@Override
		public RFilters minus(RFilter filter)
		{
			RFilterNode prev=null;
			RFilterNode me=head;
			while((me!=null)&&(me.filter != filter))
			{
				prev=me;
				me=me.next;
			}
			if((me!=null)&&(me.filter==filter))
			{
				if(prev==null)
					head=me.next;
				else
					prev.next=me.next;
			}
			return this;
		}