Which class of Dynamical Systems is governed by Lagrangian Dynamics?
How general is the Lagrangian quantization approach to field theory?
Why the interior of $\mathbb{Q}$ in $\mathbb{R}$ is empty? Why is a method not identical to itself? Does a character with 10 Constitution only need to eat every 4 days? According to the food rules,     A character can go without food for a number of days   equal to 3 + his or her Constitution modifier (minimum   1). At the end of each day beyond that limit, a character   automatically suffers one level of exhaustion.   A normal day of eating resets the count of days   without food to zero.   According to this, a character with a Constitution modifier of 0 can eat normally every 4th day*, and get no penalties from hunger despite only eating twice a week. This seems a tad ridiculous, and I'm wondering if there are other rules that I'm missing that make it a bad idea to eat less often like this, or if eating every 4th day is a totally fine thing to do, by the rules.  * They can get away with four days, because they'll only get the exhaustion penalty if they don't eat by the end of the fourth. This is even assuming the 'minimum 1' doesn't apply to the con mod portion. How to prove the property of the Lemoine point of a triangle? From Wolfram , I know there is a Lemoine point of triangle, also called symmedian point, the sum of squared distances of this point to all the three sides is algebraically minimum.    How to prove such a property? What do the E and R prefixes stand for in the names of Intel 32-bit and 64-bit registers? Preloading images with jQuery How do I see the type of a variable whether it is unsigned 32 bit, signed 16 bit, etc.?  How do I view it? How do Natures work? In at least some Pokemon games there are modifiers called "Natures" which affect pokemon stats. What do they do and how do it work? Also, what specific games possess it? I am using a chi-sq test between two proportions (). I am using this over the z-test for proportions because I do not think my data is normal.   My question is how do I get the difference (shift) estimate &amp; confidence intervals for this test.   For example,     Data1: 193/252=.77   Data2: 154/227=.68   P-value=.032 (I used the formula in the link above. I will also add my exact code below)  Shift Estimate: I assume its the difference between proportions, ie .77-.68=.09. Is this correct?   Confidence Interval: ??????????????????  Code for generating P-value (matlab):   % Pooled estimate of proportion  p0 = (n1+n2) / (N1+N2); % Expected counts under H0 (null hypothesis)  n10 = N1 * p0;  n20 = N2 * p0; % Chi-square test, by hand  observed = [n1 N1-n1 n2 N2-n2];  expected = [n10 N1-n10 n20 N2-n20];  chi2stat = sum((observed-expected).^2 ./ expected);  p = 1 - chi2cdf(chi2stat,1);  H=0; if(p&lt;.05), H=1; end Can I exchange limit and differentiation for a sequence of smooth functions? Let $(f_n)_{n\in \mathbb N}$ be a sequence of smooth functions converging to some $f$.  Under what circumstances can I exchange limit and derivative?, i.e.  $$\lim_{n\rightarrow \infty} \frac{\partial f_n(x)}{\partial x} = \frac{\partial f(x)}{\partial x}$$ I recently got my Blacksmithing skill to 100. Now in the skills menu I can press space to make it Legendary, which will put it back to a skill level of 15 and reset my perks.  I am wondering: What benefit is there from making a skill Legendary apart from being able to level up the skill more thus having infinite levels? Ending a two handed game It’s my turn. It is a two handed game of Canasta. I have three cards left in my hand. There is only one card left in the Stock pile. Can I pick up the one card and play my hand? alias fo rm command ( cp comand issue ) I've heard that exposing database IDs (in URLs, for example) is a security risk, but I'm having trouble understanding why.  Any opinions or links on why it's a risk, or why it isn't?  EDIT: of course the access is scoped, e.g. if you can't see resource foo?id=123 you'll get an error page. Otherwise the URL itself should be secret.  EDIT: if the URL is secret, it will probably contain a generated token that has a limited lifetime, e.g. valid for 1 hour and can only be used once.  EDIT (months later): my current preferred practice for this is to use UUIDS for IDs and expose them. If I'm using sequential numbers (usually for performance on some DBs) as IDs I like generating a UUID token for each entry as an alternate key, and expose that. What triggers the benefit of the bard's "Song of Rest" feature? In D&amp;D 5e, the benefit of the Bard's "Song of Rest" feature triggers "if you or any friendly creatures who can hear your performance regain hit points at the end of the the short rest."  Does Song of Rest's benefit apply just when spending hit dice to regain hit points? Or does it apply to any other way that a player might regain hit points at the end of a short rest (e.g. by casting a spell, using a Second Wind, eating a Goodberry, etc.)? Something that confuses me, but has never caused any problems... the recommended way to dispatch an event is as follows:  public event EventHandler SomeEvent; ... {     ....     if(SomeEvent!=null)SomeEvent(); }   In a multi-threaded environment, how does this code guarantee that another thread will not alter the invocation list of SomeEvent between the check for null and the invocation of the event? Why doesn't the UK ask for travel bookings for a tourist visitor visa? No Drupal Site Found when clearing cache I installed drush using composer following the instructions here:   When trying to run drush cc all I get this error:     No Drupal site found, only 'drush' cache was cleared.[warning] 'all'   cache was cleared. [success]   I added this line:  export PATH="/Applications/MAMP/bin/php/php5.6.2/bin:$PATH"   to my .bash_profile and restarted bash and MAMP. Still no luck. Any ideas?   This is my drush status:   Drupal version         :  7.36                                                               Site URI               :  http://default                                                     Database driver        :  mysql                                                              Database hostname      :  localhost                                                          Database port          :                                                                     Database username      :  root                                                               Database name          :  srod                                                     PHP executable         :  /usr/bin/php                                                       PHP configuration      :                                                                     PHP OS                 :  Darwin                                                             Drush script           :  /Users/srod/.composer/vendor/drush/drush/drush.php   Drush version          :  7.0-dev                                                            Drush temp directory   :  /tmp                                                               Drush configuration    :                                                                     Drush alias files      :                                                                     Drupal root            :  /Applications/MAMP/htdocs/srodsite                             Site path              :  sites/default      I'm running it from Drupal project folder. I would like to insert the below mathematical symbol, it looks like a big Delta but different. Is there command to obtain a similar shape? Blackboard bold variants for Greek letters It is common (or it used to be) to use a blackboard-bold variant of \mu to denote roots of unity in some mathematical papers.  However, despite searching (several times, periodically over several years) I have never been able to locate any package or technique that makes this possible, other than using Metafont or possibly hunting through the font definitions to see if it is something I can create a variant of (along the lines of the suggestions in Section 8 of the Comprehensive LaTeX symbol list).  Thus far, I haven't been sufficiently motivated to learn how to do any of this (although it probably would have resulted in a net time savings), and I feel like I cannot be the only person who would have tried.  Is anyone aware of an existing way to produce this character?