Add suggested 'The' at start of sentence

Co-authored-by: Hans Olsson <HansOlsson@users.noreply.github.com>

chapters/introduction.tex

@@ -63,7 +63,7 @@ \section{Scope of the Specification}\label{scope-of-the-specification}
   section (number of equations = number of different assigned
   variables).
 \item
-  \lstinline!when!-clauses where every \lstinline!when!-clause is treated as a set of conditionally evaluated equations, which are functions of the variables occurring in the clause (number of equations = number of different assigned variables).
+  The \lstinline!when!-clauses where every \lstinline!when!-clause is treated as a set of conditionally evaluated equations, which are functions of the variables occurring in the clause (number of equations = number of different assigned variables).
 \end{itemize}
 
 Therefore, a flat hybrid DAE is seen as a set of equations where some of the equations are only conditionally evaluated.