%% revtex.sty is. Continue to use \documentstyle{revtex}
%% (with the correct options) and REVTeX will run normally
%% in compatibility mode. Thanks to David Carlisle for
-%% pointing out this fix.
-
-\ifx\every@math@size\undefined\else
+%% pointing out this fix.
+
+\ifx\every@math@size\undefined\else
\let\old@expast\@expast
\def\@expast#1{\old@expast{#1}\let\@tempa\reserved@a}
\fi