I am switching an existing file on Overleaf from BibTeX to BibLaTeX.  I have .bib files in the folder with the file (imported from JabRef) which worked just fine with BibTeX.  For some reason, BibLaTeX is not loading them; in other words, it does not recognize any of the bibtex keys cited in the text.  My format is: \addbibresource{filename1.bib,filename2.bib}  Anyone know why this isn't working?  I have found people talking about stuff like biber, which I don't really understand.  And I can't see how to do that kind of thing in Overleaf.  I tried adding [backend=biber] to the package line but that didn't change anything. Thank you! P.S. I am switching because I would like to have abbreviated reference lists as described here:  UPDATE: Following @DavidCarlisle's point, I now have the format: \addbibresource{filename1.bib} \addbibresource{filename2.bib}  Surprisingly, the bibtex keys in the text are still not recognized. The error message reads, &quot;Package biblatex Warning: Please (re)run Biber on the file: output and rerun LaTeX afterwards.&quot; I thought I would provide this update, but moewe has kindly helped me solve my end goal (mentioned as P.S. above) in a different way:
I would like to use multiple .bib files for my article, such as file1.bib, file2.bib. However, I would like my references not to be separated (such as &quot;Primary sources&quot;, &quot;Secondary sources&quot;, etc.). These bibliographies just need to be merged into one. One way to do this is to copy-paste these .bib files into one .bib file, and this would solve the problem. However, I would like to keep it split into several .bib files, by topic (file1.bib contains articles on topic1, file2.bib contains articles on topic2, and so on). I tried to do \bibliographystyle{alpha}  \bibliography{file1} \bibliography{file2}  but this just gives me the same bibliography twice!
I think I remember reading somewhere that the Baire Category Theorem is supposedly quite powerful. Whether that is true or not, it's my favourite theorem (so far) and I'd love to see some applications that confirm its neatness and/or power.  Here's the theorem (with proof) and two applications:    (Baire) A non-empty complete metric space $X$ is not a countable union of nowhere dense sets.  Proof: Let $X = \bigcup U_i$ where $\mathring{\overline{U_i}} = \varnothing$. We construct a Cauchy sequence as follows: Let $x_1$ be any point in $(\overline{U_1})^c$. We can find such a point because $(\overline{U_1})^c \subset X$ and $X$ contains at least one non-empty open set (if nothing else, itself) but $\mathring{\overline{U_1}} = \varnothing$ which is the same as saying that $\overline{U_1}$ does not contain any open sets hence the open set contained in $X$ is contained in $\overline{U_1}^c$. Hence we can pick $x_1$ and $\varepsilon_1 &gt; 0$ such that $B(x_1, \varepsilon_1) \subset (\overline{U_1})^c \subset U_1^c$.   Next we make a similar observation about $U_2$ so that we can find $x_2$ and $\varepsilon_2 &gt; 0$ such that $B(x_2, \varepsilon_2) \subset \overline{U_2}^c \cap B(x_1, \frac{\varepsilon_1}{2})$. We repeat this process to get a sequence of balls such that $B_{k+1} \subset B_k$ and a sequence $(x_k)$ that is Cauchy. By completeness of $X$, $\lim x_k =: x$ is in $X$. But $x$ is in $B_k$ for every $k$ hence not in any of the $U_i$ and hence not in $\bigcup U_i = X$. Contradiction. $\Box$    Here is one application (taken from ):  Claim: $[0,1]$ contains uncountably many elements.  Proof: Assume that it contains countably many. Then $[0,1] = \bigcup_{x \in (0,1)} \{x\}$ and since $\{x\}$ are nowhere dense sets, $X$ is a countable union of nowhere dense sets. But $[0,1]$ is complete, so we have a contradiction. Hence $X$ has to be uncountable.     And here is another one (taken from ):  Claim: The linear space of all polynomials in one variable is not a Banach space in any norm.  Proof: "The subspace of polynomials of degree $\leq n$ is closed in any norm because it is finite-dimensional. Hence the space of all polynomials can be written as countable union of closed nowhere dense sets. If there were a complete norm this would contradict the Baire Category Theorem." Finding the id of a parent div using Jquery How to throttle callback of jQuery event? How to round a number to n decimal places in Java What I would like is a method to convert a double to a string which rounds using the half-up method - i.e. if the decimal to be rounded is 5, it always rounds up to the next number. This is the standard method of rounding most people expect in most situations.  I also would like only significant digits to be displayed - i.e. there should not be any trailing zeroes.  I know one method of doing this is to use the String.format method:  String.format("%.5g%n", 0.912385);   returns:  0.91239   which is great, however it always displays numbers with 5 decimal places even if they are not significant:   String.format("%.5g%n", 0.912300);   returns:  0.91230   Another method is to use the DecimalFormatter:  DecimalFormat df = new DecimalFormat("#.#####"); df.format(0.912385);   returns:  0.91238   However as you can see this uses half-even rounding. That is it will round down if the previous digit is even. What I'd like is this:  0.912385 -&gt; 0.91239 0.912300 -&gt; 0.9123   What is the best way to achieve this in Java? I've sectioned of this area in the sea near my base, and I need to get rid of all the water from it.  From what I've tried the only way I can see to clear it is fully cover one layer, delete the blocks, then go down to the next layer. Is that the only way I can clear the area or is there a better approach?  