How to use dynamic keys in Chrome local storage get and set?
Add a property to a JavaScript object using a variable as the name?
I need to run a bash script at boot-time as superuser in Xubuntu. I don't know where to start. I have to do something described in a Arch Linux guide. That guide says exactly:     Add following at the end of the file : /etc/rc.sysinit   # Do my action /etc/rc.d/do_my_action  /bin/dmesg &gt;| /var/log/dmesg.log   But I do not have /etc/rc.sysinit and /etc/rc.d/ in Xubuntu. I'm sure there are equivalent ones, right? How can I permanently enable cheating? Stop Mathematica from giving imaginary solutions "Cancellation", "Canceled", "Canceling" — US usage I'm trying to figure out if there is a specific rule behind the word "cancel" that would cause "cancellation" to have two L's, but "canceled" and "canceling" to have only one (in the US).    I understand the rules are very loose when it comes to double L's in English, and I have read several posts on here talking about "canceled" and "canceling" (vs "cancelled" and "cancelling"), but my specific question is more about the spelling of "cancellation".    - they do NOT mention cancelation with one "L"  - they do seem to have cancelation listed with one "L" Microsoft Word marks "cancelation" as an invalid word Same with the spell checker in Firefox   So my question is: is there a reason or rule why in US English, "cancellation" seems to have two L's (to most dictionaries), while "canceled" and "canceling" does not? Impossibility of constructing a continuum-size linearly independent set in $\Bbb R$ This is a response to the following exchange at    [Bill constructs a $\aleph_0$ linearly independent set in $\Bbb R$]  Can you extend the idea of this proof to get the right dimension? Currently, you only have a countably infinite independent set, but the dimension is size continuum. –   I believe the answer to this question is no, for the following reason. Suppose we have a spanning set for $\Bbb R$ over $\Bbb Q$, of cardinality $\frak n$. Then by definition we have the cardinality equation ${\frak c}\le^*[{\frak n}]^{&lt;\omega}\cdot \aleph_0$ (where $[{\frak n}]^{&lt;\omega}$ is the cardinality of finite subsets, and $\frak m\le^*n$ means there is a surjection from $\frak n$ to $\frak m$). If $\frak n$ is finite, then we get ${\frak c}\le^*\aleph_0$ which is false, so $\frak n$ is infinite (but not necessarily Dedekind-infinite). If we assume the axiom of choice, then the equation reduces to $\frak c\le n$, hence every Hamel basis is size continuum. But without AC I don't know any way to simplify the original equation to get anything stronger than &quot;$\frak n$ is infinite&quot;. This is at best heuristic evidence for the original question, since it is considering a different problem (spanning sets instead of linearly independent sets). How could one show that there are no ZF-constructible $\Bbb Q$-linearly independent subsets of $\Bbb R$ of cardinality continuum? A method for evaluating sums/discrete functions by assuming they can be made continuous and differentiable? Suppose I had a function that satisfied the property $f(x)=f(x-1)+g(x)$.  For any $x\in\mathbb N$, it is easy enough to see that this boils down to the statement  $$f(x)=f(0)+\sum_{k=1}^xg(k)$$  If we return to our functional equation and differentiate it $n$ times, we get  $$f^{(n)}(x)=f^{(n)}(x-1)+g^{(n)}(x)$$  Once again, for any $x\in\mathbb N$, we have  $$f^{(n)}(x)=f^{(n)}(0)+\sum_{k=1}^xg^{(n)}(k)$$  One could then integrate both sides.  For example, this asserts that  $$\sum_{k=1}^xg(k)=xf'(0)+\int_0^x\sum_{k=1}^tg'(k)dt$$  If the sum inside the intagral is generalized to any upper bound.  How would I justify this for discrete functions?    An example of this is letting $f_p(x)=\sum_{k=1}^xk^p$, as it seems to follow the above result.  We can see from the above that  $$f_p(x)=a_px+p\int_0^xf_{p-1}(t)dt$$  $$a_p=1-p\int_0^1f_{p-1}(t)dt$$  which appears to be a true recursive formula.    Under what conditions can I extend discrete functions $f(x)$ and $g(x)$ into continuous differentiable functions and apply this method? How is the value of $\pi$ ( Pi ) actually calculated? When I was a child I was taught $\pi$ (Circumference/Diameter) is an irrational number  and can be approximated to $22/7$ but $= 3.(142857)(\ldots)$.      But where does this value comes from?  In short How do I derive $\pi$? Is there any relation between the chromatic number of a graph $G$ and its complement $G'$ that are always true?  