@manooooh My option would be \exists e\,\forall x(x*e=x\land e*x=x). Using x\in A is wrong if you're expressing the axiom for the neutral element in formal language. Also combining two equalities into one is generally not allowed in formal languages.

@manooooh Of course, my real choice would be “there exists $e\in A$ such that, for every $x\in A$, $ex=x=xe$”

@egreg yes of course, we are discussing in a possible \[...\] environment

@manooooh Avoid that as much as possible. Leave formal languages where they belong.

@egreg hm, I am studying Discrete Maths and it is common to see those expressions. So I guess I am not using formal languages. But it is valid your comment IMHO

@egreg it is possible to ask this question in the main site or would it be closed as "Subjective"?

I'm struggling to set the current font to math font which supports \circ.

Oh, never mind, I needed to add \1 at the end of \font\1="cmmi10". Now I get "Cannot use \XeTeXcharglyph with cmmi10; not a native platform font."

@manooooh I know: books are full of pseudoformulas that throw in some esoterism in order to make things difficult for students.

@egreg I think pseudoformulas help students to understand what they need to prove in a statement. Of course that should not replace natural language, which is more fluid

@DavidCarlisle G'morning. Quiet here at the moment. Enjoy it while it lasts!

@bp2017 yes as l told you yesterday you can not use xetexchsrglyph with a tfm font

@HaraldHanche-Olsen QUAAAAAAAAAAAAAAAAAACK

:)

🦆

@PauloCereda DIIIIIIIIIIINNNNNNNNNNNNNEEEEEEEEEEEEEEERRRRRRRRRRRRRRR!!!!!!!

@DavidCarlisle oh no

/quacks in despair

@PauloCereda 🍗

@DavidCarlisle ooh Unicode

Oh wait

@PauloCereda @DavidCarlisle is fluent in unicode but you could try other languages sciencebasedlife.wordpress.com/2011/06/25/…

@manooooh I beg to disagree.

@UlrikeFischer ooh

@JosephWright coin coin

@UlrikeFischer ^^ practicing my French :)

@PauloCereda qua qua :-)

@UlrikeFischer ooh

Der Ententanz

@PauloCereda indifferentlanguages.com/words/oh

@PauloCereda le déjeuner

@UlrikeFischer ooh

@DavidCarlisle oh non

@UlrikeFischer looking at the url, I was wondering: is there really a website devoted to indifferent languages?

I got a mortarboard badge. The recent rep recalculation is the only explanation I can think of, since I haven't been active on the main site for a while.

Re the comment on this question: It does bug me no end that the media typically refers to temperatures in units of coulomb, sometimes helpfully converted from farad.

@HaraldHanche-Olsen :)

Hi, asking here for a suggestion/advice... as you probably don't know, placement of transistor text in circuitikz is quite broken (or has strange features, choose your own).

Text is typeset near the upper terminal and not centered, and when using flyback diodes it overlaps. I refrained to change it in name of backward compatibility, but now that I want to release a 1.0 I am not so sure...

You know: xkcd.com/1172

What do you think? Shuold I fix it (I can release a compatibility circuitikz-0.9.6 also, to help people surprised by it)? Should I add (another) option?

And I have the same doubt about the voltage direction mess... github.com/circuitikz/circuitikz/issues/314

@Rmano I think giving a package option to get the old terrible behaviour would be best (similar to what I did for ducksay, it has a version key with which you can specify that you want the old, bad behaviour back).

@Rmano mhchem does the same.

@Skillmon what I am doing is releasing with the package the old versions of everything when I do some incompatible change... so for example you can now use circuitikz-0.8.3 if you want the (broken) old direction of batteries back.

@Rmano as a complete copy of the package? Isn't that much duplicated code for this? I.e. I distribute the files ducksay.sty which loads either ducksay.code.v1.tex or ducksay.code.v2.tex and ducksay.animals.tex so that I don't have to include duplicate code (everything shared between versions remains in ducksay.sty, and all the animals are in a file of their own).

Yes, I know it's a lot of duplications, but a lot of things I added are all over the map to fix bugs or things like that, and I do not want to litter the code with \ifs all around. I don't know, labels are truly a better approach than node text (that can't be unrotated), so maybe I will let everything like it is...

