Apply suggestion for nested when-statements

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

chapters/statements.tex

@@ -416,7 +416,7 @@ \subsubsection{Restrictions on Where a When-statement may occur}\label{restricti
 \item
   A \lstinline!when!-statement shall not occur inside an initial algorithm.
 \item
-  \lstinline!when!-statements cannot be nested.
+  A \lstinline!when!-statement cannot be nested inside another \lstinline!when!-statement.
 \item
   \lstinline!when!-statements shall not occur inside \lstinline!while!-loops, \lstinline!for!-loops, or \lstinline!if!-statements in algorithms.
 \end{itemize}