Java Session Management in multiple tabs of same browser
How to differ sessions in browser-tabs?
Flows/Processes, Version Control and CI I've started using Processes and Flows and am really excited about these features -- but am still wrapping my mind about how to manage them in Version Control (which I use) and Continuous Integration (which I don't yet... but am trying to work in that direction). The underlying challenge is that each time a process or flow is edited, the metadata file is renamed to reflect its update version, e.g. MyFlow-1.flow, MyFlow-2.flow, etc. The Challenge for Version Control If each version of the flow has its own file name, this makes it more complicated to track changes to flows.  It seems like there could be two strategies here:  Rename the files to remove the version number.  I'd need a script to run through my src folder pre-commit, and remove the number so that my file name is always MyFlow.flow.  This is an annoying extra step, but makes version control simpler.  On the other hand, it probably makes deployment much harder.  Track each file in version control with its original name.  We'd need to be diligent about deleting MyFlow-1 in the commit where we add MyFlow-2 so that git would recognize this as a rename/move and show helpful diffs.  Otherwise, the whole file appears to change with every change, which makes version control rather less useful.   The Challenge for Deployment/Continuous Integration From my experiments so far, once a flow has been activated in a given environment, the metadata file can't be deployed again (either it is currently active, or has been active in the past and superseded). That means that I need to prevent my previous flow versions from being included in a deployment package (either by not tracking them at all, or by using a script to delete earlier versions).  I also need some way to determine whether the current version (in my repo) should be included in the deployment payload for a given environment or not. I could imagine a script that (1) downloads flows from the target environment, and removes *.flow files from the payload if they already exist in the target environment, but that feels complicated.  And it's even harder if I've removed the version numbers from my flow files. Are you using flows in VS or CI?  How are you managing these issues? Note:  I'm not sure whether VC and CI should be one question or two - depends on how integrated the strategy for dealing with these two challenges.  If you think these should be separate questions, comment and I'll re-post. At what time intervals does ntpd update the time? I'm running the latest ntpd.   When I start ntpd my system time synchronizes with ntp server's ntp. After synchronizing I changed my system time manually using date command date -s '1997-02-22 12:00:00'   My system time got changed as per the date command.   NTPD is still running, I want to know at what time interval my system time will sync with the internet via ntp. Prove $(1-a)(1-b)(1-c)(1-d)&gt;1-a-b-c-d$ and $ a,b,c,d$ are real and between 0 and 1.    I can do this with $$(1-a)(1-b)&gt;1-a-b  \\ 1-a-b+ab&gt;1-a-b  \\ ab&gt;0  $$  But with $c$ and $d$, this becomes much more difficult. Can someone nudge me in the right direction? I found this problem on a well-known problem solving website. It is apparently from Ramanujan.     With   $$\LARGE{a = \frac{1}{1 + \frac{e^{-2\pi}}{1 + \frac{e^{-4\pi}}{1 + \ddots}}}},$$   what is $a$?   The basic methods I know for questions of this type were not helpful to me.  I do not require a full solution, but feel free to post one if you would like. Hints or lecture notes on how to solve problems of this nature would be appreciated.   Keep in mind that I am at an undergraduate level in mathematics. C++ cast syntax styles MySQL Hashing Function Implementation I know that php has md5(), sha1(), and the hash() functions, but I want to create a hash using the MySQL PASSWORD() function.  So far, the only way I can think of is to just query the server, but I want a function (preferably in php or Perl) that will do the same thing without querying MySQL at all.  For example:  MySQL hash -> 464bb2cb3cf18b66  MySQL5 hash -> *01D01F5CA7CA8BA771E03F4AC55EC73C11EFA229  Thanks! For all $x,y∈\Bbb{R}$ define that $ x\equiv y$ if$ x^2=y^2$ For all $x,y\in\Bbb{R}$ define that $x\equiv y$ if $x^2=y^2$ . Then $\equiv$ is an equivalence relation on $\Bbb{R}$ , there are infinitely many equivalence classes, one of them consists of one element and the rest consist of two elements.  