__HEADER__(Include exercise sheets into lecture notes easily.)

\RequirePackage{xkeyval}
__LANGUAGE_OPTIONS__

__END_OPTIONS__

\RequirePackage{mkessler-fancythm}

\newcounter{__PACKAGE_PREFIX__sheet}

\declaretheorem[style=thmgreenmargin, numberwithin=__PACKAGE_PREFIX__sheet, name=__IF__(english) Exercise\else Aufgabe\fi]{__PACKAGE_PREFIX__aufgabe}

\usepackage{xkeyval}

\NewDocumentEnvironment{aufgabe}{O{}}{
\begin{__PACKAGE_PREFIX__aufgabe\expandafter}\if\relax\detokenize{#1}\relax\else[#1]\fi\label{aufgabe-\the__PACKAGE_PREFIX__aufgabe}
}{
    \end{__PACKAGE_PREFIX__aufgabe\expandafter}\relax
}

\newcommand\blatt{\refstepcounter{__PACKAGE_PREFIX__sheet}\subsection*{\the__PACKAGE_PREFIX__sheet. Übungsblatt}\addcontentsline{toc}{subsection}{\the__PACKAGE_PREFIX__sheet. Übungsblatt}}