Not really, no. But my guess is that the path is not relevant, as its steps simply contain variable names. The proof you want to have is a formal one, and I think it doesn't have to do with the path expression, but rather the formalism it implements.
2016-01-26 17:41 GMT+01:00 Adam Retter <[email protected]>: > Any chance you could offer me an example? ;-) > > On 26 January 2016 at 16:40, W.S. Hager <[email protected]> wrote: > > Hi Adam, > > > > Perhaps it helps to start with rewriting the xpath expressions as pure > > lambda expressions. Maybe that way you could apply lambda calculus? > > > > Cheers, > > Wouter > > > > 2016-01-26 17:26 GMT+01:00 Adam Retter <[email protected]>: > >> > >> Given two simple XPaths, say: > >> > >> 1. //w > >> > >> 2. /x/y/z/w[@a = 'v'] > >> > >> As a human I can very easily tell without evaluating the expressions > >> that (2) will return a subset (or the same set) of the results that > >> (1) would return *should* they both be evaluated. > >> > >> My goal here is given any two simple arbitrary XPaths expressed as > >> strings, and without evaluating them against a context, to determine > >> whether one would return a subset of the results of the other. > >> > >> I wondered if there might be an algorithm or library that someone > >> already had or has written which might be able to give me the answer? > >> > >> I realise that I can only probably cover a subset of XPath itself, but > >> it is only the path steps with predicates which I am interested in. > >> > >> Ideally I am looking for something in Java. > >> > >> -- > >> Adam Retter > >> > >> skype: adam.retter > >> tweet: adamretter > >> http://www.adamretter.org.uk > >> _______________________________________________ > >> [email protected] > >> http://x-query.com/mailman/listinfo/talk > > > > > > > > > > -- > > > > W.S. Hager > > Lagua Web Solutions > > http://lagua.nl > > > > -- > Adam Retter > > skype: adam.retter > tweet: adamretter > http://www.adamretter.org.uk > -- W.S. Hager Lagua Web Solutions http://lagua.nl
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