How to randomly teleport players using command blocks?
Is it possible to spawn mobs in random places?
A doubt from Milnor's "Topology from a Differentiable Viewpoint". This is a doubt from Milnor's "Topology from a Differentiable Viewpoint".     For a smooth $f:M\to N$, with $M$ compact, and a regular value $y\in N$, we define $n(f^{-1}(y))$ to be the number of points in $f^{-1}(y)$. It is easy to see that $n(f^{-1}(y))$ is finite. It can also be seen that $n(f^{-1}(y))$ is locally constant; i.e. there is a neighbourhood of $y$ such that for every point $y'$ in that neighbourhood, $n(f^{-1}(y'))=n(f^{-1}(y))$.   The proof for the statement in bold is the following:     Let $x_1,x_2,\dots,x_n$ be the points of $f^{-1}(y)$, and choose disjoint neighbourhoods $U_1,U_2,\dots,U_n$ of these points, which are mapped diffeomorphically into neighbourhoods $V_1,V_2,\dots,V_n$ of $y$. The required neighbourhood is $(V_1\cap V_2\cap\dots V_n)-f(M-U_1-U_2-\dots U_n)$.   I don't understand how $(V_1\cap V_2\cap\dots V_n)-f(M-U_1-U_2-\dots U_n)$ is open. I know that $(V_1\cap V_2\cap\dots V_n)$ is open. However, how can one prove that $f(M-U_1-U_2-\dots U_n)$ is closed? I can see this working if $f$ is surjective, but not otherwise. Why is an object stuck to another? So I created a Cube in Blender and then I created an Empty beside the Cube (in object mode). Now, when I move the Empty around, the Cube follows... Why? Save text area to file Running OS X Apps On Ubuntu 14.04 Is there any way that still works to run OS X apps on Ubuntu 14.04? If Darling still works, please tell me how to install it.  Thanks. :) How do I read / convert an InputStream into a String in Java? If you have a java.io.InputStream object, how should you process that object and produce a String?    Suppose I have an InputStream that contains text data, and I want to convert it to a String, so for example I can write that to a log file.  What is the easiest way to take the InputStream and convert it to a String?  public String convertStreamToString(InputStream is) {     // ??? } Groups in derived series are normal in the whole group I am considering a finitely generated, solvable group $G$ which has subexponential growth. Let $G=G_0\vartriangleright G_1\vartriangleright....\vartriangleright G_d\vartriangleright G_{d+1}=1$ denote the derived series of G.  It should be the case that $G_d$ is normal in $G$. Does anyone know why this is true? I don't know whether all of the assumptions above are necessary for the result. Difference between UART and RS-232? Most of the time  and UART come together in serial communication theories. Are they both the same? From my readings I concluded UART is a hardware form of the RS-232 protocol. Am I correct? Is the standard Canon 18-55 lens the same as 5 years ago? Can a multiclass character with 1 level of wizard copy any wizard spell they find into their spellbook? The &quot;Your Spellbook&quot; sidebar for the wizard includes the following line:  Copying a Spell into the Book. When you find a wizard spell of 1st level or higher, you can add it to your spellbook if it is of a level for which you have spell slots and if you can spare the time to decipher and copy it.  Does this mean that a Wizard 1/Cleric 19 can copy any wizard spell they find into their spellbook? Is there anything preventing them from casting these spells? Topological/Geometrical justification for $\text{CFT}_2$ being special What is the usage of Zero Ohm & MiliOhm Resistor? I am new to PCB design and I noticed that some schematics use 0Ω or 100mΩ resistors. What is their purpose and why do we need to use them in our PCB design?  Normally if we wish to probe how much current the load is taking, we put a jumper pin across the PCB trace (then measure current across the pin using a multimeter). Adding resistors for this purpose seems like it would waste a lot of PCB real-estate. Is this the sole reason why 100mΩ resistors are being placed (since I = V/0.1Ω) instead of a jumper pin?   If so, is there any consideration we should take when placing such a mΩ resistor on board so it doesn't affect the signal or behaviour of the circuit? They agreed to stay connected for hours in their provisional support group, looking for answers in their counterparts.   I want to change the bold part to say that they all shared the same problem.  Might end up using one of the above, but I feel like I need some more options to weigh in.    Edit for context: they all share the same rare cognitive impairment Avro Bengali keyboard switches to Malay (Jawi) after upgrade to Ubuntu 17.04 In chapter 2, the section on bitwise operators (section 2.9), I'm having trouble understanding how one of the sample methods works.  Here's the method provided:  unsigned int getbits(unsigned int x, int p, int n) {     return (x &gt;&gt; (p + 1 - n)) &amp; ~(~0 &lt;&lt; n); }   The idea is that, for the given number x, it will return the n bits starting at position p, counting from the right (with the farthest right bit being position 0). Given the following main() method:  int main(void) {     int x = 0xF994, p = 4, n = 3;     int z = getbits(x, p, n);     printf("getbits(%u (%x), %d, %d) = %u (%X)\n", x, x, p, n, z, z);      return 0; }   The output is:     getbits(63892 (f994), 4, 3) = 5 (5)   I get portions of this, but am having trouble with the "big picture," mostly because of the bits (no pun intended) that I don't understand.  The part I'm specifically having issues with is the complements piece: ~(~0 &lt;&lt; n). I think I get the first part, dealing with x; it's this part (and then the mask) that I'm struggling with -- and how it all comes together to actually retrieve those bits. (Which I've verified it is doing, both with code and checking my results using calc.exe -- thank God it has a binary view!)  Any help? pgrouting unexpected output Modular exponentiation by repeated squaring sed one-liner to delete everything between a pair of brackets? I am working with some text that is full of stuff between brackets [] that I don't want. Since I can delete the brackets myself, I don't need the one-liner to do that for me, but I do need a one-liner that will remove everything between them.  What about parentheses () instead of brackets? Check for missing fonts/characters in XeLaTeX? Because I began to use many Unicode characters (Japanese, some unusual diacritics, etc.) I switched from LaTeX to XeLaTeX to render my documents. Unfortunately, if a font is missing, the letters are simply left out (for example, when I had forgotten to specify the font for Japanese) without any error (and I can't seem to spot a warning either). I will read the result, but I prefer to get some early warning if some character isn't available. Is there any way to get a warning about characters that have not been rendered? An error would be even better. Prevent Word from Including Bullet Letter when Copying Text I'm copying quite a bit of text from Word into a text-based application, line by line.  The word text is structured like this:        Topic      a. Item A      b. Item B      When I highlight Item A, copy, and then paste into the text-based application, I get a.    Item A rather than just Item A as desired.  How can I prevent Word from including the bullet letter when copying? Field level permissions in Drupal 7 What is the best way to create a piece of content with multiple fields... allowing users to edit the content as a whole yet blocking the ability to edit.  The setup I have is a piece of content that has 3 fields: Body, PDF, SWF... and a "Selector" (List Text) that's tied via dependancy. So the user chooses BODY, PDF or SWF and that's what available to edit and shown on the page when live.  What I want to do is add a PHP field... that's either:     greyed out (unable to edit) if your not admin...   doesn't show up in the Drop Down list... Can't select it if you can't see it Shows up on the drop down, but the field doesn't show up in the editor without permissions.   I hope I'm making sense... I can provide an example if needed.