Papa Tango 142

If you look closely you'll see a pyramid with the cap stone empty, a circle, and from the top of the pyramid two extended lines to the horizon. After 50 years of trial and error this is the simplest way I've found to create Four D's interweaving. I know the D's are crude, but this is just a skeleton of the smooth I'm working on to illustrate 4 D's interweaving.