]{A}{B}
then A ends up on the top and B on the bottom.
The "x" commands change the position of both texts and when you change
the instance for the command the reversed order is overwritten (search for
the order key in math-stc.mkvi).
\starttext
$\xleftarrow{A}{B}$
$\mleftarrow{A}{B}$
\st
The "x" commands change the position of both texts and when you change
the instance for the command the reversed order is overwritten (search for
the order key in math-stc.mkvi).
\starttext
$\xleftarrow{A}{B}$
$\mleftarrow{A}{B}$
\st