Why my Mob Grinder/Farm isn't working?
What is wrong with my mob spawner?
failed to create symbolic link ‘/usr/bin/utserver’: File exists Does any test actually prove causation? Proof of Frullani's theorem How can I prove the Theorem of Frullani? I did not even know all the hypothesis that $f$ must satisfy, but I think that this are  Let $\,f:\left[ {0,\infty } \right) \to \mathbb R$ be a a continuously differentiable function such that $$ \mathop {\lim }\limits_{x \to \infty } f\left( x \right) = 0, $$ and let $ a,b \in \left( {0,\infty } \right)$. Prove that $$ \int\limits_0^{\infty}  {\frac{{f\left( {ax} \right) - f\left( {bx} \right)}} {x}}dx  = f\left( 0 \right)\left[ {\ln \frac{b} {a}} \right] $$  If you know a more general version please give it to me )= I can´t prove it. Yesterday I was copying a single, 8 GB file to a USB with a slow, 7 MB/s write speed, while my RAM is 3 GB. While copying the system froze, to the point where I couldn't even move the cursor.  I managed to log into the text console, and ran iotop, it showed that a process named kswapd0 was taking 99.99% of IO.  Are there workarounds so copying a large file doesn't make my system unusable? I have a friend who has got a computer that is not connected to the Internet. Is there any way to install software offline easily? Select first occurring element after another element I'm trying to write a small script to change the current directory to my project directory:  #!/bin/bash cd /home/tree/projects/java   I saved this file as proj, added execute permission with chmod, and copied it to /usr/bin. When I call it by: proj, it does nothing. What am I doing wrong? "EOL while scanning single-quoted string"? (backslash in string) import os xp1 = "\Documents and Settings\" xp2 = os.getenv("USERNAME") print xp1+xp2   Gives me error   File "1.py", line 2  xp1 = "\Documents and Settings\"                                ^ SyntaxError: EOL while scannning single-quoted string   Can you help me please, do you see the problem? .NET Casting Generic List I remember watching this one show when I was a kid in the 80's/early 90's in Canada. It was a live-action show about these two kids and had some puppet/muppet-like characters, but it kind of had a dark/mysterious element to it. I can't remember too much about it except portions of some episodes, but the main characters were kids, and they had some mysterious artifact (kind of like a compass?) that took them to this other world where there were giants and other mysterious beings that we rarely saw. The two kids weren't the only one's going to this place either, they find out kids from all around the world that also had this same artifact (and they all fit together like a round puzzle?). I seem to recall that the giants in this other world were the ones who made the artifacts, and were dying/or in desperate need of the help of the kids.  A couple episodes I remember:   There was one where the leaves were falling, and the world was doomed to end as soon as the last leaf touched the ground, so they're trying to figure out how to prevent all the leaves from falling, but after a long and suspenseful episode (for a kid) the last leaf dramatically falls, but out of no where the main girl catches the leaf and saves the world (it was very exciting for my young self, and I remember being very impressed with the pretty girl for thinking to catch the leaf).     There was another episode where the kids meet these two old guys with long white hair (muppets) sullenly working in a mine/tunnel, they're in tattered old clothes working away with their pick axes or hammers and they are connected to each other at the beard. This long old white beard grows out of one of their faces right into the other's. The kids save the day by cutting the old guy's beard in the middle, freeing them from each other. They celebrate being free from their bonds and excitedly thank the kids, but after the kids leave they continue to work away, this time in much brighter spirits. Seemingly unbeknownst to them though, as they work, their beards slowly and subtly grow back together.   Anyone else remember this show? Is there a reason why people can't just take the helicopter to mount Everest? Why is it that helicopters can't reach that high? "Next tag badge" panel score and answers counter discrepancy On the "Next tag badge" panel of  for C# tag, I see:      92/100 score   88/20 answers     But, when I open the "Select your next badge" panel, there's:     97/100 score   90/20 answers       I'm not sure which one is correct. But I believe that both displays should show the same counts.  The discrepancy is not due to a caching, I've noticed it the first time many weeks ago.  For these particular current counts: I have a single C# answer with 3 votes only in the last 5 days, last upvoted 13 hours ago (2015-10-12 19:30:05Z). So it should not cause the 5 votes and 2 answers difference.  I believe that the counters on the "Select your next badge" are correct and the counters on the "Next tag badge" are wrong, as I have:     Asked 1 non-wiki question with a total score of 6. Gave 90 non-wiki answers with a total score of 97.       Today (2015-10-16), the "Next tag badge" got bumped to 97/100. But "Select your next badge" shows 98/100 already. Will links to images be kept permanently when added to a comment and nothing else? I assume, that Stack Exchange have some clean-up subsystem, which deletes all "abandoned" images (stored at i.stack.imgur.com), that is, all of them, that were initially uploaded, but no post is actually having link to them. Am I right?  If such subsystem is implemented and is doing its job on regular basis, then what about following scenario:   Start a new question or answer, anywhere. Hit button and upload an image. Copy generated image's URL  to clipboard. Close tab and drop editing post. Go to question on answer, you actually planned to reply. Post a comment to it and paste copied image's URL from clipboard to comment's body.   Will uploaded image, with URL pasted only to comment, be kept permanent? Does clean-up subsystem (if exitst) take care of checking for image's URLs in comments as well? Calculate integral $\int_{-1}^{1} (1-x^2)^n dx $ Is there a proof that $\pi$ is an irrational number? Most math texts claim that $\pi$ is an irrational number. However, I'm having a little bit of trouble understanding that.  Since nobody has calculated all of the digits of $\pi$, how can we know that either:   one of the digits repeats (as in $\frac{10}{3}$) the number eventually terminates     Note: Please be very descriptive in your answers... I don't have anything beyond high school math. Prove/Disprove that if two sets have the same power set then they are the same set I am really sure that if two sets have the same power set, then they are the same set. I just am wondering how does one exactly go about proving/showing this?  I'm usually wrong, so if anyone can show me an example where this fails, I'd like that too.  The homework just asks for true/false, but I'm wanting to show it if possible. My thoughts are that since the power set is by definition the set of all subsets of a set, if each of the two power sets are identical, we have an identity map between each set, thus it's indistinguishable which power set is a given set's power set. I hope that wasn't verbose. Since a set has only one power set, we can conclude they are in fact the same set. Evaluate $\lim_{x\rightarrow 0} \frac{\sin (6x)}{\sin(2x)}$ without L'Hopital I am looking for a clean and fast method to force GNOME in Ubuntu 14.04 to switch between active apps only on the current workspace when pressing the shortcut alt + tab. Can a ring of positive characteristic have infinite number of elements? why __getitem__ cannot be classmethod?