Define experiment using a record.

chapters/annotations.tex

@@ -384,19 +384,23 @@ \section{Annotations for Simulations}\label{annotations-for-simulations}
 
 \begin{annotationdefinition}[experiment]
 % henrikt-ma 2021-04: Seems strange to allow 'experiment' completely without list of options -- what would it mean?
+
 \begin{synopsis}[grammar]\begin{lstlisting}
-"experiment"
-   [ "(" [ experimentOption { "," experimentOption } ] ")" ]
-
-experimentOption:
-   "StartTime" "=" [ "+" | "-" ] UNSIGNED-NUMBER
-   | "StopTime" "=" [ "+" | "-" ] UNSIGNED-NUMBER
-   | "Interval" "=" UNSIGNED-NUMBER
-   | "Tolerance" "=" UNSIGNED-NUMBER
+annotation "experiment" "(" experimentModfiers ")"
 \end{lstlisting}\end{synopsis}
 \begin{semantics}
-The \lstinline{experiment} annotation defines the default start time (\lstinline!StartTime!) in {[}s{]}, the default stop time (\lstinline!StopTime!) in {[}s{]}, the suitable time resolution for the result grid (\lstinline!Interval!) in {[}s{]}, and the default relative integration tolerance (\lstinline!Tolerance!) for simulation experiments to be carried out with the model or block at hand.
+The modifiers are for the the following record.
+\begin{lstlisting}[modelica]
+record Experiment
+  Real StartTime(unit = "s") = 0;
+  Real StopTime(unit = "s");
+  Real Interval(unit = "s");
+  Real Tolerance;
+end Experiment;
+\end{lstlisting}
+The \lstinline!experiment! annotation defines the default start time (\lstinline!StartTime!) in {[}s{]}, the default stop time (\lstinline!StopTime!) in {[}s{]}, the suitable time resolution for the result grid (\lstinline!Interval!) in {[}s{]}, and the default relative integration tolerance (\lstinline!Tolerance!) for simulation experiments to be carried out with the model or block at hand.
 If \lstinline!StartTime! is not specified it is assumed to be \lstinline!0.0!.
+Tools should use appropriate defaults for \lstinline!Interval! and \lstinline!Tolerance!.
 \end{semantics}
 \end{annotationdefinition}