Re: XML databases [ was: S.O.D.A. database Query API - call for comments ]

mikito Harairi wrote:
> In article <9earpo$def$01$1_at_news.t-online.com>, Carl Rosenberger says...
> >
> >Queries return a tree structure.
> >
> I'm sorry to sidetrack here, but
>
> 1. Does anybody know 'must read' theoretical paper about queries on tree
> structures?

Not really, but if you look at the references of Xquery

  http://www.w3.org/TR/xquery/#section-References

and trace back to the theoretical roots (look at Quilt, Lorel, YATL) then you will probably find what you are looking for. See for instance

  http://citeseer.nj.nec.com/382326.html

and anything else by Philip Wadler on (semi-)monads such as

  http://citeseer.nj.nec.com/wadler92comprehending.html

-- 
  Jan Hidders