I saw these ones: $\chi(G)\chi(G')\geq n$ and $\chi(G)+\chi(G')\geq 2n$,  but I'm not pretty sure about them. Why does append() always return None in Python? Why does a 95% Confidence Interval (CI) not imply a 95% chance of containing the mean? It seems that through various related questions here, there is consensus that the "95%" part of what we call a "95% confidence interval" refers to the fact that if we were to exactly replicate our sampling and CI-computation procedures  many times, 95% of thusly computed CIs would contain the population mean. It also seems to be the consensus that this definition does not permit one to conclude from a single 95%CI that there is a 95% chance that the mean falls somewhere within the CI. However, I don't understand how the former doesn't imply the latter insofar as, having imagined many CIs 95% of which contain the population mean, shouldn't our uncertainty (with regards to whether our actually-computed CI contains the population mean or not) force us to use the base-rate of the imagined cases (95%) as our estimate of the probability that our actual case contains the CI?   I've seen posts argue along the lines of "the actually-computed CI either contains the population mean or it doesn't, so its probability is either 1 or 0", but this seems to imply a strange definition of probability that is dependent on unknown states (i.e. a friend flips fair coin, hides the result, and I am disallowed from saying there is a 50% chance that it's heads).  Surely I'm wrong, but I don't see where my logic has gone awry... I found a problem with an application on Ubuntu.   Questions :   How do I best report the issue?  What sort of information should I provide? Is there any good reason that an empty set of round brackets (parentheses) isn't valid for calling the default constructor in C++?  MyObject  object;  // ok - default ctor MyObject  object(blah); // ok  MyObject  object();  // error   I seem to type "()" automatically everytime. Is there a good reason this isn't allowed? What is the direction of stack growth in most modern systems? I am preparing some training materials in C and I want my examples to fit the typical stack model.  What direction does a C stack grow in Linux, Windows, Mac OSX (PPC and x86), Solaris, and most recent Unixes? Is this metric space incomplete? Matching exact string with JavaScript How can I test if a RegEx matches a string exactly?  var r = /a/; r.test("a"); // returns true r.test("ba"); // returns true testExact(r, "ba"); // should return false testExact(r, "a"); // should return true How do I change the extension of multiple files? I would like to change a file extension from *.txt to *.text. I tried using the basename command, but I'm having trouble on changing more than one file.  Here's my code:  files=`ls -1 *.txt`  for x in $files do     mv $x "`basename $files .txt`.text" done   I'm getting this error:  basename: too many arguments Try basename --help' for more information "Each person's car" vs. "each persons' car" Which of the following is correct?        Each person's car has four wheels.   Each persons' car has four wheels. On a quantum scale the smallest unit is the , which is a discrete measure.  There several question that come to mind:   Does that mean that particles can only live in a discrete grid-like structure,  i.e. have to "magically" jump from one pocket to the next? But where are they in between? Does that even give rise to the old paradox that movement as such is impossible (e.g. )? Does the same hold true  for time (i.e. that it is discrete) - with all the ensuing paradoxes? Mathematically does it mean that you have to use difference equations instead of differential equations? (And sums instead of integrals?) From the point of view of the space metric do you have to use a discrete metric (e.g. the ) instead of good old Pythagoras?   Thank you for giving me some answers and/or references where I can turn to.  Update: I just saw this call for papers - it seems to be quite a topic after all: Is Reality Digital or Analog? FQXi Essay Contest, 2011. , , . One can find some pretty amazing papers over there. Prove: If $\gcd(a,b,c)=1$ then there exists $z$ such that $\gcd(az+b,c) = 1$ I can't crack this one.      Prove: If $\gcd(a,b,c)=1$ then there exists $z$ such that $\gcd(az+b,c) = 1$ (the only constraint is that  $a,b,c,z \in \mathbb{Z}$ and $c\neq 0)$ I got this question in homework:     Let $\{0,1\}^A$ the set of all functions from A (not necessarily a finite set)       to $\{0,1\}$. Find a correspondence (function) between $\{0,1\}^A$ and       $\mathcal P(A)$ (The power set of $A$).       Prove that this correspondence is one-to-one and onto.   I don't know where to start, so I need a hint. What does it mean to find a correspondence? I'm not really supposed to define a function, right?  I guess once I have the correspondence defined somehow, the proof will be easier.  Any ideas? Thanks!