root@modsmy:~# add-apt-repository ppa:webupd8team/java -bash: add-apt-repository: command not found   I got this error when I type the following:   add-apt-repository ppa:webupd8team/java
The server version of Ubuntu does not have the  command. How can I add a  (PPA) to the server without this command?
What should I do when the GETDEB repository is down? How to split a long regular expression into multiple lines in JavaScript? Device : Moto X Play ( Rooted, Stock, Android 6.0.1, msm8916 Board, XT1562)  Why do I want to limit charging ?  ( Let's leave out whether my reasons are valid or not and accept that I want to, if you disagree with my reasons)  To improve the longevity of battery , I wish to limit charging when it reaches 90%, as explained here    Is it possible?  Yes, at least on my previous device Honor 6, as brought out here , with two different ways of doing it  I have tried  unsuccessfully to identify the file responsible in which changing values would limit charging  I am looking for the system file responsible for stopping charging, with it's true path (without symlinks)  (as I saw on on my previous device, locating the path of file was a big challenge after identifying it) align vs equation I always use align in my documents, and avoid equation. Is there anything wrong with that? My reasoning behind this: align > equation, so why not use it? Counting the number of propagating degrees of freedom in Lorenz Gauge Electrodynamics How do I definitively show that there are only two propagating degrees of freedom in the Lorenz Gauge $\partial_\mu A^\mu=0$ in classical electrodynamics.  I need an clear argument that   involves the equations of motion for just the potentials $A^0$ and $\mathbf{A}$, and not the electric and magnetic fields.   includes sources $\rho$ and $\mathbf{J}$ in the equations of motion.  This is to justify the assertion that there are degrees of freedom that decouple from the rest of system. does not critically rely on quantum field theoretic arguments (although any supplementary remarks are welcome).     To illustrate the level of clarity I expect, I provide an argument in the Coulomb gauge $\nabla\cdot \mathbf{A} = 0$:  Of the four field degrees of freedom, the gauge condition $\nabla\cdot \mathbf{A} = 0$ removes one degree of freedom (the longitudinally polarized EM waves).  To show that among the remaining three degrees of freedom only two are propagating, consider the field equations of motion in the Coulomb gauge:  \begin{align} \nabla^2 A^0 &amp;= -\rho/\epsilon_0,\\ \big[\frac{1}{c^2}\frac{\partial^2}{\partial t^2}-\nabla^2\big]\mathbf{A}&amp;= \mu_0 \mathbf{J}-\nabla \frac{1}{c^2}\frac{\partial}{\partial t}A^0. \end{align}  The first equation is NOT a wave equation for $A^0$, and thus does not propagate.  The final equation IS a wave equation, and describes the propagation of two degrees of freedom (Gauss' law in first eq. can be solved, and then inserted into the second equation to show that $\mathbf{A}$ only couples to the Solenoidal part of the current). Evaluate $\int_0^1 \frac{\log \left( 1+x^{2+\sqrt{3}}\right)}{1+x}\mathrm dx$ I am trying to find a closed form for  $$\int_0^1 \frac{\log \left( 1+x^{2+\sqrt{3}}\right)}{1+x}\mathrm dx = 0.094561677526995723016 \cdots$$  It seems that the answer is $$\frac{\pi^2}{12}\left( 1-\sqrt{3}\right)+\log(2) \log \left(1+\sqrt{3} \right)$$  Mathematica is unable to give a closed form for the indefinite integral.  How can we prove this result? Please help me.  EDIT  Apart from this result, the following equalities are also known to exist: $$\begin{align*} \int_0^1 \frac{\log \left( 1+x^{4+\sqrt{15}}\right)}{1+x}\mathrm dx &amp;=\frac{\pi^2}{12} \left( 2-\sqrt{15}\right)+\log \left( \frac{1+\sqrt{5}}{2}\right)\log \left(2+\sqrt{3} \right) \\ &amp;\quad +\log(2)\log\left( \sqrt{3}+\sqrt{5}\right) \\ \int_0^1 \frac{\log \left( 1+x^{6+\sqrt{35}}\right)}{1+x}\mathrm dx &amp;= \frac{\pi^2}{12} \left( 3-\sqrt{35}\right)+\log \left(\frac{1+\sqrt{5}}{2} \right)\log \left(8+3\sqrt{7} \right) \\ &amp;\quad +\log(2) \log \left( \sqrt{5}+\sqrt{7}\right) \end{align*}$$  Please take a look . How to force Mac window to foreground? Terminology of the sequences of promoters in relation to DNA strands I'm studying molecular biology and I'm trying to understand an experiment which shows the importance of promoters in the relative transcription level (RT). The image below comes from Rolf Knippers' book "Molekulare Genetik" (8th edition).    