Unsupported MathML elements

[Omikhleia]

Maybe this is lost in some old discussion on some of the MathML implementation issue? Anyhow, here's a list (to be enriched possibly).

Some constructs SILE's MathML implementation does not support as of v0.15.5 + recent msqrt support:

• multiscripts (f2)
• mstyle (f6)
• mpadded (f22)
• mtext (f18, f19, f22) - honestly this one is much needed and shouldn't be complex...
• mphantom (f22)
• mroot - see MathML mroot and TeX-like root with degree not supported. #2120
• ms

Some other unsupported things

• Most attributes on elements, ex. linethickness on mfrac (f10)
• Improper sizing of some parentheses (f18)
• Stretchy horizontal braces (f19; f22)
• Very large vertical stretchy parentheses (f23)
• Very large vertical stretchy determiner bar (f24)

Notes

• For cross-checking see also https://w3c.github.io/mathml-core/#mathml-elements-and-attributes
• The (f-numbers) above are the tests in https://fred-wang.github.io/MathFonts/mozilla_mathml_test/ - Whatever the status of this (old) 30-scenario Firefox MathML test, having the numbered items above would imply it passes for us (all other unmentioned tests are already passing).

[Omikhleia]

Besides the above-mentioned old Firefox test, another interesting test to check: http://eyeasme.com/Joe/MathML/MathML_browser_test.html (EDIT: I has both the TeX sources and the MathML code = we could also use it for checking our TeX-like math...)