*operation* void  print_line_no(ostream& strm) 
  *traverse*
    *from* Cd_graph
    *through* -> *,source,*
     *to* Vertex
     *carry*
	*in* Cd_graph* c
	*along* *from* Cd_graph 
	         *to* Vertex
	*at* Cd_graph   c =(@ this @)
    *wrapper* Vertex
      *prefix* 
	(@ 
	this->g_print(strm);
	strm << "\t:" <<  this->get_vertex_name()->get_line_number() << "\t";
	c->print_line_used(this,strm);
	strm << "\n";@)
	
*operation* void  print_line_used(Vertex* v,ostream& strm) 
  *traverse*
    *from* Cd_graph
    *bypassing* -> *,source,* 
     *to* Vertex
 	*wrapper* Vertex
	*prefix*
	(@
	if (this->g_equal(v))
		{
		strm << this->get_vertex_name()->get_line_number() << "\t"; 
	
		}
	@)