anchor.diff:  			function get_data(): longInt;
   			
   			function equal(other: iterator): boolean;
  -			function getLink(): link;
  +			function get_link(): link;
   
   		private
   			m_link: link;
  
positive.code: 		begin
  			m_begin.next();
  			p.next();
  			p.getLink().m_prev.destroy();
  		end
  		else
  		begin
  			p.next();
  			p.getLink().setPrev(p.getLink().m_prev.m_prev);
  			p.getLink().m_prev.m_next.destroy();
  			p.getLink().m_prev.setNext(p.getLink());
  		end;
  	end;
  
  
negative.code: 		public
  			constructor create(data: longInt);
  			
  			procedure set_next(link: link);
  			procedure set_prev(link: link);
  
  		private
  			m_data: longInt;
  