clarify: no connectors in functions (#2308)

Clarify: no connectors, package or operator components (etc) in functions, this replaces #3 
and now more readable with nicer line break

chapters/functions.tex

@@ -147,9 +147,10 @@ \section{Function as a Specialized Class}\doublelabel{function-as-a-specialized-
   external function interface} (not both), which, if present, is the
   body of the function.
 \item
-  A function may only contain components of the restricted classes \lstinline!type!,
-  \lstinline!record!, \lstinline!operator record!, and \lstinline!function!; i.e. no 
-	\lstinline!model! or \lstinline!block!
+  A function may only contain components of the restricted classes 
+  \lstinline!type!, \lstinline!record!, \lstinline!operator record!, and \lstinline!function!; 
+  and it must not contain e.g. 
+  \lstinline!model!, \lstinline!block!, \lstinline!operator! or \lstinline!connector! 
   components.
 \item
   The elements of a function may not have prefixes \lstinline!inner!, or \lstinline!outer!.