Command \d invalid in math mode
How can I draw a dot under a symbol in math mode?
Getting / setting file owner in C# I'm trying modeling things like this using oracle:  An account can have 1~5 members  So I'll have a account table and a member table with a FK of account. But is that possible to check if the account have less than 5 members?  I've tried constraint and trigger but oracle doesn't allow sub queries in constraint or condition of trigger like  CHECK( SELECT ...) or IF count(*) &gt;= 5  which make things getting hard. SQL Servers has Traces and XEvents. These are used to capture and analyze what is going on with our SQL Server Instances. Events are stored in the stack for later analysis. For example,  If I decide to monitor any dead lock in the database, I just query the trace file to see the history of deadlock for a period of time. Here is my question:  While events occur, in our example deadlock event, is there a way to get an email notification using msdb.dbo.xp_send_dbmail? What are the criteria used to represent Stack Exchange sites on the sites page? (Grid view) I noticed that  has been changed, and by default sites are shown by balloons.  What is not clear to me is why some sites are shown with a bigger balloon than other sites. For example, WordPress Answers has less questions, answers and users than Programmers, but its balloon is bigger. What are the criteria used to show the sites on that page? What is the JavaScript version of sleep()? FireFox 66 Quantum disabled all my extensions at midnight! This morning I woke up to:    and the FireFox help page doesn't really help...  Help!  What should I do now??? I need NoScript and AdBlock Plus to improve my surfing speed!!! 0:-) I want to learn to use biper and biblatex in Lyx. This is how I would do it in LaTeX traditionally with biblatex and biber  \documentclass[12pt,a4paper,oneside,pdftex]{report} \usepackage[backend=biber]{biblatex} \addbibresource{minCuts.bib} ... \printbibliography \end{document}   The error is apparently originating from the \bibliographystyle command and biblatex package getting mixed, by . But I have no \bibliographystyle command in Preamble so they should not be mixed unless Lyx is somehow importing the \bibliographystyle.   How to resolve the biblioraphystyle error in Lyx with Biber and Biblatex?    Settings by the instructions  and Error        Document > Settings > Bibliography > Biber                  In Document > Settings > LaTeX Preamble                   Insert > List / TOC > BibTeX Bibliography...                        Package biblatex Error : '\bibliographystyle' invalid. I was trying to fix my audio problems using suggestions from . One of the comments suggested I execute this and only this:     killall pulseaudio   So I did, and I restarted my computer just in case, but all it did was remove my soundcard and I still couldn't hear anything. Now I don't know how to get my soundcard back.  Please note that I am extremely inexperienced when it comes to Ubuntu. The use of the Axiom of Choice in this proof of the sequence lemma Is the distance function in a metric space (uniformly) continuous? Let $(X, d)$ be a metric space. Is the function $x\mapsto d(x, z)$ continuous? Is it uniformly continuous? Trying to find a story about an unborn telepathic baby who can save a spaceship from doom There's a spaceship, nearing the end of its journey. Everybody on board is in cryosleep. For some reason the wake-up system malfunctions, and the ship will fly on indefinitely. The people at the space port realise this, and try to wake someone up. Their last resort is finding someone on board who is telepathic, and wake this person up. They find one, but it turns out to be an unborn baby. How to demystify the axioms of propositional logic? How might I go about getting some intuition on the typical axiom schemes given for propositional logic? They seem rather mysterious at first glance.  For example, these are taken from:    $\phi \to \phi$ $\phi \to \left( \psi \to \phi \right)$ $\left ( \phi \to ( \psi \rightarrow \xi \right)) \to \left( \left( \phi \to \psi \right) \to  \left( \phi \to \xi \right) \right)$ $\left ( \lnot \phi \to \lnot \psi \right) \to \left( \psi \to \phi \right)$ Inserting an image in plain TeX I used the OzTeX implementation of TeX, also I used to typeset my docs in plain TeX, not LaTeX for me, so I had no problem to insert an image using the OzTeX, now I'm back to TeX docs, am using the TeXWorks frontend, but I can't insert an .eps image file, it seems the \includegraphics macro its only for LaTeX, so I can't use it, any idea on how to insert an image when using plain TeX? Trying to purge MySQL fails I'm running in circles currently, trying to fix some mysql problem.  