A simple alternative to tikz is the usage of \framed.
\define[1]\oldfact
{\inmframed[frame=off,strut=no,leftframe=on,bottomframe=on]{#1}}
\starttext
\m{\oldfact{n}}
\stoptext
Wolfgang
Thanks a lot. It should work nicely.
--
Respect,
Shiv Shankar Dayal
