Make ndims constant.

chapters/operatorsandexpressions.tex

@@ -1292,6 +1292,14 @@ \subsection{Constant Expressions}\doublelabel{constant-expressions}
   \lstinline!edge!, \lstinline!change!, \lstinline!sample!, and \lstinline!pre!, a function or operator with constant
   subexpressions as argument (and no parameters defined in the function)
   is a constant expression.
+\item
+  Some function calls are parameter expressions even if the arguments
+  are not:
+
+  \begin{itemize}
+  \item
+    \lstinline!ndims(A)!
+  \end{itemize}
 \end{itemize}
 
 Components declared as constant shall have an associated declaration
@@ -1321,8 +1329,6 @@ \subsection{Parameter Expressions}\doublelabel{parameter-expressions}
   are not:
 
   \begin{itemize}
-  \item
-    \lstinline!ndims(A)!
   \item
     \lstinline!cardinality(c)!, see restrictions for use in \autoref{cardinality-deprecated}.
   \item