Restrict 9.1.3 to normal connectors; so that expandable connector nee…

…d not be balanced.

chapters/connectors.tex

@@ -733,7 +733,7 @@ \section{Restrictions of Connections and Connectors}\doublelabel{restrictions-of
 
 \subsection{Balancing Restriction and Size of Connectors}\doublelabel{balancing-restriction-and-size-of-connectors}
 
-For each non-partial connector class the number of flow variables shall
+For each non-partial non-expandable connector class the number of flow variables shall
 be equal to the number of variables that are neither \lstinline!parameter!,
 \lstinline!constant!, \lstinline!input!, \lstinline!output!, \lstinline!stream!
 nor \lstinline!flow!. The ``number of variables'' is
@@ -742,6 +742,9 @@ \subsection{Balancing Restriction and Size of Connectors}\doublelabel{balancing-
 variables of an overdetermined type or record class (see \autoref{overconstrained-equation-operators-for-connection-graphs})
 is the size of the output argument of the corresponding
 \lstinline!equalityConstraint!() function.
+\begin{nonnormative}
+Expandable connector classes are excluded from this, since their component declarations are only a form of constraints.
+\end{nonnormative}
 
 {[}\emph{Examples:}