Can we check statement-level annotations?

One of my dreams for this package was to turn code like this

  query = linear(head.query, t1)                  # L x Dk
  key = linear(head.key, t1)                      # L x Dk

into this

  query : LxDk = linear(head.query, t1)
  key   : LxDk = linear(head.key, t1)

where we have written

  LxDk = f32["L Dk"] 

earlier in the @jaxtyped function.

But it looks as if these annotations aren't checked?
I haven't looked into how hard that might be - is it a lot of work?

The issue centers on the @jaxtyped entry point and statement-level annotations; begin by tracing how @jaxtyped handles annotations inside a function. Use the shown LxDk example to establish the current behavior, and consider tests that verify whether those annotations are checked. Done means the intended statement-level checking behavior is implemented and covered by tests.