Ideally I'd like a survival method (if there is a better one), but any commands what could be used I'd like to hear just so I can learn more commands :) This seems to be one of those tricky examples. I only know one proof which is quite complicated and follows by localizing $\mathbb{Z}[\sqrt[3]{2}]$ at different primes and then showing it's a DVR. Does anyone know any simple quick proof? Typically Apt packages are served over bare HTTP and the downloaded contents are verified with GPG signatures. This makes it easy for  to proxy the HTTP connections and add the downloaded packages to its cache. apt-cacher-ng is unable to directly MITM an HTTPS connection created by Apt. It is possible to  apt-cacher-ng, but then the contents are not cached--they are re-downloaded from the remote server every time. This quickly gets annoying when rebuilding Docker containers that install many packages from Apt repositories served over HTTPS. Is there a way to get apt-cacher-ng to cache packages downloaded from HTTPS repositories? Why do German umlauts and sharp s (ß) work without a package in LaTeX? I am used to the fact that LaTeX will only know letters like ä, ö, ü, or ß if I use packages like  \usepackage{ucs} \usepackage[utf8x]{inputenc} \usepackage[T1]{fontenc}   Today, I tried LaTeX on a Mac for the first time, using the MacTeX distribution and texmaker. Without writing down any packages, all umlauts and ß were accepted correctly from scratch. Why is that and will the usage of special letters without using the packages cause any problems? Automatically generate thumbnails for all subfolders of a directory in Windows 7? Cannot Upgrade Xcode 11 to Xcode 11.1 I'm unable to upgrade Xcode 11GM to 11.1 for some time on my Mid 2014 MacBook Pro running macOS Catalina. I've installed Xcode from Mac AppStore ages ago (IIRC circa 2014), and upgraded step by step since then. Currently, I'm experiencing the following loop:   AppStore reports that I have an update. I open AppStore, open updates, click "Update" on Xcode. Mac Downloads ~2.5GB first. Installs that patch. Continues to get the full package (~7.6GB). It starts to install. After some churning and install, it reports "Cannot download Xcode now, please try again later."   I have more than enough space on the disk, and nothing is modified in Xcode or in the OS (no homebrew or something similar).  Did anyone experience something similar? Are there solutions to this? In what order should the Star Wars movies be watched? Please don't lynch me, but I've never sat through an entire Star Wars film. I'm aware that the 3 (new) films are technically prequels, but I feel strange watching 3 new films then 3 old films?  Do I need to watch the new ones then the old ones? What is a good set of naming conventions to use when developing on the Force.com platform? I've looked in the Apex developer's guide and a saw the   which has basically only has this:   We recommend following Java standards for naming, that is, classes start with a capital letter, methods start with a lowercase verb, and variable names should be meaningful.   I'm looking for something more in depth, such as end all Controllers with Controller and their tests with ControllerTest, etc.  What is a good set of naming conventions to use when developing on the Force.com platofrm?  It would be preferable if the answer has something that handles custom objects, classes, visualforce pages, and components and not just Apex classes. I am having a tough time building a half cylinder and have not found any tutorial showing me how to do that. How can I Remove .DS_Store files from a Git repository? How can I remove those annoying Mac OS X .DS_Store files from a Git repository? How to make Ethernet work on Android over OTG? I've followed this tutorial to install Ubuntu 15.10:    After restarting my computer I got to the grub menu and chose Ubuntu. Shortly after that I got this error:  /run/lvm/lvmetad.socket: connect failed: No such file or directory WARNING: Failed to connect to lvmetad. Falling back to internal scanning.   These messages keep adding up on a black screen every second. After a while,  I get access to the initramfs ash console.  what am I doing wrong? Suppose $f$ is a continuous single-variable function, prove that:  $$2\int_a^b \int_a^x f(x)f(y) \, dy \, dx = \left[ \int_a^b f(x) \, dx \right]^2$$  This question was just on my Calculus III final exam and I couldn't figure it out, could someone provide some insight, please? I am trying to understand Maximum likelihood estimation but it looks like I am missing something rather elementary.          suppose we have an iid random sample $X_1, X_2,..., X_n$ for which the probability density function of each $X_i$ is $f(x_i; \theta)$ where $\theta$ is an unknown parameter. Then, the joint probability density function of $X_1, X_2,..., X_n$ is given by:          $f(X_1=x_1,X_2=x_2,\cdots,X_n=x_n)=\prod_{i=1}^{n} f(x_i, \theta)$      In Maximum Likelihood estimation, we try to maximize $f$ as a function of $\theta$.  Question: Why do we maximize probability density instead of probability? In what way does it make sense?  Edit: As explained in the answers, the probability of choosing a finite number of sample points from a continuous probability distribution is zero, so maximizing probability doesn't make sense, but how does maximizing probability density make sense? I am looking for a driver for the TP-Link AC600 Archer T2U Nano, on Kubuntu 18.04 (kernel version 4.15.0-51-generic).   I already tried different drivers, none of them worked. I'm getting frequent inaccurate location as the same location, can I make this stop?