the first 100 pages set the foundation for the language of thinking about how repeating patterns (triangles, squares, -agons etc) work, and then you start getting into brainbending tesselations. Not a lot of fluff, its just straight into: ok if you reflect then rotate, then reflect again, all around a center point, you get a pattern that looks like this: and a couple, very clean, example images.

Great for designers, artists, tile-layers, and those into #MCEscher & #OpticalIllusions & #fractals but with a logic/systems/mathematics bent.