I am trying to install the desktop environment of lubuntu on Ubuntu 18.04.02 but I am getting the following error:  $ sudo apt install -y lubuntu-desktop Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  lubuntu-desktop : Depends: lubuntu-gtk-core but it is not going to be installed                    Depends: lubuntu-gtk-desktop but it is not going to be installed E: Unable to correct problems, you have held broken packages.   Any idea how to address this?
After upgrading from 10.04 to 12.04 I am trying to install different packages.  For instance ia32-libs and skype (4.0).  When trying to install these, I am getting the 'Unable to correct problems, you have held broken packages' error message.   Output of commands:  sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   After running this:  sudo dpkg --configure -a foo@foo:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
If $|f(z)|\le |g(z)|$, can we say $f$ is constant? Let $f$ and $g$ be entire functions and $g(z)\neq 0$ for all $z\in \mathbb{C}$. If $|f(z)|\le |g(z)|$, can we say $f$ is constant?  Liouville theorem says that an entire bounded function is constant, but g is not given bounded here. So I think it should be false. What else can we say about $f$? biblatex: multiple bibliographies categorised by different .bib files biblatex supports multiple bibliographies by looking up the 1) entry type, 2) keyword, or 3) category.  This is all fine, but in the use case of primary sources and secondary sources: 1) the 'type' method doesn't work, 2) it is quite tedious to key in the 'primary' and 'secondary' keywords for each .bib entry, and 3) declaring the sorting by category would entail typing all the primary keys in the document.  So, if I'm storing all my primary bib entries in one .bib file, and secondary one in another, is there a bit to tell biblatex to assign a keyword or category automatically to all the entries from that bib file as it imports them?  Done this way, entries can be easily swapped to and from the primary and secondary .bib files without fiddling individual keywords, and I don't have to type out all the primary and/or secondary entries into categories in each document. When using unicode-math, how do I get the original calligraphic alphabet back? I am happy with the great majority of what unicode-math does. But at times I find that I prefer a symbol the way it was before. With \varnothing and \complement, for example. In those cases I was able to save them under a different name before loading unicode-math, but this doesn't always work.  Right now I'm trying to access the \mathcal alphabet from plain LaTeX. How might I accomplish this?    Additional Question  I've been looking through unicode-math, trying to figure out where exactly the original \mathcal alphabet gets discarded, but I eventually gave up.  It would be interesting if someone could explain:   how/where the original \mathcal font is defined anyway, and what kind of 'switch' is thrown by unicode-math that makes it unavailable. Seeking neighborhood boundaries globally? Besides Zillow's creative-commons licensed  shapefiles, what sources of neighborhood boundaries are there? Not just in the US, but all over the world.  Free/open source is ideal, but paid sources could be interesting too. Can you flash any android device with "fastbood flash" command (of the adb)? Difference between ' and " on command line (bash)? I used to use '' and "" (single and double-quotes) interchangeably on the command line, but I recently noticed that '$HOME/some/dir' is not expanded, while "$HOME/some/dir" is. I searched around a little bit and found that "" allows some protection of special characters, while '' allows full protection. So what other characters are protected by '' and not ""?  EDIT: What are practical situations in which these differences might be significant? Can you give a simple intuitive explanation of IRLS method to find the MLE of a GLM? Background:   I'm trying to follow .  I understand the basics of MLE estimation: likelihood, score, observed and expected Fisher information and the Fisher scoring technique. And I know how to justify .    The question:   I can't understand even the first line of this method :(   What's the intuition behind the $z_i$ working variables defined as:  $$ z_i = \hat\eta_i + (y_i -\hat\mu_i)\frac{d\eta_i}{d\mu_i}$$  Why are they used instead of $y_i$ to estimate $\beta$?   And what's their relation with the response/link function which is the connection between $\eta$ and $\mu$  If anyone has a simple explanation or can direct me to a more basic-level text about this I would be grateful. butt, bottom, buttock and ass? A woman's butt was allegedly touched by a man several times during a commute on the MRT.   How to use butt, bottom, buttock and ass? I am confusing with these words. Does pointwise convergence of continuous functions on a compact set to a continuous limit imply uniform convergence on that set? The problem is in Marsden - Elementary Classical Analysis 2nd ed. Ch.5.  My approach was   Condition : $f_k, f(\in\mathcal C) : A\to N$, $f_k \to f \ \text{(pointwise)}$ and $A$ is compact. Since $A$ is compact, the range of $f_k, f$ are all compact, so bounded. Since $f_k, f\in\mathcal C_b$, if $\|f_k-f\|\to 0$ in $\mathcal C_b$ then $f_k\to f \ \text {(uniformly)}$.   