doc-src/TutorialI/Types/types.tex

 advanced material:
 \begin{itemize}
 \item More about basic types: numbers ({\S}\ref{sec:numbers}), pairs
   ({\S}\ref{sec:products}) and records ({\S}\ref{sec:records}), and how to
   reason about them.
+\item Type classes: how to specify and reason about axiomatic collections of
+  types ({\S}\ref{sec:axclass}).
 \item Introducing your own types: how to introduce new types that
   cannot be constructed with any of the basic methods
   ({\S}\ref{sec:adv-typedef}).
-\item Type classes: how to specify and reason about axiomatic collections of
-  types ({\S}\ref{sec:axclass}).
 \end{itemize}
+
+The material in this section goes beyond the needs of most novices.  Serious
+users should at least skim the sections on basic types and on type classes.
+The latter is fairly advanced: read the beginning to understand what it is
+about, but consult the rest only when necessary.
 
 \section{Numbers}
 \label{sec:numbers}
 
 \input{Types/numerics}

 \input{Types/document/Pairs}
 \index{pair|)}
 
 \section{Records}
 \label{sec:records}
-
-\input{Types/document/Typedef}
 
 \section{Axiomatic type classes}
 \label{sec:axclass}
 \index{axiomatic type class|(}
 \index{*axclass|(}

 
 \input{Types/document/Axioms}
 
 \index{axiomatic type class|)}
 \index{*axclass|)}
+
+
+\input{Types/document/Typedef}