Perhaps this will explain?

I, L. da Vinci, do not propose myself to be a mathematical genius.

In my book, zer-0 equals zer-0, and neither of these men can add up to anything of a positive nature.

If you observe closely, the shadows are wrong. I am learning much about what is called 'advertising' in these tortorous times. This one?

I do not approve.

L. da Vinci