Is \textheight in beamer slides with a title wrong?
Is there a simple command for the available height in a beamer slide?
Please add Right To Left text support in Stack Exchange You know, some of us read right to left...  Certain sites like  and  have an obvious need for this, as Arabic and Hebrew are Right To Left (RTL) languages. Many answers on those sites cite the Torah and the Quran respectively. Directly quoting these sources properly requires RTL text. Different dependencies for different build profiles Direct way leads to nowhere.  $$\lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{\sqrt {n^2 +i} } = \lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{n \sqrt {1 +\frac{i}{n^2}} } = $$  $$ = \lim_{n\rightarrow \infty} \frac{1}{n} \cdot \lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{\sqrt {1 +\frac{i}{n^2}} } = 0 \cdot \sum^{n}_{i=1} 1 = 0 \cdot n $$  So, I tried to apply squeeze theorem:  $$\lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{\sqrt {n^2 +i} } \leq \lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{n}  = 1$$  Could you help me to figure out the lower bound? I was thinking of how to create an IV for a block cipher that doesn't require stored state, and I came up with the idea of using an HMAC of the (padded) plaintext and a (possibly distinct) key as the IV.  This seems to be secure:   The IV will only be reused if there is an HMAC collision or if the plaintext and key are the same.  The former would imply that the HMAC is broken and the latter is harmless, since it is just producing the output twice. The HMAC is verified after decryption, but before padding is checked, so padding-oracle attacks should not be an issue.   In particular, if the HMAC and the block cipher use different keys, there seems to be a very simple proof of security, assuming that either (1) the HMAC cannot be distinguished from a random function or (2) the block cipher is secure against maliciously-chosen (but unique) IVs:   The attacker cannot forge the HMAC, since this would require knowledge of the signing key. Since the signing and encryption keys are different in this case, and the HMAC is assumed random, malicious IVs cannot be triggered by an attacker.   Alternatively, if the cipher is secure against malicious (but unique) IVs, then the security of the cipher+security of the HMAC seem to prove the security of the system.  This (obviously) provides no protection against replay attacks, but that requires state anyway.  However, I am not a cryptographer so I do not trust my conclusions on this matter.  If this technique is secure, it would appear to be quite useful in practice, as it is simple and provides both encryption and authentication. In the film Thor, Odin casts a spell on Mjolnir and strips Thor of his power.  He then banishes Thor to Midgard (Earth).  On Earth, Thor is seemingly just a strong and durable human.  Later in the film, he becomes worthy, and regains control of Mjolnir.  This then grants him his full power set and control over Mjolnir.  My question is, prior to this, could Thor control lightning all on his own?  Or is this purely an ability of Mjolnir? How can I type special symbols on my Android device like ☺ or ♥ as a regular character? Explicit space character? I'm wondering about the best way to do an explicit space character (I don't even know what it's properly called), like the ones you get in the \begin{verbatim*} environment. The closest I've found is  \sqcup   in math mode, but it seems like a bit of a hack to me. Is there any text symbol for what I'm looking for? Deleting files from Remote FTP-Server older than x days I have meticulously read through similar questions, answers and their comments but I still do not understand how the deletion is done. From what I understand I email the customer service and then they do what exactly?     1) They disable my account so that I can no longer use it?      2) They reassign all of my questions and answers to some other   account? To which one?      3) They delete all my questions and answers so that they go away from   public view?   What is the flexibility (if it exists) of the deletion procedure? Is it possible to erase the traces of my former association with the site. Can I request any of the following be done?     4) All of my questions and answers be deleted from public view?      5) Some of my questions and answers be deleted? If yes what criteria?      6) Can I have all of my contributions be assigned to some other   account which runs as sort of a "collective account" and already has   tons of content so that it doesn't happen like my contributions just   move to some other url but still stay grouped under that location and   therefore that location can be discovered as representing my account?      7) Can I have my contributions dispersed through several "collective   accounts?      