when the norm of $\mathcal C_b$ is defined by $\|f\|=\sup\{\|f(x)\||x\in A\}$.  I got stucked in 3, showing $\|f_k-f\|\to 0$. I don't even know the proposition is true. Can anyone give me some hint to solve this or a counterexample for this? When should we use proximity rule in "either/or", and "neither/nor"? Recommendation for mobile prepaid SIM card for smartphone + home calls in Germany What SIM card would you recommend for a smartphone user for travel in Germany?  It would be probably the only or the most important connection to the Internet, so large amounts of data and relatively fast transfer is an issue.  I need to stay in touch with friends and family, so the calls to other EU countries should be as cheap as possible.   For to the first criteria, I found the T-Mobile offer interesting. The internet costs 10 Euros/month and after reaching the transfer limit it stays relatively fast. According to tests (Galileo from Pro7, AFAIR) it has also the best coverage. However, calls to other countries are very expensive.  For to second criteria, Lebara and Mobilka are interesting. The calls are very cheap, but there are problems with signal strength in many locations, where T-Mobile has no problem. The voice quality, at least in Lebara, is also limited. They both have mobile internet with unlimited transfer, but after reaching the high speed limit, the transfer is reduced to 64 kbps, which is too slow.  I've found out that O2 has foreign calls at moderate prices, but I haven't yet checked for details. There are so many other options, making it is hard to compare them all without spending the whole weekend on it. So, if someone has found a better option than having 2 SIM cards and constantly switching them, this answer would be greatly appreciated. Could someone explain to me what the collision of two photons would look like? Will they behave like,   Electromagnetic waves: they will interfere with each other and keep their wave nature Particles: they will bounce like classical balls   I assume that energy of that system is too small to make creation of pairs possible. 2 different bibliographies I'm writing my thesis and I would like to make 2 "bibliography" references: The first one would be for the publications I'm in and the second one for external references. I've made one *.bib file right now and it's working but I have no idea how I should work with 2 *.bib files.  Any suggestion will be appreciated. $M + N$ and $M \cap N$ are finitely generated $A$-modules implies $M$ and $N$ finitely generated using exact sequences Let $0 \to M_1 \to M \to M_2 \to 0$ be an exact sequence of $A$-modules.  i) Prove: If $M_1$ and $M_2$ are finitely generated, then $M$ is too.  ii) Let $M$ and $N$ be sub-modules of an $A$-module $L$. Assume that $M+N$ and $M\cap N$  are finitely generated $A$-modules. Prove that $M$ and $N$ are finitely generated $A$-modules.  If have proved the first part, but i don't see how to do the second part. I tried to use the first part, so to find an exact sequence with $M$ in the middle and finitely generated modules in place of $M_1$ and $M_2$, but I can't find a surjective map $M \to P$ (for some f.g. $A$-module) in the sequence:  $$0 \to M\cap N \to M \to P \to 0$$  any hints/help would be appreciated. Problems after upgrading to 14.04 (only background and pointer after login) I noticed with the holiday patch that there are new trees and shrubs that spawn on my land.  One popped up today, being specifically an X-Mas tree - which costs 25,000 gold to remove.   Is there any benefit to removing this X-Mas tree?  Is there any benefit to leaving it there?    It is noticeably the most expensive obstacle to remove yet. How to split a string with any whitespace chars as delimiters What regex pattern would need I to pass to  java.lang.String.split()  to split a String into an Array of substrings using all whitespace characters (' ', '\t', '\n', etc.) as delimiters? Placing finger twice on Finger Scanner on iPhone 6 plus changes view Why are we limited to six questions per day? Limit point versus limit and implications for convergence I understand that similar questions to this have been asked  and  but I believe my question is different because with regards to (1) I am not asking about the set $X$ that contains the points of my sequence and with regard to (2) because I have the distinct definitions of limit and limit point in mind. That said:  My Question: My textbook, Fundamental Ideas of Analysis by Michael Reed, defines a limit point as:     Definition: Let $(a_n)$ be a sequence of real numbers. A number $d$ is called a limit point if, given $\epsilon &gt; 0$ and an integer $N$, there exists $\color{red}{\mathrm{ an }} \ n \ge N$ so that $|a_n - d| \le \epsilon$.    The definition of a limit is as follows:     Definition: We say that a sequence $(a_n)$ converges to a limit $a$ if, for every $\epsilon \ge 0$, there is an integer $N(\epsilon)$ so that $|a_n - a| \le \epsilon \color{red}{\text{  for all  }} n \ge N$.    From these definitions, and given this question:     If a sequence converges it has exactly one limit point. Is the converse true? If not, provide a counterexample   Can I conclude that the converse is indeed true simply by appealing to the definitions, or do I need a tighter proof. And if I do, I'm a little stuck on how to refine this proof.