Re: Comment on RDF Mapping: variables in sequence pattern

From: Mike Smith <msmith@clarkparsia.com>
Subject: Re: Comment on RDF Mapping: variables in sequence pattern
Date: Wed, 28 Jan 2009 10:53:50 -0500

> On Wed, Jan 28, 2009 at 04:08, Ian Horrocks
> <ian.horrocks@comlab.ox.ac.uk> wrote:
> 
> > On 7 Jan 2009, at 18:24, Peter F. Patel-Schneider wrote:
> 
> >> A "big club" fix would be to have a global constraint along the lines
> >> of:
> >>
> >>        No blank node can be used in more than once in these patterns.
> >>        (This means that all lists are non-cyclic and do not share
> >>        tails.)
> 
> 
> > The "big club" clearly does the job, is easy to understand, and I don't see
> > any serious disadvantages -- am I missing something?
> 
> It looks like it's in place in the wiki version of the document.
> 
> I think the wording needs some additional tweaking to make clear that
> a node can be used multiple times as a list element.  I.e., it should
> be permissible for variables y_i , y_j to match the same node and the
> current text seems to prevent that.
> -- 
> Mike Smith
> 
> Clark & Parsia

I've tweaked the wording, hopefully appropriately.

peter

Received on Wednesday, 28 January 2009 17:31:01 UTC