I created this question, but, I do not know the answer:     Is there a function $f: \mathbb R \to \mathbb R$ such that for every interval $I \subseteq \mathbb R$ we have $f(I)=\mathbb R$?   It seems to me that existence of such a function would violate almost everything that I know about analysis, but, on the other hand, it would be awesome if there is at least one such $f$, because it is known that there are many "pathological" examples in analysis. Also, many here are skilled in analysis more than I am, so I can expect an answer, curious about what it will turn to be.
I wonder  whether there is a function $f\colon\Bbb R\to\Bbb R$ with the folowing characteristic?   for every two real numbers $\alpha,\beta,\alpha\lt\beta$,  $$\{f(x):x\in(\alpha,\beta)\}=\Bbb R$$   I can't  say such a function does not exist, neither can I construct a example  Thanks a lot!
Is there an expression to indicate the strategy of wearing someone down with numerous small irritations? I would use rope-a-dope, but it's got connotations of pretending to lose that I don't need. I'm trying to describe the behavior of someone who sends twenty detailed emails a day about various projects, and the recipient of his emails has finally gotten tired of trying to parse them, so the recipient just agrees to whatever he proposes. I'd like an expression that evokes both outward earnestness and hidden creepiness, like Uriah Heep, Dickens's "Humble servant" with veiled ambition, who overdoes it with professions of humility until he's in power. Water torture would work, but comes too close to a more racist expression that I'm not comfortable with. Is there a term for an issue or activity that occurs only until the moment that you ask someone else to watch? Is there a term for the coincidence that occurs when an issue ONLY occurs until the moment that you ask someone else to watch or help you resolve it?    For example, having an issue with software until you try to show someone, then it stops being problematic.  Or an issue with the computer/phone that resolves as soon as a help ticket is put in.    The final example is when you have a problem with your car (funny noise, etc) - you hesitate taking it in for weeks because you know it will disappear as soon as the mechanic drives it...then it does.    This is different than a , where the action of applying a debugger, for example, changes the behavior of the activity being watched.  It's also different from a 'works on my machine' scenario, where only the original user has the problem.   What is it called when a problem resolves itself just by the mention of it?  Jinxing the issue? :)  I see this every day supporting my software product -- the users are experienced and are not making mistakes at one time then doing something different when I watch.  The problems also truly resolve (coincidentally) as soon as they ask for help - they do not reoccur.  I guess it's a case of synchronicity? Reflection to Identify Extension Methods On a crop sensor camera, e.g. Canon EOS 7D, what would be the best kit to travel with around Europe for a few weeks? My shooting style will focus on landscape, architecture, and general travel shots (of note would be my lack of interest for portraits).     Limit to around 1-3 lenses, and I prefer light ones.   Crop sensor camera chosen to save on weight over a full frame option. Question is open to all brands for general guidance, but I will be using a Canon body.   Cost is not a factor, I will rent the lenses I do not already own.   Quality is of paramount importance. I will not have a tripod.   I understand some may consider this subjective, but I do believe that for a crop sensor body, with weight as a consideration, and a limit to the amount of lenses, a true best kit can be determined. When should I use mmap for file access? POSIX environments provide at least two ways of accessing files.  There's the standard system calls open(), read(), write(), and friends, but there's also the option of using mmap() to map the file into virtual memory.  When is it preferable to use one over the other?  What're their individual advantages that merit including two interfaces? Whether and how to thank a girlfriend or boyfriend in the acknowledgements of thesis? How is it received by the academia if someone thanks to his/her girlfriend/boyfriend in the acknowledgements of the thesis?  I have seen writers including his/her fiancee in the acknowledgements, however I don't know if including an informal relationship in the thesis will be received well.  If it is acceptable, how should I refer to my girlfriend? I need to evaluate the limit without using l'Hopital's rule.  $$\lim_{x \to 0}{\frac{\sqrt{1+x\sin{x}}-\sqrt{\cos{2x}}}{\tan^{2}{\frac{x}{2}}}}$$ Difference between “with”, “at” and “for” with a business title and a company name When it comes to , I often read recommendations like "Use adb logcat to find some more details". Looking for a good way to backup all my apps including their data,  refers to adb backup and adb restore. In several places one can find ways to remotely do on an Android device with the use of , such as transferring files using adb push or adb pull, accessing the  via adb shell, and more. So ADB seems to be a good thing to have for an Android user.  But how to get this "ADB thingy" on my computer? Not being a developer, installing the entire  seems a bit overkill. Is there a more minimalistic approach available? Yesterday, my laptop caught a virus which caused massive damage. Since them, I have been trying to recover important files before reformatting my computer, a task the virus has not made easy.   Restoration points predating the attack have been deleted.  Most of my folders show empty.  My Start menu is essentially empty, with the exception of Trillian and Mirror's Edge. The same goes for my Desktop, which only has programs which were installed after the attack.  Searching for files through my computer is pretty much useless, as it only rarely brings up anything. I suspect most of my files have not been deleted. While my folders show empty, uTorrent still does display them and I can open them from here. Unfortunately, when I select Open Containing Folder, the folder still shows as completely empty even if I'm currently watching a video from that very folder. Further adding evidence to the not-deleted-just-missing theory, the data recovery software I'm using (Restoration) cannot find only find an handful of the missing files.   If they were deleted, I could do a forensic recovery to get them back but since they're probably still somewhere on my computer, just out out of my reach, I can't find them.   Under those circumstances, is there a way I can recover those files? Alt-C not working in Blender 2.8 I want to convert my text object to mesh. In 2.79 it was Alt-C, are the keys changed for 2.80?    