If I run  apt upgrade    in one terminal, why can’t I run  apt install chromium    in another until   apt upgrade    is done?
I was wondering why the software center doesn't download all the requested apps and install one by one as they finish to download. Or instead why the software center doesn't download an app while the other is installing
How to manually typeset text in parallel on facing pages in (Lua)LaTeX? I want to typeset a bilingual text in parallel on facing pages using LuaLaTeX. The existing solutions to automate this task have proven unsatisfactory as they don't allow for footnotes (parallel), don't allow for different font sizes of the two parallel texts (), or generally provide a poor result of aligned text chunks (eledpar).  As the text is not too long, I really came to consider breaking the pages myself. For this to do, I have to solve the following problem(s):  Consider two facing pages with ending paragraphs of different length. The following paragraphs should then begin at the same vertical position such that the beginnings of these following paragraphs face each other. For this to accomplish on has   to determine the position of the end of the longer paragraph on its page to have the means to let the next parallel paragraphs both begin at the identified position.   Is this something which is doable? Are there mechanisms provided by (Lua)LaTeX to determine positions on a page and to begin typesetting at a specific position on a page?  EDIT: The following example illustrates the task. Here the latin paragraph starting with "O tempora, o mores" (third chunk of text in the code) should begin at the facing position of the beginning of the paragraph "Shame on the age..." (fifth chunk).  \documentclass[a6paper]{scrbook} \usepackage{fontspec} \usepackage[latin,english]{babel} \begin{document} \mbox{}\pagebreak  \noindent\selectlanguage{latin}{\large quo usque tandem abutere, Catilina, patientia nostra? quam diu etiam furor iste tuus nos eludet? quem ad finem sese effrenata iactabit audacia? nihilne te nocturnum praesidium Palati, nihil urbis vigiliae, nihil timor populi, nihil concursus bonorum omnium, nihil hic munitissimus habendi senatus locus, nihil horum ora voltusque moverunt? patere tua consilia non sentis, constrictam iam horum omnium scientia teneri coniurationem tuam non vides? quid proxima, quid superiore nocte egeris, ubi fueris, quos convocaveris, quid consili ceperis quem nostrum ignorare arbitraris?\par\newpage}  \noindent\selectlanguage{english}When, O Catiline, do you mean to cease abusing our patience? How long is that madness of yours still to mock us? When is there to be an end of that unbridled audacity of yours, swaggering about as it does now?  Do not the nightly guards placed on the Palatine Hill — do not the watches posted throughout the city — does not the alarm of the people, and the union of all good men — does not the precaution taken of assembling the senate in this most defensible place — do not the looks and countenances of this venerable body here present, have any effect upon you? Do you not feel that your plans are detected? Do you not see that your conspiracy is already arrested and rendered powerless by the knowledge which every one here possesses of it? What is there that you did last night, what the night before — where is it that you were — who was there that you summoned to meet you — what design was there which was adopted by you, with{\parfillskip0pt\relax\par}  \noindent\selectlanguage{latin}{\large O tempora, o mores!\par\newpage}  \noindent\selectlanguage{english}which you think that any one of us is unacquainted?  Shame on the age and on its principles! \end{document} Find the number of solutions to $ \lfloor x \rfloor + \lfloor 2x \rfloor + \lfloor 4x \rfloor + \ldots + \lfloor 32x \rfloor =12345$ Find the number of solutions of the equation    $$\lfloor x \rfloor + \lfloor 2x \rfloor + \lfloor 4x \rfloor + \lfloor 8x \rfloor + \lfloor 16x \rfloor + \lfloor 32x \rfloor =12345,$$   where $\lfloor\,\cdot\,\rfloor$ represents the floor function.   My work: I use the fact that $$\lfloor nx \rfloor =\sum_{k=0}^{n-1} \left\lfloor x +\frac kn \right\rfloor.$$ So the equation becomes $$\lfloor x \rfloor +\sum_{k=0}^{1} \left\lfloor x +\frac k2 \right\rfloor +\sum_{k=0}^{3} \left\lfloor x +\frac k4 \right\rfloor +\sum_{k=0}^{7} \left\lfloor x +\frac k8 \right\rfloor   \\ \qquad {}+\sum_{k=0}^{15} \left\lfloor x +\frac k{16} \right\rfloor +\sum_{k=0}^{31} \left\lfloor x+\frac k{32} \right\rfloor   \\ = \lfloor x \rfloor + \left\lfloor x+\frac 12 \right\rfloor + \left\lfloor x+\frac 64 \right\rfloor + \left\lfloor x+\frac{28}{8} \right\rfloor   \\ \qquad {}+ \left\lfloor x+\frac{120}{16} \right\rfloor + \left\lfloor x+\frac{496}{32} \right\rfloor$$  What should I do next? How do I convert or upgrade roads? I'm trying to optimize my road system a bit, mostly converting regular small roads into one-way roads. But the only way I can see to do that is to remove the old road entirely and build a new one. I can't seem to just build over the old one.   I can understand that limitation in cases where the new road type is larger, but it should be possible to upgrade to roads with the same size without tearing down the old road manually.   