Generate arrow line with CSS
Border with a transparent centred arrow
If that's not possible, then a way to trigger the Dock on the screen with mouse without moving my cursor to the bottom of the screen is also an acceptable solution (I know that the launchpad appears on the screen with Dock)  Also i did see the  about this. Making a logic circuit with only NAND GATES? Unique constraint that allows empty values in MySQL Selection Tool doesn't rotate in Illustrator Why my selection tool doesn't rotate object? I selected the object and it doesn't work. How do I fix this? Different seed gives different LASSO output I'm very familiar with how symbols display differently in inline mode (with $ ... $) vs. how display math shows them (with \[ ... \] or $$ ... $$).  Two examples would be with limits  $\lim_{n\rightarrow \infty}f(x)$   vs.  \[ \lim_{n\rightarrow \infty}f(x) \]   and with sums  $\sum_{n=1}^{x} n^2$   vs.  \[ \sum_{n=1}^{x} n^2 \]   My Question is:     How do you display these things in inline mode (with all the nice inline formatting) as if they were in display mode ?   The inverse -- how to display things in display mode as if they were in inline mode -- is also of interest. I am wondering what sudo apt-get update does?  What does it update? What causes the tension in the strap between Dr. Ryan and Matt? In the scene where Dr. Ryan Stone's (Sandra Bullock) leg is entangled in Soyuz's parachute cords and she is tethered with Matt Kowalski (George Clooney) through a strap, there is tension in the strap, suggesting act of some external force. Where is this force coming form that is causing tension in the strap and pushing both Dr. Ryan and Matt outwards?  I'm guessing that the tension might be coming from centrifugal force, but immediate events before this scene, as well as other parts of ISS in same scene do not suggest presence of such force (or presence of any kind of rotation). Manipulating Partial Derivatives of Inverse Function In lectures we're told:  $$\dfrac {\partial y} {\partial x} = \dfrac 1 {\dfrac {\partial x} {\partial y}}$$  as long as the same variables are being held constant in each partial derivative.  The course is 'applied maths', i.e non-rigorous, so don't confuse me.  But anyway, if we have:  $$\xi = x - y \qquad \eta = x$$  Then $\dfrac {\partial x} {\partial \xi} = 0$ and $\dfrac {\partial \xi} {\partial x} = 1$.  The rule presumably fails because one of the partial derivatives is $0$.  But then isn't this rule useless? Since I cannot use it without checking that the partial derivative isn't in fact $0$, but then I've worked out the partial derivative manually anyway. Every finite set contains its supremum: proof improvement. Every finite subset of $\mathbb R$ contains its supremum (and its infimum)   Proof Let $A=\{a_1,...,a_n\}$ be a finite subset of $\mathbb{R}$. Since it is non-empty and it is bounded ($\max A$ is an upper bound), it has supremum, that is $\exists \sup A$ and by definition $\forall a \in A \;\, a \leq \sup A$. Let's suppose that $\sup A  \not\in A$ then, since $\max A \in A$ we have that $\max A &lt; \sup A$. But considering that $\mathbb Q$ is dense in $\mathbb R$ we can conclude that $\exists r \in \mathbb Q$ s.t. $\max A &lt; r &lt; \sup A$, but this is absurd since $r$ is an upper bound of $A$ and it is lower than the supremum. Necessarily, $\sup A\in A$.  Is there anything wrong? Is there any way to prove this without using density of $\mathbb Q$ or another property? Thanks in advance. In Ruby on Rails, how do I format a date with the "th" suffix, as in, "Sun Oct 5th"? I'm working on the question     Let $G$ be the group of invertible real matrices of the form $\left [\begin{array}{c c}a &amp; b\\ &amp; a^2\end{array}\right ]$. Determine the Lie algebra $L$ of $G$, and compute the bracket on $L$.   I'm familiar with how to derive the Lie algebra for a linear group like $U_n$, $SU_n$, etc. but I'm not sure what to do in a more explicit case like this. Prove that sequence $ x_{(n+1)}= \frac {a}{1+x_n}$ is convergent to positive root of $x^2+x-a=0,$where $a >0$ and $x_1 >0$ Prove that sequence $$ x_{(n+1)}= \frac {a}{1+x_n}$$ is convergent to positive root of $x^2+x-a=0,$where $a &gt;0$ and $x_1 &gt;0$  we have $$x_{(n+2)}-x_n=\frac{-a(x_{(n+1)}-x_{(n-1)})}{(1+x_{(n-1)})(1+x_{(n+1)})}$$  Hence from this we see behaviour of even terms subsequence and odd terms subsequence  is opposite. how to proceed from there. any hint please Not packages and not all applications. Just the applications user installed by himself from whatever source (Software Center, manually added PPA, etc.). If the above is not possible - a list of all installed applications or at least a GUI which lists the applications so I can take screenshots of it.  I've read a dozen of similar questions and people posting answers usually don't even get close to OP question merit. Please note that my question includes 'user installed'.   Answer: It is not currently possible in Ubuntu Linux.  (choosing tijybba's answer as the closest one though) I'm looking to write a script that will find and replace any characters other than [^A-Za-z0-9._-] in a specific file type (in this case .avi) with an underscore _. I want this to exec recursively from the current path. I'm using Ubuntu.  I do not want or need to change any folder names as I have control over those at the time of creation. Here's what I have now after referencing the following link:    find . -depth -exec rename 's!([^/]*\Z)/[^A-Za-z0-9._-]/_/g' *.avi {} +   I'm clearly missing something. Please help. :) Mapping Russia - Int'l dateline splitting polygon I know that I can update a snap package using  sudo snap refresh &lt;package&gt;   But is there a way to update all snaps, like   sudo apt dist-upgrade Replacing strings in files based on certain search criteria is a very common task. How can I    replace string foo with bar in all files in the current directory? do the same recursively for sub directories? replace only if the file name matches another string? replace only if the string is found in a certain context? replace if the string is on a certain line number? replace multiple strings with the same replacement replace multiple strings with different replacements How to configure Jaybird with hibernate How do I bypass restrictions on the length of the PATH variable System Properties      This environment variable is too large. This dialog allows setting values up to 2047 characters long.   I use/have used a lot of software, and my PATH has grown as a result. When I try to add new paths, I get the above message. As a workaround, I'm editing my user path, but prefer not to.