On Sat, 8 Jan 2011, Daniel Schopper wrote:

> Hi,
> are the delimiters \lgroup and \rgroup supported in MkIV?
> This
>
> \starttext
> $$\bigg\lgroup\dots\bigg\rgroup$$
> \stoptext
>
> is ok in MkII (ConTeXt ver: 2011.01.06) but when compiled with MkIV (ConTeXt 
> ver: 2010.07.30 11:35 and ver: 2010.07.30 11:35) the delimiters are not 
> shown. (By the way, the same holds true for \rmoustache and \lmoustache.)

> Am I missing something?

No. The math mappings of virtual fonts are incomplete. The symbols should 
work correctly with unicode math fonts like cambria, asana, and xits. 
But, it appears that lgroup and rgroup are missing from xits (Khaled?) and 
lmoustache and rmoustache are missing from asana! With Cambria there is 
a bug with scaling:

\setupbodyfont[cambria]
\enabletrackers[math.analyzing]
\usemodule[fnt-25]

\starttext
\showmathfontcharacters[][0x23B0]
\showmathfontcharacters[][0x3014]
$$\bigg\lgroup\dots\bigg\rgroup$$
$$\left\lgroup\sum\right\rgroup$$
$$\lgroup\sum\rgroup$$

$$\bigg\lmoustache\dots\bigg\rmoustache$$
$$\left\lmoustache\sum\right\rmoustache$$
$$\lmoustache\sum\rmoustache$$
\stoptext

@Hans, Taco, and Mojca: Do you know why the delimiters are not scaling 
properly?

Do you know how to add them to the LM virtual fonts? I tried, but could 
not get a working solution. I can add the correct mappings to 
large-to-small table in math-vfu. But adding the mappings for lgroup and 
rgroup in tex-mr table, and adding lmoustache and rmoustache to tex-ex 
table does not appear to work. Apply the attached diff file and see what 
happens with the example above. I don't know how to proceed. BTW, where 
are the math virtual fonts defined!? I could not find any use of 
mathematics.makefont.

Aditya