Re: range, domain: Conjunctive AND disjunctive semantics both supportable

On October 1, Wolfram Conen writes:
> Dear Jan and dear RDFS folks interested in range constraint discussion,
> We will make two claims in the following:
> (C1) Disjunctive/Conjunctive range constraints is not all that would be
> needed! General set-based range constraints should be able to constrain
> the range to an arbitrary set-algebraic expression.

Yes, and in OIL you can do just this.

> (C2) (Exactly) one range constraints is sufficient to express any
> set-related range contraint, if sets can be constructed from
> set-algebraic operations.

Obviously. But the trouble is that in a web environment different
people may add various constraints in various different places. It
wont in general be possible to get them all to agree to withdraw their
individual constraints in favour of a single algebraic constraint, so
we need both multiple constraints and some semantics for how to
interpret them.


Received on Monday, 2 October 2000 11:37:51 UTC