W3C home > Mailing lists > Public > www-webont-wg@w3.org > March 2002

Collection properties, was Re: SEM DESIDERATA: my initial desiderata list

From: Jonathan Borden <jonathan@openhealth.org>
Date: Fri, 15 Mar 2002 19:20:31 -0500
Message-ID: <016701c1cc80$69608d20$0a2e249b@nemc.org>
To: <las@olin.edu>, "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: "WebOnt WG" <www-webont-wg@w3.org>
Lynn Andrea Stein wrote:
> >
> > 1/ Syntax is (equivalent to) n-triples (i.e., RDF syntax).
> >    All syntax (except, maybe, datatypes) is carried in triples.
>
> Pretty clearly we will need *some* sort of (unordered) listing/grouping
> construct that is bounded, i.e., defines a list/group containing *exactly*
the
> listed/grouped elements.  daml:collection was one attempt to provide such
a
> thing.  I don't believe we can avoid having such a thing.

I agree that this is essential. To summarize.

1) daml:List is a reasonable construct for an (ordered, bounded) list.
2) numerous DAML language elements operate as if the list is _unordered_. In
which case when the daml:List construct is interpreted as a daml:Set, it's
semantics are unordered and with no repeats (I don't see a great need for an
_unordered_ Bag but don't oppose this if there is in fact a use case).

Properties such as:

<daml:oneOf> <daml:intersectionOf> <daml:union> etc etc. operate _as if_ the
List has the semantics of a set. i.e.

daml:oneOf(a b c d) = daml:oneOf(b c d a)

perhaps these Properties should be subclassed from a common owl:Set whose
semantics are defined as expected. i.e.

owl:Set(a b) = owl:Set(b a a)

I see where Intuitionist Logic comes into play here i.e. to prevent
owl:Set(a b) from entailing an infinite number of owl:Set(a b b) etc. In any
case this seems sort of essential to the semantics of daml:oneOf which is
part of DAML, and hence something that we can all agree is something part of
the language we are producing.

Jonathan
Received on Friday, 15 March 2002 19:23:37 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:57:48 GMT