I browsed it externally and I got some thing like this image as answer..   but any shortcut-keys will be easy to work! If you know one, you can comment below. Reading data from a relational database into a LaTeX table I'm using Tex Live 2009 on Debian squeeze. I can upgrade if I really, really  have to, but I'd rather not. I was wondering if it would be possible to do the following.  Given some data in a (relational) database, can I extract it and automatically format it in a LaTeX table, so one would not need to manually recreate the LaTeX table if the data changes? Could one do such a thing with Lua? One would normally use a suitable language database adaptor for this, and I see Lua has . I'd like to use PostgreSQL. I'm currently using version 8.4.  Solutions not involving Lua are also fine. Just to be clear, I don't know anything about Lua and my knowledge of LaTeX programming is also extremely skimpy. I'm looking for a recipe which I can adapt if necessary. While this is not really important for my current use case, it seems like a useful general technique if possible. What's a way to implement a flexible buff/debuff system? Overview:  Lots of games with RPG-like statistics allow for character "buffs", ranging from simple "Deal 25% extra damage" to more complicated things like "Deal 15 damage back to attackers when hit."  The specifics of each type of buff aren't really relevant.  I'm looking for a (presumably object-oriented) way to handle arbitrary buffs.  Details:  In my particular case, I have multiple characters in a turn-based battle environment, so I envisioned buffs being tied to events like "OnTurnStart", "OnReceiveDamage", etc.  Perhaps each buff is a subclass of a main Buff abstract class, where only the relevant events are overloaded.  Then each character could have a vector of buffs currently applied.  Does this solution make sense?  I can certainly see dozens of event types being necessary, it feels like making a new subclass for each buff is overkill, and it doesn't seem to allow for any buff "interactions".  That is, if I wanted to implement a cap on damage boosts so that even if you had 10 different buffs which all give 25% extra damage, you only do 100% extra instead of 250% extra.  And there's more complicated situations that ideally I could control.  I'm sure everyone can come up with examples of how more sophisticated buffs can potentially interact with each other in a way that as a game developer I may not want.  As a relatively inexperienced C++ programmer (I generally have used C in embedded systems), I feel like my solution is simplistic and probably doesn't take full advantage of the object-oriented language.  Thoughts?  Has anyone here designed a fairly robust buff system before?  Edit: Regarding Answer(s):  I selected an answer primarily based on good detail and a solid answer to the question I asked, but reading the responses gave me some more insight.  Perhaps unsurprisingly, the different systems or tweaked systems seem to apply better to certain situations.  What system works best for my game will depend on the types, variance, and number of buffs I intend to be able to apply.  For a game like Diablo 3 (mentioned below), where nearly any bit of equipment can change a buff's strength, the buffs are just character stats system seems like a good idea whenever possible.  For the turn-based situation I'm in, the event-based approach may be more suitable.  In any case, I'm still hoping someone comes along with a fancy "OO" magic bullet which will allow for me to apply a +2 move distance per turn buff, a deal 50% of damage taken back to the attacker buff, and a automatically teleport to a nearby tile when attacked from 3 or more tiles away buff in a single system without turning a +5 strength buff into its own subclass.  I think the closest thing is the answer I marked, but the floor is still open.  Thanks to everyone for the input. Iridescence In Cycles? Is it possible to create an  shader in Cycles? Specifically for something like , , , etc.. I have a header file  x.h which is included by more than one *.c source files. This header file has some structure variables defined.  I have put multiple inclusion prevention guard at the beginning of the header file as:  #ifndef X_H #define X_H ... .. //header file declarations and definitons.   #endif//X_H   On building I get linker errors related to multiple definitions. I understand the problem.   Won't a multiple inclusion prevention guard at the top of header file as I have, prevent multiple inclusions of the header file x.h and thereby avoid multiple definitions of the variables that are there in x.h? #pragma once does not work on this particular compiler, so what is the solution?  Someone had posted  answer to a similar question. It doesn't seem to work for me. How does this solution work? How can I animate the Restrict Visibility property of an object? I've been trying to create an animation where an object blinks on and off.   For example, I have a Cube and I set a keyframe on it's Restrict Visibility icon (the "eye" icon) with I, then I toggle off that "eye" so my cube doesn't show in the Viewport and again I press I to record that keyframe. Then, when I preview the animation in the Viewport, I see my cube appears and then disappears like I want, but when I render it, the cube does not disappear at all.  What am I doing wrong? Why aren't Christoffel symbols tensors? - asked from a fibre bundle perspective I was wondering if there is any rule in English that forbids us to say A Happy New Year when we wish someone Happy New Year? I know that we just say it like that, but I was trying to find the rule which would explain this. Thank you for your help. Visualization for Euclidean Algorithm In English, especially in a poetic description, ships and cars are  referred to as "she".   Maybe their owners compare their beauty and elegance with those of women, but what if a female owner wanted to describe her yacht or car?   Would she also say, "She is a real beauty", or it might be "he" then?   Does the choice of a pronoun depend on whom she is giving the description of it to — a man or a woman?  What about a man-o’-war or a merchantman? Being ships, are they also referred as "she"?  P.S.  on the use of "she" in reference to ships, but there seems to be no answer to my question there.  P.P.S. My question wasn't pulled out of a thin air. I came across a book by a prominent Russian linguist, G.Veichman, written in 1990, (Novelties in The English Grammar is my translation of the title), where I read that the rule of personification of vehicles may be added regarding a female owner talking about her car using the preposition "he". Period. No further explanation or reference examples.