[NTG-context] Bug in latest LMTX

[Otared Kavian]

Hi Hans,

It seems that \cap is not anymore defined in the latest LMTX: the following gives an error

\starttext
$A \cap B$
\stoptext

with current version: 2020.07.21 18:39.

Also, I would like to place a request about the reporting of errors: can we get back the nice reporting of errors we had a few months ago? 
Indeed while a few months ago the reporting of errors was extremeley clear and helpful, now one gets a cryptic message like this in the html file produced:

Error	   ! Missing } inserted
File 	   chapitre-1.tex
Line 	   834

Of course there is no missing } error in that file and that line, and one has to spend a lot of time to find what the error would be. In this case I could guess that the error comes from the fact that \cap is not defined, but it wasn't easy (the file used to typeset correctly with version 2020.07.13, and it typesets correctly with mkiv).
In eralier versions, ConTeXt would tell the user 
	undefined control sequence \cap
and one could fix things very quickly.

Best regards, and please pardon my early morning request…
Otared