RTL directionality in LaTeX

Dear all,

As part of the conversion between MathML and LaTeX, we need to express the
MathML dir attribute in LaTeX (attribute used to express the
directionality, for example rtl as right-to-left).

We do not care at all that the notation is not an actual LaTeX package
implementation but something that will be implemented in the future by
WIRIS, MathJax or any other lightweight Web based implementation of LaTeX.

Our suggestion is to use something like \dir{rtl}{x^2} for <math
dir="rtl"><msup><mi>x</mi><mn>2</mn></msup></math>

Dani