\input regression-test.tex
\documentclass{article}
\usepackage[mode=script]{osglecture-modes}
\usepackage{osgstyler}
\UseOsgStandardInlineCommands

\ExplSyntaxOn
\cs_new_protected:Npn \__osgstyler_test_reverse_semantics:nn #1#2
  { \TYPE{reverse=#1} #2 }
\cs_new_eq:NN \TestReverseSemantics \__osgstyler_test_reverse_semantics:nn
\ExplSyntaxOff

\begin{document}
\SetOsgSemanticProcessor{\TestReverseSemantics}
\START
\emph<script>{shown}
\emph<presentation>{omitted}
\TYPE{reverse-modes=done}
\END
\end{document}