Backward traversal

You can do backward traversal, using "^" instead of "." as punctuation. For example, if we know Dan's mailbox...

:dan con:mailbox <mailto:connolly@w3.org>

then we can write this expression for Dan:

<mailto:connolly@w3.org>^con:mailbox

Note: This is rather unlike javascript, python, and other object-oriented programming langauges