RE: Testcase comment and question

On Tue, 2005-03-29 at 14:50 -0500, Geoff Chappell wrote:
> 
> > -----Original Message-----
> > From: Dan Connolly [mailto:connolly@w3.org]
> > Sent: Tuesday, March 29, 2005 12:02 PM
> > To: public-rdf-dawg-comments@w3.org; Geoff Chappell
> > Subject: Re: Testcase comment and question
> > 
> 
> > Both the current editor's draft and the latest public working
> > draft give this formal specification:
> > 
> > [[
> > Definition: Optional Matching
> > 
> > Given graph pattern GP1, and graph pattern GP2, let GP = (GP1 union
> > GP2).
> > 
> > The optional match of GP2 of graph G, given GP1, defines a pattern
> > solution PS such that:
> > 
> > If GP matches G, then the solutions of GP is the patterns solutions of
> > GP else the solutions are the pattern solutions of GP1 matching G.
> > ]]
> 
> Thanks. I guess it wasn't fair to imply there was no definition. I do think,
> though, that this one will need some tightening up. For example it seems to
> imply that if _any_ solutions can be found in GP, then no solutions will be
> used from GP1.

Yes, that's what it says.

>  And assuming that's not the case,

Er... why not? Am I missing something?

>  it doesn't have much to say
> about how to determine exactly which solutions of GP1 are disallowed because
> they are solutions of GP (especially in the tricky cases where vars(GP) !=
> vars(GP1)). 
> 
> Geoff
-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
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