Once again I am playing with negative space--the pattern seems more about the four-point stars than the pentagons. This pattern (with different the colouring) is on the cover of the Tilings and Patterns: An Introduction (A Series of books in the mathematical sciences) by Branko Grunbaum and G. C. Shephard which is a great book. The last couple of blog entries have convinced me to slightly augment the language of the programming language of PolygonR&D to make the programs slightly easier to write. I'll let you know if it was worth it....