I think simplifying notions of path expressions aren't necessary. IMO the challenge here is to come to discreet formal steps. I'd start with applying all normalisations in http://www.w3.org/TR/xquery-semantics/#id-axis-steps, from which a single evaluable function could be derived. The function should be rewritable as yielding the same set (for /x/w and //w). Next the relation to the subset should become obvious.
Op woensdag 27 januari 2016 heeft Michael Kay <[email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');>> het volgende geschreven: > > > > > > > If you want to do a formal proof, you might want to use simplified > notions of XML documents and path expressions. > > It seems to be a long-standing tradition that computer scientists, when > asked to prove a difficult conjecture C, respond by giving a proof for a > simplified conjecture C'. While this might lead to progress in the long > run, and enables them to get papers published in the academic literature, > it is totally useless to practical engineeers who want to know whether they > can safely rely on C. > > Michael Kay > Saxonica > > > > -- W.S. Hager Lagua Web Solutions http://lagua.nl
_______________________________________________ [email protected] http://x-query.com/mailman/listinfo/talk
