It makes the rule for ending a lifetime more syntax directed.

For now though, I think I'll leave the other version on paper... there, not being syntax-directed is way less of a problem

By letting them only speak about lits in their conclusions, and use [length] as the length parameter of vec. Also simplified substitutions of vectors.

also strengthen local lifetime context to not add laters in front of the inherited ownership

change cont_postcondition to True... because we can, and because that would allow us to show adequacy with a terminating continuation

This (finally) requries us to add thread-local tokens to various judgments