8) Can my current public name be removed from any comments to my posts   so that my posts cannot be identified later as once belonging to me?   Please be polite with me. I wouldn't have asked if I have found the answer in the other questions. The other questions are also old and it is not clear what the situation is as per 05/2012.  UPDATE (for those interested):  I asked the Stackoverflow team about the procedure. Apparently none of the points 2-8 I asked above are possible, only 1 will take place. The link to my user page from my contributions is going to be removed and replaced with non-clickable text of an anonymized user name like "user1234". Whether this number is the same as my current user_id is not clear. That's all the information I got.  I'm going now to rename myself to "Anonymous" then request the account deletion. Those interested in the procedure will witness the exact result on this page.  Farewell. Use #ifdefs and #define to optionally turn a function call into a comment Is it possible to do something like this  #ifdef SOMETHING #define foo // #else #define foo MyFunction #endif   The idea is that if SOMETHING is defined, then calls to foo(...) become comments (or something that doesn't get evaluated or compiled), otherwise it becomes a call to MyFunction.  I've seen __noop used, but I don't believe I can use that.  EDIT(s):  I don't think I can really use a macro here, because MyFunction takes a variable number of arguments.  Also, I'd like to make it so the arguments are NOT evaluated!  (So doing something like commenting out the body of MyFunction doesn't really give me what I need, as the arguments will still be evaluated) Decide if the series converges and prove it using comparison test: $\sum_{k=1}^{\infty}\frac{1}{2k+3}$ Decide if the series converges and prove it using comparison test:   $\sum_{k=1}^{\infty}\frac{1}{2k+3}$   $$\frac{1}{2k+3} &lt;\frac{1}{2k}&lt;\frac{1}{k}$$  and since $\sum_{k=1}^{\infty}\frac{1}{k}$ diverges (we have defined that in our readings, so I can claim it here), the complete series will diverge, too.  Did I do everything correctly? What makes me feel a bit unsure is that there is no "$\leq$" sign anywhere and when I look up the comparison test on the internet, I don't see any "&lt;" or ">" in the definition.  Is it correct anyway? Show $S = f^{-1}(f(S))$ for all subsets $S$ iff $f$ is injective Let $f: A \rightarrow B$ be a function. How can we show that for all subsets $S$ of $A$, $S \subseteq f^{-1}(f(S))$? I think this is a pretty simple problem but I'm new to this so I'm confused.  Also, how can we show that $S = f^{-1}(f(S))$ for all subsets $S$ iff $f$ is injective? Jackknife vs. LOOCV Display bare HTML from hook_menu() What would be the cleanest way to route URLs to functions and return only the HTML output from those functions (a.k.a. the menu callback)?  If I use hook_menu() the string that's returned will be the HTML within the rest of the site. I want the page to display only the string returned from the menu callback.  Should I use drupal_set_header() in the same way drupal_json() does? Is this not inefficient having fully bootstrapped Drupal, and then changing the header at the last minute?  I want the fastest code path possible since this is going to be for widgets on external sites.  I could start with a standalone .php file and bootstrap what I need but the hook_menu routing is nice.    How should you do this? I've been reading about a lot of different types of philosophies, religions, ways of thinking etc. I was wondering what are the most recently created philosophical ways of looking at the universe? Where can one find out about new cutting edge ideas?  Example: Before we had Marxism, Communism, Zen, Christianity etc. Now X,Y, and Z have been created building on and evolving the ideas of A,B,C.   Everything I read about are ideas that were created a long time ago. What is new and updated? Review option on mobile phone not available? How do I "Show total up and down vote counts" since I'm at 1K rep? What is the argument selector tracking a defined score (not [score_min=])? What if I want to make a command like this:  execute @e[score_A=10] ~ ~ ~ summon Creeper   So that the entity must have a score of 10 (not less, not more)?  Does it even exist that or a [score_A_max=] argument?  I know about scoreboard players test, but i guess it is not the case to use it. I am travelling to Athens, Greece, shortly, and have seen . Should I be worried? Should I cancel my trip?  Update  It's fine, taxis are currently on strike, but Syntagma Sqaure is fine: Is there a set of lines in $\mathbb{R}^3$ such that their union is equal to the set of points with not all coordinates rational? Does there exist a set L of pairwise disjoint lines, each line in an axis direction, in $\mathbb{R}^3$ such that their union is equal equal to $\{ x : x \text{ has at least one irrational coordinate}\}$?