No need to mark the start as non-normative anymore.

chapters/statemachines.tex

@@ -1,6 +1,5 @@
 \chapter{State Machines}\label{state-machines}
 
-\begin{nonnormative}
 This chapter defines language elements to define clocked state
 machines. These state machines have a similar modeling power as
 Statecharts (Harel 1987) and have the important feature that at one
@@ -44,7 +43,6 @@ \chapter{State Machines}\label{state-machines}
   latter case, the equations are integrated between the previous and the
   next clock tick, if the corresponding state is active).
 \end{itemize}
-\end{nonnormative}
 
 \section{Transitions}\label{transitions}