while we are at it: how to do do strikethrough text? there is a changelog
on contextgarden which says it was added, but \strike or \strikethrough are
not defined.

i have (a diagonal) one here, but it doesn’t really work in math mode (the
text inside is normal). that being said, is there something like
\ifthiswascalledinmathmode{then}{else}?

\def\strike#1{\tikz[baseline=(c.base)]{
    \node[inner sep=0pt] (c) {#1};
    \draw (c.south west) -- (c.north east);
}}