Hi Jonathan,
On Wed, Sep 1, 2021 at 11:45 AM you wrote in part:
I'd like to see an online LaTeX syntax checker, that's linked to a help system.
In 1998 I concluded that such a thing is impossible if it is to include all documents that run "correctly" -- hard to define, e.g. think about $f(x$) -- through latex the program (which now is one of pdflatex, xetex, or lualatex -- maybe also the various guises of tex4ht and latexml).
-- Bill
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