"Polish l" in bibliography using sharelatex I am using sharelatex with a separate bibliography file. Some of the authors cited use a lowercase Polish l in there name. The LaTeX code for this symbol is \l{}. Here is a typical entry:   @article{123, AUTHOR = {Karo\'{n}ski, Micha\l{} and \L{}uczak, Tomasz and Thomason, Andrew},...}   However, sharelatex keeps interpreting the \l{} as an incomplete math symbol (according to the compiler error) and is not producing proper output in my bibliography. Here is the compiler error:  &lt;inserted text&gt;                  $ l.99 Alan Frieze and Micha\l                             {} Karo\'nski. I've inserted a begin-math/end-math symbol since I think you left one out. Proceed, with fingers crossed.    BTW, \L{} and \'{n} both work just fine, along with all other foreign accents in names and titles in my bibliography, but the \l{} looks like \ell and everything after \l{} is in math mode.  Any ideas on work arounds out there?
How to write “ä” and other umlauts and accented letters in bibliography? How to write in bibliography (package natbib) letter "a" with two dots above? Specially, I mean the word Birkhäuser.  Is there a general rule or way how to write such umlauts or other accented letters in bibliographies?
In many practical applications, one can consider the Earth-Centered Inertial () reference frame approximately as an inertial reference system, though strictly speaking, it is non-inertial.   Is there any quotable reference, where this claim is supported by a detailed estimation how small the effects are that one neglects if one considers the Earth's frame as inertial? Deleting missing data with CountryData How to prove that you have significant ties with family in your home country? How can I prove the immigrant officers that I have significant ties in my home country?  Are there any documents that I need? Sum of the series $\frac{1}{2\cdot 4}+\frac{1\cdot3}{2\cdot4\cdot6}+\dots$ I am recently struck upon this question that asks to find the sum until infinite terms $$\frac{1}{2\cdot 4}+\frac{1\cdot3}{2\cdot4\cdot6}+\frac{1\cdot3\cdot5}{2\cdot4\cdot6\cdot8}+.....∞$$ I tried my best to get something telescoping or something useful, but I failed. I even made a recurrence as $t_n=t_{n-1}\frac{2n-1}{2n+2}$, but this question was expected to be done with simple logic of series (Also that the recurrence on solving gives a higher order charasteristic polynomial, which might be difficult to solve without calculator). So, thus I ended up being confused with this question. So, can anyone prode a small solution to this (might be easy) problem  . Primitive of holomorphic Function $\frac{1}{z}$ on an Annulus. Given an Annulus with $A(0,r,R)$ show by considering Cauchy's Theorem for primitives that there is no holomorphic function with $f'(z)=\dfrac{1}{z}$.   I am struggling to picture this since but it seems like there are issues because $f(z)=\log z$ isn't well defined in the same range as $\dfrac{1}{z}$.  Am I looking to show that $\int_Ag(z)dz = 0$ where $g(z) = \dfrac{1}{z}$? messenger()->addMessage not working after a $form_state->setResponse In the submitForm of a custom form, I have this:    switch ($form_state-&gt;getValue('suscribe')) {   case 0:     $iStatus = 1;     break;   case 1:     $iStatus = 3;     $sFileName = 'sites/default/files/_private/bulletins/' . $form_state-&gt;getValue('adherent')[1] . ".pdf";     $response = new BinaryFileResponse($sFileName);     $response-&gt;setContentDisposition(       ResponseHeaderBag::DISPOSITION_ATTACHMENT,       'bulletin.pdf'     );     $form_state-&gt;setResponse($response);     break; }  $storage = \Drupal::entityTypeManager()-&gt;getStorage('member'); $id = $form_state-&gt;getValue('adherent')[0]; $entity = $storage-&gt;load($id); $entity-&gt;status = $iStatus; $entity-&gt;save();  \Drupal::messenger()-&gt;addMessage($this-&gt;t('Your wish has been recorded.'));   suscribe is a Yes/No radio button. $form_state-&gt;setResponse($response); triggers the automatic download of a pdf document.    The message (Your wish...) is correctly displayed in case 0. In case 1, the message shows only if I refresh the page (or go to another page). How can I have the message displayed without doing another action after submitting the form in case 1?    By the way, database is correctly updated in both cases. I'm using Drupal 8.6.10. How can I prevent my Wi-Fi connection from glitching? In the book &quot;Quantum Mechanics and Path Integrals&quot; Feynman &amp; Hibbs state that  the probability $P(b,a)$ to go from point $x_a$ at time $t_a$ to the point $x_b$ at the time $t_b$ is $P(b,a) = \|K(b,a)\|^2$ of an amplitude $K(b,a)$ to go from $a$ to $b$. This amplitude is the sum of contributions $\phi[x(t)]$ from each path. $$ K(b,a) = \sum_{\text{paths from $a$ to $b$}} \phi[x(t)]$$ The contributions of a path has a phase proportional to the action $S$: $$ \phi[x(t)] = \text{const}\ e^{(i/\hbar)S[x(t)]}$$  Why must the contribution of a path be $\sim e^{(i/\hbar)S[x(t)]}$? Can this be somehow derived or explained? Why can't the contribution of a path be something else e.g. $\sim \frac{S}{\hbar}$, $\sim \cos(S/\hbar)$, $\log(S/\hbar)$ or $e^{- (S[x(t)]/\hbar)^2}$ ? Edit: I have to admit that in the first version of this question, I didn't exclude the possibility to derive the contribution of a path directly from Schrödinger's equation. So answers along this line are valid although not so interesting. I think when Feynman developed his formalism his goal was to find a way to quantize systems, which cannot be treated by Schrödinger's equation, because they cannot be described in terms of a Hamiltonian (e.g. the Wheeler-Feynman absorber theory). So I think a good answer would explain Feynman's Ansatz without referring to Schrödinger's equation, because I think Schrödinger's equation can only handle a specific subset of all the systems that can be treated by Feynman's more general principle. I'm using a flow to set a field to a certain value (01, 02, 03) depending on the value of another field on the same record. I initially wanted to do it with process builder but because of the mapping it seems I would need three 'criteria nodes' or a formula field. Furthermore, it seems Salesforce is recommending using flows instead of process builder for before update actions as it is faster.  