Add example for array sizes in declarations.

Closes modelica#2221

chapters/classes.tex

@@ -193,19 +193,22 @@ \subsection{Component Declaration Static Semantics}\doublelabel{component-declar
 
 Array dimensions shall be scalar non-negative parameter expressions of type Integer, 
 a reference to a type (which must an enumeration type or Boolean, see \autoref{enumeration-types}), 
-or the colon operator denoting that the array dimension is left unspecified.
+or the colon operator denoting that the array dimension is left unspecified (see \autoref{array-declarations}).
 All variants can also be part of short class definitions.
 
 \begin{nonnormative}
 Example of variables with array dimensions.
 \begin{lstlisting}[language=modelica]
 model ArrayVariants
-  type T=Real[:];
+  type T=Real[:];                     // Unspecified size for type
   parameter T x=ones(4);
-  parameter T y[3]=ones(3, 4);
-  parameter Real a[2]=ones(2);
-  parameter Real b[2, 0]=ones(2, 0);
-  parameter Real c[:]=ones(0);
+  parameter T y[3]=ones(3, 4);        
+  parameter Real a[2]=ones(2);        // Specified using Integer
+  parameter Real b[2, 0]=ones(2, 0);  // Size 0 is allowed
+  parameter Real c[:]=ones(0);        // Unspecified size for variable
+  parameter Integer n=0;
+  Real x[n*2]=cat(1,ones(n),zeros(n)};// Parameter expressions are allowed
+  Boolean notV[Boolean]={true,false}; // Indexing with type
 end ArrayVariants;
 \end{lstlisting}
 \end{nonnormative}