\documentclass[
    12pt,
    DIV=10,
    BCOR=4mm,
    twoside=semi,
    chapterprefix=true,
    headinclude=true,
    footinclude=true,
    usegeometry=true,
    headings=big]{skript}
\usepackage[top=2cm,bottom=2cm]{geometry}
\usepackage{versions}
\AtBeginDocument{
\excludeversion{proof}
\excludeversion{beweis}
\excludeversion{beweisidee}
\excludeversion{noproof}
\excludeversion{bemerkung-nn}
% \excludeversion{beispiel-nn}
% \excludeversion{beispiele-nn}
% \excludeversion{beispiel}
% \excludeversion{beispiele}
}
\input{common.tex}