Solution  True. To show that $\equiv$ is reflexive we need to show that $\forall x\in\mathbb{R} :x\equiv x$. Let $x\in\mathbb{R} , x\equiv x \mbox{ if } x^{2}=x^{2}$, which is obvious.  $[x] ={y\in\mathbb{R} |x\equiv y} =[0]={y\in\mathbb{R}|0\equiv y}={0}$. Hence $y^{2} =0^{2} =0$ which implies that $y=0$.  Can anyone please give me correct answer to this question. How to treat differentials and infinitesimals? In my Calculus class, my math teacher said that differentials such as $dx$ are not numbers, and should not be treated as such.  In my physics class, it seems like we treat differentials exactly like numbers, and my physics teacher even said that they are in essence very small numbers.   Can someone give me an explanation which satisfies both classes, or do I just have to accept that the differentials are treated differently in different courses?  P.S. I took Calculus 2 so please try to keep the answers around that level.  P.S.S. Feel free to edit the tags if you think it is appropriate. I have the following browsers on my phone:   stock Dolphin Mini Opera Mobile Firefox   I don't want to set a catch-all default because some pages render better on some browsers than on others.  When I click on a link on a non-browser app (e.g. google search or google reader) it asks me which browser to choose (as expected).  Can I set a default browser for some pages and a different default for others? After reading a couple of answers and comments on some SQL questions here, and also hearing that a friend of mine works at a place which has a policy which bans them, I'm wondering if there's anything wrong with using backticks around field names in MySQL.  That is:  SELECT `id`, `name`, `anotherfield` ... -- vs -- SELECT id, name, anotherfield ... Can't see a glass object through another glass object in Eevee Why is looping over find's output bad practice? This question is inspired by    I see these constructs  for file in `find . -type f -name ...`; do smth with ${file}; done   and  for dir in $(find . -type d -name ...); do smth with ${dir}; done   being used here almost on a daily basis even if some people take the time to comment on those posts explaining why this kind of stuff should be avoided... Seeing the number of such posts (and the fact that sometimes those comments are simply ignored) I thought I might as well ask a question:  Why is looping over find's output bad practice and what's the proper way to run one or more commands for each file name/path returned by find ? Assumed True until proven False. The Curious Case of the Vacuous Truth Given two statements, $P$ and $Q$, and the logical connective, $\implies$, the truth table for $P \implies Q$ is:  $$\begin{array}{ c | c || c | }   P &amp; Q &amp; P\Rightarrow Q \\ \hline   \text T &amp; \text T &amp; \text T \\   \text T &amp; \text F &amp; \text F \\   \text F &amp; \text T &amp; \text T \\   \text F &amp; \text F &amp; \text T  \end{array}$$  Lines one and two are quite clear. What is ambiguous is lines three and four.  One explanation as to why $P \implies Q$ is true when $P$ is false, provided by Velleman goes:     Let $P(x)$ be the statement $x&gt;2$ and $Q(x)$, $x^2 &gt; 4$. When $x=3$, $P$ is true, and $Q(x) = 9$ thus $Q$ is true. If $P(x) = 1$ then $Q(x) = 1$ and they are both false. If $P(x) = -3$ then $Q(x) = 9$ and so the statement is true.   This explanation was quite unsatisfactory to me. Looking at Enderton, we have:     For example, we might translate the English sentence, ”If you're telling the truth then I'm a monkey's uncle,” by the formula ($V \implies M$). We assign this formula the value $T$ whenever you are fibbing. In assigning the value $T$, we are certainly not assigning any causal connection between your veracity and any simian features of my nephews or nieces. The sentence in question is a conditional statement. It makes an assertion about my relatives provided a certain condition — that you are telling the truth — is met. Whenever that condition fails, the statement is vacuously true.      Very roughly, we can think of a conditional formula ($p\implies q$) as expressing a promise that if a certain condition is met (viz., that $p$ is true), then q is true. If the condition $p$ turns out not to be met, then the promise stands unbroken, regardless of $q$.   Though a significant improvement over the Velleman explanation, I still feel uncomfortable with it.  Really, it seems we can conjure up as many silly counter-examples as we like, such as:     If pigs can fly, then I can walk on water.   Though following the above truth table, the implication is that my ability to walk on water is true.  