Thanks for the comments anyway; I would like to have the nice mechanism that for example, pgfplots has with its compat key, but I think it's quite complex at this stage to add it retroactively. Maybe I'll try to add it past-1.0...

@Rmano would be great (and yes, that's another package that has a feature like this).

@Rmano do you use the built in package rollback option so \usepackage{circuitikz}[=0.8.3] ?

@DavidCarlisle (blush) I read the article on TUGboat..., but given that I am "running" with TeXLive 2017 (the PC here have deployed Ubuntu Long Term...) I did not try with it. I have in my plans to change to that mechanism after 1.0; I am not sure on how complex it would be. For now I am packing circuitikz-0.8.3.sty-style files in the package...

@UlrikeFischer Recently, there was a question about Flash obsolecence and the consequences for future media support in PDF. Therefore, I'd like to know whether PDF-2.0 ISO has something new to offer. Would you please do me the favour and have a look?

Also, I am worried about ConTeXt compatibility, which I break every two edits ;-( --- I have no experience with it.

@UlrikeFischer In that case, I would try to get a legal copy of the iso.

@Rmano you need to do that anyway (look at array-*.sty in tools) the [=..] just gives a slightly nicer interface to it (or actually a not much nicer interface but one that if standardised across multiple packages, people will get used to)

@AlexG well yes. the chapter is much longer than in the older version. 9.2 (sounds) and 9.3 (movies) are declare obsolete in pdf 2.0. They are superseeded by 13.7 "rich media" which start with

"PDF 2.0 introduces rich media annotations providing a common framework for video, audio, animations and other multimedia presentations. For the allowed instances of rich media see "Table 342 — Entries in a RichMediaConfiguration dictionary". The framework includes general controls most of which are commonly needed to stage, present and control an animation, video or other interactive presentation."

@UlrikeFischer new pdfcolmk package on github, 4 less tokens than indentfirst is quite an achievement in optimised tex coding, I think.

@DavidCarlisle ;-). And I got the message about the next repo ;-).

@UlrikeFischer yes epstopdf is OK actually (unless we switch it to use l3image at the back end) but it means that the core graphics package has a dependency on teh entire oberdiek collection which I want to avoid

@UlrikeFischer Ah ok, RichMedia. Thanks a lot! RichMedia is what media9 already implements. But RichMedia is based on Flash! RichMedia isn't new, as of Acrobat 9 in fact, and used to be defined in an addendum to the PDF-2008 specification. Now that it is blessed as being part of the ISO, I am really curious how Adobe will resolve this.

@UlrikeFischer possibly.

@AlexG I don't see any reference about flash. It sounds everything rather vage about the actual media type. But I don't have now the time to look more closely.

@UlrikeFischer No problem. Thank you anyway.

@HaraldHanche-Olsen -- Sigh. I guess I'm guilty of that too, but the only computer I've got available doesn't deal well with Unicode, and it's so old that trying to upgrade would almost certainly result in nothing working at all. I'm responsible for too much to take that chance. (I hope this situation can be fixed early next year.)

@JosephWright I got fed up of not being to tell my github organisations apart so I have added images to them all, but uktug branding still a bit feeble. I stole Robin's picture from his interview here, hope that's OK (there doesn't seem any place to credit uploaded images in the gh gui)

@DavidCarlisle ooh

@PauloCereda two of them are yours (but you get no credit for that either:-)

@DavidCarlisle <3

@DavidCarlisle -- What! You're not a TUG member? I guess we've got to improve our methods of gentle persuasion.

@barbarabeeton does tug have a github organisation? (I thought being in 20 was quite enough:-)

@DavidCarlisle -- The last time I checked (while I was still gainfully employed), github access had to be on an individual basis. So I don't remember whether or not I ever registered; if I did so then, it would really have been for the benefit of AMS tech-support, although I would have had to register in my own name. (And that's the main reason why I didn't add the large number of amsmath "issues", but sent you a separate list.)

@DavidCarlisle -- Regarding TUG association with github, I'm not aware of any, but can check.

