have gone to or have been to?
What is the difference between "I've been to China" and "I've gone to China"?
Is `if (condition = value)` the correct syntax for comparison? How to make clickable links and cross-references in pdfs produced by LaTeX? Clicking on tags in global search results is broken Transferring Lyx Keyboard Shortcuts I recently updated my version of Lyx from 1.6.7 to 2.0.6. I would like to transfer my old keyboard shortcuts to this new version, but I am having difficulty because I was inconsistent with the way that I set them up:   Some were defined in the specified .bind file,  but others were modified in the lyx preferences menu.   I found that when importing my old .bind file into this updated version of lyx, it imported the keyboard shortcuts that were in the .bind file, but not those that I had added in the preferences menu.  Does anyone know if these keyboard shortcuts that were added via the preferences menu are stored in another .bind file somewhere in the lyx directory? Has anyone else successfully transferred keyboard shortcuts that had been implimented in the preferences menu? Exact value for $\cos 36°$ Good morning! I'm having trouble with this problem... It's just taking me forever and I'm worn out and I'm lost on how to use a double angle identity for $72=2⋅36$  The problem reads as follows  An exact value for $\cos36°$ can be found using the following procedure. Begin by considering $\sin108°$. Note that $108=72+36$ and use the sine sum identity. Also note that $72=2⋅36$ and use double angle identities. If there are any common factors in each term, factor them out and cancel them if they are not equal to zero. You should eventually obtain a quadratic equation containing $\cos36°$. Use the quadratic formula to obtain the exact value for $\cos36°$. (Note that the quadratic formula should give two solutions. One can be disregarded - why?  Thank you in advance to anyone who can help. ISP blocking port 25 My ISP has started blocking port 25 so I can not send email through my dedicated server any more.   I have several options:   Send email through the SMTP server provided by my ISP. Any problems with this? Setup mu server so that it receives email on another port instead of port 25     No one else sends email through my server so it should be OK. How do I do this on a Linux server? Buy a static client IP - these are not being blocked so far.   Which one is preferable? Is there any evidence or reason why FIFA is so against adding instant replay to soccer? I find myself seeing many unlucky or just plain wrong decisions made by refs that could be corrected with instant replay. I would like footnote numbering to continue over pages and chapters. In my document it's reset every chapter. I'm using the report documentclass. Proving $\frac{1}{\sqrt{x}}\ge \frac{2}{x+1}$ for $x> 0$ Prove: $$\frac{1}{\sqrt{x}}\ge \frac{2}{x+1}, \quad\forall x&gt;0$$  Yeah, pretty much it. I've tried all manner of rearranging and just can't seem to get it. Thanks. I am using \tableofcontents to create TOC in my document. however it is appearing as shown in the image. As the numbers increase the gap between the number and text is reducing.   Thanks for your help Aku Converting from DMS to DD using Python in Field Calculator? I need to convert lat/long that is expressed as degrees, minutes, and seconds in the data into decimal degrees. For example, in the data, they are listed as N335042.06 in the Latitude column, and W86031.04 in the Longitude column. I have done this problem before where I created a script which converted DMS to DD, and vice-versa, so I guess I could use bits from that. But the problem I'm having is how to ignore (for lack of a better word) the 'N' and 'W' in the data? Can I skip them? And DMS are listed all together without any symbols or spaces.  Can I use len(), range(), split() to specify what part to read from the value? For example, can do the following?  N335042.06 where, 33 = degrees 50 = minutes 42.06 = seconds ...?  I came across  ESRI article, but it's in VB. Will probably use it as a reference but some of the terminology/syntax is different from Python.  Final code that works!   # Pre-logic def latDD(x):   D = int(x[1:3])   M = int(x[3:5])   S = float(x[5:])   DD = D + float(M)/60 + float(S)/3600   return DD  # Expression latDD(!Latitude!) I'd like to update the label of an operator when it's called. But this :  def execute(self,context):     self.bl_label = "good night"   ... apparently doesn't work if the bl_label property has already been defined. Am I wrong ? The dialog box in question here is the one you get with the context menu option "open with other applications". Wine seems to have inserted more than a dozen or so entries for each application I install, which makes it a pain to find the correct application:     What can I do to remove the duplicates?     