The following works outside xmlsetups but not inside it. It seems to bolt on the % with: ! LuaTeX error <main ctx instance>:1: ')' expected near '<eof>'. <inserted text> ....pitex.print("pi = " .. (x - x} This in spite of the wiki telling me: To circumvent this problem, ConTeXt defines a environment called \startluacode ... \stopluacode. This sets the catcodes to what one would expect in lua. Basically only \ has its usual TeX meaning, the catcode of everything else is set to other. So, for all practical purposes, we can forget about catcodes inside \startluacode ... \stopluacode. The code is: \startxmlsetups xml:mycommand \startluacode local x = math.pi tex.print("pi = " .. (x - x\%0.01)) \stopluacode \stopxmlsetups When I try to escape the % with \% the result is no better: ! LuaTeX error <main ctx instance>:1: ')' expected near '\'. <inserted text> ...rint("pi = " .. (x - x\%0.01))} Is it not possible to directly use Lua inside these setups? If do, why the nonconforming behaviour? Hans van der Meer