collaboration GrammarUsedButNotDefined {
  cd {{ Grammar = List(Production).
	Production = <lhs> NonTerminal <rhs> Body.
	Body = ...
	NonTerminal = Ident.
	Main = .
     }}
  classes
    {{ class Main {
         public static void main(String args[]) throws Exception {
         Grammar c = Grammar.parse(System.in);
	 ClassGraph cg = new ClassGraph(true, false);
         c.usedButNotDefined(ClassGraph);
         System.out.println("done");
         }  
       }
    }}
  subCollaborations
    collaboration UsedButNotDefined {
      cd {{ Sys = List(Definition).
    	    Definition = Item Body.
	    Item = Ident.
	    Body = List(Item).
         }}
      interfaces 
        {{interface SysI {
    	     public void usedButNotDefined(ClassGraph cg);
	     abstract String get_defs();
	     abstract String get_uses();}
        }}
      classes
        {{ class Sys implements SysI {
             public void usedButNotDefined(ClassGraph cg){}
             HashSet definitions(ClassGraph cg){
 	       cg.traverse(this,get_defs(), new Visitor() {});
	     }
           }
        }}
     }  
  adapters
    class_map 
      UsedButNotDefined.Sys played_by {Grammar}
	with 
          implement 
             signature {{ abstract String get_defs() }}
             body {{ return new String
		 ("from Grammar bypassing Body to NonTerminal");
             }}
	;
    class_map
      UsedButNotDefined.Item played_by {NonTerminal}
}