Update: Neither of the two solutions really work. The bug is interesting, but the symptoms does not match my problem (I'm not having problem with uninstalling applications, but rather the things that are inserted after installing them), and with the other one, all references to the Wine application are removed, which actually makes the problem worse (although it may be an acceptable solution if nothing else can be found). So this is still an open question; any takers? Getting javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher? I have an instance of an application running in the cloud on Amazon EC2 instance, and I need to connect it from my local Ubuntu. It works fine on one of local ubuntu and also laptop. I got message "Permission denied (publickey)" when trying to access SSH to EC2 on another local Ubuntu. It's so strange to me.  I'm thinking some sort of problems with security settings on the Amazon EC2 which has limited IPs access to one instance or certificate may need to regenerate.  Does anyone know a solution? I have IIS7 on my computer, and I can access it through other computers in my house on the same network through my computer's IP address - 192.168.1.10x  Instead of typing in http : //192.168.1.10x/ I want to be able to go to http : //somename/  I know you can change the hosts file to add it but I'd have to do that on each computer and I'd still have to type in the IP to access it from my iPod/Wii... etc. With the new  and the upcoming release of  film, JK Rowling has been awesome and given us new writing on the .  In the introduction it is stated that there are eleven established/registered schools. There are writings for six of them. I don't think we need a new writing for Hogwarts... so that means seven have been located and defined.   Hogwarts School of Witchcraft and Wizardry - Great Britain  - France  - Northern Europe (possibly Estonia, Latvia, or Belarus)  - Japan  - Africa (possibly Congo/DRC)  - Brazil  - United States   Do we know anything of possible location or names of the other four schools? I know Koldovstoretz was mentioned as school in Russia, but is that still canon?   Koldovstoretz - Russia (maybe depending on current canon)   The final three are my guesses based on the population and geography on the world.   Name Unknown - China (based on population) Name Unknown - India (based on population) Name Unknown - Australia (based on geography)   Related: Prove that every Lebesgue measurable function is equal almost everywhere to a Borel measurable function Suppose $(\mathbb{R},\Sigma(m),m)$ is our measure space, where $m$ is Lebesgue measure.  Also, suppose $f : \mathbb{R} \to [-\infty, \infty]$ is a Lebesgue measurable function.  The problem:     Prove that $f$ is equal almost everywhere to a Borel measurable function.   My attempt:  We only have to prove this assertion for a non-negative Lebesgue measurable function $f$ because the result will follow for all Lebesgue measurable functions.  Furthermore, since any Lebesgue measurable function can be approximated by a sequence of non-negative, monotonically increasing, Lebesgue measurable simple functions $s_{n}$, we only need to prove the claim for an arbitrary Lebesgue measurable simple function.  So, let $s: \mathbb{R} \to [-\infty, \infty] $ be a Lebesgue measurable simple function.  We can write $s$ canonically as $$ s(x) = \sum \limits_{i = 1}^{n} \alpha_{i} \chi_{A_{i}}(x)$$ where $\alpha_{i} \in [-\infty, \infty]$, $\bigcup \limits_{i = 1}^{n} A_{i} = \mathbb{R}$, and $A_{i} \cap A_{j} = \emptyset$ if $i \neq j$.  For each $i$, since $A_{i}$ is Lebesgue measurable, we can find a Borel set $B_{i}$ such that $A_{i} \subseteq B_{i}$ and $m(B_{i} \setminus A_{i}) = 0$.  Clearly, this implies that $\bigcup \limits_{i = 1}^{n} B_{i} = \mathbb{R}$.  Now we just need the $B_{i}$'s to be pairwise disjoint, with each $B_{i}$ still retaining $A_{i}$.  To make them pairwise disjoint, I constructed the following sets:  $\tilde{B_{i}} = [B_{i} \setminus (\bigcup \limits_{j \neq i} B_{j})] \cup A_{i}$.  This construction gives us that the $\tilde{B_{i}}$'s are pairwise disjoint (I think....) and $A_{i} \subseteq \tilde{B_{i}}$.  But I don't know that $\tilde{B_{i}}$ is necessarily still a Borel set. :( :(  Am I approaching this problem all wrong? how to prove an element is non-zero in a tensor-product I was studying the following example from Atiyah &amp; MacDonald's Introduction to Commutative Algebra:   Let $x$ be the non-zero element in $N := \mathbf{Z}/ 2\mathbf{Z}$, $M := \mathbf{Z}$, and $M' := 2 \mathbf{Z}$. The element $2 \otimes x$ is zero in $M \otimes N$, but non-zero in $M' \otimes N$. I suppose this can be seen by the fact that $2 \otimes x$ generates $M' \otimes N$, and the tensor-product $M' \otimes N$ is non-zero.   However, I was wondering, what one would do if that element weren't a generator of $M' \otimes N$. So my question is:   What are the methods to prove that an element is non-zero in a tensor-product of modules?   Thanks a lot! Why are the even and odd Regge trajectories degenerate?