- From: <tim.glover@bt.com>
- Date: Tue, 29 Sep 2009 10:22:07 +0100
- To: <david@dbooth.org>, <phayes@ihmc.us>, <semantic-web@w3c.org>
<=============
Furthermore, it is perfectly legal to declare the domain of a property
more than once, such as:
P rdfs:domain GreenItems .
P rdfs:domain BlueItems .
Then if you write a statement like:
x P y .
the domain declarations imply that x is in both GreenItems and
BlueItems.
=============>
OK...
<============
Note that the effect is that the domain of P is the
*intersection* of GreenItems and BlueItems -- not the union.
============>
OK, but personally I found the terms intersection and union a bit
confusing in this context. Just to clarity... In an assertional language
like RDFS it is not possible to place any restrictions on anything by
adding a new triple. So, adding
x P y
asserts that x is in both GreenItems and BlueItems, but adding
P rdfs:domain BlueItems
in no way implies that the domain of P is smaller than the set of
GreenItems... Is that right?
Tim Glover
Received on Tuesday, 29 September 2009 09:22:52 UTC