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Jonathan Borden wrote:
> Gavin Thomas Nicol wrote:
> > I'm entirely in agreement with this. You say "an element HAS-A gi", so
> > this is obviously an attribute of the object (as all names are
> > ultimately.... a rose by any other name...).
> It is not a simple fact at least if we are still talking about XML. XML 1.0
> says that the _type_ of an element is its name or GI. Generally the 'type
> attribute' has a special place in the list of 'attributes', i.e. the "isa"
To be sure! The same is true for SGML, even more so. The GI is
"just" another attribute (or property), but it's by far the most
important one since so many other things depend on it.
> So, not (element has-a GI) rather (element isa GI).
Actually it's both: the element has-a GI, which determines
the (principal) is-a relationship.
The main thing is that other attributes besides the GI
can *also* express is-a relationships. That's AFs.
> [...] In any case it is not typical to equate "isa" and
> "has-a" links and I suspect that if you do so, you will lose processing
I believe the opposite is the case. The rule "an element
IS-A foo whenever it HAS-A bar", where "bar" can be
"a GI with value X" or "an attribute named Y with value Z"
is more flexible; IS-A can be a relation instead of a function.