I couldn't use apt-get for a while now, because it always stuck at the line Setting up mysql-server-5.6 (5.6.27-0ubuntu0.15.04.1) ... and didn't let me do anything. So I tried to reinstall mysql, purging it. While I was able to remove mysql-server and mysql-client eventually, I'm still unable to purge mysql-common. Obviously, I managed to corrupt something, but how can I get my system back and running at this point?  ...:~# apt-get purge mysql-common Reading package lists... Done Building dependency tree        Reading state information... Done The following packages will be REMOVED:   mysql-common* 0 upgraded, 0 newly installed, 1 to remove and 5 not upgraded. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] Y (Reading database ... 423600 files and directories currently installed.) Removing mysql-common (5.6.27-0ubuntu0.15.04.1) ... Purging configuration files for mysql-common (5.6.27-0ubuntu0.15.04.1) ... update-alternatives: error: /var/lib/dpkg/alternatives/my.cnf corrupt: invalid status dpkg: error processing package mysql-common (--purge):  subprocess installed post-removal script returned error exit status 2 Errors were encountered while processing:  mysql-common E: Sub-process /usr/bin/dpkg returned an error code (1)   -  ...# sudo dpkg -P --force-all mysql-common (Reading database ... 424733 files and directories currently installed.) Removing mysql-common (5.6.27-0ubuntu0.15.04.1) ... Purging configuration files for mysql-common (5.6.27-0ubuntu0.15.04.1) ... update-alternatives: error: no alternatives for my.cnf dpkg: error processing package mysql-common (--purge):  subprocess installed post-removal script returned error exit status 2 Errors were encountered while processing:  mysql-common   -  ...:~# lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description:    Ubuntu 15.04 Release:    15.04 Codename:   vivid   My goal is to just get it back and running again (mysql). Lowest voltage drop diode possible I am harvesting energy from an NFC device using a tuned antenna on my PCB. Though this method I am able to generate about 3.05V. I would like to charge a super capacitor using the power harvested from the NFC device. To do this I have  used the simple diode circuit provided  (and shown in Figure 1 below).  The problem I am facing is my circuit requires a minimum of 3V to operate within operating conditions, however with the added drop by typical diodes I believe there with be various situations where the generated voltage will drop below the required 3V. Are there any Diodes available which have ultra low voltage drops of less then 0.01V? and is that even possible?  Please note:   my system load will be &lt; 5mA  The 3.05V generated was without a diode in the circuit Is it "5–6 weeks are a lot of time" or "5–6 weeks is a lot of time"? I was just copyediting  and my native English speaker Sprachgefühl told me I had to correct the grammar of one sentence:     ... 5–6 weeks are a lot of time ...   by changing the are to is. But as I was doing so I started wondering why is it that in this case it seems that I have to make the verb disagree with the plural subject?  So is my feeling for English going bad or if I did the right thing, how could I explain this to somebody who's learning English for instance? Let $b_n$ decrease monotonically to zero, prove $\sum b_nz^n$ converges for $|z|\leq 1$ and $z\neq 1$ I have B1/B2 Visa. Can I travel for Business trip to US with this Visa? How secure is Activation Lock on iOS 7 (and later)? Apple showed this new feature in iOS 7 called Activation Lock, that if you enable "Find My iPhone" on a device that is lost or stolen, a person that finds/gets the iPhone will not be able to wipe it or reset it. I'm curious whether the lock is designed to prevent these avenues to defeat the lock:   Can they completely drain the battery and leave the phone in that state for a couple of months and then try it? Or, can they use any third-party software that can access iPhone from outside the iTunes and wipe it that way? Or, can they simply "jailbreak" it and forget about this Activation Lock?   By what methods can this lock be defeated or bypassed? Indicating a name change after publication My wife has publications under both her maiden name and her married name. How should she indicate that this is the case on her CV, if she wants to mention publications from both time periods?