Better definition of comments.

chapters/lexicalstructure.tex

@@ -26,24 +26,31 @@ \section{Comments}\label{comments}
 The following comment variants are available:
 %TODO-FORMAT should be a table instead of lstlisting?
 \begin{lstlisting}[language=modelica]
-// comment & Characters from // to the end of the line are ignored.
-/* comment */ & Characters between /* and */ are ignored, including line terminators.
+// Rest-of-line comment: Everything from // to the end of the line are ignored.
+"Not part of comment"
+/* Delimited comment: Characters after /* are ignored,
+  including line termination. The comment ends with */
 \end{lstlisting}
 
 \begin{nonnormative}
 The comment syntax is identical to that of C++.
 \end{nonnormative}
 
-Modelica comments do not nest, i.e., /* */ cannot be embedded within /*
+Delimited Modelica comments do not nest, i.e., /* */ cannot be embedded within /*
 */. The following is \emph{invalid}:
 \begin{lstlisting}[language=modelica]
-/* Commented out - erroneous comment, invalid nesting of comments!
-  /* This is an interesting model */
-  model interesting
-    $\ldots$
-  end interesting;
+/* Invalid nesting of comments, the comment ends just before 'end'
+ model Interesting
+  /* To be done */
+ end Interesting;
 */
 \end{lstlisting}
+Rest-of-line comments can safely be used to comment out blocks of code without risk of conflict with comments inside.
+\begin{lstlisting}[language=modelica]
+ //model Valid // Some other comment
+ // /* To be done */
+ //end Valid;
+\end{lstlisting}
 
 There is also a description-string, that is part of the Modelica language and
 therefore not ignored by the Modelica translator. Such a description-string may