I can't figure out what is meant in my text books with the "Either / Or" statements. I'm in a math proof class trying to wrap my head around this. See example below.  Either Jim or Bob has red hair P = Jim has red hair Q = Bob has red hair   Does this mean:  P v Q   or  (P v Q) ^ (~P v ~Q)   Thanks
I have a statement,     Either p or q   and I have to write it in terms of logical connectives but I don't get which logical connector should I be using? Here is what I did (I think there could have been a better way to do this)     $(p \lor q ) \land (\neg((p \Rightarrow q) \land (q \Rightarrow p)))$
How do you join or create a server in multiplayer? How do I easily rename multiple files using command line? How to recover files from dead windows using dos? How to quickly send commands to nested tmux sessions? I have the following in my .tmux.conf  set -g prefix M-j bind-key j  send-prefix   I need to press (Atl+J) + (J) + bound-key to send something to the nested tmux session. I feel it is rather slow. Is there any better way? For example, I would love to be able to do (Alt+J) + (2x bound-key) to do stuff in the nested session. I constantly execute commands in the top tmux session instead of executing them in the nested one. Also, how come everybody binds prefix to C-a? I find it awfully slow and unpleasant to type this combination. Am I missing something? If you finish a world without fighting the Broodal, can you still fight them later? I've just seen that in a speedrun: If you collect enough moons to move on to the next world, and cash them in at the ship, the broodal ship just leaves.  Does that mean that the Broodal fight wont happen, so you missed the triple moon it gives? Or if you go to the arena, even without the ship you will have the fight happen?  Clip where this happens : The easy way: Install Nvidia drivers, CUDA, CUDNN and Tensorflow GPU on Ubuntu 18.04 Why are .NET timers limited to 15 ms resolution? Illustrating op amp feedback without control theory We are teaching op amps in a high school class, before calculus.  So we can't use control theory to teach how op amps respond.  All the same, I would like to have an intuitive explanation for how a feedback circuit works.  Take the negative feedback, for instance.  Is there a clear way to show how an initial difference of delta between V+ and V- leads to a very large (G(V+ - V-)) difference in the output, which then leads to ...  I'd like to be able to take that argument and show how the voltage of the output converges in addition to the standard virtual short argument.  Can anyone explain it clearly? "I have never said" versus "I never said" I have never said this.   I never said this.    Is the usage of have in the first sentence justified or grammatically correct?   What is the difference in meaning?   When should I use one form over the other? I'm trying to understand the /etc/rsyslog.conf file, but I'm missing something. For example, this is a part of the file:  auth,authpriv.*         /var/log/auth.log *.*;auth,authpriv.none      -/var/log/syslog cron.*              /var/log/cron.log daemon.*            -/var/log/daemon.log kern.*              -/var/log/kern.log lpr.*               -/var/log/lpr.log mail.*              -/var/log/mail.log user.*              -/var/log/user.log   According to  page:     The facility is one of the following keywords: auth, authpriv, cron,   daemon, kern, lpr, mail, mark, news, security (same as auth), syslog,   user, uucp and local0 through local7.      The priority is one of the following keywords, in ascending order:   debug,info, notice, warning, warn (same as warning), err, error (same   as err) crit, alert, emerg, panic (same as emerg). The keywords error,   warn and panic are deprecated and should not be used anymore. The   priority defines the severity of the message.      An asterisk ("*") stands for all facilities or all priorities,   depending on where it is used (before or after the period). The   keyword none stands for no priority of the given facility.      You can specify multiple facilities with the same priority pattern in   one statement using the comma (",") operator. You may specify as much   facilities as you want. Remember that only the facility part from such   a statement is taken, a priority part would be skipped.      Multiple selectors may be specified for a single action using the   semicolon (";") separator. Remember that each selector in the   selector field is capable to overwrite the preceding ones. Using this   behavior you can exclude some priorities from the pattern.   So, this is pretty understandable but what about the file path on the right. It can be just a path, or path with | or - before it (or maybe even something else). What is the difference between the three? This is a weird phenomenon.  Consider the following code:  \documentclass{article} \begin{document}   $$Z^* \frac{Z^*}{Z^*}$$ \end{document}   It produces the following picture:    The asterisks appear in various places in comparison to the Z. This looks particularly bad in the denominator. Any idea what's behind this? System of linear equations having a real solution has also a rational solution. Dr Math told his family to write 4 different integers from 1 to 9 on to the 4 ] How do I tail a log file and keep tailing it when the latest one changes date? My random variable $X$ is normally distributed with mean $b$ and variance $p$. I defined a new RV, $Y$, such that $Y=1/X$. Does anyone know how to find the mean of $Y$ and $Y^2$? Numbering of appendices in the backmatter of a book I'm using the standard book class. If I write  \documentclass{book}  \begin{document}  \frontmatter \tableofcontents  \mainmatter \chapter{foo} \section{Donald}  \backmatter \chapter{bar} \section{Mickey}  \end{document}   I expect to have chapter bar numbered as appendix A and section Mickey as A.1. Instead chapter bar is not numbered and section Mickey is 1.2, following section Donald. If I insert the appendix command to obtain  \documentclass{book}  \begin{document}  \frontmatter \tableofcontents  \mainmatter \chapter{foo} \section{Donald}  \backmatter \appendix \chapter{bar} \section{Mickey}  \end{document}   then chapter bar is unnumbered and section Mickey is numbered as .1.  What am I doing wrong? Why would I vote for an increase in the number of authorized shares? Ubuntu 16.04 sftp and vscode ssh not working There appears to be a giant security vulnerability with Android that seems to basically affect all phones.  wrote:  The vast majority of Android phones can be hacked by sending them a specially crafted multimedia message (MMS), a security researcher [Joshua Drake] has found. ... Drake found multiple vulnerabilities in a core Android component called Stagefright that’s used to process, play and record multimedia files. Some of the flaws allow for remote code execution and can be triggered when receiving an MMS message, downloading a specially crafted video file through the browser or opening a Web page with embedded multimedia content. ... The MMS attack vector is the scariest of all because it doesn’t require any interaction from the user; the phone just needs to receive a malicious message. For example, the attacker could send the malicious MMS when the victim is sleeping and the phone’s ringer is silenced, Drake said. After exploitation the message can be deleted, so the victim will never even know that his phone was hacked, he said.  What can a regular user do to mitigate the issue? Disable Google Hangouts? Given that $xyz=1$, prove that $\frac{x}{1+x^4}+\frac{y}{1+y^4}+\frac{z}{1+z^4}\le \frac{3}{2}$ Given that $xyz=1$, prove that $$\frac{x}{1+x^4}+\frac{y}{1+y^4}+\frac{z}{1+z^4}\le\frac{3}{2}.$$  I proved this with , but: is there a better/more elegant way?