Minutes: MathML core meeting on 23 March, 2020

MathML Core Meeting of Mar 23, 2020

Attendees:

   -

   David Carisle
   -

   Neil Soiffer
   -

   Bruce Miller
   -

   Murray Sargent
   -

   Fredrick Wang
   -

   Charles LaPierre
   -

   Rob Buis




Agenda:  https:
https://github.com/mathml-refresh/mathml/issues/8#issuecomment-600108281



The meeting was recorded but hasn’t come through yet.


MathML conference

FW: Conference won’t happen in May. Maybe move to fall or next year. Some
thought was to do online, but that’s not the same as in person.
Default rule thickness? #69 (comment)
<https://github.com/mathml-refresh/mathml/issues/69#issuecomment-599541998>

(use OS/2.yStrikeoutSize or POST.underline instead of measuring U+005F LOW
LINE) ; see also MicrosoftDocs/typography-issues#285 (comment)
<https://github.com/MicrosoftDocs/typography-issues/issues/285#issuecomment-598878917>



FW: Fallback for OpenType math table. Many values rely on a default rule
thickness, but not defined. Some ideas were to use the above values.



NS: what about the idea of matching the fraction line and the “-”. Maybe
use that for the default.

FW: this is just for fallback when there is no OpenType math table.

FW: google doesn’t want us to measure the glyph because it is slow

MS: we measure glyphs a lot in Office

NS: can’t we cache the value so it only computed once?

FW: google doesn’t like caching

NS: think of it as lazy evaluation. Let’s discuss this is the github issue



FW: space after script is a constant, but this can’t be right for varying
font sizes.

FW: it is 1/2pt for 12pt size. Should scale to font size.

DC: LaTeX doesn’t scale and no one has ever complained. On the web, larger
fonts are probably more common.

DC: people really should use an OpenType font with a math table. They
shouldn’t expect good results if they don’t. It’s hard to explain that for
people who want to use a non-TeX font with TeX. I think we need to make
sure that people understand that if they don’t use a proper font, they
can’t expect good typesetting. Hence, I don’t think we should spend much
time thinking about fallback values.
font-family: math #37 (comment)
<https://github.com/mathml-refresh/mathml/issues/37#issuecomment-492964464>

FW: ‘math’ is already defined as a generic font style (like “serif”) in CSS
spec, so we can just use it.

FW: good thing is that people can list preferred math fonts.

NS: It would be good to choose the matching math font to the current font
in use.

...discussion on matching a math font with the surrounding text font..

FW: someone can use CSS to specify the font family for a math tag. It’s up
to them to do the matching, but it is simple to do.

NS: do they have to use a web font? Having a math font on their machine has
been a problem with math on the web..

FW: they would have to specify that. MathML won’t do anything with that.
Operator dictionary status? #87
<https://github.com/mathml-refresh/mathml/issues/87>

NS: We are updated to V13. I’ve been slowly working through the characters,
throwing out some that aren’t really operators and moving others to the
property priority and/or spacing/airity.

FW: There are some suspicious values whose spacing can probably be unified
with other values.

NS: Thanks, I haven’t gotten to those yet, but it helps to be told to look
out for them. It takes minutes/character to look up reasons for being in
Unicode and if I can find any usage, so the whole thing takes a very long
time.
cramped: #164 (comment)
<https://github.com/mathml-refresh/mathml/issues/164#issuecomment-598892217>

FW: I was cleaning up the Chromium code. When you layout the children, you
can only rely on what the children are doing, not what the parents are
doing. One way to do that is via CSS, so create a new CSS property. Can’t
select inflow children, just children. TeX lacks multiscripts. Don’t know
what should be cramped

FW: cramped only applies to denominators and subscripts and maybe radicals,
but it is hard to detect subscripts in multiscripts in MathML. Can’t write
a CSS rule for that case.

MS: In Office, I need to look what happens.

NS: We should review the rules for cramped.

FW: Actually, maybe there is a way in CSS to grab the subscripts and make
them be in cramped style.
negative linethickness: #195
<https://github.com/mathml-refresh/mathml/issues/195>

FW: proposal is to treat it as 0. Consistent with MathML 3.

DC: not consistent with TeX, but what TeX does isn’t sensible.

NS: two choices: either clamp it to 0 or fallback to default

DC: I think 0 is more understandable than jumping back to the default once
it goes negative.

NS:  I don’t care, but I don’t think continuity is a strong argument.

FW: Firefox and webkit use 0.

Resolved: use 0.

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