Basically, it'd require changing things like (table) and (cons) so they return annotated functions, and then changing the built-ins (like keys, vals, car, etc.) to use the annotated functions. That's what that post is about: describing the core functions (keys, car, etc.) in Arc itself.
Oh, yeah, and change apply/eval so when they see something with type 'table or 'cons, they use the annotated functions too. I should be able to add this to py-arc without too much trouble.
