I believe I might have been the person who raised the initial issue
about object-property/data-property punning, but was not a party the
process of fixing the problem. I continue to feel that such punning is
a) not useful, and b) extremely likely to cause (and exacerbate
existing) user error. User confusion between object and data
properties is quite common in practice, and right now misuse can be
detected as a syntax error. Allowing such punning would make these
common errors completely undetectable---users would just get very
different semantic effects than they intended. I very much hope we're
not going to re-open an issue that has already been addressed and
solved.
On 10 Jul 2008, at 09:38, Bijan Parsia wrote:
>
> On Jul 10, 2008, at 9:29 AM, Peter F. Patel-Schneider wrote:
>
>> You may remember that the OWL 1.1 proposal allowed unrestricted
>> punning. The current inability to pun between Datatypes and Classes
>> and the among Object, Data, and Annotation Properties results from
>> perceived problems with the RDF serialization that allowed
>> unrestricted punning and the extra mis-alignment between DL and
>> Full that comes from this unrestricted punning. A number of
>> working group members reluctantly allowed the above arguments to
>> overcome the coherent design in OWL 1.1, and went so far as to
>> design the current situation.
>
> [snip]
>
> And, of course, right now, this removal is considered to cause
> problems with other sorts of punning. Which is a technical problem
> (of sorts) with the removal. So we should put object/data punning
> back in.[*]
>
> Cheers,
> Bijan.
>
> * I know Alan has a problem with the "discrete" interpretation of
> cardinality over punning vs. the unity, but that's just an issue of
> which semantics to use.
>