# Re: [NTG-context] units module has bug with markIV?

Aditya Mahajan wrote:
>
> I am just writing to say that I looked at your original message, but
> could not figure out what is going wrong. \Micro is expanded to μ, but
> then something
> goes wrong.
>
> Hans, Taco, can you see what is happening here?

That took some thinking. The error is caused by the \mathcode of µ,
it is "7116, but it should be "0116. The '7' in the current
definition makes it switch along with \fam. \dimensiontypeface
expands to \tf, so \fam is set to 11, and that is \rm.

So you end up with this minimal file:

\starttext
$\rm µ$ % that's U+03BC
\stoptext

The latin modern text (\rm) font does not have a greek alphabet.
If it did, all would have worked ok. Since that cannot easily be
fixed and I suspect most text fonts do not have greek, so changing
the mathcode of the greek characters is probably the best solution
(it affects normal math mode as well, as you can see)

And as an aside, it would be nicer to use U+00B5 (mu latin) in the
units module instead of U+03BC (mu greek).

\def\Micro {\dimensionprefix{\iftextdimensions u\else\hbox{µ}\fi}}

The \hbox is needed because \fam11 is using ec encoding, I think.
(and that is problematic in its own way, but let's not go there)

Best wishes,
Taco
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