Hi everyone, could you tell me how to use the Ubuntu font for the math
command \max in the following example?

\definefontfamily [mainface] [sans] [Ubuntu]
[regularfont=ubuntu,italicfont=ubuntuitalic,boldfont=ubuntubold]
\definefallbackfamily [mainface] [math] [Ubuntu]
[preset=math:lowercaseitalic,tf=name:ubuntu]
\definefontfamily     [mainface] [math] [Latin Modern Math]

\setupbodyfont[mainface]

\starttext
$ abc \max$ abc max
\stoptext

I am also interesting by knowing where I can find all the features
"preset=math:" possible.

Best regards,
Flavien.