Re: REL and REV attributes (Was: More comments on HTML 3.0)

Paul Burchard (
Tue, 25 Apr 95 15:42:10 EDT

Bert Bos <> writes:
> Paul Burchard <> writes:
> |Bert Bos <> writes:
> |> I still don't see why we need both REL and REV. They have
> |> exactly the same meaning.
> |(I assume you meant, exactly the _opposite_ meaning.)
> No, I mean the *same*.

That's wrong. A non-symmetric relation is *not* equal to its
reverse relation. And most of these relations are non-symmetric.

> The choice of REL or REV depends only on whether you can
> invent a name for the relationship:
> REL=parent is equivalent to REV=child
> REL=successor is equivalent to REV=predecessor
>[... ad nauseum...]

Using ad hoc word association to describe a precise mathematical
operation is a bad idea. That's exactly what I don't want to see.


Drop REV, but add general relational operators to the syntax
of REL. E.g., REL="Reverse(Child)" in place of REV="Parent",
and REL="Join(Glossary,Author)" to refer to the author of the
document's glossary. (Any standard relational notation we
should use?)

Murray Maloney <murray@sco.COM> writes:
> While it is possible to use REL and REV to describe the same
> relationship in reverse, that is clearly not useful or helpful.

Um...but that's exactly what your examples are advocating. And I
agree with your examples, so I'm not sure where the confusion is.

Paul Burchard <>
``I'm still learning how to count backwards from infinity...''