Utility Mill

This comes from Imri Goldberg's L String project

What are Lstrings? Imri Goldberg tells us:

LStrings are strings with three possible characters: ‘f’ - meaning forward, ‘l’ meaning left, and ‘r’ meaning right. Drawing such a string is easy - just like ‘ye olde Logo’. So far nothing interesting - until you iterate on them. Iterating on a string means replacing each occurrence of ‘f’ with the original string. This gives a fractal like behavior, and can actually be used to draw some fractals.