Clarified "operator".

Closes modelica#3171

chapters/classes.tex

@@ -840,7 +840,8 @@ \section{Specialized Classes}\label{specialized-classes}
 Similar to \lstinline!record!; but operator overloading is possible, and due to this the typing rules are different, see \cref{interface-or-type-relationships}.  It is not legal to extend from an \lstinline!operator record! (or \lstinline!connector! inheriting from \lstinline!operator record!), except if the new class is an \lstinline!operator record! or \lstinline!connector! that is declared as a short class definition, whose modifier is either empty or only modify the default attributes for the component elements directly inside the \lstinline!operator record!.  An \lstinline!operator record! can only extend from an \lstinline!operator record!.  It is not legal to extend from any of its enclosing scopes.  (See \cref{overloaded-operators}).
 
 \item \lstinline!operator!\indexinline{operator} --
-Similar to \lstinline!package!; but may only contain declarations of functions.  May only be placed directly in an \lstinline!operator record!.  (See also \cref{overloaded-operators}).
+May only contain declarations of functions.
+May only be placed directly in an \lstinline!operator record!.  (See also \cref{overloaded-operators}).
 
 \item \lstinline!operator function!\indexinline{operator function} --
 Shorthand for an \lstinline!operator! with exactly one function; same restriction as \lstinline!function! class and in addition may only be placed directly in an \lstinline!operator record!.