Recursion on a Cardinal, 16 Essence of Set Theory

Watch my videos Ad-free & free: Odysee: https://odysee.com/@MiroslavOlsak:9?v... Vimeo: https://vimeo.com/user129589056 Download: http://olsak.net/mirek/manim/my_video... The formal definition of a cardinal number, and its usage for constructing a set intersecting every circle in exactly three points. Download: http://www.olsak.net/mirek/manim/eost...