password recovery security issue
How is being able to break into any Linux machine through grub2 secure?
mongodb group values by multiple fields Get index of parent div from child divs Lock in mysql database What is the maximum or minimum tire width I can fit on my bicycle HABTM dropdown items not selected How do you display the archives of a Custom Post Type by Year &amp; Month? What happens if you increment an iterator that is equal to the end iterator of an STL container How can I convert JPG into PDF easily? In  it states that      [xkcd] means calling the Ackermann function with Graham's number as the arguments just to horrify mathematicians.   $A(g_{64},g_{64})$  In  it states that      Even simply making $g_{65}$ dwarfs the number $A( A(g_{64}, g_{64}), A(g_{64}, g_{64}))$ into insignificance.   So:  Is $g_{65}$ greater than $A(g_{64}, g_{64})$?  And is it greater than $A( A(g_{64}, g_{64}), A(g_{64}, g_{64}))$? What are Extension Tubes? What are Extension Tubes? Division ring if and only if it has no proper left ideals. I'm running into this weird problem with Google spreadsheets: if the cells have comments on them and I sort the spreadsheet, the rows sort but the comments stay in the same position, and don't move with the cells they're attached to.  In other words, the cells look like this:  A C  &lt;-- comment on this cell B   and then I sort by this column:  A B  &lt;-- comment remains on this cell (stays in position) C  &lt;-- comment should have remained attached to this cell   This means that sorting is completely broken and I can't use it at all, because I clearly need the cell comments to stay with the cell they're attached to.  Is this a bad bug in Google Spreadsheets, or am I missing something here? Why did Eve die with Maelon's data available? I saved Wrex in ME1, I saved Maelon's data in ME2, the import screen in ME3 confirmed this.    When I get to the missions on Tuchanka, I completed every one of the side missions before starting the mission where they take down the Reaper and distribute the genophage cure.  Then when I finally get to the lab, Mordin tells me that Eve has died.    Yet every site I've been to says that keeping the data allows her to live.  So why did she die? Show that $A \setminus ( B \setminus C ) \equiv ( A \setminus B) \cup ( A \cap C )$ Show that  $A \setminus ( B \setminus C ) \equiv ( A \setminus B) \cup ( A \cap C )$  This is an exercise I was trying to do ( not homework ) and I got stuck as follows:  Working from $A \setminus ( B \setminus C )$:  $x \in A \wedge x \notin ( B \setminus C )$ $x \in A \wedge ((x \in B \wedge x \in C) \vee (x \notin B \wedge x \in C) \vee (x \notin B \wedge x \notin C) )$  At this point I'm not sure how to proceed.  Working from the other side $ ( A \setminus B) \cup ( A \cap C ) $:  $ x \in ( A \setminus B) \cup ( A \cap C ) $  $ x \in ( A \setminus B) \vee x \in ( A \cap C ) $  $ ( x \in A \wedge x \notin B ) \vee ( x \in A \wedge x \notin C ) $  $ x \in A \wedge (x \notin B \vee x \notin C ) $  $ x \in A \wedge x \notin ( B \cap C ) $  $ A \setminus ( B \cap C ) $  I could also use some formating tips like how display logical not and how to get the lines to display properly without blank lines inbetween. :-) Dimensional analysis, and the notion that quantities with different units cannot be equal, is often used to justify very specific arguments, for example, you might use it to argue that a particular formula cannot possibly be the correct expression for a particular quantity. The usual approach to teaching this is to go "well kids, you can't add apples and oranges!" and then assume that the student will just find it obvious that you can't add meters and seconds.  I'm sorry, but... I don't. I'm not convinced. $5$ meters plus $10$ seconds is $15$! Screw your rules! What are the units? I don't know, I actually don't understand what that question means.  I'm specifically not convinced when this sort of thing is used to prove that certain formulae can't possibly be right. Maybe the speed of a comet is given by its period multiplied by its mass. Why not? It's a perfectly meaningful operation - just measure the quantities, multiply them, and I claim that the number you get will always equal the current speed of the comet. I don't see how "but it doesn't make sense to say mass times time is equal to distance divided by time" can be a valid counterargument, particularly because I don't really know what "mass times time" is, but that's a different issue.  If it's relevant, I'm a math student and know extremely little about physics. Can you find all classes in a package using reflection? Solve congruence system $\ x\equiv m_i-1 \pmod{m_i}\,$ for $\,i = 1,\ldots, k$ Find natural number $x$ so that $$\begin{align}x&amp;\equiv 9\pmod{10}\\ x&amp;\equiv8\pmod9\\ &amp;\ \ \vdots\\ x&amp;\equiv 1\pmod2\end{align}$$ 16.04 LTS upgrade alert- How to handle it? I am running Ubuntu 14.04 LTS. Today when I logged into my computer I got an update alert saying that I could upgrade to Ubuntu 16.04 LTS. The other options were not now or do not upgrade. If I chose to upgrade will it delete my /home directories and the installed software under /opt and /usr/local ? Anyone can optimized this code for better explanation and easy to understand? Move the Add Favorite / Ignored Tags boxes to the top It seems that most people who use the ignored tags feature end up with a fairly long list of those tags.  Although , it is sometimes necessary to add new ignored tags manually (typically when adding some-tag*).  It would be a lot easier if the add box was above the long list of ignored tags rather than below. I suppose the same would apply to the favorites tags for consistency's sake.