After considering it, it seems to me that $\implies$ is only meaningful when $P$ is true, then we can look at it in relation to $Q$. However, if $P$ is false, then we actually know nothing about the relationship between $P$ and $Q$. This would give a truth table of:  $$\begin{array}{ c | c || c | }   P &amp; Q &amp; P\Rightarrow Q \\ \hline   \text T &amp; \text T &amp; \text T \\   \text T &amp; \text F &amp; \text F \\   \text F &amp; \text T &amp; \text ? \\   \text F &amp; \text F &amp; \text ?  \end{array}$$  where the $?$ denotes that given $P$ we actually don't know anything about $ \implies $.  Thus. one way to clear this up would be to assume that $? = T$. Thus the vacuous truth is a "definition of convenience" in a sense.  The above is my take on the matter.  Could someone provide some clarification on the conditional logical connective? Solving "mv: Argument list too long"? Hi I don't know how to show that $\langle 2,x \rangle$ is not principal and the definition of a principal ideal is unclear to me. I need help on this, please.   The ring that I am talking about is $\mathbb{Z}[x]$ so $\langle 2,x \rangle$ refers to $2g(x) + xf(x)$ where $g(x)$, $f(x)$ belongs to $\mathbb{Z}[x]$. Starting services in batch file on windows 7 How to switch from Natbib to Biblatex in pre-made document class/template? I am using  to write my thesis. The template uses Natlib for references, whereas I really need Biblatex.   When I simply try to change \usepackage[natbib] for biblatex I get the error message  This is BibTeX, Version 0.99d (TeX Live 2016/Debian) Capacity: max_strings=100000, hash_size=100000, hash_prime=85009 The top-level auxiliary file: aagot-1-report.aux The style file: acm.bst Illegal, another \bibstyle command---line 80 of file aagot-1-report.aux  : \bibstyle  :          {acm}  I'm skipping whatever remains of this command Database file #1: Mendeleytry.bib.bib Warning--I didn't find a database entry for "" You've used 14 entries,code here   The solution  \usepackage[backend=bibtex, natbib=true, style=numeric]{biblatex}   didn't work.  Another possible solution was said to be to recompile from scratch to delete the .aux file, but that resulted in  /usr/share/texlive/texmf-dist/tex/latex/biblatex/biblatex.sty:462: LaTeX Error:  Command \bibhang already defined.            Or name \end... illegal, see p.192 of the manual.  See the LaTeX manual or LaTeX Companion for explanation. Type  H &lt;return&gt;  for immediate help.  ...                                                l.462 \newlength{\bibhang}   I have tried to use this "marco" to override the \requirePackage settings, but that also didn't work and resulted into  LaTeX Error: Two \documentclass or \documentstyle comm ands.  See the LaTeX manual or LaTeX Companion for explanation. Type  H &lt;return&gt;  for immediate help.  ...                                                l.45 \documentclass[whitelogo]{                            tudelft-report}    Where I can't seem to delete any of the document classes without getting the functionality of the tudelft-package and the biblatex citing (or in fact getting it to work at all!)  (no line number): [0] Config.pm:343&gt; INFO - This is Biber 2.5 [0] Config.pm:346&gt; INFO - Logfile is 'aagot-1-report.blg' [62] biber:290&gt; INFO - === Tue Apr 24, 2018, 22:24:06 [246] Utils.pm:165&gt; ERROR - aagot-1-report.bcf is malformed, last biblatex  run probably failed. Deleted aagot-1-report.bbl [246] Biber.pm:113&gt; INFO - ERRORS: 1   Is there any way I can still make this template work with Biblatex? Natlib seems to deeply rooted in the file and I don't know how to change it/access the settings/the ".sty"-file. Can I use the example documentclass combined with biblatex (instead of the standard natbib) without losing the great parts of the rest of the document class?  Thanks very much :) How to change XML Attribute How can I change an attribute of an element in an XML file, using C#? Is there a name for this database schema of key values? $[S]$ means linear span of S. Then $[S] = [[S]]$ My definition of span:   Suppose a vector space $(V,+,\cdot)$, and       $$S = \{u_1,\cdots,u_n\}$$      (and $S$ is a subset of $V$, not a subspace)      $$[S]=:\bigcap_{W\subset V, W\supseteq S} W$$      In other words, $[S]$ is, by definition, the intersection of all $W$,   such that $W$ is a subspace of $V$ and $W$ contains $S$.   Well, then I need to prove that   $$[S] = [[S]]$$  My strategy:  $[[S]]$ means the intersection of all subspaces that contain $[S]$. If all the subspaces contains $[S]$, so does their intersection. Therefore, $[S]\subset[[S]]$  However, I'm having trouble proving the converse:  $$[[S]]\subset[S]$$  Any hints?