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Re: [dgd@cs.bu.edu: BOS confusion (analysis; suggestion to resolve Newcomb/Bryan conflict)]



At 10:25 PM 01/01/97 -0500, David G. Durand wrote:
>    On my proposal, the companion of a companion is a companion (we take
>the transitive closure of the companion relation). So we get the same
>ability to express things that we have following entity tree. What we have
>gained is decoupling of "companionship declaration" from entity
>declaration. I can imagine authors who want to do a lot of linking, but not
>use entity declarations -- they would be accommodated by this. I can also
>imagine that many authors will have links that should _not_ indicate
>companions.

This seems right to me, too. There is clearly a big conceptual difference
between the significance of the entities in:

<!ENTITY fig349     SYSTEM "C:\pix\desk.gif" NDATA GIF>
<!ENTITY my-ilinks  SYSTEM "C:\link-sets\private.hytime">]
...
<BOOK>
<USE-LINKS-FROM ent=my-ilinks>
<p>...
<graphic end=fig349>...

The figure entity doesn't contain links (that's not to say graphics can't,
just that fig349 does not). But my-ilinks contains all kinds of crucial info
-- like maybe 99% of the links applicable to this document! It seems to me
we most definitely want a way to say "that entity over there has links that
you really should make available when viewing this document". This is not hard.

You sure don't want to have to fetch every entity a document may mention,
just *in case* it has links in it. This would be enormously slow and
painful, and the time is wasted, because the user probably isn't going to
actually follow *most* of the links that are around. Imagine the Web if
every time you followed a link your browser starting going off to fetch all
the document that are 4 links away or les... Being able to bound recursion
levels is only an illusion of help -- even one level is way too much of a
performance penalty (not to mention that integers other than zero and one
are almost always a sign of design problems in computing systems).

Steve D