# [NTG-context] Euler with fallback

Hi all,


This is to announce that the latest beta supports creating virtual math fonts with fallback. The main test case is to use Euler font with missing characters taken from Pagella but the mechanism is general and can be used to replace a specific set of math glyphs from a font.


This feature is not extensively tested. As such it will be useful if everyone interested in math fallback mechanism could test this out and report any bugs or inconsistencies.


To use this feature you have to use pagellaovereuler as your math font. For example, to use Euler with DejaVu fonts, use:


\usetypescriptfile[euler]
\starttypescript[mainface]
\definetypeface[mainface][rm][serif][dejavu]          [default]
\definetypeface[mainface][ss][sans] [dejavu]          [default]
\definetypeface[mainface][tt][mono] [dejavu]          [default]
\definetypeface[mainface][mm][math] [pagellaovereuler][default]
\stoptypescript

\setupbodyfont[mainface]

\appendtoks \rm \to \everymathematics
\setupmathematics
[lcgreek=normal, ucgreek=normal]


There is a built-in typescript euler-with-pagella to use pagellaovereuler as the math font and pagella as the text font.


If you are interested in implementing similar fallback mechanisms for other fonts, see type-imp-euler.mkiv and euler-math.lfg for details.