Challenging Maths in SILE with a real-world example

[Omikhleia]

Math initial support was added in SILE 0.12; but as of 0.14, it still suffers from a number of limitations. It's hard to tell whether it's used... if it's actually usable... and it was worth of the effort...

Let's take this "small" ready-to-go article:
https://drive.google.com/file/d/18st8NSitO4Zk8BQqyT73Xu6kfcK0vL2_/view?usp=share_link

The SILE-ready sources are here = more precisely, the article in Djot with TeX-like maths, a SIL preamble and a (slightly) customized resilient style file.

The maths in it are not that bad -- looked from afar, at least -- but they are not that good either... with plenty of small problems (despite my attempt at working around some of them by inserting groups [ ... }, \mo, \, and whatnot's here and there).

So I am sharing it here with our great community of developers and math enthusiasts.
Having an example to work with, perhaps that would help renewing the interest in implementing the missing bits and fix some issues? It would make a rather nice showcase, then, wouldn't it? Can we make the maths in this example any better?
What do you think?

[Omikhleia]

Related issues:

• Consecutive math fractions are too close #1801
• Equation numbering in display math #1800
• Parentheses or brackets size adaptation in display math #1799
• binary/unary operator in TeX-like math mode #1642
• MathML msqrt not supported #1604 --> Frankly annoying
• Some MathML that fails #1293
• Wrong position of sub/superscripts in math on big content #2122

[Omikhleia]

I'm still on my own challenge, with PR #2119