The legend says (among other things):     Die erste Zeile gibt die normale "Wildtyp"-Sequenz der 5'-flankierenden Region wieder.   Which, in english, means something like:     The first line repeats the normal wild-type sequence of the 5' flanking region.   The column on the right gives the relative transcription (RT) level, 1.0 being the highest possible level of transcription. As we can see, the lines where some parts of the "5' region" have been deleted give quite low RT levels, since some regions of the promoter are missing.  My questions are the following:  1) According to  and , I understand that RNA polymerase reads and uses both coding and non-coding strands in order to synthesize RNA. Therefore, how did they manage to use the sequences strands regions had been deleted to make a polymerase "read them" and perform transcription?  2) If the polymerase reads the template strand in the 3' -> 5' sense, shouldn't we talk of "ATAT box" or "TAAC box" instead of "TATA" or "CAAT" boxes? Does it mean that the "promoter" regions they are using on the graphic above are actually on the coding strand?  Thanks a lot for your help. \mathcal(O) and font size I use the following mystic TeX so as to display the Landau's notations for big and small O.  There is one partial solution to improve the scriptscriptstyle so as to not use a small o : see the secund answer below. The problemen with \smallOBis is the wrong spacing, contrary to \smallO. How can I do this ?  % Sources : %     1) http://forum.mathematex.net/latex-f6/bonnes-commandes-de-base-t12278.html %     2) http://tex.stackexchange.com/questions/30944/mathcalo-and-font-size  \documentclass{article}     \usepackage{amsmath}     \usepackage{amsfonts}     \usepackage{amssymb}      \usepackage{graphicx}      \newcommand{\bigO}[1]{\ensuremath{\mathop{}\mathopen{}\mathcal{O}\mathopen{}\left(#1\right)}}      \newcommand\smallO[1]{         \mathchoice             {% \displaystyle                 \ensuremath{\mathop{}\mathopen{}{\scriptstyle\mathcal{O}}\mathopen{}\left(#1\right)}             }             {% \textstyle                 \ensuremath{\mathop{}\mathopen{}{\scriptstyle\mathcal{O}}\mathopen{}\left(#1\right)}             }             {% \scriptstyle                 \ensuremath{\mathop{}\mathopen{}{\scriptscriptstyle\mathcal{O}}\mathopen{}\left(#1\right)}             }             {% \scriptscriptstyle                   \ensuremath{\mathop{}\mathopen{}{o}\mathopen{}\left(#1\right)}             }     }      \newcommand\smallOBis[1]{         \mathchoice         {% \displaystyle             \scriptstyle\mathcal{O}\left(#1\right)         }         {% \textstyle         \scriptstyle\mathcal{O}\left(#1\right)         }         {% \scriptstyle         \scriptscriptstyle\mathcal{O}\left(#1\right)         }         {% \scriptscriptstyle         \scalebox{0.8}{$\scriptscriptstyle\mathcal{O}$}\left(#1\right)         }     }   \begin{document}  \[     \renewcommand{\arraystretch}{1.2}%     \begin{array}{llll}          \textbf{Style}            &amp; \verb!\bigO!         &amp; \verb!\smallO!                          &amp; \verb!\smallOBis!         \\ \hline         \verb!\displaystyle!      &amp; \displaystyle      \bigO{\frac{1}{n}}         &amp; \displaystyle      1 + \smallO{\frac{1}{n}} - 2 &amp; \displaystyle      1 + \smallOBis{\frac{1}{n}} - 2         \\         \verb!\textstyle!         &amp; \textstyle         \bigO{\frac{1}{n}}         &amp; \textstyle         1 + \smallO{\frac{1}{n}} - 2 &amp; \textstyle         1 + \smallOBis{\frac{1}{n}} - 2         \\         \verb!\scriptstyle!       &amp; \scriptstyle       \bigO{\frac{1}{n}}         &amp; \scriptstyle       1 + \smallO{\frac{1}{n}} - 2 &amp; \scriptstyle       1 + \smallOBis{\frac{1}{n}} - 2         \\         \verb!