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Re: [ba-ohs-talk] GUI Ideas and NODAL

On Mon, 2001-11-12 at 06:45, Peter Jones wrote:
> I'm reading from
> NODAL A Filesystem for Ubiquitous Collaboration.htm
> Section 4.7
> "The second type is a more traditional hyperlink. This construct is built on
> the range type, which represents the collection of nodes between two paths
> that are the inclusive end-points of the range (note that a simple path is
> also a range that identifies exactly one node). This collection of nodes is
> determined by the path difference between the two paths: a relative path
> from the range start to the range end. Any node in or below the relative
> path is considered to be part of the graph fragment identified by the range.
> A hyperlink is then constructed from two or more such range expressions and
> can be either unidirectional or multidirectional, embedded or external. All
> such hyperlinks are managed by a linkdatabase that maintains these paths
> through modifications and delivers link descriptions along with published
> documents." 31C (0120)
> Can someone explain to me what the 'or below' in,
> "Any node in or below the relative path is considered to be part of the
> graph fragment identified by the range.",
> means.    (01)

Maybe this is a little to complicated to actually achieve, but the
notion that a Path is an algebraic unit over which addition and
subtraction have meaning was what led to this.  It is fairly easy to
understand what is meant by a range within a single sequence.  We have
a start and and end Path and the Range referes to those data items
at "or below" those sequence items covered.  Thus if the sequence in
question is a sequence of Nodes, then the subgraphs accessible from
those Nodes are part of the referent of the Range.  It's probably just
hair-splitting semantics, but the simple idea is that referring to a
Node is actually a reference to the whole subgraph addressed by that
Node's components.    (02)

Lee Iverson                    
leei@telus.net                 #105-2700 Acadia Rd., Vancouver B.C. V6T
http://www.ai.sri.com/~leei/   (604) 222-9312    (03)