Thank you for this, your post was one of the most helpful replies. Although it is clear that I can see exactly WHAT is going on and WHEN by the method you demonstrate, I still do not have a real understanding of WHY the events are occurring when they do or WHY the values are what they are at those points. I don't think any amount of tracing or visualization of program flow will explain this. Perhaps I will never really understand this type of recursion.
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