[plt-scheme] Excersise 14.2.3 - HtDP - Ordered list of binary tree nodes

Charlie Turner wrote:
> Maybe the template is whats getting me into trouble. I struggle on
> occasion to decide where I should put the "natural recursions".

When you write down data definitions, are you drawing the arrows like 
the book does?  Recursions in data tell you where to recur in the 
template.  When designing with structural recursion, this much follows 
solely from the shape of the data.  If you're finding yourself trying to 
decide, you haven't mastered templates.

David