@barbarabeeton Not one I know of ..

@barbarabeeton that was a github page that I was showing, see the left sidebar at github.com/davidcarlisle

@DavidCarlisle -- I figured that was where the graphic was from. If it's the TUG logo you're looking for, I'm sure I can find that (or ask someone who knows where it's hiding). It will be on the TUG pages, not on github; probably a .jpg or .eps file.

I'm trying to use it in expl3. The expression works but not in expl3.

@barbarabeeton no if tug don't have a github organisation then tug logo is not needed:-) they are not "real organisations I am in" they are "github groups to which I have write access"

@barbarabeeton I have no control over the images and organisations shown there other than not being in the organisation. So in the case of uktug it's showing an H-style automated gravatar but only an admin of the uktug github can change that, I can't change it from my profile

@DavidCarlisle -- Okay. Now I understand. I'll check.

@barbarabeeton I don't think they do (otherwise it would show up in a search for tex user group on gh)

@DavidCarlisle -- I think that's true, but maybe it would be useful (for some definition of useful). Still worth asking.

@barbarabeeton well it's only useful if you have some files that you want to check in to a git repository

@bp2017 show a real test document and someone could debug

@barbarabeeton Lovely! The ducky is so cute! Thank you!

@barbarabeeton looks tasty

@PauloCereda and @yo' (and anyone else who enjoys classical music with a little extra in the way of visual interest) -- "Line riders" is a rather amazingly coordinated animation. There are several, but I'd start with this one: youtu.be/vcBn04IyELc

@DavidCarlisle you are mean

@barbarabeeton ooh

Can TeX macros include underscores? I usually only use alphabets.

@FaheemMitha in the name? only if you change the catcode (or build the name with csname)

@FaheemMitha all expl3 macros have underscores in their name for example.

@DavidCarlisle So, do you change the catcode or build the name with csname, then?

I sort of remembered that, but wasn't sure whether there was some magic involved.

@PauloCereda I see it's business as usual here.

@FaheemMitha it depends, clearly in expl3 code where there are thousands of macros it would be inconvenient and slow to not be able to use \foo_bar_zzz:nnn to refer to every single token in the code, but for one off use csname can work

@FaheemMitha nothing special about _ (there are no special characters built into tex) same is true of & or \ or any other character

@DavidCarlisle I think this seems like an apposite time to quote from T S Eliot. "Do I dare?" "Do I dare disturb the universe?"

@FaheemMitha in package code or for commands to use in a document? (don't do the latter)

@DavidCarlisle Well, there are default assignments, aren't there?

@DavidCarlisle For use in a document.

Maybe I'll skip it, then.

@FaheemMitha only \ and a-z, but for example $ and & don't have their plaintex meanings when tex starts up, nor do { and }

@DavidCarlisle Oh. So they get defined in plain TeX somewhere? Is plain TeX a collection of macros too?

@FaheemMitha yes (and separately set in latex, which doesn't load plain)

@DavidCarlisle Oh. I always thought plain TeX was a "hardwired" thing.

@FaheemMitha no just a set of macros, look at /usr/local/texlive/2019/texmf-dist/tex/plain/base/plain.tex

@DavidCarlisle Ok, looking.

@DavidCarlisle It's /usr/share/texlive/texmf-dist/tex/plain/base/plain.tex here.

Not a very large file.

@FaheemMitha well yes from wherever your tex root is, so you are using a linux supplied tex, not upstream texlive

@FaheemMitha plain tex is a very simle format, just really as a teaching example for the texbook

@DavidCarlisle Yes, the TeX Live Debian packages.

@DavidCarlisle I thought that is what Knuth originally used for writing his books.

@FaheemMitha but "large" is relative, it was quite a large file in 1980

@DavidCarlisle 1241 lines here.

Quite modest by modern standards.

@FaheemMitha no they use manmac (which loads plain then adds some more)

@DavidCarlisle ?

$ kpsewhich manmac.tex
/usr/local/texlive/2019/texmf-dist/tex/plain/knuth-lib/manmac.tex

@DavidCarlisle Oh, by they you mean Knuth's books.

@FaheemMitha yes manmac == manual macros

@DavidCarlisle Oh. Never heard of them.

