\documentclass{article}
\usepackage{agda}

\begin{document}

\AgdaHide{
\begin{code}%
\>[0]\AgdaKeyword{module}\AgdaSpace{}%
\AgdaModule{OneSpaceIndent}\AgdaSpace{}%
\AgdaKeyword{where}\<%
\end{code}
}

\section{Syntax}
Text1

\AgdaHide{
\begin{code}%
\>[0]\AgdaKeyword{module}\AgdaSpace{}%
\AgdaModule{Defs}\AgdaSpace{}%
\AgdaKeyword{where}\<%
\\
%
\\[\AgdaEmptyExtraSkip]%
\>[0][@{}l@{\AgdaIndent{0}}]%
\>[1]\AgdaKeyword{postulate}\<%
\end{code}
}

Text2

\begin{code}%
\>[1][@{}l@{\AgdaIndent{1}}]%
\>[2]\AgdaPostulate{Base}\AgdaSpace{}%
\AgdaSymbol{:}\AgdaSpace{}%
\AgdaPrimitive{Set}\<%
\end{code}

Text3
\end{document}
