2024/1/1
- fixed message matching bug in naive-scalar-net/make-prop-net

2023/12/29
- jumping into project after a couple days
- fixed bug in let binding of prop-net
- TODO:
  - check that adding a neighbor always adds to alert-all-propagators
    and they are never removed
  - debug message matching: match doesn't match symbol messages and
    errors on keyword messages