@FaheemMitha no reason to really, they are not written for general use they are specifically for those books

@DavidCarlisle I understand.

Random, totally off-topic question. Has German changed much since Goethe? Or, to put it a different way, did Goethe write in modern German?

@barbarabeeton, ha, I seldom listen to classical music but the video was amusing (not only funny but kind of sad, poor cyclist[s]). Looks like a very complex program was involved in making it too. I wonder if it was done with TeX (it must've been).

@FaheemMitha Yes, it did change quite a lot at least in terms of wording and orthography. That does not mean that the words did alter that drastically, we cannot understand Goethe's German anymore (although some idioms may not be in use anymore)…

on stack exchange, \partial works, but I just need the regular d for derivative, anyone know what that is? (google search is failing me...)

@TeXnician Oh. Your wording is a bit confusing. Specifically the second sentence. But I think you mean to say that Goethe is still understandable by a modern German speaker.

@FaheemMitha Exactly. See, while English is a Germanic language it is not enough German to accept German grammar ;)

@AaronHall Should be just d (or \mathrm{d} if you want it upright)

right

that's it, thanks! :)

@AaronHall You're welcome

@AaronHall er, d ?

@PhelypeOleinik oh you'd answered already:-)

@DavidCarlisle I'm fast :-)

(except when I'm not)

@PhelypeOleinik I was counting tfm files

@DavidCarlisle Oh, that. I wonder what it is for...

@PhelypeOleinik OP's style to not give any hint of actual use case but to ask a series of low level tex questions, all good for earning tex-core rep if nothing else:-)

@DavidCarlisle It's a shame expl3 is being ruled out in most questions. I'd have a badge by now ;-)

@TeXnician Yes, I thought that was probably Germanic sentence structure. Though I don't know German, so cannot say for sure.

@PhelypeOleinik Why is it being ruled out?

Oh, perhaps you're talking about a particular user's questions.

Some questions asked with "no expl3, please". But my comment is not to be taken seriously :-)

@PhelypeOleinik the trick to getting gold badges is to ignore the OPs instructions and just give sensible answers anyway, see I got a tikz badge like this:

@DavidCarlisle I remember that comment. Did you get a TikZ gold badge?

I'm surprised TikZ users are willing to be fobbed off with picture or pstricks.

@FaheemMitha naturally. I got by far the most number of my tikz-pgf points for this:

@FaheemMitha I can confirm it works. TikZ and a table without neither TikZ nor tabular: tex.stackexchange.com/a/438916/134574

@FaheemMitha Oh, yes, and that Super Mario Bros question. That one got out of control...

@PhelypeOleinik I think that second answer is from the user formerly known as marmot.

Paraphrasing Bernoulli, I can tell the marmot by his paw.

@FaheemMitha Yes, that was him :)

@AlanMunn Thank you very much for your edit.

@JosephWright Btw, are you in regular contact with someone at Overleaf other than me here in the chat?

@yo' No, only my occasional Twitter ping

@JosephWright ok, interesting to know. Well, if you wanted to discuss soemthing, I can certainly seek opinion of others and stuff. Btw, any plans for Rochester?

(oh, is the link to learn latex broken?)

@yo' That's because I've not paid for it yet ...

@yo' I was just pondering, really: you get some quite 'cute' HTML5-based sites for learning programming. Even a dozen short pages done in Markdown/Jekyll could look good and link through to a 'real' TeX system (hence thinking Overleaf, though of course it then gets 'interesting' if supported by a user group)

@JosephWright well, I know it's not interactive, but check "Overleaf learn" (not at a PC, I hope google find it), which is an actively maintained wiki by OL.

It's true tho thatcs it's not with "try this directly in OL" links that would open a template...

Still trying to fit this into a box.

@yo' Sure, I know that Overleaf have some good resources, I was just thinking a simple site with a clear URL would be handy

@AlanMunn LOL

@JosephWright possibly. Now I gotta go, I have my organ lesson tomorrow and still have to practise.

@yo' Have a lot of fun

@JosephWright J.L. Krebs (one of J.S. Bach's most proficient students) is always fun :)