Merge branch 'jh/fn_notation' into 'master'

theories/lang/notation.v

theories/typing/examples/get_x.v

theories/typing/examples/init_prod.v

theories/typing/examples/lazy_lft.v

theories/typing/examples/nonlexical.v

theories/typing/examples/rebor.v

theories/typing/examples/unbox.v

theories/typing/function.v

theories/typing/lib/arc.v

theories/typing/lib/brandedvec.v

theories/typing/lib/cell.v

theories/typing/lib/diverging_static.v

theories/typing/lib/fake_shared.v

theories/typing/lib/ghostcell.v

theories/typing/lib/join.v

theories/typing/lib/mutex/mutex.v

theories/typing/lib/mutex/mutexguard.v

theories/typing/lib/option.v

theories/typing/lib/panic.v

theories/typing/lib/rc/rc.v