Is there an easier way to convert or upgrade roads, or do I have to manually remove the existing road every time? Why does change in speed of a wave make it refract? When a light wave enters a medium with a higher refractive index (e.g. from air to standard glass) and its speed decreases, why does that make it refract/bend?  I understand that wavelength decreases and frequency stays the same and therefore its speed decreases, but I can't find anywhere whatsoever why the speed decrease cause the wave to refract. So could someone please explain this? How to know that your machine learning problem is hopeless? Is the size of a Form in Visual Studio designer limited to screen resolution? Can I get the output of a command line program with TeX (using e.g. \read18)? After some searching, I find very little on the incorporation of observation weights/measurement errors into principal components analysis. What I do find tends to rely on iterative approaches to include weightings (e.g., ). My question is why is this approach necessary? Why can't we use the eigenvectors of the weighted covariance matrix? Proof that the Euler characteristic is additive I'm reading through a set of notes which assumes that the Euler characteristic is additive, but doesn't give a proof, so I would like to understand why this is.  Let $A_n$ be a finitely generated Abelian group, non-zero for $0&lt;n&lt;k$. Consider the long exact sequence  $ \cdots \rightarrow A_n \rightarrow B_n \rightarrow C_n \rightarrow A_{n-1} \rightarrow B_{n-1} \rightarrow C_{n-1} \rightarrow \cdots $  where $B_n$, $C_n$ defined similarly to $A_n$.   I know that the Euler characteristic of $A$ is given by $\chi(A) = \sum_0^k (-1)^n \text{rank}(A_n)$, with similar definitions for $B$ and $C$. I want to prove that $\chi(B) = \chi(A) + \chi(C)$.  The notes say that for an exact sequence  $0 \rightarrow X \rightarrow Y \rightarrow Z \rightarrow 0$  of finitely generated Abelian groups $X,Y,Z$, we have the result rank($Y$) $=$ rank($X$) +  rank($Z$), and that the additivity of the Euler characteristic follows from this fact, but I can't see how. Isomorphism between quotient modules Is it true for a commutative ring $R$ and its ideals $I$ and $J$ that if the quotient $R$-modules $R/I$ and $R/J$ are isomorphic then $I=J$? How is the Starkiller Base supposed to work more than one time, given how it draws its power? In Star Wars: The Force Awakens, once the Starkiller Base has depleted the star it is drawing power from, is it supposed to travel to another star where it can draw more power? Or is it non-mobile and supposed to fire a few, limited shots only? Or can it somehow reuse the star it is drawing power from, even after it has been depleted?  Its name suggests that it will "kill" or completely deplete the star it is drawing power from, but I haven't noticed an indication in the film that the Starkiller Base can travel to other stars. How to find a computer name in a LAN from the IP address? My network includes machines running Linux and others running Windows. And my machine is running Linux. Interpreting spline results The use of "were- should- had” at the beginning of sentences instead of “if” Conditionals in English are usually formed by using if with normal word order; but for the three past (subjunctive) forms were, should, and had, it is also possible to express the conditional through subject–auxiliary inversion alone, with no if in the conditional clause.  Does forming conditionals in this manner differ semantically from if-conditionals? Is some aspect of the conditional statement or the conditionality emphasised more in one version than in the other? Or are there differences in how and when they are used? Or are they simply completely interchangeable?  For example:     If I were you, I would try it again   Were I you, I would try it again      If I had seen it, I would have told you   Had I seen it, I would have told you      If you should drink, don’t get behind the wheel   Should you drink, don’t get behind the wheel Do I need a firewall for my desktop? I don't have a  router, but I mostly use my desktop for online shopping and torrenting. So, do I have to enable the firewall? I hope not, because I'm really dumb and I don't think I will be able to configure the firewall. At the start of A New Hope are Yoda and Obi-Wan really the last remaining Jedi? I have never read any Star Wars books and have no knowledge outside of the Star Wars films, but after seeing Episode III I am left wondering if there are any other Jedi that escape death and remain in hiding like Yoda did. I mean with regard to the "official" events in the Star Wars universe. Are all multiplicative functions additive? Suppose $cf(x)=f(cx)$ and $f:\mathbb{R}\to\mathbb{R}$. I believe it follows that $f(x+y)=f(x)+f(y)$.   Proof: There is some $c$ such that $y=cx$. Then  $$f(x+y)=f\left((1+c)x\right)=(1+c)f(x)=f(x)+cf(x)=f(x)+f(cx)=f(x)+f(y)$$  QED.  I wonder if the same thing holds for when $f:\mathbb{R}^n\to\mathbb{R}^n$? I can't use the same trick, because all vectors are not scalar multiples.  I tried thinking of it in terms of basis units, but didn't get anywhere. Bootstrap 3 - Why is row class is wider than its container? I worked on a Word document and also saved the file on my flash drive.  When it asked me to save, I pressed the Replace document option by mistake.    I can see the missing work under the Properties menu. Will I be able to recover the lost work? How do I create a 50x3 cell array from a 50x3 matrix. Keep just getting a 1x1 cell array with a 50x3 submatrix?