@UlrikeFischer See if now it's better: tex.meta.stackexchange.com/a/7399/101651

@barbarabeeton In my opinion a proof should hardly ever end with a math display; it should not consist of an enumerated (or itemized list) either: labeled paragraphs are sufficient. Anyway, a lonely tombstone below a display is really horrible.

hello @egreg, please do you have an idea why \catcode\z@=15\relax in latex.ltx, is this documented anywhere

@touhami Simple: char 0 is not generally allowed

so no ignored char in latex?

@JosephWright there is so no ignored char in latex?

hello @DavidCarlisle

@touhami why do you want an ignored character:-) char 0 is catcode 9 in plain and 15 in latex, if that's what you mean.

@DavidCarlisle i don't need any of them. It just to know, as i say i can't see this documented anywhere.

@DavidCarlisle it's initex not plain :-)

@touhami so it is, anyway if there are null in the file, throwing an invalid character error seems better than ignoring them

@DavidCarlisle thanks sir and good day :-)

@touhami Some operating systems with fixed length records might fill the record with null bytes, but this should be taken care of by the TeX file reading machinery, so null bytes that remain are almost guaranteed to be wrong bits.

Re this question, and the comments there, wouldn't it be nice if we had a search engine that would accept any command or environment name, and tell us what package(s) define that name? The haskell world has two such search engines: hoogle and hayoo, both excellent. I wonder how hard it would be to build the database for such a search engine.

@HaraldHanche-Olsen Various editors do more-or-less exactly this

@DavidCarlisle is \begin{aligned}[t/b] actually mentioned in the amsmath manual? I think I learned it from Emacs/auctex asking me about it. Related: tex.stackexchange.com/q/388155/3929

@daleif Page 8.

"Like the array environment, these -ed variants also take an optional [t] or [b] argument to specify vertical positioning."

@TorbjørnT. thanks missed that.

@Aditya Have you ever considered to make your mathalign My Way up-to-date? I don't know the current status of numbering subformulas, for example.

@JosephWright I didn't know that. It seems like a quite sophisticated task for any editor to undertake. May I ask what editors? Not a complete list, just what you get off the top of your head …

Friends, is this expected?

There seems to be no space after equation/cases.

@PauloCereda So \belowdisplayskip glue is not inserted? I can't recall seing that, no.

@HaraldHanche-Olsen I am quite surprised as well.

\documentclass{article}
\usepackage{amsmath}
\usepackage{lipsum}
\begin{document}
\lipsum[1]

\begin{equation}
a =\begin{cases}
b \\
c
\end{cases}
\end{equation}

\lipsum[1]
\end{document}

@HaraldHanche-Olsen ^^ what's the output for you?

Not a lot of space. But if I include an equation without any cases, more or less the same thing happens. \belowdisplayskip is 10.0pt plus 2.0pt minus 5.0pt; I would expect a bigger space.

Wait, this is weird: When I shorten the paragraphs to be just one line, there is more space!

@HaraldHanche-Olsen Wow!

Looks like the lipsum package is doing something with \par … why?

@HaraldHanche-Olsen \lipsum starts with a \par, \lipsum* doesn't, I think.

Wait, that doesn't matter there. Sorry.

@PauloCereda Playing around with a similar example with tracing turned on, I see that it chooses \belowdisplayshortskip some times. Trying to find out why … for sure, the final line in the preceding paragraph is not at all short!

@HaraldHanche-Olsen Intriguing indeed! Perhaps one for @egreg and/or @barbarabeeton.

@PauloCereda A bit more experimentation shows that the “short” display skips are used if the display is not in a paragraph, i.e., if there was a preceding \par (explicit or implicit).

@HaraldHanche-Olsen oh!

Forget the \trywith macro. It's debris from my experiments.

@HaraldHanche-Olsen: ouch, silly me! David told me that I should not leave an empty line yesterday...

@PauloCereda -- don't be surprised. what you've got is too much space above the cases. there shouldn't be a blank line between text and a display. reason: it allows a page break at that point, which in proper math publishing is a no-no. (this has been pointed out many times in answers and comments on the main site here.)

@barbarabeeton Indeed, I found that out too late. :(

@PauloCereda -- tsk. well, at least you're working on your thesis ... i think ...

@barbarabeeton No, no, it's the “thesis”.

@barbarabeeton Yes! :)

@HaraldHanche-Olsen -- the "alleged thesis". well, i'll just have to keep nagging.

@PauloCereda Anyhow, I got tripped up by this too. I should have known better. Perhaps. But now I'll remember next time.

