then get it close to the dimensions I would think the Ten Commandments might look like. I then bevel the top using the bevel modifier. But in doing it this way I don't have any cross sub divisions on the face of the object. I have tried sub dividing first but then I find that I can't bevel the top arches as far as I would like. I still don't know how to add divisions after I bevel the top. Yes I am still a novice at this program.  In any case I did figure out how to make text and turn them into an object. When I make the texts I do all four of the commandments for one side and then the other six for the other side. So this makes allot of texts to cut out.  When doing the Boolean operation in Difference sometimes nothing happens. I am thinking I need to have some sub - divisions on the face of the sized cube after it is beveled but am not really sure if this is the problem.  This whole thing about normal's is still Greek to me. I have watched some videos on how to cut letters into a cube but for some reason it does not work this easy after I bevel the top of the cube. Or it could be that Blender does not like a bunch of texts all at once.  Could someone show me a video or give me some simple steps to make my project work? Detecting pattern at the end of a line with grep Trichromelibrary was suddenly downloading from Google Play Store Counting set for generating functions Give  a  proof  of  the  following  identity  by  counting  two  sets  of  partitions  in  two  different ways.  \begin{equation*}  \prod_{i\geq 0}(1+x^{2i+1})=1 + \sum_{n\geq 1}x^{n^2}\prod_{j=1}^n\frac{1}{1-x^{2j}}  \end{equation*} To prove this inductively, i only successfully complete the base cases, however the counting set for the left side i concluded that would be the number of partitions of n with distinct odd parts and for RS the product part would be the number of partitions of n with even parts, how would the summation of $x^{n^2}$ come into play with counting set. How would i initiate my proof? I'm running a VPS of a german provider and want to switch from Ubuntu to CentOS. There I tried to install firewalld (was not preinstalled), but it always fails with the error  ERROR: Failed to load nf_conntrack module: modprobe: ERROR: could not find module by name='nf_conntrack' modprobe: ERROR: could not insert 'nf_conntrack': Function not implemented modprobe: ERROR: Error running install command for nf_conntrack modprobe: ERROR: could not insert 'nf_conntrack': Operation not permitted   Obviously the nf_conntrack kernel module was not found. Since this is a VPS, I cannot tinker with the kernel modules. On the support site of my provider I found a list of available kernel modules, for example:  ip_conntrack_netbios_ns ipt_conntrack    ip_conntrack    ip_conntrack_ftp    ip_conntrack_irc   Since nf_conntrack is not listed here, does that mean, that I cannot use firewalld? Is it possible to run it without this module?  I guess I could use iptables, if I wanted to (it seems to run correctly). But as I have more experience with firewalld, I would like to stick with it.    CentOS Linux release 7.7.1908 (Core)  uname -a: Linux xxxxxx.xxxxxxxx.xxx 3.10.0-042stab140.1 #1 SMP Thu Aug 15 13:32:22 MSK 2019 x86_64 x86_64 x86_64 GNU/Linux Another simple series convergence question: $\sum\limits_{n=3}^\infty \frac1{n (\ln n)\ln(\ln n)}$ I'm being asked to determine if $\displaystyle\sum\limits_{n=3}^\infty \frac1{n (\ln n)\ln(\ln n)}$ converges. So, using Cauchy's Condensation Test, I reduced the problem to one of determining the convergence of $\displaystyle\sum\limits_{n=3}^\infty\frac 1{n\ln (n\ln 2)}$. Am I on the right path, and how do I proceed from here? TRON: Game A.I algorithm? I want to create a circuit that can detect audio frequencies and flash RGB LEDs different colors depending on the detected frequency. The frequency range will be from 20 Hz to 12 kHz, after looking at the chart below.   (source: )    So my question is: what circuit design should I choose to make a good frequency detector? I suppose I would need    Preamp for the microphone (is it necessary for the ADC?) Band pass filters (active or passive?) A microcontroller with an onboard ADC that has a sampling rate of at least 24 kHz.   Before I get too excited, are there any circuits out there that already do this? In recent versions of PostgreSQL (as of Dec 2013), can we share a query between two or more cores to get a performance boost? Or should we get faster cores? There has been some recent behavior change on SE (around July 2015).  I have two accounts I use, one Google openId based for one set of sites (call it Account-A) and another SE login based for a different set of sites (Account-B).  Used to be that I could be logged into one set of sites with the first user and a different set with the other users.    But now I am logged in with the Account-A on Site-1.  When I go to one of the sites I use the other account for and click "log in" under the SE menu, I go to a page where I only have an option to confirm creation of an account based on my Google login.  It does not present a way to log in with an SE account.    How can I log in with my other account here?  (and before you flag this as a duplicate, please ensure the other question is recent enough and that the answer is relevant.  This behavior has definitely morphed over the years... and I am having trouble finding something that is relevant.  For instance this question  simply points out how to merge the accounts which is NOT what I want  .  This question  talks about presenting different user info on each site but that's not what I want -- I want totally separate accounts).