By default this parameter is filed by the namespace lft_userN. The old method, hard-wiring this parameter to lft_userN, had the defect of requiring to place libraries' namespacec in it *in advance*. The weak branch has always used such a parameter.

We use fnrec: for recursive functions and fn: for non-recursve functions. This is both shorter and closer to Rust.

strengthen lifetime logic: make lft_userN disjoint from lftN so it remains available during atomic accessors

This commit makes typed_val and typed_instruction_ty a definition. Together
with the previous commit on notations for contexts, this seems to fix all
notations issues.

Instead, I have added subscripts to the inclusion notations. This makes pretty
printing much more reliable, and generally even shortens things, as no scope
annotations are needed.

also update Iris