[texhax] left-hand side superscript?

[Philip G. Ratcliffe]

> I wonder if there is any good way to obtain a superscript on the
> left-hand side
> of a variable in LaTeX. Currently I am using the following hack:
>
> {}^{A}B

Somewhere, I'm sure, there is something but I can't put my finger on it
right now.  Anyway, this is certainly a little better as it will respect the
height of the following token:

\newcommand\Prefix[3]{\vphantom{#3}#1#2#3}

usage:

\Prefix^{A}{B} and \Prefix_{A}{B}

Cordialmente,  Philip G. Ratcliffe