Zig Zag was meant to represent a very general set of data structures, if you're interested in documents then you, probably, would have a more specific interest

Zig Zag was meant to represent a very general set of data structures, if you're interested in documents then you, probably, would have a more specific interest in his (very long running) Xanadu project - https://en.wikipedia.org/wiki/Project_Xanadu https://en.wikipedia.org/wiki/Project_Xanadu - which in some ways is very similar to OP's stuff - http://youtu.be/En_2T7KH6RA?t=3m27s http://youtu.be/En_2T7KH6RA?t=3m27s