\scriptscriptstyle! &amp; \scriptscriptstyle \bigO{\frac{1}{n}}         &amp; \scriptscriptstyle 1 + \smallO{\frac{1}{n}} - 2 &amp; \scriptscriptstyle 1 + \smallOBis{\frac{1}{n}} - 2     \end{array} \]  \end{document} I'm new to linux and the terminal. As I learn how to use the terminal to navigate through directories, I like to use the gui file explorer to mirror my terminal navigation. The icons and file extension info in the gui file explorer help me figure out what everything is. However, I can't access the root folder via the gui, I can only access it via the terminal. Is there a way to enable access to the root folder outside of the terminal? Access to journals for individuals outside of an institution? For all that is said about the wealth of information that is freely available on the internet, the fact is that most of it is incomplete, dumbed down, lacking in context or downright wrong.   Individuals spend the best part of 20 years completely oblivious to the existence of journals and the process of peer review and even then we'd be lucky if 10% of those with access to journals (usually through an institution) actually bother to invest in them.   Granted that some journals will be totally inaccessible to those without a solid background in some particular field but by and large exposure is a good thing and there are many areas of research where individuals will benefit directly from having read these.  Where does this come from?  I decided I wanted to read Popular Politics in the Late Medieval City: York and Bruge in The English Historical Review today, mainly because it looks interesting and I'm hoping to invest more time into learning about British and European History. Incidentally I also wouldn't mind tucking into Super Stable Clocks, Nature 500, 505 (29 August 2013) and a number of data analysis and big data journals in order to advance my career.   Now, not being affiliated with an institution that subscribes to these journals means that I would typically have to pay between £5 ($10) and £15 ($25) per article that I read... I could probably spend £100 just to pass an hour by.  Question   What's being done to address the lockdown on 'higher' education material? I've noticed that the Directory of Open Access Journals publishes open articles and other firms are doing similar, mainly with journals in new fields? How could I, as an individual outside of an institution, gain journal access without it costing so much money? Derivative of $(y-XB)' h(y-XB)$ with respect to $B$ Can I access the App Store from within the iOS Simulator? Can one PC throw another? For example, if there is a lava river surrounding a castle. There is a drawbridge that can be lowered, but the lever is on the other side. PCs couldn't find a hidden passageway,either because PCs failed necessary check and couldn't find it or just because there isn't one. They don't have rope to try to pull the lever down. Or if PCs want to rob a house, but can't pick a lock, they see that window on the second floor is open. Can one PC use his Strength to throw another PC that is one size smaller, with other PC using his Dexterity or Strength to not fall down or lose balance? How to format table with long column head entries? What exactly is 'Dark Matter'? Batch update/delete EF5 Label and caption without float I’d like to have an environment that works much like a float, except that it doesn’t float.  That is, in fact, I’d like to be able to define an environment that has a label and a caption.  I explicitly do not want to use a floating environment, though. For one thing, floats do many things fancy which I just don’t need, nor want (such as spacing) and for another, floats have their share of problems (for example consider the problem of ).  Is there a ready-made way to achieve this? Of course, I could always write my own based on the result of the other answer, i.e. harnessing \refstepcounter. But I’m not sure how to use that, documentation is scarce, and I’d prefer an existing solution. sudo apt update &amp;&amp; sudp apt upgrade -y now shows the error message E:The package linux-modules-5.4.0-56-generic needs to be reinstalled. But I can't find an archive for it.  and nothing proceeds. How can I fix this problem? Thanks. I've been reading about a lot of different types of philosophies, religions, ways of thinking etc. I was wondering what are the most recently created philosophical ways of looking at the universe? Where can one find out about new cutting edge ideas?  Example: Before we had Marxism, Communism, Zen, Christianity etc. Now X,Y, and Z have been created building on and evolving the ideas of A,B,C.   Everything I read about are ideas that were created a long time ago. What is new and updated?