Interesting; this article says the rewrite rule is F -> F+F-F-F+F , but Wikipedia says F → F−F++F−F . I think Wikipedia's is right, as (for a beginning) there a

Interesting; this article says the rewrite rule is F -> F+F-F-F+F , but Wikipedia says F → F−F++F−F . I think Wikipedia's is right, as (for a beginning) there are only four line segments in step N+1 for each line segment in step N. Take out the F between the minus signs in this article's rule, and it would be correct ( F -> F+F--F+F ), allowing for mirroring of the Wikipedia formula.