【latex tips】在 latex 中实现「子定理」

documentclass{article}

usepackage{amsmath}
newtheorem{myDef}{Definition}
newtheorem{subDef}{Definition}[myDef]

begin{document}
begin{myDef}
content...
end{myDef}

stepcounter{myDef}
begin{subDef}
content...
end{subDef}
begin{subDef}
content...
end{subDef}

begin{myDef}
content...
end{myDef}
end{document}