Hi chat!

this site here,I am unable to view it in a readable form ,its in raw latex form

how do i convert this intto readable form

any easy step

@BAYMAX It's probably not LaTeX, but MathJax. That's a big difference for us here.

hmm i see

@TeXnician @BAYMAX Actually, seems like that's just images, and that the images didn't load.

@TorbjørnT. As far as I can tell those are images that should get generated by a rendering site...

@TeXnician Yeah, looking again seems that you're right. Either way a problem for Wordpress/that site.

thanks

@PauloCereda The space below the equation is \belowdisplayshortskip and there's an empty line before it, because of the blank line (and the \par at the end of \lipsum[1]). It would be the same with \lipsum*[1] (and no blank line, of course), because the paragraph ends with just a short word. If you try \lipsum*[2], you get \belowdisplayskip.

@egreg Understood, sorry for the noise. It was really driving me crazy... :(

@PauloCereda No surprise at all.

@egreg In other news: ctan.org/pkg/checkcites

@PauloCereda :-)

@egreg Petra asked me if they should include you as maintainer. :)

@PauloCereda Better stay with you.

@egreg Nah I like a challenge. :)

only my second palindrome!

@barbarabeeton Yay

@barbarabeeton And your first palindrome, was it 1?

@HaraldHanche-Olsen -- no, 22422 : chat.stackexchange.com/transcript/41?m=24570570#24570570 ... well, i guess 1 is a palindrome, but a rather wimpy one, hardly worth mentioning.

@PauloCereda Sad story: rp-online.de/nrw/staedte/koeln/…

@barbarabeeton Yes, but as you surely know, we mathematicians like to account for the trivial cases as well. So it's your second nontrivial palindrome. That you know of, anyway.

@HaraldHanche-Olsen -- actually, i know that at least one other happened, but at the time i was on a system where i couldn't see the actual count. (gotta get a new laptop ... or at least upgrade the operating system, which may not be possible on account of the widget's age.)

@UlrikeFischer Oh :'(

@barbarabeeton, @AlanMunn: sorry for the off topic subject, but this might amuse you: there's an antagonist in the Mario & Luigi game series (published by Nintendo) named Fawful which is quite notable for speaking in Engrish (grammatically incorrect English), as a parody of low-quality video game translations, and making obscure food metaphors. Some of the dialogue jewels: "And this battle shall be the delicious mustard on that bread! The mustard of your doom!"

@PauloCereda -- and a really sad story for you ... theguardian.com/environment/2017/aug/24/…

@barbarabeeton Oh no!

@barbarabeeton Not only for @PauloCereda, for the all humankind! :'(

@barbarabeeton At first I read Brazil abolishes Amazon and wondered what it is about ;-).

@barbarabeeton congrats, but i think David will complain about the comma

@StrongBad -- david always complains about commas. i'm used to it.

@barbarabeeton the comma is misplaced!

@DavidCarlisle -- complaint, as predicted. i keep telling you, i'll never make it to 6 digits while you and @egreg have a 6 hour head start.

@daleif hmm it's in texdoc amsmath,pdf that is the amsmath.dtx documented source if you get as far as page 52....

@barbarabeeton think of it as being 18 hours behind

@DavidCarlisle -- the earth doesn't spin in that direction. although i've seen two allegedly intelligent sources recently who got east and west reversed; one in print, the other in a web announcement. isn't geography taught any more?

@barbarabeeton but it does spin so there isn't really anyone ahead of anyone else

@DavidCarlisle -- you mean it isn't really a big stack of turtles, all the way down?

@barbarabeeton apparently it's round

@DavidCarlisle -- when will you be back home and able to look at an amsmath question?

@barbarabeeton I'm relying on local transport, so can't say exactly ^^^

@barbarabeeton you could send the question anyway:-)

@DavidCarlisle hmmm. it really looks like the front of that conveyance should be headed more uphill. a cog railway? i think i'd like to try that out sometime.

The psnfss2e.pdf says there is a narrow helvetica available with family "phv" and series "mc". How do I select that series?

@DavidCarlisle -- the question (based on tex.stackexchange.com/q/388218 and several others of that ilk) is why doesn't \raisetag work with aligned, alignedat and gathered (maybe more; haven't looked too hard), as it's supposed to and it says so in the amsmath users guide, but it does work with split? (it's been listed as a bug for about 10 years; no progress.)

Never mind, just found out.

@barbarabeeton yes-)

@barbarabeeton Hmm OK will look

@barbarabeeton actually it's more surprising it works with split, I'll look later. with aligned etc in equation the equation number isn't being placed by amsmath it's just the primitive $$ equation number logic

@DavidCarlisle -- interesting. thanks.

@barbarabeeton but \raisetag could detect it's in an equation and do something more sensible