Make it explicit that tools can show the value of variables for asserts

chapters/equations.tex

@@ -506,6 +506,7 @@ \subsection{assert}\label{assert}
   \lstinline!condition! needs to be implicitly treated with \lstinline!noEvent! since otherwise events might be triggered that can lead to slightly changed simulation results.
   \end{nonnormative}
 \end{itemize}
+Tools are recommended to provide more information than just the given message of a failed assertion, in particular the condition and the values of variables used in it.
 
 \begin{nonnormative}
 The \lstinline!AssertionLevel.error! case can be used to avoid evaluating a model outside its limits of validity; for instance, a function to compute the saturated liquid temperature cannot be called with a pressure lower than the triple point value.
@@ -518,6 +519,9 @@ \subsection{assert}\label{assert}
        AssertionLevel.warning);
 assert(T > 200 and T < 500, "Medium model outside feasible region");
 \end{lstlisting}
+
+It is recommended that asserts have a simple message as above, formulated with the recommended tool behavior in mind.
+Writing \lstinline!assert(T<500, "Temperature = "+String(T)+" was above 500")! is thus not recommended, and is likely to lead to duplicated information.
 \end{nonnormative}
 
 \subsection{terminate}\label{terminate}