What is the name of the Cygwin package manager?
Installing Cygwin packages from the command-line
Firstly, how do I read it? Is below right? With braces   $$p \vdash (q \Rightarrow p)$$  The given proof is:    ${p}$, premise ${q}$, assumption  $p$ by (1) // what???  ${q} \Rightarrow p$ by implication introduction with 2 and 2.1 QED...    I can't really get the link between $p$ and $q$ in 2.1 ... How can I ensure my exit from the US by land is recorded? Seeing as the US does not perform border control on exit (save for occasional spot checks, usually when traffic is moving slowly at the border), how do I make sure my exit by land is recorded so that I'm not incorrectly flagged as an overstayer?  When exiting the US by air or sea, this is not a problem, as airlines and shipping companies send passenger records to US authorities. What about exiting by land though? Redshift and conformal time What is the relationship between redshift and conformal time ?   For example in a paper i found:   taking $z_e = 3234 $ at the time of radiaton-matter equality yields the conformal time $\frac{\eta_e}{\eta_0} = 0.007$ and taking $z_E=0.39$ at matter-$\Lambda$ equality yields $\frac{\eta_E}{\eta_0}=0.894$ and setting redshift at decoupling $z_d=1089$ yields $\frac{\eta_d}{\eta_0} = 0.0195$  where $\eta_0$ is the present decoupling time.  Further some cosmological parameters are given as :  $\Omega_r = 8.36 \times 10^{-5}, \Omega_m = \Omega_b + \Omega_{dm} = 0.044 +0.226, \Omega_\Lambda = 0.73,  H_0=0.72$  Now how can i calculate all those $\eta_e, \eta_E, \eta_d, \eta_0$ from given redshift values and/or above parameters ? I searched whole of my text books trying to find an explicit relation for conformal time $\eta$ but all i got was $ \mathrm{d}t=a(t)\mathrm{d}\eta$. Any help would be very helpful. I have already dual systems : Windows 7 and Ubuntu installed on my laptop. The Windows 7 had been installed when I bought this laptop, and I don't have a CD.  I just installed VitrualBox under Ubuntu, hoping that I could install another Windows in this virtual machine, so that I could run some applications of Windows even under Ubuntu.  But it seems that I need a CD or ISO of Windows to boot inside this virtual machine. Otherwise, there is an error: FATAL: No bootable medium found! System halted. My question is where I could find a CD or ISO?  At the moment, I am downloading ISO from this , but do not know if it will work. By the way, I am not sure if I should pick the 32-bit or 64-bit? As my CPU is 64-bit but my Ubuntu is i386.  Could anyone help? Thank you very much. Why "?v=hash" is added to my URLs? I'm new to wordpress, I set up everything, but there's something that bothers me: on every single URL or link, there's a "?v=hash" appended everywhere (example.com/?v=d21feabed96b).  I tried to see inspect every plugin, I don't understand how this parameter is added.  It looks like it's added in js, because if I see the source, there's no trace of this hash, but I can see in firebug live source.  Plugins installed:   jetpack sumome wp-piwik wp super cache woocommerce   Theme: Storefront  I tried to disable everything, but still I get this hash, does anyone knows how and why it's added?  I'm also using cloudflare Selenium/PhantomJS raises error I have come across both the phrases - 'on the internet' and 'over the internet.'   I'm pretty sure that both are correct but then which to use when?  Please note, I'm well aware of all over the Internet which I'm not concerned about. how to show image in table cell through json parsing Is it possible to make abstract classes in Python? There has been a trend now two persons downvote it then it goes on like that. So let there be down voting but do not display the downvotes till the user votes on it. Else the user reads it with an impression that the question is not good.  Am I missing something? Support for N-Gons (polygons consisting of more than 4 vertices) has been in Blender for a while now, but many of us still may not know when to use them, and how to do so effectively.  In what situations do N-Gons really come in handy? When should they be just plain left out? Do they have any place in finished models? How to enable touchpad? Yesterday, suddenly my touchpad on my MSI Laptop started to not respond. In other words, in Login screen, touchpad is working as expected. However, in Desktop screen, after I have logged in, touchpad is not working.  How can I enable touchpad in Desktop? How can I produce a 'ring (or wheel) chart' like that on page 88 of the PGF manual? I really like the 'ring chart' or 'wheel chart' given as an example on page 88 of the PGF manual. It is like a pie chart, but with a label in the centre. Unfortunately, the manual doesn't give the source for that chart. Does anyone have an example? Thanks. I have customer data from 2 brands. The data structure are the same, but I expected the customer behaviour to be different in different brand.  So I could train 2 models, 1 for each brand, or I could train one model on both brands, but flag which brand the customers belongs to within the data.  So my question is, would training on both brands with flags be too much more work for the Machine Learning (I'm using neural network), and therefore be harder to achieve good accuracy than to have dedicated models for each brand? If $\sum (a_n)^2$ converges and $\sum (b_n)^2$ converges, does $\sum (a_n)(b_n)$ converge? If $\sum (a_n)^2$ converges and $\sum (b_n)^2$ converges, does $\sum (a_n)(b_n)$ converge?  Could someone help me to solve this or at least give me a hint?, I have tried using Cauchy's criterion, the Dirichlet test for convergence, etc, but I can´t prove it.Honestly I don´t know where to start. Any help will be appreciated. I am constructing a bibliography of as much of the prior research in a field I am working in. I would like to use BibTeX to print the citation in the pdf, and then I would like to add the details of the paper after the citation. Only then would I like to print the next citation. For example:  [1] Jahan M. Dawlaty and Yunquing Chen. Measurement of the optical absorption of graphene in the terahertz. Applied Physics Letters, 2008. Research Group: Cornell Pump Wavelength: 500 nm. Probe Wavelenth: 7 microns. Relaxation Time: 50 fs. [2] Paul George and Dmitry Vekslar, Measurement of Ultrafast Carrier Dynamics in Graphene. Applied Physics Letters, 2009.  . . . and so on. Does anyone know how this could be done? Webforms and jQuery, how to match the ID's? I want to use jQuery with asp.net webfoms.  Do I need to get a special toolkit so the .net controls spit out friendly Control ID's?  Reason being, I don't want to write javascript referencing my html ID's like control_123_asdfcontrol_234.  Has this been addressed in version 3.5?  (I remember reading you have to get some special dll that makes ID's friendly). Adding Multiple Maps in QGIS Composer? How can author deal with late reviews? How can I start automatically a command on Ubuntu 18.04? I have a small command like this  xinput set-prop "XP-PEN G430S Pen Pen (0)" --type=float "Coordinate Transformation Matrix" 1.155756, 0.000000, 0.000000, 0.000000, 1.529, 0.000000, 0.000000, 0.000000, 1.000000   to use my XP-PEN tablet, I have to start it automatically every time that I start my PC. How can I do that?