You might argue that 'not existing' in general does not even exist. It reminds me of the ted ex talk where a man states that the universe does not exist becaus

You might argue that 'not existing' in general does not even exist. It reminds me of the ted ex talk where a man states that the universe does not exist because it is everything and if we would make a list of everything, the list would not be included as a topic of the list.