Some notes

[stopachka]

1. Do we need a special "bel-nil" symbol? Why can't it be java null? Perhaps that'll make things even cleaner -- I wouldn't need to wrap math functions at all for example
2. I used to have pairs as ArrayList[car, cdr]. Maybe use a more efficient type?
3. backquotes + commas + splice are their own types. Why not just make them pairs? I also did a pretty hasty implementation. We may want to add more tests and make something more elegant.
4. One common optimization is to separate analysis from evaluation. Maybe we can try this?