The problem with Flows is that I found a way to trigger it when the record is new or updated but not when the specific field is changed so it triggers every time the whole record is updated even when the field stay the same.  On Process Builder, you can use isChanged and then call the flow with specific record but that kinds of defeat the point of using flows for before Update.  So is there a possibility to do the same thing directly in flow ?  Thank you for the help ! Cannot determine size of graphic If there are 5 points on the surface of a sphere, then there is a closed half sphere, containing at least 4 of them.  It's in a pigeonhole list of problems. But, I think I have to use rotations in more than 1 dimension.  Regards Why is 248x248 the maximum bi dimensional array size I can declare? Prove: if $a,b\in G$ commute with probability $>5/8$, then $G$ is abelian Suppose that $G$ is a finite group. If $P( ab=ba ) &gt;5/8$, prove $G$ is abelian. What does the "@" symbol do in SQL? I was browsing through the questions and noticed this:  SELECT prodid, issue FROM Sales  WHERE custid = @custid  AND datesold = SELECT MAX(datesold)               FROM Sales s               WHERE s.prodid = Sales.prodid                   AND s.issue = Sales.issue                   AND s.custid = @custid   I was wondering what the "@" does in front of custID?  Is it just a way of referencing the custID from the table being selected? Tall curly brace I would like to put a tall (long) left curly bracket on the left side of the following:  \documentclass[12pt]{article}  \begin{document}  \noindent c: $\{$1, ..., n$\}$ $\rightarrow$ $\{$1, ..., n$\}$, such that  \hspace{20 mm}  \noindent c($a_i$) = $a_{i+1}$ for 1 $\le$ $i$ &lt; $l$  \hspace{20 mm}  \noindent c($a_l$) = $a_1$   \end{document}   Please let me know if you can help. Thanks! When moving around the sites on Stack Exchange using Safari on my iPad (not the Stack Exchange App), I am fine when moving to any site other than SuperUser.  When logged in, I can switch sites and stay logged in, but when I switch to Super User I need to log in again. If I choose not to log in and switch to another site, I am logged in there. Is there a problem with the login handling for Super User? If it helps, I log in with a Stack Exchange account, not through Facebook or Google. Update After getting fed up with the problem, I took the advice given in the answer below which was to use Chrome, and the problem still exists. The same goes for Firefox. Have I missed something?  As you can see from the screenshots below, there are no cookie settings to be found. Chrome for iOS settings page  Privacy settings page  Content settings page  Google app settings page We have this large database (>1TB) that we intend to "shrink".  The database revolves around one main entity, let's call it "Visit".  For discussion, let's say it is a database for a medical practice.  There are a total of 30 visit "types", such as procedure, annual, follow-up, immunisation etc, each of which is a subsidary table to "Visit", e.g. "visit_immuno".  The database has accummulated some 12 years of data since 2000.  Someone has proposed that we keep about 3 years of data in the "live" version and have the rest live in an "old_data" database.  The date is ONLY stored in the "Visit" table since it is normalised.  The Visit table also contains a ROWVERSION column and a BIGINT pseudo-identity (clustered) column.  For all intents and purposes, let's say the clustering key is populated by a SEQUENCE (SQL Server 2012 Enterprise) - we shall name it cid.  The visit.date is not always in the same order as the clustering key, for example when a doctor goes on extended visitations and returns with his "briefcase" of data, it gets merged into the main table.  There are also some updates to the "visit" table that will cause the ROWVERSION column to be out of sync with both the cid and date columns - to put it simply, neither ROWVERSION nor cid would make suitable partition keys for this reason.  The business rule for removing data from the "live" is that the visit.date must be greater than 36 months and a child visit_payment record must exist.  Also, the "old_data" database does not contain any of the base tables except visit%.  So we end up with:  Live DB (daily use) - All tables Old-Data DB - older data for the visit% tables  The proposal calls for a Combined DB that is a shell containing Synonyms to ALL the base tables in the Live DB (except visit%) plus Views that UNION ALL across the visit% tables in the two databases.  Assuming the same indexes are created in the Old-Data DB, will the queries perform well on the UNION-ALL Views?  What type of query patterns might trip up the execution plan for the UNION-ALL Views? Splitting text files based on a regular expression I have a text file which I want to split into 64 unequal parts, according to the 64 hexagrams of the Yi Jing. Since the passage for each hexagram begins with some digit(s), a period, and two newlines, the regex should be pretty easy to write.  But how do I actually split the text file into 64 new files according to this regex? It seems like more of a task for perl. But maybe there's a more obvious way that I'm just totally missing. Learning development with Force platform. Any good books? I'm a bit familiar with Java and SQL, any good books to get on coding in Apex for salesforce? Make flash drive bootable with MULTIPLE Windows Installers I have seen many ways to make a USB an installer for about any Windows OS. But how can I (using grub or something like that) make it bootable to all editions on Windows XP and 7?   I have tried Googling it and researching, I've even tried to do it, But I dont understand much about GRUB or linux at all.  Please keep in mind that I am not very good with linux, so please use as many details as possible.