When I issue sudo apt-get update on the command line I get the following error:  E: Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable) E: Unable to lock directory /var/lib/apt/lists/   How can I fix that?
I get this error when trying to use apt-get:  E: Could not get lock /var/lib/dpkg/lock - open (11 Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/) is another process using it?     How can I fix this?
How can I remove myself from India's visa blacklist? Words with different meanings in American and British English This is similar to , but not quite the same.  There are quite a few words which have totally different meanings in American and British English and which are likely to cause confusion when heard by non-local speakers.  What are they?  We are looking for the same word with different meanings (for example jumper), and not words which are different between the two dialects (for example truck and lorry). Is there a standard function in C that would return the length of an array? Let $K$ be a field and $f(x)\in K[x]$. Prove that $K[x]/(f(x))$ is a field if and only if $f(x)$ is irreducible in $K[x]$. Let $K$ be a field and $f(x)\in K[x]$. Prove that $K[x]/(f(x))$ is a field if and only if $f(x)$ is irreducible in $K[x]$.   How to prove? I really have no idea... Thank you a lot. My current understanding:  $\vdash$ is "syntactic consequence", e.g. if we have $a \vdash b$ it means if we've written down $a$ as something we know, we can immediately write down $b$ as something we know. This is saying nothing about whether any of these pieces are true, false, something else, etc, it's just saying that we can say something about $b$ by virtue of being able to say something about $a$.  $\vDash$ is "semantic consequence", e.g. if we have $a \vDash b$, then it (usually) means if $a$ is always true in every interpretation (i.e. no matter how we mess with any of the underlying variables driving $a$'s valuation), then $b$ is true as well. However I don't know if this is necessarily just a "true"-only thing. It seems conceivable that we could make one for falsehoods too, i.e. if $a \vDash b$ might mean if $a$ is always false then $b$ is always false, of if $a$ is always "dog" then $b$ is always "dog", etc. But I am unsure of this one.  $\to$ is material implication, which exists solely within the logic system (as opposed to the previous two metalogical relations) and has a specific semantic meaning / definition in terms of a truth table in something like prepositional logic ($a \to b$ is always true unless $a$ is true and $b$ is false). It's defined this way simply because it is a helpful / useful model to describe things like "whenever $a$ is true, $b$ is true".  Do I have the right idea so far? How to access the Keyboard Layout Options in 13.10+ Why doesn't Normal[] work on GeometricTransformation? How should you interview for QA *Automation* positions? Prove that $T$ has a cyclic vector iff its minimal and characteristic polynomials are the same Is it a goal if, during kicks from the penalty mark, the ball goes outside the penalty area and then into the goal? Proof that $(x-1)^2$ divides a $nx^{n+1} – (n+1)x^{n}+1$ How do I set a background image while I am editing? What is the name for these type of images? I love these kind of graphics and it's so flat which totally matches my current product development.      Do we have a name for it? A name will make it easier to search for examples and how to's. The situation is somewhat like-  var someVar = some_other_function(); someObj.addEventListener("click", function(){     some_function(someVar); }, false);   The problem is that the value of someVar is not visible inside the listener function of the addEventListener, where it is probably being treated as a new variable. Compact operators on an infinite dimensional Banach space cannot be surjective Using Fermats prime numbers to prove that there is infinitely many prime numbers Arguments for/against same birthday for siblings? My son is born on October 1st three years ago. My wife is pregnant again and the calculated delivery date is October 22nd. Both children are boys, 3 years apart. We might end in a situation where the delivery is earlier, for reasons irrelevant to this question.   I believe that around their birthdays is the only time in the whole year that the actual date matters. It really does boil down to practical considerations around patience (gifts) and planning. I think that if there is, say, a week or more between the birthdays then it's easy to separate but if the difference is only a very few days then it gets complicated, and that's the situation I'd like to avoid.  I know from friends that having the same birthday makes events easier to plan, from the parents' perspective. It would also remove the unhappiness of a small child saying "why does he get presents today and I don't." Being a twin, and married to one, I know that there's nothing problematic in sharing a birthday as long as both get their fair share of attention.    What are practical arguments for, and against, choosing the same birthday for the second child? What considerations apply when the second child's birthday is only a very few days after the elder sibling's? Completeness and Incompleteness Through browsing questions asked in the past about Godel's completeness and imcompleteness theorems, I've come to see that the sense of completeness in both of the theorems are different. However, I can't see how they are different!   Does this distinction boil down to that of truth and proof? Is it the case that the completeness theorem talks about the relationship between truth and proof, while the incompleteness theorems only relate to provability?  Could someone please elaborate on the sense in which both notions of completeness are different? Why is electric field lines away from (+) and toward (-)? I have a questions about the electric field lines.   Well in the basic learning, we know that:   The electric field lines extend away from a positive charge They move forward a negative charge   Let's take parallel plates, which make a uniform electric field.If we take the basic learning, which I mentioned, in accounts, it's very easy to understand that this is the direction of a positive charge object if we put the object between the plate (move away the positive charged plate and toward negatively charged plate).  The problem is if we put a negative charged object between. Isn't the electric field reversed ? Using sed what is an one liner to print the first n characters?  I am doing the following:  grep -G 'defn -test.*' OctaneFullTest.clj  | sed ....