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

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*
> listed/grouped elements.  daml:collection was one attempt to provide such
> 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.


Received on Friday, 15 March 2002 19:23:37 UTC