A possible type-based model for scope restrictions on ~Escapable types

Hello, folks. For the last few months, I've been thinking about where we're going with ~Escapable types and lifetime dependencies. My conclusion is that we need a somewhat radical shift in the basic language model of the feature, away from the system of value dependencies that we currently use towards a world in which scope restrictions are encoded in the types of values. This is a rather large and complicated question, so I've written it up as a rather long and obscure design document. I'm af...